Plastic bag making machines

A plastic bag making machine turns rolls of blown PE or PP film into finished bags by sealing, cutting, punching and stacking or winding them. Pick the type by bag style: T-shirt machines for carrier bags, bottom seal machines for garbage and produce bags, side seal machines for bread and garment bags, and bag-on-roll lines for rolled garbage bags.

How a bag making machine works

Every bag machine starts from a mother roll of film, usually flat or gusseted tube made on a blown film line. The unwind holds the roll under constant tension, an edge position controller (EPC) keeps the web centred, and a servo draw roll pulls exactly one bag length per cycle. A heated seal bar welds the layers together, a knife cuts or perforates between bags, and the bags are stacked, punched or wound onto rolls. On printed film a photocell reads a print mark every cycle so the seal lands in the same place on each bag.

Speed is quoted two ways, and the difference matters when you compare quotes. Cycles per minute is how often the seal bar closes. Bags per minute is cycles multiplied by the number of lanes running side by side. The Hemingstone HM-1200V4A T-shirt machine, for example, is rated at 250 cycles per minute and up to 1,000 bags per minute, but only on four lanes with bags 250 mm wide or less. At its full 500 mm bag width it runs two lanes.

Main machine types

T-shirt bag machines

A T-shirt machine seals across a gusseted tube, then a punching knife cuts out the handles and mouth so the bag opens like a vest. Most run several lanes at once to multiply output on narrow bags. Useful features to look for are independent punching modules per lane, an EPC guide on each lane and a seal-line shift that stops stacked bags sticking together, all of which Hemingstone lists on the HM-1200V4A.

Bottom seal machines

Bottom seal bags have a flat front and back and one seal across the width, which suits heavy or bulky contents. The Mamata WIN 800 B uses a flying knife that seals and cuts while the web keeps moving, with the distance between seals set on the touch screen. Its published range is 150 to 800 mm wide with draw lengths up to 2,000 or 4,000 mm depending on configuration, and it runs HDPE, LDPE, LLDPE, PP and CPP.

Side seal machines

A side seal machine welds folded film along both edges and leaves one side open. Because the print runs continuously around the fold, side seal bags carry large graphics well, and zippers or handles are easier to add. The Hemingstone HM-1000HSE-X can also be set up for bottom seal bags, and it reads two print marks so it can run one wide printed film or two narrower ones.

Bag-on-roll lines

These lines seal and perforate a continuous web and rewind it into retail rolls, on paper cores or coreless. The Lung Meng TA-S-750XL-2Q makes star seal garbage bags on two lanes with a servo shuttle track that seals while the film moves, winding finished rolls up to 130 mm in diameter from thin HDPE of 0.008 to 0.015 mm.

How to choose: the specs that matter

• Bag size envelope. Check width and length against your whole product list, and check how many lanes the machine can run at each width. Headline output usually assumes the narrowest bag.
• Film type and gauge. Makers quote HDPE and LDPE separately because softer, thicker LDPE needs more seal energy. Lung Meng lists 0.008 to 0.025 mm HDPE but 0.020 to 0.060 mm LDPE on its TPA-GP T-shirt series.
• Seal motion. Intermittent machines stop the web for each seal. Flying knife and shuttle systems seal on the move and hold linear speed on long bags.
• Registration. Printed bags need photocell tracking on every lane you intend to run with print.
• Output end. Stacking conveyors, hot punching, counting, core feeding and automatic roll change decide how many people stand at the end of the line.
• Changeover. Servo feeds with stored job settings cut setup time when you run many short orders.

What your plant needs

• Power. Bag converting is a light electrical load next to extrusion. Hemingstone lists 11 kW for the HM-1200V4A, 7 kW of it for heaters, and 15 kW for the HM-1000HSE-X. Asian builders usually wire for 380 V, so a plant on 600 V three-phase needs a step-down transformer or a 600 V build; see our 600 V power guide and the notes on CSA certification and field evaluation.
• Compressed air. Punches, loaders and clampers need clean, dry air. Hemingstone specifies a 7.5 hp compressor for both machines above and does not include it.
• Floor space. The HM-1200V4A is 8.8 m long and 2.1 m wide (about 29 x 7 ft) and weighs 3,300 kg. Add room for mother rolls, a roll lift, packing tables and finished goods.
• Film supply. Buy film rolls or extrude your own. In-house extrusion gives control of gauge, colour and recycled content, but adds a much larger line, resin handling and far more power.
• Scrap. Punch-outs and trim are clean PE that a film plant can regrind. A converting-only plant needs a collection and resale route.

Running costs

Film is the main cost in every bag. Width, gauge and seal allowance are fixed when the bag is designed, so a few microns saved on a bag that still passes its load test add up quickly at volume. After film, the cost drivers are:

• Electricity for seal heaters and servo drives, plus the compressor.
• Wear parts: seal bar coverings, cutting and perforating knives, and punching dies made for each bag shape.
• Scrap during setup and after registration faults, which is where servo feeds and good edge guiding pay back.
• Labour at the output end: counting, packing and roll changes, reduced by automatic core feeding and roll exchange such as on the Chovyting CW-1000PR+C2.

Applications and Canadian rules

Typical products are garbage, compost and recycling bags, produce and bulk food bags, bread and bakery bags, garment and mailer bags, industrial liners and printed retail bags. If you plan to sell carrier bags in Canada, check the federal rules first. Under the Single-use Plastics Prohibition Regulations, plastic film checkout bags may not be manufactured, imported or sold for use in Canada, while bags for garbage, organic waste, recycling and loose bulk food are outside the rules according to Environment and Climate Change Canada (ECCC). As of 2026 the regulations remain in force: the Federal Court of Appeal upheld their legal basis in January 2026, and an application for leave to appeal to the Supreme Court of Canada was filed in March 2026. The rules on manufacturing for export are also under review. Our guide to the single-use plastics rules has the detail; confirm your product with ECCC before you commit to a line.

Still choosing a material? The paper vs plastic vs non-woven comparison sets the three bag lines side by side.