The production of BOPP plastic film is to make the melt of high molecular polypropylene into sheet or thick film through a long and narrow head, and then in a special stretching machine, at a certain temperature and a set speed, at the same time or step by step in two vertical directions (Vertical, horizontal)
On the stretch, and after appropriate cooling or heat treatment or special processing (Such as Corona, coating, etc)Made of plastic film.
BOPP Film can be produced by tube membrane method or flat membrane method.
The properties of BOPP plastic films obtained by different processing methods are also different.
BOPP film produced by flat film method has large drawing ratio (Up to 8-10)
Therefore, the strength is higher than that of the tube Film method, and the uniformity of the film thickness is also better.
In order to obtain better comprehensive performance, multi-layer composite method is usually used in the production process.
BOPP can be compounded with a variety of different materials to meet special application needs. For example, BOPP can be used with LDPE (CPP)
, PE, PT, PO, PVA, etc. are compounded to obtain high gas resistance, moisture resistance, transparency, high and low temperature resistance, cooking resistance and oil resistance, different composite membranes can be applied to the packaging of oily food, rare food, dried food, impregnated food, various cooked food, monosodium glutamate, pancakes, rice cakes, etc.
BOPP Film is a very important flexible packaging material. BOPP plastic film is colorless, odorless, tasteless and nontoxic, it also has high tensile strength, impact strength, rigidity, strength and toughness and good transparency.
BOPP Film has low surface energy and needs Corona treatment before gluing or printing.
After Corona treatment, BOPP plastic film has good printing adaptability and can be printed with color to obtain exquisite appearance effect, so it is often used as the surface material of composite film.
BOPP plastic film also has shortcomings, such as easy accumulation of static electricity, no heat sealing, etc.
In the high-speed production line, BOPP Film is easy to generate static electricity, and an electrostatic remover needs to be installed.
In order to obtain heat-Sealable BOPP Film, the surface of BOPP plastic film can be coated with heat-sealable resin glue liquid after Corona treatment, such as PVDC latex, EVA latex, etc. , and solvent glue can also be coated, the heat-Sealable BOPP film can also be produced by extrusion coating or co-extrusion composite method.
The film is widely used in the packaging of bread, clothes, shoes and socks, as well as the cover packaging of cigarettes and books.
The initiation tearing strength of BOPP plastic film is improved after stretching, but the secondary tearing strength is very low. Therefore, there cannot be any cuts left on both ends of BOPP Film, otherwise, BOPP Film is easy to tear when printing and compounding.
BOPP can produce sealing tape after coating self-adhesive, which is a market with large amount of BOPP.