Films polyester is a kind of thin-film material, which is made of polyethylene terephthalate as raw material by extrusion and drawing. Depending on the raw material and drawing process used in the production of films polyester, there are two types:
1. Biaxially oriented polyester films are made of light materials, and Bopet films are characterized by high strength, good rigidity, transparency, and high glossiness, odorless, tasteless, colorless, non-toxic, and outstanding toughness Its tensile strength is 3 times that of PC film and nylon film, and its impact strength is 3-5 times that of Bopp film, at 120 ° C, it shrinks only 1.25% after 15 minutes, it has good antistatic property, can be vacuum aluminized, and can be coated with PVDC, so as to improve its heat sealing property, barrier property and printing adhesion Bopet also has good heat resistance, excellent resistance to cooking, low-temperature freezing resistance, good oil resistance, and chemical resistance. Bopet films can not be dissolved by most chemicals except nitrobenzene, chloroform, and benzyl alcohol. However, Bopet will be attacked by strong alkali, should be careful when using it. Bopet film has low water absorption, good water resistance, suitable for packaging high water content food.
2. Unidirectionally oriented polyester films (CPET) are thin films made from a semi-extinction material (titanium dioxide is added to the raw material polyester chips), which are dried, melted, extruded, cast and lengthwise stretched, in the films polyester grade, and the lowest price, mainly for pharmaceutical tablets packaging. Due to less use, manufacturers have less large-scale production, accounting for about 5% of the field of films polyester, our enterprises fewer imports, and the standard thickness of 150 μm.