What is blown film?

Film blowing is a plastic processing method, which means that plastic particles are heated and melted and then blown into thin films. Usually, the polymer is extruded to form a tubular film blank, which is blown to the required thickness by high-pressure air in a good melt flow state, and then cooled and shaped to form a film.

Most PE is used for blown film processing, and generally low density polyethylene (LDPE) or linear low density polyethylene (LLDPE) can be used. HDPE film grade is generally used in places where super tensile property and excellent impermeability are required. For example, HDPE film is often used in commodity bags, grocery bags and food packaging. PE film processing generally adopts ordinary film blowing processing or flat extrusion processing.

The main advantages of blown film are:

1, the whole film is formed in one unit production;

2, the width and thickness of the film can be effectively adjusted;

3, the extrusion temperature is uniform, which avoids the instability of the film edge quality;

4, the film can be stretched in two directions, and the obtained film has uniform mechanical properties;

5. It can be used to manufacture coextruded multilayer films.

Extended data

Typical applications include:

Industrial packaging: shrink film, stretch film, bag film or container lining;

Consumer goods packaging: frozen product packaging film, transport packaging shrink film, food packaging film, packaging bag;

Filling and sealing packaging film: aluminum or paper laminated for packaging, such as milk or coffee;

Barrier film: a film used for packaging food to block fragrance or oxygen;

Agricultural film: greenhouse film, silage film.

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