Complete Introduction to the Production and Packaging Process of Water-Coated Film for Bagged Water

Food-grade PE particles, reinforcing barrier masterbatch, and puncture-resistant additives are selected and precisely mixed according to the formula; all raw materials meet food contact standards, with no recycled waste and no plasticizers, preventing the release of harmful substances. The materials are fed in layers to multiple independent extruders, corresponding to the outer layer, middle barrier layer, and inner drinking water contact layer, respectively.

Each extruder is heated to melt and plasticize the plastic particles, which are then conveyed to the multi-layer die head; the three layers are concentrically bonded in the molten state, without mixing or delamination, forming a one-piece tubular film bubble, eliminating the need for glue bonding, leaving no solvent residue, and ensuring safe compatibility with drinking water packaging.

tubular film bubbles, which are rapidly and evenly cooled and shaped by a cooling air ring. The traction unit performs bidirectional stretching, precisely controlling the film thickness to ensure uniform thickness, toughness, and puncture resistance throughout the roll. The film bubbles are then flattened into a double-layer flat film by a flattening frame.

corona treatment on the film surface increases surface tension, ensuring strong ink adhesion and preventing ink fading or discoloration. This process is mandatory for all custom-printed designs; blank base film can be selected upon request.

Dedicated printing rollers are manufactured based on customer designs. Food-grade environmentally friendly water-based inks are used for full-page printing of logos, patterns, text, and specifications. The ink is dried in a high-temperature drying tunnel, ensuring the printed layer is on the outside of the film, preventing contact with water and ensuring safety and no pollution. Online quality control cameras detect missing prints, color differences, and dirt spots in real time, automatically marking and rejecting defective products.

Slit the roll material to the customer's required width, remove burrs, and rewind under constant tension to ensure a smooth, wrinkle-free, and unstretched film surface with a tight core, suitable for various filling equipment film racks.

Laboratory testing: thickness, tensile strength, heat seal strength, barrier properties, ink adhesion, and food safety testing;
Appearance inspection: no pinholes, damage, scratches, or bubbles;
Qualified roll material is wrapped with moisture-proof protective film, sealed in cardboard boxes, and stored in a cool, dry finished product warehouse. 

The water-coated film roll is installed onto the film rack of the filling machine; the film is automatically conveyed into the sterilization tank, where it undergoes double sterilization via immersion in clean water and ultraviolet light, eliminating bacteria on the film surface and ensuring drinking water hygiene.

The film is automatically folded into a cylindrical shape by the forming device; a vertical heat-sealing mechanism seals the sides at high temperature, forming a complete tubular water bag blank.

Clean purified water/mineral water is injected into the bag through aseptic pipes; during filling, air inside the bag is expelled by squeezing, reducing oxygen levels and extending the shelf life of the water.

After filling, the bag opening is sealed at high temperature with double-layer heat sealing to prevent leakage; cooling rollers quickly shape and seal the bag, preventing heat-sealed edges from sticking and leaking.

A synchronous cutting mechanism cuts the continuous film roll into individual finished bagged water products, which are then conveyed off the production line.

Finished products undergo a light inspection station, with both manual and machine checks for leaks, pinhole damage, insufficient water content, and blurry printing defects. Defective products are sorted and discarded separately.

Simple Version: Directly stacked and boxed;
Commercial High-End Version: Individual bags encased in transparent outer bags/colored carrying bags to enhance the sales experience;
Large-sized bagged water: Uniformly packed into cartons with corner protectors to prevent crushing.

After packing, affix product labels and production dates; stack in a dry, ventilated warehouse, controlling stacking height to prevent crushing, awaiting delivery to stores, homes, and corporate customers.