与暗卫们欢爱np_色吧电影网_亚洲精品国产精品_亚洲人成色777777老人头_国产久久精品_国内精品视频一区二区三区八戒_一个人看的www日本高清视频 _日本久久久久亚洲中字幕_国产精品女同一区二区

BOPP film is bidirectional tensile polypropylene film.

BOPP film production is the polymer polypropylene melt first through the long and narrow head into sheet or thick film, and then in the special stretching machine, at a certain temperature and set speed, at the same time or step by step in the vertical two directions (vertical, horizontal) of stretching, And through appropriate cooling or heat treatment or special processing (such as corona, coating, etc.) made of thin film.

classification

Commonly used BOPP films include: ordinary bidirectional stretching polypropylene film, heat sealed bidirectional stretching polypropylene film, cigarette packaging film, bidirectional stretching polypropylene pearling film, bidirectional stretching polypropylene metallized film, matting film and so on.

advantage

BOPP film is a very important flexible packaging material, BOPP film colorless, odorless, tasteless, non-toxic, and has high tensile strength, impact strength, rigidity, toughness and good transparency.

The surface energy of BOPP film is low, and corona treatment is required before gluing or printing. After corona treatment, BOPP film has good printing adaptability, can be color printing and get exquisite appearance effect, so it is commonly used as the surface layer material of composite film.

insufficient

BOPP film also has shortcomings, such as easy to accumulate static electricity, no heat sealing and so on. In the production line running at high speed, BOPP film is easy to generate static electricity, so an electrostatic remover should be installed.

In order to obtain heat-sealable BOPP film, the surface of BOPP film can be coated with heat-sealable resin adhesive, such as PVDC latex, EVA latex, etc., after corona treatment, can also be coated with solvent adhesive, can also use extrusion coating or co-extrusion composite method to produce heat-sealable BOPP film.

The film is widely used in bread, clothes, shoes and socks packaging, as well as cigarettes, books cover packaging. The tear initiation strength of BOPP film is improved after stretching, but the secondary tear strength is very low. Therefore, the two ends of BOPP film can not leave any incision, otherwise the BOPP film is easy to tear during printing and composite. BOPP coated with self-adhesive can produce sealing tape, is a large amount of BOPP market.

Production process

BOPP films can be produced by the tube film method or the flat film method. The properties of BOPP films obtained by different processing methods are also different. The BOPP film produced by the flat film method has higher strength and better thickness uniformity than the tube film method due to its larger tensile ratio (up to 8-10).

Precautions

In order to obtain better comprehensive performance, the multilayer composite method is usually used in the production process. BOPP can be compounded with many different materials to meet special application needs. For example, BOPP can be combined with LDPE(CPP), PE, PT, PO, PVA and so on to get high gas resistance, moisture resistance, transparent, high and low temperature resistance, cooking resistance and oil resistance, different composite film can be used in oily food, precious food, dry food, impregnated food, all kinds of cooking cooked food, monosodium glutamate, pancakes, rice cake and other packaging.