EVA thermal transfer

EVA thermal transfer

1. Application of EVA thermal transfer

EVA is a copolymer of ethylene and acetic acid. Its Chinese chemical name is ethylene-vinyl acetate copolymer (ethylene-vinyl acetate copolymer), and its English chemical name is Ethylene Vinyl Acetate Copolymer.

EVA has a wide range of applications, and its market consumption is constantly increasing, especially in the shoemaking industry, where it is used in the soles of mid-to-high-end tourist shoes, mountaineering shoes, slippers, and sandals.

In daily life, a large proportion of other foam products we see are also made of EVA.

However, EVA products with a vinyl acetate content of 20-28% can be used for EVA thermal transfer.

However, the application of EVA thermal transfer technology on EVA products is relatively small.

2. Difficulty of EVA thermal transfer

EVA thermal transfer product pictures

Why is the application of EVA thermal transfer technology on EVA products rare?

Among the various substrates of different materials that can be thermally transferred, EVA products are the softest. (With a light press, the surface of EVA will sink).

The process of thermal transfer is to melt the ink and the product surface into one through the thermal transfer machine [heating and pressurizing], so as to achieve the purpose of "perfectly" transferring the transfer pattern to the product surface.

Due to the above reasons, the difficulty of EVA thermal transfer has doubled, mainly in the following two aspects:

1. EVA thermal transfer - soft
During the EVA thermal transfer process, when the thermal transfer rubber roller "carries" the thermal transfer film "on" the surface of the EVA product, the surface is "collapsed" because it is "too soft", resulting in the thermal transfer film being unable to be transferred to the surface of the EVA product.

2. EVA thermal transfer - bubbles/textures
EVA products are mostly plastic products formed by high-pressure bulk polymerization. During the high-pressure polymerization process, a large number of fine bubbles and textures will be generated.

The resolution of the thermal transfer film pattern reaches more than 300dpi. During EVA thermal transfer, the tiny bubbles and textures on the surface of the EVA product seriously affect the effect of transferring the thermal transfer film pattern to the product surface.

If the EVA thermal transfer is not treated before, the surface of the transferred product will be densely "pockmarked".

3. EVA thermal transfer solution

In order to solve the various problems caused by EVA thermal transfer due to the characteristics of EVA materials. According to the characteristics of flat thermal transfer, thermal transfer technicians have come up with a solution: "glue" the surface of the EVA material to make it smooth and free of bubbles; secondly, apply multiple layers of glue to the surface of the EVA material to make the surface reach the "hardness" for thermal transfer. With the customized EVA thermal transfer mold, a breakthrough in thermal transfer technology in the EVA field has been achieved.