Advanced Garment / Shopping Bag Film Line: High-Speed Thin Film Extrusion with In-Line Printing 2026
A garment / shopping bag film line is a high-speed blown film system that produces thin, transparent or printed films for retail and clothing bags. The film is typically 15-30 µm thick, with lay-flat widths of 300-1200 mm, made from LDPE, LLDPE, or blends with high clarity and good printability. The extruder is a high-output single-screw (often 3-layer for strength and print surface) with a barrier screw and a high-efficiency air ring. IBC is often added to boost output. The line speed is high (150-200 m/min). The film is collapsed, measured by a thickness gauge, and then passes through a corona treater to increase surface energy for printing. An in-line flexographic printer applies one or more colors. The printed film is then fed into a bag-making machine that folds, seals, perforates, and cuts the bags (e.g., T-shirt bags with handles). The integration of printing and bag-making in one line reduces handling and labor. In summary, the garment/shopping bag line is a high-speed, integrated system that produces finished printed bags directly. The operator must synchronize the extruder, printer, and bag machine. The print registration must be maintained; any stretch in the film affects it. The line's control system must compensate for film elongation.
The printing process requires precise tension control to avoid stretching the thin film. The corona treater must provide a consistent dyne level (38-42 dyne/cm) for ink adhesion. The flexographic printer uses anilox rolls to transfer ink; the ink viscosity and drying must be optimized for the line speed. The bag-making section includes a folding board (for gusseting), seal bars (for bottom seal), and a die-cutter (for T-shirt handles). The seal temperature and pressure must be set for the thin film. The perforation blade creates tear-off lines. The finished bags are stacked or wound in rolls. In practice, the garment bag line often runs with high recycled content (up to 30%) to reduce cost, but the outer layer may be virgin for print quality. The operator must regularly check print quality and bag dimensions. The line's efficiency depends on the reliability of the printer and bag machine. In conclusion, the garment/shopping bag film line is a versatile, high-speed system that efficiently produces printed retail bags, combining extrusion, printing, and converting in a single, continuous operation.
Blown Film Machine
Key line components: – Extruder: single or 3-layer, high-speed, with IBC. – Thickness gauge: with AGC. – Corona treater: for printability. – Flexographic printer: 1-4 colors, with drying. – Bag machine: folding, sealing, perforating, cutting. – Stacker or winder. Process parameters: – Film thickness: 15-30 µm. – Line speed: 150-200 m/min. – Seal temperature: 130-170°C. – Print registration: within ±1 mm. – Corona: 38-42 dyne/cm. – Bag length: adjustable (e.g., 400-800 mm). Quality checks: – Print quality: clarity, registration. – Seal strength. – Bag dimensions. – Perforation quality. In practice, the line is often run with quick changeover for different sizes and prints. The operator must maintain the printer and bag machine regularly. In conclusion, the garment/shopping bag line is a high-efficiency system for retail bag production, delivering printed bags with consistent quality and minimal labor.
