Transfer printing method

Abstract

A transfer printing method includes coating the solvent-type adhesive on the surface of product, semi-drying, attaching a transfer film to it, pressing, and tearing off the plastic film. Another method is also disclosed.

Description

technical field [0001] The invention relates to a transfer printing method, in particular to a transfer printing method for transferring a pattern on a transfer printing film to the surface of a workpiece. Background technique [0002] At present, most of the transfer printing process is realized by thermal transfer printing. The thermal transfer printing method disclosed in the Chinese patent No. ZL03126622 "Thermal Transfer Printing Method" divides the transfer film into several pieces, which is especially suitable for the upper side of the transfer printing. The frustum-shaped workpiece with the reverse edge, and overcomes the quality problems such as the deformation of the transfer pattern when transferring the frustum-shaped workpiece in the past. The processing process needs to use a high-temperature pressing head to press the transfer workpiece; A hot press transfer printing method disclosed in "Method of Printing" is used to transfer the image on a photo paper to a c...

AI Technical Summary

Problems solved by technology

[0003] 1. The processing cost is high, heating and transfer printing needs a lot of heat energy, it uses a lot of expensive hot melt adhesive, the processing process is long, and the whole set of mechanical equipment takes up a lot of space

[0004] 2. It is difficult to guarantee the processing quality, because it must be heated, resulting in thermal expansion and contraction of the processed object, resulting in dimensional errors after the processed object is transferred. If the product needs further reprocessing, the product defective rate will be skewed. High, poor printing dimensional stability, uncertain relative position of cutting and other defects

Because the processed object will expand with heat and contract with cold, it is often necessary to prepare a large amount of space to store the processed object so that the processed object can be completely cooled and reduce the adverse factors caused by thermal deformation. However, the external environment temperature also affects The cooling efficiency of the processed object, so the size of this part of the space and whether the processed object is completely cooled are not easy to grasp; also because the transferred object will expand with heat and contract with heat after heating, the transferred The size of the ink will shrink after the processed object is completely cooled. If the elasticity and elongation of the ink itself are not higher than the processed object, the cold shrinkage of the processed object after cooling will cause partial or partial damage to the transferred ink. Partial cracking, in order to avoid this kind of phenomenon, it is necessary to use ink with high stretch rate, such as PU series, EVA series, soft PVC series, etc., but the price of this kind of transfer film is higher than that of general transfer film, and must be It is necessary to use a special transfer film printing machine to manufacture, because this type of ink has a high elongation rate and viscosity, and the printing machine speed must be faster during printing to clearly print the ink on the transfer film, but after the speed is increased, generally The oven length of the standard printing machine table is not long enough to be completely dried, so this type of transfer film needs to be printed on a special printing machine with an extended oven, but the extended oven printing machine is a special type with a small number of machines. There are few supply manufacturers, so the cost of this type of transfer film is relatively high

[0005] 3. When thermal transfer products are used at higher temperatures, because of the use of hot melt adhesives as adhesives, the bonding effect will reduce the viscosity due to the increase in temperature, and some of them will be completely destroyed when the temperature is as high as 90 degrees. Its viscosity, resulting in poor transfer effect

[0006] 4. The thermal transfer printing method is not suitable for processing closed foam workpieces. The inner tissue of the closed foam body is like densely packed small balloons. When the foam is heated, the balloons in the tissue will expand, making the original object The size becomes larger, but the size of the transfer film to be transferred is fixed. How can it be processed? The existing technology adopts the following two methods: a: Use the original size of the object to be processed for thermal transfer processing. After the heat transfer is completed, when the object to be processed is completely cooled, it will be found that the size of the graphics on the transfer film will shrink. And the higher the heating temperature, the more serious the size of the transferred pattern will shrink. If our product requires continuous transfer, it will be more difficult, because the size of the processed object will become longer when it is heated, and more The length of the transfer film cannot be matched with the size of the transfer film without size change, which often results in a defective rate of nearly 1 / 3

If the processed object is a long rolled foam, the phenomenon of thermal expansion and contraction of the processed object will be doubled, and the factors of thermal expansion and contraction will become irregular, such as the elongation rate of the front, middle, and rear After the whole roll is transferred, the size of each pattern is different, and the next process will be very difficult to process

b: Reduce the size of the processed product and then transfer to cater for the increase in the size of the processed product caused by thermal transfer. Although this method can reduce the defective rate, the degree of reduction in the size of the processed product must be considered externally Affected by the ambient temperature, the processing process brings a lot of inconvenience

Images