Commercial Printing, Packaging, Carton, Corrugated Cardboard, Paper Converting, Folding Carton and Flexible Packaging HVAC Duct Guide

Why printing and packaging HVAC is its own discipline

Walk into a six-colour B1 sheet-fed offset hall in Mt Waverley or Eastern Creek at the start of a Monday day shift and you can read the HVAC design from the air. If the dampening solvent smell hangs in front of the delivery end of the press and the operators have set up portable fans behind their stations, the system was designed for the building shell rather than the process. If the air at the operator station is quiet and slightly cool, the press hood is drawing a visible plume of fount vapour up and away from the sheet trail, and the powder-spray collector at the delivery hopper is keeping its filter clean for an entire shift, the engineer who specified that hall understood that printing and packaging HVAC is a discipline in its own right.

The discipline is its own because the process exposes the ductwork to a combination of conditions found in few other light-manufacturing environments. Solvent vapour from isopropanol fount, blanket wash and ink reducers measured in parts per million at the operator's breathing zone but in grams per cubic metre inside the dryer enclosure. Combustible cellulose dust from die-cutting, folder-gluer and waste-stripping operations capable of deflagration at concentrations as low as 30 to 50 grams per cubic metre. Hot wet steam at 80 to 120 C from the corrugator double-backer with starch glue carryover that fouls heat exchangers within months if the duct geometry is wrong. Ozone at the UV curing station with a workplace exposure standard of 0.1 ppm TWA. Heat-set web dryer exhaust at 250 to 320 C heading to a regenerative thermal oxidiser. Ink rooms classified as Zone 2 hazardous area under AS/NZS 60079. And alongside all of this, the operational reality that commercial printing and packaging is a margin business where the HVAC system either earns its capital cost back in productivity, ink yield and energy recovery, or it loses the operator money on every reel and every shift.

This guide is the working reference SBKJ engineers use when scoping ductwork machinery for printing, folding carton, corrugated cardboard, paper converting and flexible packaging projects across Australia and the broader Asia-Pacific region. It is written for the consulting mechanical engineer specifying a new sheet-fed plant in Erskine Park, the project manager planning a corrugator relocation in Coolaroo, the works engineer at a Maryvale paper mill trying to upgrade the converting hall extract, and the operator commissioning a new rotogravure line with solvent recovery for flexible food packaging. Where SBKJ machinery is the right tool we say so, with the actual specifications and the duct quantities the project will need. Where the project needs something off-machine, like an FRP fume hood for a plate processor or an HDPE-lined acid extract for a deinking line, we say so as well.

The structure of this guide follows the process. We start with the press hall — sheet-fed offset, web offset heat-set and coldset, flexography, rotogravure and digital — because that is where the solvent capture, ink mist and powder spray problems dominate. We then work outward into post-press converting (UV varnish, lamination, coating, die-cutting, folder-gluer, embossing, stitching and binding), into the substrate processes (corrugator, honeycomb board, paper bag), and end with the support functions (ink room, pre-press, wash-up, storage and warehouse). The Australian operator landscape — IVE Group, Ovato, Pact Group, Visy Industries, Amcor, Orora, Opal, Detmold, Pro-Pac — is covered explicitly, because every project has to reference the way the resident Australian printers and packaging converters run their plants. SBKJ machine recommendations are integrated through the text and consolidated at the end.

Sheet-fed offset press hall — the hood, the powder and the fount

The sheet-fed offset press is the backbone of Australian commercial print and folding carton manufacturing. From the two-colour B3 presses at a Newcastle jobbing printer through to the eight-colour double-coater B1 perfectors at the larger commercial houses in Sydney and Melbourne, the basic HVAC problem is the same: capture the dampening solvent vapour, the ink mist and the anti-set-off spray powder above the delivery, before any of it reaches the operator's breathing zone or settles onto the sheets in the stacker.

The vapour composition is dominated by isopropanol (IPA) from the dampening fount. Modern offset presses run IPA-reduced founts in the 3 to 8 percent range, with a few high-quality houses on alcohol-free founts entirely. At 8 percent IPA, a six-colour B1 press consuming 1.5 litres per hour of fount across the dampening systems is putting roughly 120 millilitres per hour of IPA into the air around the press. That is small in absolute terms but it concentrates in the operator's breathing zone unless capture is engineered properly. The Safe Work Australia workplace exposure standard for isopropanol is 400 ppm TWA, which is well above the typical operator exposure on a well-ventilated press, but exceeding the WES is not the design target — the design target is a clean working environment, which usually equates to operator exposure below 50 ppm or about 12 percent of the WES.

Ink mist is the second issue. Conventional inks shed a fine aerosol from the ink fountain and the roller train at running speeds above 12,000 sph. The aerosol is mostly mineral oil-based vehicle for sheet-fed work, with pigment carryover at trace levels. The aerosol settles on every horizontal surface in the press hall over time and is the primary source of the dark grey colour you see on the underside of every press-hall light fitting after twelve months without cleaning. The capture is engineered at the press hood with face velocity 0.4 to 0.6 m/s, which is enough to draw the rising aerosol up and away from the operator without disturbing the running web or the sheet feed.

Anti-set-off spray powder is the third. The starch-based powder applied at the delivery to prevent freshly inked sheets from sticking is dispersed as a fine aerosol that settles inside the delivery section, on the floor, on the press operator and on every adjacent surface. The dedicated powder-spray collector at the delivery hopper has a HEPA-rated bag filter and runs continuously through the shift, returning clean air to the press hall. The extract is round duct, transport velocity 12 to 15 m/s to keep the powder fines moving, and the bag filter is sized for an air-to-cloth ratio of 1 to 1.5 m/min.

Capture and dilution sizing for a typical six-colour B1 sheet-fed offset press in an Australian commercial print or folding carton plant follows the AS 1668.2 framework with the ASHRAE Applications Chapter 33 industrial ventilation overlay:

• Press hood extract — 1,500 to 2,500 m3/h per press over the inking, dampening and impression units, capture face velocity 0.4 to 0.6 m/s, branch transport velocity 10 to 15 m/s, galvanised AS 1397 G275 duct to AS 4254 Class B.
• Delivery powder extract — 1,000 to 1,800 m3/h per press at the delivery hopper, HEPA bag filter, transport velocity 12 to 15 m/s, round galvanised or 304L duct.
• Press hall dilution — 6 to 10 air changes per hour overlay on top of process capture, supplied at high level with displacement diffusers near the operator stations to provide thermal comfort and clear the operator's breathing zone.
• Wash-up station LEV — 800 to 1,500 m3/h per blanket-wash station, capture face velocity 0.5 to 0.7 m/s at the cleaning point, 304L or coated mild steel duct, transport to solvent recovery or thermal oxidiser per AS 1940.
• Ink room mechanical extract — 12 to 20 ACH continuous, hazardous area Zone 2 per AS/NZS 60079, intrinsically safe sensors, 10 percent LFL alarm and 25 percent LFL shutdown, 304L stainless duct sealed to AS 4254 Class A.

The press-hall mains run in galvanised duct produced on the SBAL-V auto duct production line — this is the routine work that the line is designed for. A six-press hall with the capture quantities above totals roughly 12,000 to 25,000 m3/h of extract, which translates into 600 to 1,200 square metres of duct per press hall once the supply, return and exhaust systems are fully built out. At an SBAL-V output rate of 16 metres per minute of finished duct, the entire press-hall duct programme for a new build is two to three weeks of production time on a single line.

Web offset press hall — heat-set, coldset and the dryer afterburner

Web offset is a different beast from sheet-fed. The web is fed continuously from a paper reel at 6 to 12 metres per second, printed through four to eight units, dried in a hot-air dryer at 250 to 320 C exhaust temperature, chilled on a cooling drum, and folded or sheeted at the end of the line. Heat-set web is the dominant configuration for high-quality magazine, catalogue, brochure and folding carton work; coldset web is used for newspaper and lower-grade work that does not require the gloss and rub-resistance of a heat-set ink.

The dominant HVAC problem on a heat-set web is the dryer exhaust. The dryer enclosure is fed from the impingement air system at 250 to 320 C and exhausted through the afterburner at 300 to 400 C exhaust gas temperature. The afterburner is either an integral thermal oxidiser inside the dryer module or a separate regenerative thermal oxidiser (RTO) on the roof; in either case its function is to destroy the volatile organic compounds (VOC) driven off the mineral oil-based ink during the drying step. The duct between the dryer and the afterburner runs at exhaust gas temperatures up to 400 C and must be 304L stainless to ASTM A240 or insulated mild steel rated for continuous service at that temperature.

NFPA 86 governs the dryer interlock chain. The exhaust gas must be maintained below 25 percent of the lower flammable limit (LFL) under normal operation, with automatic shutdown of the ink feed and the press web at 50 percent LFL. The LFL monitoring is a continuous gas analyser on the dryer exhaust, calibrated for the specific ink solvent and verified quarterly. A trip on the LFL monitor stops the press in seconds — this is one of the few interlocks in the printing industry that puts a multi-million-dollar press into emergency stop without operator intervention, and the gas analyser is treated as a safety-critical instrument with redundancy on larger presses.

The clean exhaust from the afterburner stack at 200 to 280 C is a strong heat recovery candidate. A glycol run-around coil between the afterburner stack and the outdoor air intake of the press hall recovers 40 to 60 percent of the sensible heat at typical Australian winter conditions. For a single eight-unit heat-set web running at 10 m/s web speed with a 1,600 mm web width, the dryer afterburner rejects 600 to 1,200 kW of sensible heat to atmosphere. Recovering even half of that offsets the entire press-hall outdoor air pre-heat for ten months of the year in Melbourne, Sydney and Adelaide climates.

Coldset web offset is the simpler case. No dryer, no afterburner, just the press hall capture, the dampening solvent control and the operator station extract. Dampening on a coldset web is conventional fountain solution with low IPA, and the volume of fount in the press hall is much smaller per press than a sheet-fed installation of equivalent area. ACH 5 to 8 with point extract at the operator stations is usually sufficient. Coldset newspaper presses are largely in decline in Australia as titles consolidate and shift to digital, but the residual coldset capacity at Australian regional dailies and the directory print sites continues to need HVAC maintenance and occasional upgrade work.

Flexography — water, solvent and UV

Flexographic printing is the workhorse of Australian flexible packaging, label, corrugated post-print and folding carton work. The ink is applied by a soft elastomeric plate mounted on a sleeve, transferred through an anilox roller from an ink fountain, and printed onto the substrate in a series of stations. Each station has its own ink type — water-based, solvent-based or UV-curable — and each requires a different HVAC capture strategy.

Water-based flexo is the dominant ink chemistry for corrugated post-print, paper bags and most fibre-based flexible packaging. The ink is a water-based dispersion of pigment, resin and additives, dried in a hot-air dryer at 60 to 120 C between stations. The HVAC problem is moisture and a small amount of co-solvent vapour (typically ethanol or glycol ether at low concentration). Extract from the dryer at 0.8 to 1.2 m/s face velocity, transport in galvanised duct to atmospheric discharge, no afterburner required. The dryer exhaust at 60 to 100 C is a low-grade heat recovery candidate for hot water pre-heat or local space heating.

Solvent-based flexo is used where the substrate demands a solvent ink — biaxially oriented polypropylene (BOPP) and polyethylene (PE) films for flexible packaging, low-energy plastic substrates that water-based inks cannot wet. The solvent is typically ethanol, ethyl acetate or a blend of both, at 50 to 70 percent of the ink by mass. The capture strategy mirrors the rotogravure section below: hood capture at each print station, dryer enclosure capture, solvent recovery train (activated carbon adsorption) or thermal oxidiser. Duct material 304L stainless on the capture side, AS 4254 Class A seal. The Safe Work Australia WES for ethanol is 1000 ppm TWA, for ethyl acetate 200 ppm TWA — the design target is operator exposure well below 25 percent of the WES.

UV flexo is increasingly common for label and folding carton work. The ink contains photoinitiators and monomers that cross-link under UV light at the curing station. The HVAC problem is ozone at the lamp face, generated by the UV interaction with atmospheric oxygen. Ozone has a Safe Work Australia WES of 0.1 ppm TWA, the lowest of the common printing-process contaminants. Capture is engineered as a hood directly over the lamp, face velocity 0.5 to 0.8 m/s, transport in 304L or HDPE-lined duct to atmospheric discharge above roof level with dispersion analysis confirming compliance at the property boundary. LED-UV curing is steadily replacing arc-lamp UV on new installations and dramatically reduces the ozone capture load — LED-UV is essentially ozone-free at the lamp face, with only minor process VOC from the ink itself.

Capture and dilution sizing for a typical eight-station flexo line:

• Water-based station extract — 800 to 1,500 m3/h per station dryer, transport velocity 10 to 15 m/s, galvanised duct, discharge to atmosphere.
• Solvent-based station extract — 1,500 to 3,000 m3/h per station with hood capture and dryer enclosure, 304L duct, transport to solvent recovery train or RTO.
• UV station ozone extract — 600 to 1,200 m3/h per UV head, 304L or HDPE-lined duct, atmospheric discharge with dispersion analysis.
• Press hall dilution — 8 to 12 ACH across the hall with displacement supply at low level.
• Ink room hazardous area extract — 12 to 20 ACH continuous, AS/NZS 60079 Zone 2, 304L duct, AS 4254 Class A seal.

Rotogravure — the solvent recovery problem

Rotogravure is the niche but technically demanding end of Australian printing. Rotogravure is used where image quality and run length justify the engraved cylinder — high-volume flexible food packaging, decorative laminates, currency, security printing, and a small amount of long-run magazine and catalogue work. The process uses a copper-plated steel cylinder mechanically or laser-engraved with the image, doctored by a steel blade, with the ink lifted from the cells onto the substrate at 6 to 12 m/s web speed.

The dominant HVAC challenge is solvent. Rotogravure ink is typically 50 to 80 percent solvent by mass — toluene for older publication-grade rotogravure, ethyl acetate for modern food packaging-grade work, ethanol for some flexible packaging operations. A single eight-cylinder rotogravure line running 10 hours per shift consumes 400 to 800 kilograms of solvent per shift. That solvent ends up in one of three places: in the printed product (a small residual), in the workshop atmosphere (if capture is inadequate — not acceptable), or in the extract system. The capture target is 95 to 99 percent of the consumed solvent into the extract system, recovered or destroyed.

Solvent recovery by activated carbon adsorption is the dominant technology for single-solvent operations — particularly toluene service. The capture stream from the print station hoods and dryer enclosures is drawn through an activated carbon bed at a face velocity of 0.3 to 0.5 m/s through the carbon. The carbon adsorbs the solvent vapour; when the bed approaches breakthrough (typically 12 to 24 hours of operation), it is regenerated by steam stripping — steam is passed through the bed, desorbing the solvent into a steam-solvent mixture, which is condensed and gravity-separated into a solvent layer and a water layer. The recovered solvent is returned to the ink store; the water phase is treated through a solvent-stripping column before discharge to sewer or a closed-loop water-treatment system. Recovery efficiency on single-solvent toluene is 95 to 99 percent at well-engineered Australian installations.

For mixed-solvent service — ethyl acetate, ethanol, isopropanol blends — the carbon bed is less efficient because the recovered solvent is a mixture that needs distillation to separate. Many Australian flexible-packaging rotogravure operations have shifted from carbon adsorption to regenerative thermal oxidiser (RTO) treatment for this reason. The RTO operates at 800 to 900 C with a ceramic media bed providing heat exchange between the inlet and outlet streams. Inlet exhaust at 60 to 100 C is heated by the outgoing clean exhaust to 750 to 850 C before reaching the combustion chamber; the combustion chamber operates at 800 to 900 C, destroying the VOC to better than 99 percent; the outgoing clean exhaust at 750 to 850 C heats the incoming gas before leaving the stack at 100 to 200 C. The thermal efficiency of the RTO is 90 to 97 percent at well-engineered installations, which keeps the auxiliary gas burn modest.

The capture-side duct from the print stations and dryer enclosures runs 304L stainless to ASTM A240, sealed to AS 4254 Class A because outward leakage of solvent vapour into the workshop is a regulatory event. The transport velocity is maintained at 12 to 18 m/s and the duct geometry avoids low points where condensate could accumulate — the solvent has a higher density than air and can settle in dead zones. Pitched duct routing and condensate drainage points are standard. The fan is direct-drive, intrinsically safe or ATEX-rated for the hazardous area classification, with sealed shaft and seal pot oil reservoir to prevent solvent migration into the bearings.

For the rotogravure VOC return riser from the press station collection to the solvent recovery or RTO, the SBTF-1602 spiral tubeformer is the right SBKJ tool. The SBTF-1602 handles 304L stainless cleanly to 1.2 mm at the spiral seam quality the AS 4254 Class A seal requires. Larger-diameter risers above 1,200 mm move to the SBTF-2020 for the same construction.

Digital press — the simpler case

Digital presses (HP Indigo, Heidelberg Versafire, Canon imagePRESS, Xerox Iridesse, Konica Minolta AccurioPress and Ricoh ProC) have become the dominant short-run technology for Australian commercial printing, photo books, marketing collateral, transactional mail and the smaller end of folding carton work. The HVAC requirement is simpler than analogue presses because the ink chemistry is contained — HP Indigo uses an electrostatic liquid toner with a low volatility, the dry-toner machines use polyester-based toner that is fused thermally onto the sheet, and the inkjet-based digital presses use water-based or UV-curable ink.

For the typical digital press hall in an Australian commercial printer, the HVAC requirement is general office-grade conditioning with ACH 5 to 8 across the room, supply at high level with displacement diffusers, return at low level near the operator stations, and a dedicated extract from the fuser exhaust on each thermal-fusing machine at 200 to 400 m3/h. The extract is galvanised duct to AS 4254 Class B, discharge to atmosphere above roof level. The thermal fuser exhaust at 80 to 120 C is generally not worth recovering for heat, but it should be ducted out of the hall rather than recirculated — the trace VOC from the fuser is below WES thresholds at the discharge but can accumulate over a shift if it is allowed to circulate.

HP Indigo presses have a slightly different requirement because of the imaging oil. The ImagOil base is a low-volatility hydrocarbon that does not contribute significantly to operator exposure but does require capture of any vented oil mist from the imaging cabinet. A dedicated extract at 600 to 1,200 m3/h per press from the imaging cabinet exhaust, ducted through a mist filter and discharged to atmosphere, is the standard installation. Galvanised duct, atmospheric discharge, no thermal oxidiser required.

UV varnish, coating and lamination — the post-press capture

Post-press operations are where folding carton manufacturers add the gloss, scuff resistance and barrier properties that lift the printed sheet from a substrate to a finished pack. The HVAC requirement varies by process.

UV varnish stations apply a clear UV-curable coating to the printed sheet at full-coverage or spot-varnish patterns. The varnish is cured under UV lamps at the back end of the coater. The HVAC capture problem is identical to UV flexo — ozone at the lamp face, captured at 0.5 to 0.8 m/s face velocity, transported in 304L or HDPE-lined duct to atmospheric discharge. The varnish itself is a minor contributor to VOC capture, with most of the residual volatile content cured into the film during the UV exposure step. LED-UV varnish curing has displaced arc-lamp UV on most new installations.

Aqueous (water-based) coating is the dominant high-volume coating chemistry for folding carton work. The coater applies a water-based dispersion of acrylic resin and additives, dried in a hot-air dryer at 80 to 140 C between the coating head and the rewind. The HVAC capture is moisture and trace co-solvent (typically a glycol ether at low concentration), extracted at 1.0 to 1.5 m/s face velocity over the dryer, transported in galvanised duct to atmospheric discharge. The dryer exhaust at 60 to 100 C is a candidate for low-grade heat recovery into local hot water or space heating. Aqueous coating does not require an afterburner.

Solvent-based lamination uses an adhesive dissolved in solvent (typically ethyl acetate) applied to one web, with the solvent evaporated in a dryer tunnel before the second web is laminated. The HVAC capture is identical to solvent flexo or solvent gravure — hood capture at the adhesive applicator, dryer enclosure capture, transport to solvent recovery or RTO, 304L duct, AS 4254 Class A seal. The Safe Work Australia WES for ethyl acetate is 200 ppm TWA. Solvent-based lamination is being progressively replaced by solventless lamination, where the adhesive is applied without solvent — the HVAC problem disappears with the chemistry change.

Hot-melt and water-based lamination adhesives applied at folder-gluer stations need minimal HVAC capture — a local extract at the glue applicator to control any minor solvent vapour or hot-melt fume, 400 to 800 m3/h per applicator, galvanised duct to atmospheric discharge. Hot-melt formaldehyde-free adhesives have replaced most formaldehyde-resin systems in Australian folding carton manufacture, reducing the HVAC burden significantly. Where formaldehyde residual is still present (typically in older melamine-formaldehyde laminations), the WES is 1 ppm short-term and dedicated capture is required.

Die-cutting, folder-gluer and the paper-dust problem

The most under-engineered area in many Australian folding carton and corrugated converting plants is the post-press finishing line. Die-cutting, scoring, slotting, waste-stripping, embossing and the folder-gluer station all generate fine cellulose dust as the paperboard or corrugated board is cut, scored and folded. The fines accumulate inside the machine, around the operator station, on every horizontal surface in the plant, and most importantly inside the LEV ductwork and the bag house downstream.

Cellulose dust is a combustible particulate under NFPA 654 (and now the consolidated NFPA 660) and AS 3957 dust hazard assessment. Kst values for cellulose dust from paperboard, corrugated board and SBS (solid bleached sulfate) carton stock are typically 50 to 150 bar.m/s with minimum ignition energy (MIE) in the 30 to 100 mJ range. This is firmly in the combustible-dust hazard class. A deflagration in the bag house or the LEV duct will rupture the bag house unless a deflagration vent or pressure-relief panel is fitted, and will propagate upstream through the LEV trunk unless explosion isolation is provided at the building entry point.

The LEV capture strategy for a high-speed flatbed die-cutter or rotary die-cutter is engineered at the die exit and the waste-stripping station:

• Die exit capture — hood at 1.0 to 1.5 m/s face velocity over the cutting nip, sized for the maximum sheet width plus 100 mm each side.
• Waste-stripping capture — pneumatic conveying of stripped waste to the waste compactor, with transport velocity 22 to 28 m/s for paper waste to keep the strips airborne to the compactor.
• Fines extract — secondary capture at the delivery and stacking section at 0.5 to 0.8 m/s face velocity, transport velocity 18 m/s minimum horizontal and 15 m/s minimum vertical.
• Bag house — external to building, deflagration-vented, with pressure-relief panels sized to the dust deflagration index, K-rating 1.5 to 3 m2 vent area per cubic metre vessel volume.
• Explosion isolation — passive flap valve or active rotary isolation at the building entry point, protecting the upstream LEV trunk from a bag house deflagration.
• Spark detection and extinguishing — infrared or UV spark detectors on the LEV trunk, with high-pressure water mist or CO2 extinguishing actuation, protecting against the residual ignition source from hot-cut edges or embossing fines.
• Bonding and earthing — every duct section, every flexible joint, every fan, every accessory bonded and earthed to AS 1020, with periodic resistance testing to confirm continuity.

The duct construction is heavy-gauge mild steel, 1.6 mm minimum, in round cross-section. Round duct survives a deflagration overpressure event; rectangular duct in this service is a structural failure waiting to happen. The duct flanges are welded or full-strength bolted; rubber gaskets are avoided in favour of woven fibreglass or compressed mineral fibre because rubber loses its seal at the overpressure event. Cleanout doors at every 90-degree elbow and every 5-metre straight run are standard for the fines extract because cellulose dust accumulates on the underside of horizontal runs and at every change of direction.

The folder-gluer station has a similar requirement at lower scale. The waste-stripping at the folder-gluer infeed and the dust generation at the folding sections is captured at the same transport velocity, with a smaller bag house or in some cases ducted back to the main converting-line LEV trunk.

Corrugator — steam, starch and the double-backer extract

The corrugator is the heavy industrial heart of an integrated corrugated board manufacturer like Visy Industries, Orora or Opal. Liner board and medium are fed into the corrugator from large reels, the medium is fluted between heated corrugating rolls at 180 to 200 C, starch adhesive is applied to the flute tips, the fluted medium is bonded to the inner liner at the single-facer, and the combined web is bonded to the outer liner at the double-backer with steam-heated hot plates. The finished corrugated board exits the corrugator at 30 to 60 m/min, is cut to length and stacked.

The HVAC problem at the corrugator is wet steam, hot air and starch carryover. The double-backer hot plates run at 160 to 180 C surface temperature, with steam generated as the starch adhesive cures on the flute tips. The steam, carrying entrained starch and trace organic acids from the corrugating process, rises from the double-backer at 80 to 120 C and must be captured before it reaches the building roof, where it would condense and create dripping condensate, fungal growth and chronic structural damage.

Capture is engineered as a hood above the double-backer at face velocity 0.6 to 1.0 m/s. Volume per hood typically 8,000 to 18,000 m3/h depending on corrugator width (the Australian standard corrugator runs 2.5 to 3.3 m web width). The duct is carbon steel or 304L stainless with a condensate knock-out drum immediately downstream of the hood to remove the bulk condensate before the fan. The hood and the first 5 to 10 metres of duct are insulated externally to keep the wall temperature above the dew point and prevent condensation on the inside surface. The duct slopes downward toward the knock-out drum at a minimum 1 to 50 gradient. The fan is direct-drive with a stainless impeller to handle the wet exhaust without erosion.

The corrugator exhaust at 80 to 120 C is a low-grade heat recovery candidate. A condensing heat exchanger downstream of the knock-out drum can recover 20 to 40 percent of the heat for local hot water pre-heat or space heating. The starch carryover means the heat exchanger surfaces must be designed for periodic cleaning — either a removable tube bundle or an in-place cleaning system with caustic wash on a monthly cycle. Many Australian corrugator operations have installed heat recovery in the last decade as the gas price has made the payback attractive.

The single-facer section operates at higher steam load per linear metre than the double-backer but with a smaller capture zone. The starch slurry tank and the glue machine require local extract at 800 to 1,500 m3/h to control the small amount of glue vapour and minor steam carryover, with the capture ducted into the main double-backer extract or to a separate atmospheric discharge.

The corrugator splice station, the slitter-scorer and the rotary cutter at the corrugator exit are all sources of paper dust in the same NFPA 654 / AS 3957 category as the die-cutting line described above. The dust capture is engineered along the same lines — round duct, heavy-gauge mild steel, transport velocity 18 m/s minimum, deflagration-vented external bag house, bonded and earthed, spark detection and extinguishing.

Honeycomb cardboard board manufacturing

Honeycomb cardboard board manufacturing is a smaller but growing segment of Australian packaging and structural board production. The process expands and cures paper sheets into a honeycomb core, faced on both sides with kraft or recycled liner board, dried, cut and finished. The HVAC requirement is dominated by the curing oven, the adhesive station and the cutting line.

The curing oven operates at 120 to 160 C with hot air convection, driving off the moisture in the laid-up honeycomb structure. Exhaust at 1.5 to 3.0 m/s face velocity over the oven, transport in galvanised or 304L duct to atmospheric discharge, heat recovery candidate at the 60 to 100 C exhaust temperature. The adhesive station — typically a water-based PVA or starch adhesive — needs minor capture at the applicator. The cutting line generates the same cellulose dust capture problem as a die-cutter and is handled identically.

Honeycomb board manufacturing is a niche enough segment in Australia that most operations are part of larger integrated packaging plants — Detmold Group, Visy, smaller specialty converters. The HVAC scope is integrated into the main plant rather than a standalone package.

Paper bag manufacturing — the simpler converting line

Paper bag manufacturing is the simplest of the packaging converting processes from an HVAC perspective. Kraft paper is fed from reels, printed (typically flexography for the surface print), formed into a tube on a tubing machine, bottom-glued and folded, and stacked. The HVAC requirement is essentially the flexography section already described, plus minor extract at the gluing stations and the cutting / sealing sections.

Press hall ACH 5 to 8, flexo station extract 800 to 1,500 m3/h per station for water-based ink, glue station extract 400 to 800 m3/h per applicator. Heat recovery from the flexo dryer is a candidate. The cellulose dust capture at the cutting and sealing sections is the same as any paper converting line — round duct, NFPA 654 compliance, deflagration-vented external bag house.

Cleaning room — press blanket and cylinder wash

The cleaning room or wash-up station is the single most operator-exposure-critical zone in a printing plant. The blanket wash and cylinder wash solvents — MEK, ethyl acetate, proprietary blanket washes, IPA-water blends — are applied manually with rags or with automatic wash systems. Operator exposure to the wash solvent vapour during wash-up is the highest exposure event in the operator's shift, often higher than the in-running press exposure by a factor of three to five.

Capture is engineered as a dedicated local extract at the wash station at 0.5 to 0.7 m/s face velocity, drawing the solvent vapour away from the operator's breathing zone during the wash event. Volume per wash station typically 800 to 1,500 m3/h. The duct material is 304L stainless or coated mild steel; the transport is to a solvent recovery or thermal oxidiser station, or to atmospheric discharge with environmental approval. The wash-up station is treated as a Zone 2 hazardous area under AS/NZS 60079 during the wash event — the area classification reverts to non-hazardous outside the wash event provided ventilation is maintained.

Modern automatic blanket wash systems on press cylinders reduce the operator exposure significantly because the wash is enclosed and the solvent return is captured at the press rather than at the operator. The trend in Australian commercial printing has been toward automatic wash on new and refurbished presses, partly for operator safety and partly for reduced solvent consumption (typically 30 to 50 percent reduction versus manual wash).

Plate processor and pre-press — the chemical fume hood

Pre-press platemaking generates a different HVAC problem — chemical fume from the plate processor. CTP (computer-to-plate) platemaking uses laser exposure followed by a wet processor with dilute caustic developer (sodium silicate or sodium hydroxide-based), water rinse, gum coating and dry-off. The processor is normally enclosed with a vapour hood drawing the developer vapour and the trace caustic mist to a dedicated extract.

The extract material must resist the caustic vapour — FRP (glass-reinforced polyester) or HDPE-lined carbon steel are the standard choices. Galvanised will degrade within months under caustic exposure. The extract volume per processor is 600 to 1,200 m3/h at 0.5 m/s face velocity over the processor enclosure. The discharge is typically a wet scrubber upstream of atmospheric discharge if the local environmental approval requires scrubbing — in most Australian commercial print plants the developer vapour is sufficiently dilute that direct atmospheric discharge is approved.

Processorless CTP, where the plate is developed in a single-step on-press process or by laser ablation without wet chemistry, eliminates the plate-processor HVAC problem entirely. The trend in Australian commercial printing has been toward processorless CTP for new platemaking installations.

Ink room and bulk solvent storage

The ink room is the highest-risk zone in a printing plant from the hazardous-area perspective. Bulk ink and solvent inventory typically 1,000 to 10,000 litres in tank or drum storage, with mixing, dispensing and filling operations generating flammable vapour. The room is classified Zone 2 (vapour present in abnormal operation) under AS/NZS 60079, with the inside of mixing tanks classified Zone 1 (vapour present in normal operation).

HVAC for the ink room is continuous mechanical extract at 12 to 20 ACH with intrinsically safe gas detection, alarm at 10 percent LFL and shutdown at 25 percent LFL. The supply air is from a non-hazardous adjacent space at slight positive pressure to the ink room; the extract is to atmosphere through a dedicated stack above roof level. The extract duct is 304L stainless or coated carbon steel sealed to AS 4254 Class A. The fan is direct-drive with explosion-proof motor (Ex de IIB T4 or equivalent), located outside the room at the discharge end of the duct so the fan motor is in a non-hazardous area.

Bulk solvent storage is governed by AS 1940. Outdoor bunded storage for IBC and drum inventory above the building threshold quantity is the standard arrangement — indoor storage rooms are limited by AS 1940 quantity caps and are increasingly avoided on new builds. The bunded storage compound is naturally ventilated, with covers to keep rain out and grating to allow vapour escape. Vapour management at the dispensing point uses a small local extract during transfer, ducted to a vapour-recovery unit or a small thermal oxidiser.

For the ink room ventilation duct itself — the 304L stainless extract, the supply plenum, the bag-filter housing on the recirculation side — the SBSF-1525 stiffener former is the right SBKJ machine to produce the longitudinal stiffener bars on the larger duct cross-sections. The SBSF-1525 at 2.5 kW handles 304L cleanly and produces the stiffener geometry that AS 4254 Class A construction requires on long duct runs.

Embossing, foiling and the heat extract

Hot-foil stamping and embossing stations apply a thin metallised film under heat and pressure to the printed sheet. The heat output is modest — 100 to 200 C foil tooling, with minor heat capture required at the embossing head. Extract per embossing station typically 200 to 400 m3/h, galvanised duct to atmospheric discharge. Cold foil and digital foil (UV-cured foil adhesive followed by foil application) eliminate the heat capture but introduce the UV ozone capture handled in the UV varnish section.

Stitching and binding lines — saddle-stitch, perfect-bind, PUR-bind — have minor HVAC requirements. The PUR-bind line uses a polyurethane reactive adhesive that requires extraction at the glue applicator to control the moisture-cure reaction vapour at 0.5 m/s face velocity, transported in 304L duct to atmospheric discharge. The Safe Work Australia WES for isocyanate compounds in PUR adhesives is 0.005 ppm TWA — the same as the polyurethane RIM moulding industry — and the capture must be engineered to keep operator exposure well below.

Storage warehouse, finished goods and the fire suppression overlay

Printed paper, board stock, finished folding cartons, and roll stock for flexible packaging accumulate in significant volume at any well-run commercial printer or packaging converter. Paper stock at 6 to 12 metre rack height represents a significant fire load. The HVAC for the storage warehouse is general dilution at 2 to 4 ACH with the fire suppression overlay dominating the engineering attention.

NFPA 11 foam systems are the standard for bulk ink and bulk solvent storage rooms. Sprinkler systems with foam concentrate injection at storage tank deluge nozzles deliver the foam blanket on a flammable liquid spill at the design rate — typically 6.5 to 10 L/min/m2 foam solution application rate for a fixed foam system. The sprinkler ductwork is not a major design item but the HVAC must integrate with the sprinkler system for smoke management and post-fire ventilation. NFPA 11 covers low-, medium- and high-expansion foam; medium-expansion at 50:1 to 200:1 expansion ratio is the most common for printing-plant solvent storage.

For the paper and board stock storage, ESFR (early suppression fast response) sprinkler heads are the standard suppression at storage heights above 4 metres. The HVAC supply and extract for the warehouse must coordinate with the ESFR layout — supply diffusers offset from the sprinkler heads, return grills routed to allow smoke layer formation in the event of a fire, and post-fire mechanical smoke clearance at 2 to 4 ACH with high-level discharge.

The Australian commercial printing and packaging operator landscape

Every project has to reference the way the resident Australian commercial printing and packaging operators run their plants. The landscape in 2026 is dominated by a small number of large integrated operations alongside a long tail of specialist printers and converters. Understanding who runs which process is essential context for any HVAC duct project — the specifications, the production rates and the regulatory exposure all vary by operator scale and process portfolio.

IVE Group ASX:IGL — Australia's largest commercial printer

IVE Group, headquartered in Sydney and listed on the ASX as IGL, is Australia's largest commercial printing and marketing services group. The group operates eight major print plants across Sydney, Melbourne, Brisbane and Perth, with sheet-fed offset, web offset, digital and specialty finishing capacity covering magazines, catalogues, direct mail, books and folding carton work. IVE's web offset operations include heat-set web for the high-volume catalogue and brochure work that dominates Australian retail print. The HVAC scope across the IVE estate is significant — press hall extract, dryer afterburner and stack heat recovery, ink room hazardous area extract, paper-dust LEV at the converting lines, and warehouse fire suppression integration across multiple plant locations.

Ovato (formerly PMP Limited) — multi-site web offset

Ovato, the company that emerged from the restructure of PMP Limited, operates web offset and sheet-fed plants across Australia, with operations historically in Sydney, Melbourne, Brisbane and Perth. The web offset capacity is dominated by heat-set work for catalogue and retail collateral. Following the restructure, the asset footprint has consolidated, but the HVAC scope at the remaining sites is the same as IVE — heat-set web dryer extract, afterburner stack heat recovery, ink room hazardous area extract and paper-dust LEV at the converting lines.

Pegasus Print Group, Spicers, BJ Ball — mid-market and merchant

Pegasus Print Group is a mid-market commercial printer with strong positions in marketing collateral and short-run catalogue work. Spicers and BJ Ball are the dominant paper merchants in Australia, handling distribution rather than printing themselves but holding significant warehouse stock that drives the HVAC scope for their distribution facilities. Avery Dennison Australia is a specialty label printer with multiple Sydney and Melbourne plants running UV flexo and digital label presses. The HVAC scope at these mid-market operations is smaller per site than IVE or Ovato but no less technically demanding.

Pact Group ASX:PGH — rigid packaging

Pact Group, headquartered at Mulgrave in Victoria and listed on the ASX as PGH, operates 80-plus packaging plants across Australia and New Zealand. The group is the dominant Australian rigid plastic packaging manufacturer — injection moulding, blow moulding, thermoforming for food, beverage, personal care, industrial and pharmaceutical packaging. The HVAC scope at the Pact plants is covered in more detail in our plastics manufacturing HVAC duct guide; for the printing and decorating end of the Pact operations (label printing, in-mould labelling, container decoration), the HVAC requirement falls within the flexography and UV-print sections of this guide.

Visy Industries — Australia's largest integrated packaging operation

Visy Industries, the privately held packaging and recycling giant led by Anthony Pratt, is Australia's largest single packaging operation. The Visy footprint includes integrated paper mills, corrugator plants, folding carton plants, beverage container plants and recycling operations across Coolaroo (Victoria), Hexham (NSW), Coomera (Queensland) and multiple other sites. The HVAC scope at Visy spans every process in this guide — corrugator double-backer steam extract, folding carton press hall, die-cutting and folder-gluer LEV, ink room hazardous area, paper mill mechanical vapour recompression and steam management. Visy's scale makes it the single largest customer for HVAC ductwork in the Australian packaging industry.

Amcor PLC ASX:AMC NYSE:AMCR — global flexible packaging

Amcor, headquartered in Hawthorn (Victoria) with a dual ASX and NYSE listing, is one of the world's largest flexible packaging manufacturers with multiple Australian plants. The local operations include flexible packaging extrusion, lamination, rotogravure and flexo printing on film substrates. The HVAC scope is heavy on the solvent recovery side — rotogravure with carbon adsorption or RTO, solvent-based lamination capture, ink room hazardous area, blown-film extrusion ventilation. The Hawthorn corporate office and the local plant footprint together represent a major presence in Australian packaging engineering.

Pro-Pac Packaging ASX:PPG — flexible packaging mid-market

Pro-Pac Packaging, listed on the ASX as PPG, is a flexible packaging converter with operations across Australia and New Zealand. The product portfolio includes flexible food packaging, industrial bags, stretch and shrink film, and specialty films. The HVAC scope is the flexible packaging set — extrusion, flexo or gravure printing, lamination, slitting and finishing.

Detmold Group — paper-board and plastic film

Detmold Group, with major operations at Brendale in Queensland under the Detpak brand, is a vertically integrated paper-board and plastic film packaging manufacturer. The group runs corrugator plants, folding carton converters, paper-cup manufacturing lines and plastic film extrusion. The HVAC scope spans corrugator double-backer steam, folding carton press halls, paper-cup forming-line extract and plastic-film extrusion ventilation. Detmold's vertical integration makes the HVAC engineering for the combined site particularly complex because supply, return and exhaust streams interact across multiple processes within the same building envelope.

Orora ASX:ORA — integrated paper, board and beverage cans

Orora, listed on the ASX as ORA with corporate offices in Hawthorn (Victoria) and major operations at Botany (NSW), runs an integrated portfolio of fibre packaging (paper, corrugator, folding carton) and beverage cans. The fibre packaging operations are similar in HVAC scope to Visy and Opal — corrugator double-backer steam extract, paper mill steam systems, folding carton press hall, die-cutting and folder-gluer LEV. The beverage can operations are a different process altogether (metal coating, can-forming, printing on cans) with their own HVAC scope — coating oven extract, ink solvent capture, and metal-stamping LEV. The Botany operations are one of the largest single-site packaging operations in Australia.

Opal (formerly Australian Paper) — Maryvale and Nine Mile

Opal, the company that emerged from the rebrand of Australian Paper, runs the integrated kraft paper mill at Maryvale (Victoria) and the corrugator operation at Nine Mile (Queensland) alongside other regional sites. Maryvale is one of the largest single industrial sites in Victoria, producing kraft liner and medium for the integrated corrugator network. The HVAC scope at Maryvale is heavy industrial — paper machine wet end and dry end ventilation, recovery boiler exhaust, lime kiln exhaust, woodyard dust capture — all of which sit within paper-mill engineering rather than light-manufacturing HVAC, but the converting and corrugator sides of the Opal operations sit firmly within this guide.

Pro-Pac Group, Bonson Industrial, Cospak Plastic — mid-market plastics and packaging

The Australian packaging mid-market includes a long list of specialist converters — Pro-Pac Group, Bonson Industrial, Cospak Plastic, Aussie Sealing in caps and closures, and a number of smaller folding carton and flexible packaging operators. The HVAC scope per site is smaller than the Pact or Visy scale but the technical demands are the same — press hall extract, ink room hazardous area, paper-dust LEV, lamination capture.

Confectionery and food carton manufacturing

Cadbury (now part of Mondelez International) at Claremont in Hobart, Tasmania, runs in-house and outsourced carton manufacturing for chocolate packaging. The site combines a major confectionery manufacturing operation with carton printing and finishing for the packaging. Mars Wrigley at Ballarat (Victoria) runs a similar combined confectionery and packaging operation. The HVAC scope at these sites combines food-grade manufacturing HVAC (HACCP-aligned, EN 1822 filtration) with conventional folding carton press hall and finishing extract.

Direct mail and transactional print

Australia Post StarTrack runs a major direct mail printing and fulfilment operation. LeadingEdge and a number of specialist direct mail printers cover the remainder of the market. The HVAC scope is conventional sheet-fed and digital press, with the dominant engineering attention on the high-speed inserting and mail-handling lines rather than the press itself.

Industry bodies — PVCA and AIIA

The Print & Visual Communication Association (PVCA) is the dominant industry body for Australian commercial printing, with annual conferences, training programmes and standards advocacy. The Australian Industry Group (AIG, sometimes referenced as AIIA in older documents) is the broader industrial industry body. Both organisations are good first-port references for HVAC engineering best practice in the printing and packaging sector, and their published guidance on solvent management, dust hazard and ventilation typically aligns with the AS code framework summarised in this guide.

Material selection by zone — the engineering matrix

Material selection for ductwork in an Australian commercial printing and packaging plant follows a zone-by-zone matrix. The wrong material in the wrong zone is the most common cause of premature duct failure, with replacement cost typically 2 to 5 times the original capital cost of the duct itself.

• Press hall general extract and dilution — galvanised AS 1397 G275, 0.6 to 1.2 mm gauge per AS 4254, Class B seal. Service life 15 to 25 years in this duty.
• Sheet-fed delivery powder extract — galvanised, with periodic cleaning programme. Powder is mildly abrasive but service life still 15 years if cleaning is done on schedule.
• Heat-set web dryer exhaust to afterburner — 304L stainless to ASTM A240, 1.2 to 1.6 mm gauge, insulated externally, rated for continuous service at 400 C. Service life 15 to 25 years.
• Rotogravure solvent recovery line — 304L stainless, AS 4254 Class A seal, with condensate drainage and explosion isolation. Service life 20 years plus.
• Flexo solvent station extract — 304L stainless or coated mild steel, AS 4254 Class A seal. Service life 15 to 20 years.
• UV station ozone extract — 304L stainless or HDPE-lined carbon steel, atmospheric discharge. Service life 15 to 20 years for stainless, 25 years plus for HDPE liner if intact.
• Lamination solvent extract — 304L stainless. Service life 15 to 20 years.
• Ink room hazardous area extract — 304L stainless, AS 4254 Class A seal, explosion-proof fan. Service life 20 years plus.
• Wash-up station LEV — 304L stainless or coated mild steel. Service life 15 to 20 years.
• Plate processor fume hood — FRP (glass-reinforced polyester) or HDPE-lined carbon steel for caustic resistance. Service life 20 years plus for FRP.
• Die-cutting and folder-gluer paper dust LEV — heavy-gauge mild steel, 1.6 mm minimum, round cross-section, bonded and earthed to AS 1020. Service life 20 years plus with periodic abrasion inspection.
• Corrugator double-backer steam extract — 304L stainless or coated carbon steel with knock-out drum, insulated. Service life 15 to 25 years.
• Storage warehouse general HVAC — galvanised. Service life 25 years plus in dry storage duty.

For 304L stainless production on the SBAL line, the tooling is configured for stainless feed and the longitudinal seam is welded rather than lock-formed. The SBPC1500 plasma cutter handles the stainless penetrations and end caps; the SBAL-V running with stainless coil produces straight duct sections at near-galvanised throughput rates. For the heavy-gauge mild-steel paper-dust LEV at 1.6 mm gauge, the SBAL-V runs within its 0.5 to 1.5 mm capacity at the upper end — for the very heaviest gauges, off-line fabrication on a press brake and welding station may be more economic.

Seal class to AS 4254 — getting the leakage right

AS 4254 defines three seal classes for ductwork construction:

• Class A — allowable leakage 4 percent of design flow at 1.5 times design static pressure. Required for cleanroom supply, hazardous area extract, solvent recovery line, regulated emission line, and any duct where outward leakage of regulated vapour into the workshop is a notifiable event.
• Class B — allowable leakage 8 percent of design flow at 1.5 times design static pressure. Standard for general commercial HVAC, press hall extract and dilution, die-cutting paper-dust LEV downstream of the bag house, and the bulk of ductwork in a printing or packaging plant.
• Class C — allowable leakage 16 percent of design flow at 1.5 times design static pressure. Acceptable for outdoor air intake plenums, dilution-only systems and low-pressure return air duct.

The seal class is achieved by the joint type (TDF flange, slip joint, welded), the gasket material (compressed mineral fibre, EPDM, woven fibreglass for high-temperature service) and the workmanship at the site joint. The pressure decay test at 1.5 times design static pressure for 15 minutes is the verification — the duct is sectioned off, pressurised, and the rate of pressure decay measured against the AS 4254 allowable leak rate.

For the printing and packaging sector, the Class A duct on the rotogravure solvent return riser, the ink room extract, the heat-set web dryer afterburner line and the high-risk solvent recovery sections represents 10 to 20 percent of the total duct programme by length but 30 to 40 percent of the engineering attention at design and commissioning. The remaining bulk of the programme — press hall extract, dilution supply and return, paper-dust LEV downstream of the bag house — is Class B and is the routine work that the SBAL-V production line handles.

Heat recovery economics in printing and packaging plants

Heat recovery on printing and packaging HVAC exhaust is some of the most attractive heat recovery in light manufacturing. The combination of high exhaust temperatures (heat-set web afterburner stack at 200 to 280 C, lamination oven at 150 to 200 C, corrugator double-backer at 80 to 120 C) and continuous operation across two- or three-shift production gives the recovery system year-round duty at high heat flux.

A typical mid-size commercial heat-set web printer with a single eight-unit press and an integrated converting line rejects 600 to 1,200 kW of sensible heat through the dryer afterburner stack at 200 to 280 C, plus 200 to 400 kW through the lamination oven exhaust at 150 to 200 C. Recovering 40 to 60 percent of the high-grade stack heat through a glycol run-around coil or air-to-air heat wheel offsets the entire press-hall outdoor air pre-heat requirement for ten months of the year in Melbourne, Sydney and Adelaide. The capital cost of the recovery system is 15 to 25 percent of the value of the gas displaced in the first three years, giving a typical payback of 2.5 to 4 years at 2026 Australian industrial gas prices.

An integrated corrugator operation like Visy Coolaroo, Orora Botany or Opal Maryvale rejects 400 to 800 kW per corrugator line at 80 to 120 C from the double-backer extract. The lower temperature makes the recovery economics less compelling on a per-line basis, but the continuous duty across the year and the low-grade heating load (sheet metal shop space heating, cleaning hot water, building outdoor air pre-heat) provides a strong match. A condensing heat exchanger downstream of the knock-out drum recovers 20 to 40 percent of the heat with a 4 to 6 year payback at 2026 prices.

The duct geometry on the recovery side must accommodate the recovery coil with adequate face area, slope to drain for any condensate, and access for periodic cleaning. The face area is typically 1.0 to 1.5 m2 per 10,000 m3/h of exhaust at a coil face velocity of 2.0 to 2.5 m/s; the slope is 1 to 50 minimum toward a drain point; the access is a removable end cap or a cleanout door for tube-bundle removal.

Hazardous area classification under AS/NZS 60079

AS/NZS 60079 is the Australian/New Zealand adoption of the IEC 60079 hazardous area standard. The classification is based on the likelihood of a flammable atmosphere being present:

• Zone 0 — flammable atmosphere present continuously or for long periods. Limited to the inside of solvent and ink storage tanks during transfer; rare in printing and packaging plant external duct work.
• Zone 1 — flammable atmosphere likely to be present in normal operation. Inside ink mix tanks, bulk solvent rooms during dispensing, and the immediate vicinity of solvent printing stations and lamination cabinets during operation.
• Zone 2 — flammable atmosphere not likely to be present in normal operation, but if it occurs will exist for short periods. Press halls during normal operation, ink rooms outside dispensing windows, lamination galleries.
• Zone 21 / 22 — combustible dust equivalent of Zone 1 / Zone 2. Zone 21 around bag-house hoppers and dust-collection points where combustible cellulose dust persists; Zone 22 in the extended dust-prone area.

Cable, fan, fitting, instrument, motor and lighting selection follows the zone classification. The bulk of a printing or packaging plant is non-hazardous; the hazardous zones are restricted to the ink room, the bulk solvent storage, the print stations of solvent flexo and rotogravure lines, the lamination cabinets and the dust-collection points. The hazardous-area scope is significant but not dominant, and the duct construction follows the zone — AS 4254 Class A seal on hazardous-area exhaust, intrinsically safe sensors in hazardous-area instrument lines, explosion-proof fans on hazardous-area discharge.

The SBKJ machine recommendation for printing and packaging duct fabrication

SBKJ Group's machine range is designed to handle the duct construction programme for an Australian printing or packaging plant from press hall through to bag house in a single fabrication shop:

• SBAL-V auto duct production line — the workhorse for the galvanised press hall extract, supply and return programme. 16 m/min line speed, 87 kW total drive, 0.5 to 1.5 mm coil capacity, up to 1500 mm coil width, producing TDF flanged rectangular duct in one operation. For a typical commercial print plant building a 600 to 1,200 m2 duct programme, the SBAL-V completes the work in 2 to 3 weeks of single-shift production.
• SBAL-III — 14 m/min, 15.7 kW, 0.5 to 1.2 mm coil. The right scale for mid-size folding carton and flexible packaging converters with a 300 to 600 m2 duct programme.
• SBAL-II — 18 m/min, 5.5 kW, 0.5 to 1.2 mm coil. The compact option for smaller printers and converters.
• SBTF-1500C / SBTF-1602 / SBTF-2020 — spiral tubeformers for round duct. Diameter 80 to 2000 mm depending on model. The SBTF-1602 is the natural choice for the rotogravure VOC return riser between print station and afterburner because it handles 304L stainless cleanly to 1.2 mm at the spiral seam quality required by AS 4254 Class A.
• SBEM-1250 — elbow former for standard fittings, radius bends and transitions.
• SBSF-1525 — stiffener former, 2.5 kW, producing longitudinal stiffener bars on large duct cross-sections. The right tool for the stainless ink-room ventilation duct stiffener requirement.
• SBFB-1500 — box folder, 7.5 kW, 1.20 m/min line speed, for plenum panels and fan-housing parts.
• SBHF — hydraulic flange former for heavy-gauge fan-plenum and bag-house ducting.
• SBPC1500 — plasma cutter for stainless penetrations, end caps and accessory cuts.
• SBLR-600 / SBLR-600A — lockformers, 7.6 m/min, for longitudinal seams on rectangular duct.

For 304L stainless work on the solvent recovery line and the ink-room hazardous-area extract, the SBAL line is configured with stainless tooling, plasma cutting and a longitudinal seam welding station. For the paper-dust LEV at the die-cutting and folder-gluer lines, spark-resistant fans (bronze impeller or non-sparking blade) are specified downstream of the duct fabrication — the SBKJ duct programme covers the duct, with the fan selection done from the wider equipment supplier base. For glass-reinforced polyester (FRP) on the plate processor fume hood and any HDPE-lined acid extract, the duct is fabricated off-line at a specialist FRP fabricator rather than on the SBKJ line.

Energy, sustainability and the APCO overlay

The Australian Packaging Covenant Organisation (APCO) sets the producer-responsibility framework for packaging waste in Australia. Every printer and converter that produces consumer packaging is a covenant signatory or contributor, with annual reporting on packaging volume, recyclability and waste-reduction targets. The covenant has driven significant investment in recyclable substrates (mono-material flexible packaging replacing multilayer laminates), water-based ink chemistry (replacing solvent inks where the substrate allows), and lightweighting of folding carton and flexible packaging. None of this changes the HVAC scope dramatically, but the trend toward water-based inks and aqueous coatings does shift the load away from solvent recovery and toward moisture and low-grade heat capture — which is good news for HVAC complexity and cost.

FSC (Forest Stewardship Council) and PEFC (Programme for Endorsement of Forest Certification) chain-of-custody certification is the substrate side of the sustainability framework. Most Australian printing and packaging plants run an FSC or PEFC chain-of-custody programme to demonstrate that paper and board substrates come from certified sustainable forestry. The certifications do not directly affect the HVAC scope but they do drive the documentation and audit overlay on the plant.

The ISO 12647 graphic technology standards govern colour and process control in printing. Compliance with ISO 12647-2 (sheet-fed offset), ISO 12647-3 (newsprint), ISO 12647-4 (gravure) and ISO 12647-6 (flexography) requires tight process control on temperature and humidity at the press, which translates into HVAC supply at the press station with controlled temperature (22 to 24 C typical) and relative humidity (50 to 55 percent for sheet-fed offset, 45 to 55 percent for flexography). The HVAC supply is sized to maintain these conditions through the operating shift; the press hall extract is sized to remove the process load without disturbing the controlled supply.

ISO 12944 corrosion protection is referenced for the protective coating on carbon steel duct in solvent-vapour service. Class C2 protection (mild atmosphere) is typical for press hall general extract; Class C3 (moderate atmosphere) for ink room and lamination extract; Class C4 (severe atmosphere) for rotogravure solvent recovery line and chemical fume hood return. The coating system is two-pack epoxy primer plus polyurethane topcoat for C3 and C4 service; galvanised hot-dip primer is acceptable for C2 service.

Air quality, boundary monitoring and the AS 3580 overlay

AS 3580 is the Australian standard for boundary air-quality monitoring at the property fence line. For a printing or packaging plant with a solvent recovery installation, an environmental approval will typically include a monitoring condition at the boundary with the neighbouring property, measuring VOC concentration on a continuous or periodic basis. The boundary VOC limit depends on the local environmental authority — EPA Victoria, NSW EPA, Queensland DES, WA DWER, SA EPA, NT EPA, Tasmania EPA, ACT — with limits typically in the 1 to 10 ppm range as an averaging concentration over an hour or longer.

The boundary monitoring drives the upstream engineering. If the solvent recovery efficiency drops or the carbon bed approaches breakthrough, the boundary VOC will rise and the regulator will be notified. The plant's response is either to regenerate the carbon bed earlier, fit a polishing bed downstream of the primary recovery, or upgrade to RTO treatment of the captured stream. The HVAC duct downstream of the recovery system is sized to handle the maximum atmospheric discharge rate; the duct material is selected for the discharge composition (typically galvanised or 304L for the cleaned exhaust stream).

For plants near residential or sensitive receivers (schools, hospitals, aged care), the boundary monitoring is typically supplemented by an odour assessment at the property line. Olfactory thresholds for printing-plant solvents are typically far below the WES — toluene is detectable at 1 to 3 ppm against a WES of 50 ppm; ethyl acetate at 5 to 50 ppm against a WES of 200 ppm. The odour assessment usually drives more stringent capture and recovery than the boundary VOC concentration alone.

Fire safety integration — AS 1530.4, NFPA 86 and the safety case

AS 1530.4 governs fire-rated penetrations in Australian construction. Every duct penetration through a fire-rated wall or floor needs a tested system — either a fire damper that closes on detection of fire and isolates the duct, or a fire-rated wrap or coating that maintains the fire rating of the wall or floor through the duct penetration. The fire-resistance level (FRL) is specified by the building classification — FRL 60/60/60 for typical commercial and industrial occupancies, FRL 120/120/120 for ink rooms and bulk solvent stores, FRL 240/240/240 for fire-isolating walls between major fire compartments.

For a printing or packaging plant the typical penetration count is 50 to 200 fire-rated penetrations across the building envelope, depending on plant complexity and fire-compartmentation strategy. Each penetration is documented in the safety case with the FRL test report (the tested system from a manufacturer's product data sheet referenced to AS 1530.4), the as-installed configuration, the inspection record and the maintenance schedule. Fire dampers are drop-tested annually under AS 1851 with full operational verification — release on fusible link or smoke detector, closure to the locked position, manual reset and re-arming.

NFPA 86 governs the dryer and oven interlock chain on heat-set web offset, lamination ovens, drying tunnels and afterburners. The interlock chain includes LEL monitoring on the dryer exhaust, automatic shutdown of ink feed and web on LEL excursion, purge cycles on startup and shutdown, fuel train shutoff valves, and combustion air supervision. NFPA 86 compliance is verified at commissioning and re-verified on each maintenance cycle. The HVAC duct between the dryer and the afterburner is part of the NFPA 86 scope — the duct material and the duct integrity affect the LEL excursion behaviour and the recovery time after a trip.

The overall safety case for the plant integrates AS 1530.4 fire-rated penetrations, NFPA 86 dryer interlocks, AS/NZS 60079 hazardous area classification, AS 1940 flammable liquid storage compliance, NFPA 654 / 660 combustible dust assessment, NFPA 11 foam suppression on bulk solvent storage and AS 4801 occupational health and safety. The safety case is reviewed annually and re-validated on major plant changes. The HVAC engineering team is a major contributor to the safety case because the duct system is the carrier for the regulated streams — solvent vapour, combustible dust, hot exhaust, hazardous-area extract — that the safety case is managing.

Commissioning and verification — the closeout package

The closeout package on a printing or packaging plant HVAC project includes:

• Capture velocity verification at every hood with a calibrated anemometer. Field measurements documented against the design face velocity, with corrective action if any measured value is more than 10 percent below the design.
• Dilution ACH verification by tracer gas decay or supply-air flow measurement. Field measurements documented against the design ACH for every zone.
• Pressure decay testing of duct sections per AS 4254 Class A and Class B. Test pressure 1.5 times design static for 15 minutes. Leak rate documented against the seal class.
• Personal exposure monitoring for IPA, toluene, ethyl acetate, MEK, ethanol, formaldehyde, isocyanate, NMP and ozone as applicable to the plant inventory. Time-weighted average and short-term exposure measurements documented against Safe Work Australia WES.
• Boundary VOC monitoring per AS 3580 where required by the environmental approval. Continuous or periodic measurements documented against the boundary limit.
• Solvent recovery efficiency verification by mass balance over the carbon train or by direct measurement on the RTO destruction efficiency. Field measurements documented against the design recovery rate.
• Fire damper drop test under AS 1851. Every fire damper actuated and verified to close to the locked position.
• NFPA 86 dryer interlock function test. LEL excursion test, ink feed shutoff test, fuel train shutoff test, purge cycle verification.
• Hazardous area cable, fitting and instrument continuity inspection under AS/NZS 60079. Earth continuity, intrinsic safety circuit isolation, gas detector calibration.
• NFPA 654 / 660 combustible dust system verification. Spark detector function test, explosion isolation valve actuation test, deflagration vent inspection, bonding and earthing continuity test under AS 1020.

The commissioning package is the handover to operations. The maintenance regime then takes over: quarterly capture velocity spot checks, annual pressure decay re-testing on Class A sections, annual fire damper drop test, annual hazardous area inspection, annual NFPA 86 interlock function test, annual combustible dust system verification, monthly bag-filter inspection and cleaning, weekly fan inspection. The maintenance regime is documented in the operating manual and forms part of the safety case.

Final notes from the engineering bench

Printing and packaging HVAC is one of the more rewarding disciplines in industrial ventilation because the process exposes the engineer to a broad spread of capture, dilution, dust, fume and emission problems within a single facility. The same plant that runs a sheet-fed offset press with conventional ink will also run a heat-set web with afterburner stack, a rotogravure line with solvent recovery, a folding carton converting line with NFPA 654 dust capture, a corrugator with double-backer steam extract, and a hazardous-area ink room with explosion-proof extract. Designing the HVAC for one of these zones is one problem; designing it for all of them in a shared building envelope is the integration problem that defines the discipline.

The Australian standards framework — AS 1668.2, AS 4254, AS 1530.4, AS 1530.3, AS/NZS 60079, AS 1940, AS 3957, AS 4801, AS 3580 — supplemented by NFPA 86 for heat-set dryers, NFPA 654 / 660 for combustible cellulose dust, NFPA 30 for flammable liquid storage, NFPA 11 for foam suppression, and the ASHRAE Applications Chapter 33 framework for industrial ventilation — provides the regulatory baseline. The Safe Work Australia workplace exposure standards provide the air-quality target. ISO 12647, ISO 12944, FSC, PEFC and APCO provide the broader operational overlay. The plant's own production schedule, energy budget and capital constraint provide the design boundary. Within that frame, the engineer's job is to deliver capture and dilution that protects the workforce, contains the regulated emissions, recovers the heat where economic, and does so with a duct system that performs through the operational life of the plant.

SBKJ Group's role in this is the duct-forming machinery. The SBAL-V, SBAL-III and SBAL-II auto duct production lines, the SBTF-1500C, SBTF-1602 and SBTF-2020 spiral tubeformer range, the SBEM-1250 elbow former, the SBSF-1525 stiffener former, the SBFB-1500 box folder, the SBHF hydraulic flange former, the SBPC1500 plasma cutter and the SBLR-600 / SBLR-600A lockformers are the tools that turn the engineer's specification into the installed duct system. The machinery is configured for Australian production conditions, supported from Box Hill North, Victoria, and proven across Australian commercial printing, folding carton, corrugated cardboard and flexible packaging fabrication shops.

If you are scoping a printing or packaging plant ductwork programme — new build, expansion, retrofit or refurbishment — we can help with the machinery selection, the duct programme estimation, the fabrication shop setup and the operator training. Reach out through the contact page and you will get an engineer's reply, not a sales pitch.

Discuss your printing or packaging plant ductwork project with SBKJ →

FAQ

What capture velocity is required at a sheet-fed offset press hood?

0.4 to 0.6 m/s capture face velocity at the press hood over the inking, dampening and impression units, with branch transport velocity 10 to 15 m/s. Volume per six-colour B1 press typically 1,500 to 2,500 m3/h for the press hood plus 1,000 to 1,800 m3/h for the delivery powder extract. Press hall dilution overlay 6 to 10 ACH. Galvanised AS 1397 G275 duct to AS 4254 Class B for the press hall, 304L stainless for the wash-up and ink-room return riser.

How is solvent vapour handled on a heat-set web dryer?

Dryer exhaust at 250 to 320 C to an afterburner (thermal oxidiser or RTO) operating at 800 to 900 C. Duct between dryer and afterburner is 304L stainless or insulated mild steel rated to 400 C continuous. NFPA 86 governs the interlock chain — LEL monitor at the exhaust, automatic shutdown at 50 percent LFL. Clean stack at 200 to 280 C is a strong heat recovery candidate; glycol run-around coil recovers 40 to 60 percent of the heat for press-hall outdoor air pre-heat.

How is rotogravure solvent recovery configured?

Capture at print station hoods and dryer enclosures, transport in 304L stainless to AS 4254 Class A seal, routed to either an activated carbon adsorption train (95 to 99 percent recovery on toluene) or a regenerative thermal oxidiser (RTO at 800 to 900 C, 99 percent VOC destruction) depending on solvent inventory. Single-solvent toluene operations almost always carbon adsorption; mixed-solvent ethyl acetate / ethanol operations often RTO. Safe Work Australia WES: toluene 50 ppm, ethyl acetate 200 ppm, ethanol 1000 ppm TWA.

How is paper dust from die-cutting and folder-gluer captured to NFPA 654?

Round duct, heavy-gauge mild steel (1.6 mm minimum), transport velocity above 18 m/s horizontal and 15 m/s vertical, deflagration-vented bag house external to building, explosion isolation at building entry, bonding and earthing of every section per AS 1020, spark detection and extinguishing on the LEV trunk. Cellulose dust Kst 50 to 150 bar.m/s, MIE 30 to 100 mJ. Hood capture 1.0 to 1.5 m/s face velocity at the die exit and waste-stripping station.

What materials should be specified for ductwork in a printing and packaging plant?

Galvanised AS 1397 G275 for press hall general extract and dilution; 304L stainless for heat-set dryer afterburner line, rotogravure solvent recovery, ink room hazardous-area extract, lamination solvent extract and wash-up LEV; 316L for heavy-solvent gravure VOC return riser if specified; FRP or HDPE-lined for plate processor fume hood; heavy-gauge mild steel for paper-dust LEV with bonded earthing.

Which SBKJ machine is the right fit for printing and packaging duct fabrication?

SBAL-V (16 m/min, 87 kW, 0.5 to 1.5 mm coil, 1500 mm width) for the bulk galvanised press hall programme. SBAL-III (14 m/min, 15.7 kW) and SBAL-II (18 m/min, 5.5 kW) for mid-size converters. SBTF-1500C / SBTF-1602 / SBTF-2020 spiral tubeformers for round duct — SBTF-1602 is the natural choice for the rotogravure VOC return riser in 304L stainless. SBSF-1525 (2.5 kW) stiffener former for stainless ink-room duct. SBEM-1250 elbow former. SBFB-1500 (7.5 kW, 1.20 m/min) box folder for plenums. SBHF hydraulic flange former. SBPC1500 plasma cutter. SBLR-600 / SBLR-600A (7.6 m/min) lockformers. Spark-resistant fans on the paper-dust LEV downstream of the duct programme.

What AS and NFPA standards apply to printing and packaging plant ductwork?

AS 1668.2 mechanical ventilation, AS 4254 ductwork construction, AS 1530.4 fire-rated penetrations, AS 1530.3 ignitability, AS 1397 galvanised steel, AS/NZS 60079 hazardous areas, AS 1940 flammable liquids, AS 3957 dust hazard, AS 4801 OHS, AS 3580 boundary VOC monitoring, AS 1020 static control, AS 1807 cleanroom testing where required. NFPA 86 dryer / oven interlocks, NFPA 654 / 660 combustible dust, NFPA 30 flammable liquid storage, NFPA 11 foam suppression, ASHRAE Applications Chapter 33 industrial ventilation. ISO 12647 graphic technology, ISO 12944 corrosion protection, FSC / PEFC substrate certification, APCO packaging covenant.

Why is heat recovery so attractive in printing and packaging HVAC?

Heat-set web dryer afterburner stack at 200 to 280 C, lamination oven at 150 to 200 C and corrugator double-backer at 80 to 120 C all reject high-grade sensible heat continuously across two- or three-shift production. A typical commercial heat-set printer rejects 600 to 1,200 kW per press through the afterburner stack; a corrugator line rejects 400 to 800 kW through the double-backer extract. Recovering 40 to 70 percent through glycol run-around coils, air-to-air heat wheels or condensing heat exchangers offsets press-hall outdoor air pre-heat and provides low-grade heat for hot water and space heating. Payback 2 to 4 years at 2026 Australian industrial gas prices.