Extrusion cast film
DATE：2019/5/14 8:25:40 / READ： / SOURCE：This station
Extrusion cast film
1. Characteristics of extrusion casting method
The extrusion casting method is to add the material to the extruder and mix and plasticize into a melt under a certain temperature and pressure; the molten material passes through the T-die and is cast down to the surface of the cooling roller to cool the shaped film. After being pulled, the film is cut into a sheet-like film, and the film roll is taken up by a winding device.
Plastics for producing films by extrusion casting mainly include polyethylene, polypropylene, polyamide, ethylene acetic acid, ethylene copolymer and the like.
Compared with the extrusion blown film method, the extrusion casting method has the following characteristics.
1) High transparency (low haze), good gloss, softness and good hand feeling
2) Small thickness deviation, especially suitable for printing, dry compounding, automatic packaging and other processing operations
3) The film is cooled sufficiently and the production line speed is high;
4) It is not easy to produce adhesive defects of the tubular film, and is suitable for producing a low-density, self-adhesive sheet-like film.
5) The width of the film is limited by the equipment, generally 1-4m;
6) If the film is not stretched in both directions, its longitudinal and transverse mechanical properties are not as good as those of extrusion blown film.
7) The price of production equipment is relatively high.
The extrusion casting method is not only used for producing a single layer film, but also for producing a multilayer co-extruded composite film. Extruded cast single or multi-layer film, which can be unidirectional (longitudinal or transverse) stretched or biaxially stretched (stepwise double
A stretch oriented film is produced by stretching or multi-stage simultaneous biaxial stretching.
The production equipment for extruding a cast film generally includes an extruder, a T-die, an air knife, a cooling roll, a pulling roll, a trimming and waste film recovery device, a winding device, and the like.
2. Extrusion casting method common film and use
1) Extrusion cast polypropylene film (CPP)
PP antistatic film: electrostatic dispersion packaging film and bag;
Retort-resistant film: resistant to 100~120 °C cooking system packaging composite film substrate;
High-temperature cooking film: high-temperature cooking and sterilization packaging composite film substrate resistant to 140 ° C or higher;
Composite substrate film: composite film substrate for extrusion compounding and dry compounding;
Vacuum aluminized film: vacuum aluminized film substrate;
Matting film: food packaging bags.
2) Extrusion cast polyamide film (CPA6)
PA antistatic film: electrostatic dispersion packaging film and bag;
Meat packaging film: high temperature cooking and frozen packaging composite film substrate;
Composite substrate film: a composite film substrate for dry composite.
3) Extrusion cast polyethylene film (CPE)
PE antistatic film: electrostatic dispersion packaging film and bag;
Medical material film: film base for medical cream, medical insurance products (gloves, shoe covers, etc.);
Composite substrate film: composite film substrate for extrusion compounding and dry compounding;
Packaging film: film for automatic mechanical packaging;
Stretch film: food wrap film, wrapping film.
1. Characteristics of extrusion casting method
The extrusion casting method is to add the material to the extruder and mix and plasticize into a melt under a certain temperature and pressure; the molten material passes through the T-die and is cast down to the surface of the cooling roller to cool the shaped film. After being pulled, the film is cut into a sheet-like film, and the film roll is taken up by a winding device.
Plastics for producing films by extrusion casting mainly include polyethylene, polypropylene, polyamide, ethylene acetic acid, ethylene copolymer and the like.
Compared with the extrusion blown film method, the extrusion casting method has the following characteristics.
1) High transparency (low haze), good gloss, softness and good hand feeling
2) Small thickness deviation, especially suitable for printing, dry compounding, automatic packaging and other processing operations
3) The film is cooled sufficiently and the production line speed is high;
4) It is not easy to produce adhesive defects of the tubular film, and is suitable for producing a low-density, self-adhesive sheet-like film.
5) The width of the film is limited by the equipment, generally 1-4m;
6) If the film is not stretched in both directions, its longitudinal and transverse mechanical properties are not as good as those of extrusion blown film.
7) The price of production equipment is relatively high.
The extrusion casting method is not only used for producing a single layer film, but also for producing a multilayer co-extruded composite film. Extruded cast single or multi-layer film, which can be unidirectional (longitudinal or transverse) stretched or biaxially stretched (stepwise double
A stretch oriented film is produced by stretching or multi-stage simultaneous biaxial stretching.
The production equipment for extruding a cast film generally includes an extruder, a T-die, an air knife, a cooling roll, a pulling roll, a trimming and waste film recovery device, a winding device, and the like.
2. Extrusion casting method common film and use
1) Extrusion cast polypropylene film (CPP)
PP antistatic film: electrostatic dispersion packaging film and bag;
Retort-resistant film: resistant to 100~120 °C cooking system packaging composite film substrate;
High-temperature cooking film: high-temperature cooking and sterilization packaging composite film substrate resistant to 140 ° C or higher;
Composite substrate film: composite film substrate for extrusion compounding and dry compounding;
Vacuum aluminized film: vacuum aluminized film substrate;
Matting film: food packaging bags.
2) Extrusion cast polyamide film (CPA6)
PA antistatic film: electrostatic dispersion packaging film and bag;
Meat packaging film: high temperature cooking and frozen packaging composite film substrate;
Composite substrate film: a composite film substrate for dry composite.
3) Extrusion cast polyethylene film (CPE)
PE antistatic film: electrostatic dispersion packaging film and bag;
Medical material film: film base for medical cream, medical insurance products (gloves, shoe covers, etc.);
Composite substrate film: composite film substrate for extrusion compounding and dry compounding;
Packaging film: film for automatic mechanical packaging;
Stretch film: food wrap film, wrapping film.
Author：admin