Wuhan modern plastic film printing
DATE：2020/12/28 14:30:27 / READ： / SOURCE：This station
Wuhan modern plastic film printing
1. Necessary conditions for film printing
(1) Adhesion with ink polyethylene or polypropylene film due to poor adhesion, usually to surface treatment.
(2) There is no unevenness and thickness.
(3) no fish eye or crystal point or rigid block.
(4) No adhesion.
(5) The use of root shed products requires transparency, etc. these properties should be fully discussed, such as permeability, heat sealing, rigid climate, Yin hot bamboo, Lishui, drug resistance and wrinkle resistance. Coating machine www.handertn.com
2. The surface treatment of plastic film is the most suitable thin ring.
The adhesive force of plastic film with small surface "free energy" to oil is also very small. This is because the amount of oil can not be attached to the solid surface with lower "free energy" than itself. Therefore, the ink with wetting tension of 3.6 ~ 4.2x 10-0n / cm (36-42dyn / cm) is obviously not easy to adhere to the polyethylene film with wetting tension of 3.1x10-4n / cm (31dyn / cm).
In addition, according to the principle of polarity equivalence, kufu. Especially when the resin contains stabilizer, non-polar polyethylene, polar oil phase opener, antistatic agent and other additives which are incompatible with the resin, it is more difficult to maintain the printing quality. Therefore, before and after printing, it is necessary to carry out surface treatment for the films with low plate property, good chemical stability and not eroded by organic solvents, such as vinyl and polypropylene handle.
3. Printing ink coating machine for plastic film www.handertn.com
(1) The basic composition of gravure ink plastic film printing is mostly used in gravure, the basic composition of the ink is as follows:
Pigment or dye colorant 30 ~ 40%;
Pigment (pigment mixed with oil, qingmou, etc.) 0 ~ 20%
Solid adhesive resin 10 ~ 40% 1
Volatile organic solvents 40 ~ 80%;
Plasticizer, plastic resin, paraffin dispersant and other dispensing agent 0 ~ 5% 1
The above is only the principle, and the specific composition should be determined according to the type and application of the film.
(2) The function of various components in ink
① Binder is one of the main components of ink. The binder of gravure printing oil is generally made of synthetic resin, natural resin and its binder, chlorinated rubber and its derivatives and solvents which have adhesive effect with the printed matter. Basic requirements for resin:
1) identical or compatible with the printed matter
2) It can change the surface properties of the printed matter to produce polar groups or polar bonds;
3) It is similar to the printed matter in physical properties.
The title material is one of the most important groups, which largely determines the properties of the base. Because the amount of chemical ink in the physical and chemical properties are put forward higher requirements. Coating machine www.handertn.com
The general principles of pigment selection are: 1) strong coloring power and bright color; 2) good dispersion and good fluidity. No precipitation; ③ good chemical stability, no reaction or precipitation with resin, solvent, additive, etc.; ④ large oil absorption, stable color development. It can meet the requirements of light resistance, heat resistance and chemical resistance. At present, the ink used more organic dyes, a small number of inorganic pigments.
Author：admin