Silk screen printing as a kind of application range is very wide, depending on the substrates can be divided into: fabric printing, plastic printing, printing, metal ceramic printing, glass printing, printing of electronic products, lottery printing, electricity ACTS the role of screen printing, advertising board metal screen printing, advertising board stainless steel screen printing, light reflector screen printing, silk screen printing electrochemical aluminum, silk screen print and lacquer screen printing and so on.
Plastic screen printing
Plastic screen printing, plastic products in mechanic (or rework).The so-called secondary processing is in plastic injection molding, after again decorative surface treatment, such as: plastic electroplating, plastic spraying, plastic hot stamping, plastic printing, etc.Plastic products so must carry on the secondary processing, mainly is decided by the performance of the plastic itself, such as its dyeing is more onefold, and color of the sun resistance is poor.In order to compensate for these shortcomings, improve the appearance of the plastic decoration, is the need for secondary processing.
There are many types of plastic products, but in terms of screen printing method, sheet and flat body with flat screen printing method;Body can be expanded into a flat surface with curved surface screen printing method;Special-shaped products use indirect screen printing method.Plastic solid resins, additives, and different method of molding, the surface properties of the difference is very big, especially the surface smoothness, polarity, and the problem of electrostatic plastic screen printing the root causes of failure.
1. PVC plastic screen printing of polyvinyl chloride (PVC) put into industrial production in 1931.Polyvinyl chloride (PVC) plastic with bright color, not easily broken, acid, alkali, price is low wait for an advantage.But as a result of manufacturing PVC plastic, add some auxiliary material, often with toxicity, so PVC products should not be informed.Polyvinyl choride (PVC) breed of design and color is various, commercially available of colorful plastic, artificial leather, etc are mostly polyvinyl chloride (PVC) products.
2.ABS plastic screen printing plastic, ABS resin is a kind of engineering plastics.In recent years is widely used in products such as television, computer and many fields of national economy.ABS plastic is propylene eyes, butadiene, styrene terpolymer.Because ABS plastic is a terpolymer, both common characteristics of three groups of yuan, resistance to chemical corrosion and propylene eyes makes copolymer has a certain surface hardness;Butadiene can make polymer has rubber toughness;Styrene can make polymer has the characteristics of easy processing and forming.ABS plastic with all sorts of color, products has a shiny appearance, bibulous rate is low, to a certain temperature range has good impact strength and surface hardness, good dimensional stability.Most of ABS resin in - 40 ℃ temperature still has considerable impact strength, toughness, its products using temperature range in - 40 ~ 60 ℃, ABS plastic of high molecular weight, good physical performance, easy to processing molding, printing eligibility is better.
3.Polyethylene, polypropylene plastic screen printing of polyethylene (PE) plastic: polyethylene plastic, widely used by extrusion and injection molding process is made all kinds of finished products.Polyethylene molecules are composed of methylene long chain, contains a certain amount of side group.Side group in the polymer chain, the more the longer, the lower the polymer crystallinity.That is to say, the density of polyethylene is higher the more unfavorable to the surface finishing.Polyethylene in a variety of solvents is not clear, but the temperature exceeds 70 ℃, polyethylene can a small amount of dissolved in solvent such as toluene, butyl acetate.PE this nature, provides conditions for surface finishing.Available solvent soak plastic heating, make its surface swelling, destruction of fractional crystallization to improve ink film on the surface of the plastic, adhesion.Fuming sulfuric acid, nitric acid and chromic acid and sulfuric acid mixture, at room temperature can slow action in polyethylene;In 90 ~ 100 ℃ when sulfuric acid and nitric acid, can quickly destroy polyethylene;With heavy lead acid potassium, a mixture of sulfuric acid, distilled water, soak polyethylene plastic under 70 ~ 75 ℃, is conducive to enhance the ink film on the plastic surface adhesion.
Polypropylene (PP) plastic, polypropylene is one of the important varieties of plastic development for many years.Applies to all molding method.Can do all kinds of steel tubes, all kinds of boxes and thin films, fibers, etc.Industrial polypropylene with high degree of regularity of the space, a high degree of crystallinity, hereby index in 89 ~ 95% range, at the same time contains a small amount of crystals of random vertical structure and low crystalline solid block structure of macromolecular chain.Melting point within the range of 170 ~ 175 ℃, isotactic polymer glass transition temperature is 13 ~ 0 ℃, and the rules between the polymer for O ℃.Nitric acid and fuming sulfuric acid etching polypropylene, under high temperature, soluble in aromatic hydrocarbons and chlorinated hydrocarbons, room temperature can only make it swell.Acids and esters of it also has certain corrosion effect, along with the isotactic polymer content is higher, solvent resistance and improve accordingly.
Overall polyethylene and polypropylene are high crystallinity, low surface tension of non-polar molecule structure of polymer materials.In their molecular structure without polarity such as carbon, carboxyl and hydroxyl groups, compare with polyethylene, polypropylene surface finishing easier.
4. Electronic products electronic products, especially the screen printing plastic parts radio products such as radios, tape recorders, TV sets, etc., to the requirement of appearance is very high.Graphic designers to product the appearance of the decoration is very seriously, and now used for exterior decoration process is less in our country, limiting the design personnel's mentality, so that they can only by the size of the products, the use of all sorts of line, the color of the plastic itself is limited, to change the appearance of the product.The adornment of the plastic screen printing after development for electronic products brought convenient, so in recent years the domestic plastic screen printing of various electronic products has been widely used.
5.In recent years, the screen printing plastic signs, plastic signs and plastic molding for silk screen graphics text decoration parts development soon after.Such as PVC hard board (PVC), polycarbonate, ABS, organic glass, modified polystyrene plastic screen printing presses, has been widely used, and achieved good decorative effect and economic benefits.
6.Soft and hard plastic screen printing (1) plastic hose screen printing.Plastic hose printing there are several kinds of methods, the main methods for thermal transfer method.Thermal transfer method is to use sublimation dye ink or other materials, the graphic printed on the transfer paper first, and then with the substrates joint together, from the transfer paper on the back of the heating, make dye sublimation and graphic transfer printing paper on the substrates.Plastic hose after surface treatment by sun gas, transfer paper between the hose and a heating plate, heating plate will transfer paper to the hose, heating to complete the transfer.Transfer after the hose into the drying device, drying temperature about 65 ℃.(2) soft plastic screen printing.Soft plastic used to make more toys, such as inflatable cartoon toys.Production is usually put on soft sheet plastic logo printing, cutting, thermal forming again.The thickness of the materials used are generally 0.8 ~ 3.0 mm.If more than two color silk screen printing, most of the plastic will have scale, in the name of the second and the first color color matching color error.This tinted error make goods lost its original value, not as a qualified products on the shelves.Multicolor printing can only be used for this, can be fixed long soft plastic printing press and there is no it.During long printing machine, printing substrates to use adhesive fixed.It is important to note that the toy printing must use non-toxic, harmless ink stipulated in the relevant standards.(3) hard plastic products of screen printing.Hard plastic products, which has two kinds of rigid plate and FRP products.Tickets, signs, instrument dial, cosmetics containers are made of hard plastic.
7. The surface of the instrument panel screen printing panel material can be metal, all kinds of plastic, and paint, etc., choose the appropriate printing ink, screen printing some text and graphics on the panel, said some of the instruments and equipment function, but also beautify the panel.Screen printing of text and graphics requirements clear, good adhesion, abrasion resistance, but also requires the simple but elegant is tonal downy, give people a feeling of beauty.Here we mainly discuss how to improve the quality of the panel by screen printing process.
8.Color polyester label screen printing of polyester label is developed rapidly in recent years the domestic varieties of signs.Because it has a bright color, adornment sex is good, easy to paste, the manufacture method is simple, the advantages of low cost, which is popular among the masses of users, and quickly in high, medium and low-grade electronic products, household appliances, as well as cultural goods obtained the widespread application.The current domestic many professional factory production this kind of sign.However, because the factory production process is according to the mass need to design the sign processing, thus much for those varieties, less number of polyester sign products, both in terms of process technology, production costs or ways, are unable to adapt.Here introduces a kind of using screen printing method to print color polyester sign technology, for small batch and many varieties to reference color polyester sign producer.