Surface processing technology of the most popular

Surface processing technology of printed matter

surface processing is to properly treat the surface of printed matter, increase the gloss of printed matter, or increase the light resistance, heat resistance, water resistance, wear resistance, etc. of printed matter, so as to protect printed matter

the surface processing of printed matter includes: varnishing, composite plastic film, waxing and other processes

I. glazing process

glazing is to increase the beauty of printed matter, and has the effects of moisture-proof, heat proof and sun resistance. Generally, book covers, illustrations, calendars, trademark decorations, etc. are used

1. printing machine polishing

this method is used in small batch production. It does not need to add additional equipment, and you can use the printing machine to print polish oil

gloss oil is a transparent body with certain viscosity, which is composed of resin, dry vegetable oil, desiccant, etc. it has good drying performance, strong gloss, and smooth conjunctival surface

on the printed products, use a printing plate of the same size as the product, but without graphics and text, and then print a light oil. The printing paper with light oil, the more absorbent it is, sometimes it is also inlaid with special steel at the jaw, or sprayed with steel grit on the surface of the jaw, etc Poor, the better the effect

2. The coating cover is oil-free

it is coated by the glazing machine. The gloss oil is composed of alcohol soluble synthetic resin, alcohol, ester bath agent, etc. it has the characteristics of high resin content, low viscosity, fast drying, good leveling, high brightness and good toughness. The gloss oil can be directly coated on coated paper. On white board and offset paper, it is first used for casein primer, and then coated with gloss oil

when coating, the temperature of the drying channel of the coater is 65 ~ 75 ℃, the length of the drying channel should be more than 10 meters, and the time for the printed matter to pass through the full drying channel should not be less than 40 seconds, so as to ensure the complete drying of the gloss oil

II. Composite film

printed matter becomes a composite material after film compounding. These composite materials can be compounded by the same kind of materials or different kinds of materials. After compounding, they have unique excellent properties that other materials do not have

there are four methods of composite films

1. Warm compounding method

is that the water-soluble adhesive is coated on the substrate that the first youth should take the difficult environment as an opportunity to hone themselves, and then overlapped with the second substrate to dry and compound. The water-soluble adhesive has a deposit. China's plastic machinery enterprise market will more open up the water solution of powder, paste, Arabic gum, bone glue, polyvinyl acetate latex, nitrile latex, synthetic resin, natural resin latex and other latex

this method has low cost and is commonly used for the compounding of paper/paper, paper/plastic film, and paper/aluminum foil. Due to the use of water-soluble adhesives, it has no water resistance and is only suitable for dry conditions

2. Dry compounding method

the dry compounding method is formed by using polymers such as vinyl acetate, vinyl chloride, acrylate, synthetic rubber, natural rubber, epoxy resin, polyurethane and other thermosetting resin solvents, first coating on the first substrate, removing the solvent in the dryer, and then heating and compounding the second substrate under heating

this method can compound all kinds of plastic film, paper, aluminum foil and other materials. In order to enhance the adhesive strength of the composite part, the general polyethylene, polypropylene, nylon and other films should be treated with corona first, and then select the appropriate adhesive according to the type of film, and use polyurethane or epoxy curing resin, which has good heat resistance and water resistance

3. Hot melt compounding method

hot melt compounding method is to use wax or modified wax added with ethylene vinyl acetate copolymer, ethylene acrylate copolymer or polyisobutylene, polybutylene, petroleum resin, etc., heat it to a solution state, coat it on the film substrate, the second substrate is directly attached to it, and then cool it by cooling and rolling

this method does not need the drying process after coating the adhesive. The device is simpler than the dry compounding method and is suitable for the compounding of aluminum foil/paper, plastic/plastic, plastic/lead foil

4. extrusion compounding method

extrusion compounding method is to use titanate compound, isocyanate compound, imino compound, etc. to dissolve in organic solvents such as vinyl acetate, and water-soluble and solvent based primer that dissolves polyhexene imino resin, cyanamide formalin, cyanamide urea resin, etc. in water or organic solvents, and apply it on the substrate, and use polyethylene, poly64 fiber to strengthen calcium silicate board propylene Polyvinyl chloride, Elon and other resins form films by melt extrusion, which are bonded with the substrate in the molten state

this method uses melamine compound as adhesive, which has good cooking resistance and is mostly used for the packaging of cooked food

III. waxing treatment

waxing treatment is to make prints moisture-proof, water-proof and oil resistant. The wax takes paraffin as the main component, which melts when heated and solidifies when cooled. Waxing is carried out on the waxing machine, and the wax is coated while heated. Therefore, the ink used for prints should be steam solidified ink and condensed ink

this treatment is mainly used for the processing of instrument packaging or paper containers