Comparison of pof shrink film ,pp,pe,pvc shrink film
Comparison of pof shrink film ,pp,pe,pvc shrink filmComparison of various plastic film
Plastic film as a printing material, its history is relatively short, it was used as packaging by printing with a light transparent, moisture and oxidation, air tightness, toughness folding, smooth surface, to protect goods, but also to reproduce the goods shape, color and so on. With the development of petrochemical industry, more and more varieties of plastic film, commonly used in plastic film of polyolefin shrink film,(pof shrink film),polyethylene (PE), polyvinyl chloride (PVC), polystyrene, polyester film (PET), polypropylene (PP) , stretch film nylon and so onpackaging material.
Performance of different kinds of plastic film, printing different degrees of difficulty, as the use of packaging materials are also different.
Polyethylene film is a colorless, tasteless, odorless, non-toxic translucent insulating material, a large number of bags used for packaging; food bags, but also the production of container. It is inert material, it is more difficult to print, must be treated before they can print good effect.
PVC thin film of light resistance, aging resistance is better and has a good tear resistance, can be breathable, is a clean, colorless, transparent film, usually by adding plasticizers, which can be dissolved in acetone , cyclohexanone and other solvents. Therefore, you can use PVC resin system ink. For bags, book covers and so on.
Polyolefin shrink film is soft and tough films, clean, colorless and transparent, without plasticizer, the film is always soft, resistant to freezing, storage is not aging, printing synthesized by oxidative polymerization of the ink binders, can Imprinted fastness is good.
Polyester film is a colorless, moisture, transparent, airtight, soft, high strength, acid oil ester and solvent, on the high and low temperature are not afraid of the material, by electric discharge treatment, the surface of the ink has good fastness. For packaging and composite materials.
polyolefin shrink film has good gloss and good transparency, heat resistance to acids, solvents, abrasion resistance, tear, can be breathable, less than 160 ℃ can not seal.
Nylon polyethylene film strength of the film than the large, tasteless, non-toxic, not through bacteria, oil, ester-resistant, resistant to boiling water and most solvents, generally used for loading, and wear-resistant packaging, as well as cooking and packaging (food re-heat) It can be printed without surface treatment.
Polyethylene molecules with polar groups are not essential, is a non-polar high marks in India, polypropylene molecules, each structural unit contains a methyl, this minute weak polar groups, basically also belong to non-polar polymer, therefore, their affinity for the ink than the poor, so before printing processed before printing can be satisfied with the printed pieces.
Most of approach is through oxidation, so the higher polarity, the surface structure change. Treatment methods specific discharge (commonly known as the corona, EDM), flame method, ultraviolet radiation, acid (sulfuric acid, chromic acid) treatment method, etc. several. And to discharge method is relatively simple and universal.
Corona treatment effect is good or bad, and handling equipment, output power, the distance between two electrodes, the electrode discharge area, processing speed and processing methods (the heat treatment or cold treatment) and frequency have a relationship, and the treated films must be immediately printed, or may still be invalid.
In EDM processing, the corona discharge produced by free radical reactions may occur cross-linked polymer, the surface has become rough and increase the wettability of polar solvents, in general, plastic thin film rarely been treated by thirty improve the printing area (performance: You can use anti-static additives) with three hydroxyl second amide of ethyl quaternary ammonium perchlorate, in order to enhance the reduction of electrostatic charge decay strong adhesion of the ink into the effects of concentration and hand gravure of printing, the solvent wet ink has been improved.
Stretch film printing method, can be flexo, gravure and screen printing.
Printing ink, requires a large viscosity, adhesion, and can dry the ink molecules firmly attached to the plastic surface, and it easily with oxygen in the air conjunctiva and dry and so on. General gravure ink is used in plastic film by: hope amine synthetic resin to alcohol-based organic solvent and disperse pigment formed by the full mobility with good colloidal fluid, is the evaporation drying type ink, with printing performance, adhesion fastness, bright color, dry quickly and so is suitable for rotary gravure printing machine .