Application of electro-aluminum transfer printing for fabric printing

With the rapid development of China's industry, a large number of new products have emerged. Screen printing technology has been widely used in various industrial products, especially electronic products, various packaging and printing products, textile printing and dyeing products, and ceramic printing products. In the mid-1980s, modern screen printing technology began to rapidly spread in China. Especially in textiles, silk screen and special printing technology increased the added value and appreciation value of goods, and enriched people's lives.

Fabric special printing technology is developed on the basis of silk screen technology. Various types of foaming printing, photoluminescent printing, electro-aluminum transfer printing, electrostatic transfer printing, discoloration printing, fragrance printing, photosensitive printing, etc. have the same features as traditional printing technologies. point. So we collectively call them "fabric special prints." The application of special printing also promotes the development of screen printing technology.

Electrochemical aluminum transfer printing and flocking transfer printing are similar, that is, they are all solid phase transfer by hot pressing.

1 characteristics and application of electro-aluminum transfer printing.

"Anodized aluminum" is commonly known as "bronzing paper." It is the use of vacuum coating method to form a variety of colors on the polyester film, the current domestic aluminum has six colors. Electrochemical aluminum is used as a high-grade mounting material and has been widely used in paper and plastic products. The traditional “bronze” (electro-aluminum transfer) process is accomplished by heating and pressing of a letterpress (copper and zinc plate), and the clarity and fastness of hot stamping on the fabric cannot be solved.

The use of screen printing methods to transfer galvanized aluminum fabric printing has many advantages such as easy operation, low cost, attractive appearance, and good washability. At the same time can also enrich the variety of fabrics. Electro-aluminum transfer printing operation is similar to ordinary printing except that it has a hot pressing transfer process.

2 Electro-aluminum transfer printing equipment and materials.

a. equipment. Traditional fabric screen printing equipment and hot pressing machine.

b. Material.

Electro-aluminum (bronzing paper): Domestic-made electro-aluminum has been fully applied, and some small-pattern transfer printing can use electro-aluminum scrap.

Transfer Adhesives: Anodized transfer printing adhesives are a key issue. Currently, suitable adhesives are not yet available, and they are usually formulated using conventional adhesives purchased. The requirements for transfer adhesives are as follows:

a) Has strong adhesion and softness, and has a certain degree of elasticity.

b) Good screen printing adaptability, good mixing with paint printing paste.

c) The drying time should be moderate.

d) It can reflect strong adhesion after being heated.

e) Good wash resistance.

Printing paste: Electrochemical aluminum transfer printing paste should have good screen printing adaptability, and the color can be prepared according to the color of the transfer printing of the aluminum foil. Printed paint pastes sold at stores are often used.

3 Electro-aluminum transfer printing process and precautions.

The electro-aluminum transfer printing process mainly includes ordinary printing (different printing materials) and hot-pressing transfer of electro-aluminum.

a. Process flow:

Pattern design—→drawing——→Preparation of printing plate and printing material (special adhesive ten color paste) Screen printing pattern→→Anodized aluminum hot pressing→→Exfoliation of excess anodized aluminum→→finished product

b. Note:

The key factor affecting the quality of the transfer of aluminum is the choice of transfer adhesive. Electro-aluminum transfer printing adhesive is also a kind of hot-melt adhesive. Although the hot-melt adhesive used in this type of hot-melt adhesive and electrostatic flocking is the same, it can use polyethylene, poly- thiol, polyester, EVA resin, etc. However, the adhesive form is different. The former is used in powder form, and the electro-aluminum transfer is a hot-melt adhesive in the form of an emulsion. The formula is as follows (weight ratio):

EVA Emulsion 90 Emulsified Pulp 15 Penetrant 1 Coloured coating (or dye) Appropriate amount of water

As the aluminum is itself a metal, the texture is hard. If it is necessary to print on a soft fabric, the pattern design should not consider large-area printing. It is only suitable for the printing of small areas of dots and lines.

In order to prevent the incomplete transfer of galvanized aluminum or the detachment of the galvanized aluminum after washing, the appearance of the overall pattern is affected. Therefore, the depth of the color of the printed adhesive should be as close as possible to that of the galvanized aluminum.

The degree of dryness of the adhesive after screen printing directly affects the transfer effect of the electrodeposited aluminum, and it is appropriate to perform hot pressing under a condition close to dryness.

The temperature and time of hot pressing should be taken into account in the degree of tolerance of the fabric. Some fabrics cannot withstand high temperatures and transfer printing cannot be performed.

The hot press temperature and time depend on the properties of the adhesive. Usually hot pressing temperature can not be too high, high (aluminum itself is also coated with adhesive) no graphic part easy to transfer adhesive.

The stripping of galvanized aluminum paper must also be very careful. It should be lifted along the warp (weft) direction of the fabric to prevent it from being broken and the speed of peeling and peeling should not be too fast.

Source: Coinprint