Silk screen printing as well as other printing need accurate reproduction of the original graphic and tonal.Silk screen printing office, in principle, the manuscript and other printing method used in the original is not very big difference, but in the concrete practice of plate making, printing, its requirements are different, this is mainly due to the screen printing features.Especially because of the silk screen printing ink layer thick, bright color and so on should fully consider the manuscript and plate making screen printing special effects.
The characteristics of the silk screen printing:
1) silk screen printing can use multiple types of ink.I.e., oily, water-borne, synthetic resin emulsion, powders and so on various types of ink.
(2) layout of soft.Silk screen printing surface soft and has a certain flexibility is not only suitable for printing on paper and cloth and other soft items, but also suitable for printing on hard goods, such as glass, ceramics, etc.
(3) screen printing stamping force is small.Because of low pressure used in printing, also suitable for printing on the easy broken shopping body.
(4) ink layer thick, covering power.
(5) without being limited by the shape of the surface of the substrates and area size limit.From the foregoing, the printing, silk screen printing not only in the plane and can be printed on the surface or spherical;It is not only suitable for printing on small objects, but also is suitable for printing on large objects.This way of printing has a lot of flexibility and extensive applicability.
Plastic screen printing, the plastic products of secondary mechanic (or reprocessing) one of the so-called secondary processing is langfang printing plant in plastics injection molding, and then conduct a survey of decoration of disposal, such as: plastic, plastic spraying, electroplating, plastic hot stamping, plastic printing, etc. Plastic products so must carry on the secondary processing, important function resolution is made of plastic, such as its dyeing property than a single force, and the color of sun resistance is poor. In order to replenish these mistakes, to improve the surface of the finished plastic decoration, is necessary for secondary processing.
Plastic product variety, but in terms of screen printing way, sheet and three-dimensional body three-dimensional printing method;Can be carried out into a three-dimensional curved surface in screen printing method;Special-shaped products with direct screen printing method. Plastic products, increasing agent and forming solid resin way, its function is a big different, especially the overview of be bored with smoothness, polarity, and the problem of electrostatic become plastic screen printing crisis in nature.
1. PVC plastic screen printing of polyvinyl chloride (PVC) put into industrial production in 1931. PVC plastic have bright beautiful, is not easy to break, acid, alkali, price is low wait for an advantage. But because the production of PVC plastic, to take part in some of the help material, often with toxicity, PVC finished products is so unfavorable cheng fang food. Polyvinyl chloride (PVC) film pattern variety, commercial colorful plastic sheeting, natural leather, etc. Most are PVC products.
2. ABS plastic screen printing plastic, ABS resin is a kind of engineering plastics. Than to spread use in products such as television, care about and many people economic category. ABS plastic is propylene eyes, butadiene, styrene terpolymer. Because ABS plastic is a terpolymer, is combined with characteristics of three groups of yuan, propylene eyes makes copolymer chemical decay and must have an overview of the hardness.Butadiene can make polymer with rubber toughness;Styrene can make polymer has the characteristic of easy processing forming. ABS plastic with all kinds of color, the finished product with light appearance, bibulous rate is low, the temperature must be within the category have excellent fighting strength and hardness, good size not disorderly. 40 ℃ temperature greatly ABS resin in - there is still considerable combat strength, toughness, in its use temperature of the product category - 40 ~ 60 ℃, ABS plastic part quantity is high, the perceptual can good, easy to processing molding, printing eligibility is better.
3. The silk screen printing of polyethylene, polypropylene plastic polyethylene (PE) plastic: polyethylene plastic use throughout, can be made through the process of extrusion and injection molding process of all kinds of products. Polyethylene part is composed of methylene long chain, is contained in the quantitative side base. The longer the more side group in the polymer chain, the lower the polymer crystallinity. Also is said the general situation of the density is higher the more bad luck in polyethylene coating. Polyethylene in a variety of solvents is not clear, but when the temperature over 70 ℃, melting polyethylene can be a little in solvent such as toluene, butyl acetate. Polyethylene this temperament, to supply general finishing with the premise. The available heating solvent soak plastic, make its swelling, crushing department ink film crystallization to progress in the plastic profile of the output. Fuming sulfuric acid, nitric acid, chromium acid and sulfuric acid mixed liquid, at room temperature can slow reform in PE;In 90 ~ 100 ℃ when sulfuric acid and nitric acid, agile crushing polyethylene;With heavy lead acid potassium, mixed solution of sulfuric acid, distilled water, soak polyethylene plastic under 70 ~ 75 ℃, is beneficial to strengthen ink film in the plastic profile of the output.
Polypropylene (PP) plastic, polypropylene is one of the nervous type plastic growth for many years. For all molding way. To do all kinds of steel tubes, all kinds of cabinets 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%, also contains a little noncrystalline random set low crystal plane negotiations big part of the chain block layout. In the realm of melting point at 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 low temperature, soluble in aromatic hydrocarbons and chlorinated hydrocarbons, room temperature can only make it shrink. Acids and esters on it has certain corrosion influence, along with the isotactic polymer content is higher, solvent resistance and response to progress.
Generally, polyethylene and polypropylene are high crystallinity, high profile low tension of non-polar part of layout part material. In their part of the layout as carbon-based polar group, carboxyl, hydroxyl madly, and polyethylene than force, polypropylene coating easier.