Basic knowledge of plastic film

In THE NATIONAL PACKAGING GENERAL terms (GB4122-83), the definition of flexible packaging is: flexible packaging refers to the packaging that can change the shape of the container after filling or removing the contents. All kinds of bags, boxes, sets and envelopes made of paper, aluminum foil, fiber, plastic film and their complexes are flexible packaging. Generally, sheet plastics with a thickness of less than 0.25mm are called films. Plastic film is transparent, flexible, with good water resistance, moisture resistance and air resistance, good mechanical strength, stable chemical properties, oil resistance, easy to print fine text, can heat seal bag. It can meet the packaging requirements of all kinds of items, is used in the packaging of easy to store, easy to put convenient food, daily necessities, supermarket small package goods ideal material. Guangdong Danqing Printing Co.,Ltd has 30 years of experience in flexible packaging manufacturing, mainly producing spout pouch, stand up zipper bag, plastic roll film and so on; Offer exquisite printing, can print up to 13 colors.

Flexible packaging printing based on plastic film plays an important role in packaging printing. According to statistics, since 1980, plastic packaging in some advanced countries in the world accounts for 32.5% ~ 44% of the whole packaging printing.

Generally speaking, because the single film material is not ideal for the protection of the interior, so more than two kinds of films are used to compound into a layer of composite film, to meet the requirements of food preservation, aseptic packaging technology. Composite film outer material selection is not easy to scratch, wear, good optical performance, good printing performance of the material, such as: paper, cellophane, tensile polypropylene, polyester, etc.; The middle layer is a barrier polymer, such as: aluminum foil, steamed aluminum, polyvinyl diazene electric inner layer materials are mostly selected non-toxic, tasteless polyethylene and other thermoplastic resin.