Cailong attended 2019 Plastic Flexible Packaging production Technology (Hangzhou) Seminar

Vacuum metallized film refers to a new process for forming a composite film by vapor-depositing metal aluminum on the surface of a film substrate under vacuum. It is widely used to replace aluminum foil composite materials such as aluminum foil/plastic, aluminum foil/paper.   The main types of vacuum metallized film are:

1. BOPET (polyester) vacuum metallized film

BOPET (polyester) film has high transparency and is a polar film. The surface tension is stable above 45~50dyn, so the degree of firmness of the BOPET aluminized film is very good. After aluminizing, it has higher brightness than other aluminized films, and it can be stored for a long time without removing aluminum. If it is not wet, the storage period can be more than one year. It can be used as the base film of the composite flexible packaging or the middle layer of the base film. It is the best intermediate aluminum-plated material for composite flexible packaging. The electrical insulation properties of BOPET films are very good. After vacuum aluminum plating, it can be used as a capacitor film for coiled capacitors. The BOPET film has excellent gas barrier properties. It not only blocks gas, but also has good oxygen barrier and water vapor resistance. It can be used as a barrier layer for vacuum packaging or pumping inflatable bags. However, since the aluminum layer of the vacuum aluminized film will fall off after being wet, it is not suitable for use as a cooking bag.

2, BOPP (biaxially oriented polypropylene) vacuum metallized film

Because BOPP film is divided into single-face corona treatment film, double-sided corona treatment film and heat-sealable film, the performance and use after aluminum plating are different. Because of their poor oxygen barrier properties, they cannot Do vacuum or retort packaging.

(1) BOPP vacuum metallized film treated with single-sided corona can only be used as decorative film, holographic printed anti-counterfeiting film, and surface material of composite film.

(2) Double-sided corona-treated BOPP vacuum-aluminized film can be printed on the surface layer or as a middle film material of the composite film.

(3) The heat-sealable BOPP vacuum metallizd film can only be used as the inner layer of the composite film. The BOPP vacuum aluminized film should be used in time, and should not be hoarded in a large amount. The general storage period should not exceed six months, otherwise the adhesion of the aluminized layer will decrease.

3, CPP (casting polypropylene) vacuum metallized film

Vacuum metallized CPP film can only be used as the inner film material of composite packaging, and can not be vacuum or retort packaging. The storage period of CPP vacuum aluminized film is 3~6 months. The over-period preservation corona treatment will disappear, and the adhesion of the aluminum layer will also be weakened. Pay special attention to moisture protection during storage.