The substrate is aluminum printing plate, printing ink on the surface of aluminum due to adhesion between aluminum and lower during transport collision extrusion, easy to damage the overall effect of printing patterns, which seriously affects the quality of printing plate, aluminum printing post-press finishing,so it is particularly important. Combined with the actual situation of the printing plate finishing the two key processes of glazing and packaging are analyzed, using the essentials and matters needing attention in the implementation process.

Varnishing
On the cover also known as light, is in the printing surface coated with a layer of light oil (as a protective cover, so called light cover), the purpose is to enhance the adhesion of the ink, the printing pattern protection from scratch hard objects. Aluminum plate after printing, printing patterns on the surface hardness was increased (up to 4H the pencil hardness), brightness printing pattern is enhanced, the visual effect is more ideal. But if the Polish operation requires master misconduct, should not be underestimated the negative impact on the product. The relationship between the following main glazing and print the hardness and brightness, color changing printing plate after glazing glazing process, coating machine feed products effect of impact angle on the quality of the printing plate on plate are analyzed as follows.

1.  Hardness and brightness of printed aluminium plate after glazing

Light oil printing aluminum used to belong to the thermosetting properties, which must be cured by heating, so after glazing of printed patterns of hardness and baking time oil can be completely cured. There is a direct relationship between the detection method in accordance with the national standard < recommended hardness determination of film hardness by pencil test >GB / T6739 - 1996 test, the film hardness pencil. Determination of two kinds of test methods >: test machine and manual method. The materials and equipment test: a group of Chinese brand senior drawing pencil (9H, 8H, 7H, 6H, 5H, 4H, 3H, 2H, H, F, HB, B, 2B, 3B, 4B, 5B 6B, 9H, 6B) the most hard, soft, Great Wall advanced drawing eraser, 400 water sandpaper, pencil sharpener, pencil hardness tester. The materials used manual method and A method for the same, but there is no pencil hardness tester. Usually use a manual test, testing instrument is simple and easy to operate, printing. The hardness of not less than 4H pencil Hardness. The experiment showed that the same kind of light oil curing under different temperature, the hardness is different. In the range of light oil allows baking, Wen Hao Xubo of high gloss and hardness, different light oil have different best curing temperature. Therefore the production must adopt different baking temperature according to the different light oil, to avoid blindly set the same temperature and make the products reach the hardness requirements.

The brightness and gloss printing aluminum plate after the film thickness. The so-called "thickness", is the unit area or after curing varnish coating dry film weight, usually expressed in g／㎡. In the production of film thickness measurements using the advanced coating thickness gauge, also can use simple, practical test board the plate is measured. Measurement of aluminum with 10cm * 10cm coating varnish or paint, aluminum sheet weight minus after baking varnish or paint coated with aluminum sheet weight multiplied by 100 is the film thickness. The size of glazing products in a certain range, the higher the thickness of endometrium, printing more light, but also will increase the cost of products, so manufacturers should pay attention to control the film thickness, neither too low (too low printing products no brightness), can not be too high (high cost manufacturers will make almost no profit to be made in Guangdong). 100 BV8290 light oil as an example, the film thickness control in 2G / recommendations m ~ 3G / Square meters is appropriate.

2.  Attention to printing aluminum plate E light after baking color

Part of the printing plate glazing after baking, printing color change, especially for spot color ink matching is the most common color. There are two main reasons, one is the ink color, on the other hand is light oil color, and different light oil color is different. So the production process should include color glazing before printing samples and after glazing of the printed samples as glazing before reference. If the light oil should be replaced on the prenatal test, confirm the effect of light oil on the color printing plate, do prenatal control; production control, to minimize the influence of light oil on aluminum printing color.

3. Polishing process, coating machine rejection, affecting the quality of printed aluminum

The printing plate glazing normally use coater. The coated gloss cots is moving, the centrifugal force makes the light oil opt cots. On the staff, if improper operation, it is easy to cause the oil into the strip thrown to the printing on the aluminum plate, curing outstanding printing effect of printing plate aluminum plane,influencing appearance . So ensure the normal operation of equipment, and constantly in the production process to inspect equipment operation.

4. Adhesion in the aluminum surface of printing putty affect the quality of products

Angle plate is printed in Polish aluminum baking, due to incorrect posture caused by conveying aluminum, aluminum corner of a form-work. Insert the flower angle plate will be deposited at the bottom of the oven dust stirred, the dust adhered to not completely cured varnish, completely solidified in black impurities formed aluminum printing product surface, leading to the unqualified products. Therefore, in the process of polishing, oven entrance should be assigned responsibility for the delivery status check plate, and the tail is inserted at the inspection stacking angle plate, if timely stop check, take remedial measures.

Package

Aluminum printing packaging requirements more stringent, because aluminum is soft, easy deformation, and easy to be scratched. Unqualified packaging, aluminum will cause the printing surface of the scratch, collision injury and other defects, so the packing should be designed according to its properties. Packing weight aluminum printing goods, packaging methods have strict requirements, only comply with the corresponding requirements, in order to ensure the product in customer service, customers are very satisfied with the quality of the printing plate.

1. Product packaging weight requirements of aluminum sheet metal, aluminium sheet per unit volume of heavy, which requires the weight of each package can not be too large, or packaging bear. Large packing weight should not exceed 500kg, excessive weight causes sliding of aluminum sheets, forming a friction scratch.

2. The packaging method of printing aluminum plate is easy to bruise, scratches, affecting the quality of products, causing serious returns. Therefore, according to the product transport distance, easy to slip degree, the following 3 types of packaging.
(1) Ordinary printing plate, short distance transport (100 km range): the bottom of the wooden pallet smooth, to prevent the aluminum version due to soft paper deformation, upper shell angle soft, fiber board edge, a # word with iron waist, to prevent folding, casual bags.
(2) Ordinary printing plate, long-distance transport: the bottom with the wooden pallet smooth, soft aluminum for preventing deformation of upper triangular iron beads with iron back to prevent # word folding, bulk bag, and then use the wooden box on the trap, SD, and then hit the # word iron waist packaging.
(3) Sheet packing requirements with the adhesive and back with lubricant and long-distance transport packaging printing plate: the same kind of plate is more smooth, pieces of aluminum in the printing packing case, gently push plate will slide ground bottom. The wooden pallet smooth, soft aluminum for preventing deformation at the top of the triangle, edge, with iron waist hit # word to prevent folding, bulk bag, and then use the wooden box on the trap, SD, and then hit the # word iron waist packaging.

Glazing and packaging is aluminum printing finishing process, although the last procedure,the importance can not be ignored. Many of the fine print plate, because the polish or unqualified packaging, printing plate caused by the unqualified, not only delayed the completion date, and bring a lot of economic losses to the enterprise.