Thermal transfer technology (5)

5. Transfer printing process

Pressurized transfer embossing process. For polyester, for example, the most suitable process conditions should be 20 to 30 seconds at 205°C. At 170-180°C and 10s, the effect is not good. At 180-190°C and 15-10s, only the ring dyeing effect can be achieved. If it is 230 to 240° C. and 40 s or more, the handle becomes rough, and if it is 240° C. and more than 45 s, it is nearly melted. Different types of fabric fibers, the transfer conditions are also different, see Table 2.

Table 2 Transfer conditions of dyes in different fabrics

Fabric Fiber Transfer Temperature (°C) Time (s)
Nylon 6 180 10-15
Nylon 66 230 15 to 20
Polyacrylonitrile 190~240 10~15
Polyester 230~240 20~40

In addition to temperature and time, pressure during transfer printing is also a very important condition. If the pressure is too small, the gap between the fabric and the floral paper is large, and the yarn is round, so that the dye gas molecules collide with the air and escape, resulting in poor results, and the dye is also easily ooze, the lines are thick and the pattern is blurred. If the pressure is increased, the yarn can be flat, the gap between the fabric and the floral paper is small, the transfer coloring effect is good, the pattern is clear, and the lines are smooth and fine. However, the pressure is too large to cause changes in the shape of the deformed, fluffy, and heavy fabrics, and produces aurorae, which results in coarse touch and surface appearance defects.

6. Let's introduce the use of screen-printed sublimation inks

The ink is not dye vaporized at a temperature of about 200°C, so that the ink is dyed on a variety of plastics and polyesters.

Now it can not only be used on fabrics, but also can be dyed and stained on a variety of materials such as computer keyboards and eyeglass frames. See Table 3 for details.

Table 3 Use of Thermal Sublimation Screen Printing Inks

Color Types Red, Yellow, Blue, Black, Transparent Use paper High quality paper is best when using paper.
In the case where plastics, etc., require deep dyeing, or when long-term dyeing is required under low temperature conditions, the use of a piece of gold paper is effective.

The printing ink is designed to be printed in the same way as the original ink, but when the viscosity is high, an appropriate amount of a special solvent can be used.
The standard mesh size of the screen is 200-270 mesh.
Plates can be washed with thinner.

The ink is dried and dried for 20-30 minutes (temperature of 25°C). Such as 40 ~ 5O °C warm air drying, the drying time can be shortened.
It is best to transfer on the next day.
Urgent use of warm wind can accelerate drying.

Transfer operation A. Temperature polyester transfer temperature is 190 ~ 200 °C (3Os), if the temperature is too high, the fabric becomes hard, the temperature is too low and the transfer density becomes low. When using plastic, first confirm the heat resistance of the plastic, and then transfer it within its allowable range, but it takes a long time.
B. If the pressure is too high, the transfer density becomes lower, the pressure is too small and the printed pattern is blurred. The appropriate pressure is 1 to 2 kg/cm2.
C. The heat source uses a direct thermal plate transfer time (20 ~ 30s), and the transfer time with a hot oven is longer (please confirm the test). When the polychloroprene is used for resistance, it has good light resistance and washing resistance. When using plastics, there are some problems with light resistance, pollution over time, and warm water pollution. Therefore, after confirming beforehand, do a printing job.