BOPP Film BOPP Packing Straws

The BOPP packaging film produced by our company is the film product of biaxial stretching process. The following is the brief introduction of our company's production process:

1、 The production process is as follows:

Raw material treatment and feeding - → meltextrusion - → chill casting - → longitudinal stretching - → transverse stretching - → traction trimming - → thickness measurement - → corona treatment - → winding - → aging treatment - → slitting (including large slitting and small slitting).

2、The process description of each process is as follows:

Raw material treatment and feeding: before feeding, the external packaging shall be cleaned. If the raw material has been stored for a long time or has serious water absorption, it shall be dried to remove water. The auxiliary materials put into different hoppers are measured and mixed by the measuring unit in a certain proportion.

Melt extrusion: the main and auxiliary materials mixed in a certain proportion are plasticized by the extruder, measured by pressure equalization, and filtered out by the filter to form a uniform molten fluid.

Chill casting: the melt of the extruder flows through the die head and is forced to cool to a thick sheet suitable for drawing.

Longitudinal stretching: after preheating, the cooling formed thick sheet is stretched and shaped along the longitudinal direction at a certain rate under a certain temperature.

Transverse stretching: after longitudinal stretching, the thick sheet is preheated, and then the transverse expanding is carried out at a certain temperature, and the heat setting and cooling are carried out. Compared with the non stretched films, the properties of the films have been greatly improved, such as higher strength, better transparency and glossiness, higher gas and water vapor barrier, and higher heat and cold resistance.

Traction edge cutting: in the process of on-line cutting of the edge that fails to stretch or is not fully stretched in the process of transverse stretching, it is recycled.