In life, people have a certain understanding of the dangers of static electricity. For example, the static electricity of clothes can be “electrically shocked†from time to time. Therefore, people attach great importance to the prevention of static electricity. But with reasonable technology, static electricity can also bring many benefits. Electrostatic dust removal, electrostatic photocopying, electrospinning, and electrostatic flocking are good examples of the use of static electricity to benefit people. In particular, electrostatic flocking technology has advantages such as simple process, high production efficiency, strong three-dimensional effect, low production cost, no environmental pollution, wide range of product applications, and good economic benefits, etc., and has become an attractive highlight in the textile industry.
The earliest electrostatic flocking started in Germany in the 1930s. Since then, Japan began to study in the early 1950s. However, China began to rise in the 1970s. Currently, Germany, Italy, Japan, and the United States are all leading in this regard. And Taiwan's development is also faster.
The principle of electrostatic flocking is to use electrostatic effects to achieve the purpose of flocking. It is a certain conductive villi, placed in a high-voltage electric field with a certain electric field strength, it moves along the potential difference as a charged carrier, at the level of the adhesive coated material as ground potential, fluff will be vertical Implantation of the adhesive-coated surface, and the formation of a layer of upright fuzz on the carrier printing product, is electrostatic flocking printing technology. Electrostatic flocking printing technology has been widely used in clothing, shoes and hats and various trademark labels in China. In recent years, it has also begun trials in bedding, interior decoration, and process decoration, and has achieved very good decorative effects. Higher than computer embroidery products. In foreign countries, flocking products can be seen in many famous luxury cars such as Mercedes-Benz and BMW. Therefore, some people say that flocking is like makeup and can make ugly things beautiful. Electrostatic flocking technology can be described as a stunning technology to decorate the South. In short, the development prospect of electrostatic flocking technology is very broad. For this reason, the following describes several color flocking screen printing processes, which will have completely different effects from traditional printing, and give unique freshness.
one. Sublimation dyeing
Sublimation dyeing is a dyeing process that completes coloration by relying on the effect of sublimation dyes becoming gaseous and having a diffusion and affinity effect on the villous fibers. The method is to add the sublimation dye to the flocking adhesive. When flocking and gluing, the dye is also coated on the substrate with the glue. When the fiber is baked after being flocked, curing and dyeing are completed at the same time. The dye sublimates from the binder to a gaseous state to escape and transfer to the fluff.
The process flow is:
Colouring the base fabric - flocking - drying - baking - dyeing
Process points:
(1) Choose dyes with good sublimation performance under high temperature. When color matching, colored dyes should have similar sublimation performance.
(2) The new force of the dye on the villi should be greater than the affinity on the base fabric, adhesive, etc.
(3) Select the colorless fluff, after the baking, the dye is normal hair color, the color of the fiber is bright.
(4) If the colored fluff is used, color matching and flocking can be carried out according to the spelling principle. For example, the basic cloth bottoming paste is a blue dye, and the fluff is yellow, and finally green fluff can be obtained after curing.
(5) The choice of base fabric is also very important. If it is a cotton cloth, the sublimation dyes do not stain the cotton cloth but stain it. The dyestuffs are mostly dyed on the fluff. The fluff is colored darker and richer; if the base fabric is a polyester fabric, the dyestuffs Both the fluff and the base fabric are dyed, so the fluff yield is reduced and the color development is relatively shallow.
(6) Most screen printing companies can use equipment to reduce capital investment.
two. Thermal transfer method
This method uses a full area of ​​colorless fluff, and then thermal transfer with disperse dyes. The basic production method of transfer printing is to first apply the dyestuff to the color ink, and then print it into a paper, and then overlay the paper with the piled fluff, heating, pressurizing or depressurizing. The pattern on the paper contains The dye will sublimate into a vapor phase and transfer to the fluff. The required transfer paper can be purchased from the market or printed on its own.
Process flow:
Colorless fluff is placed on the whole area of ​​the base cloth - drying - printed transfer printing paper - overlapping fleece base fabric and printing paper - heating and pressing - peeling off the printing paper - printing is completed
Process points:
(1) This method should use nylon or polyester fluff. Polyester fluff has the best effect.
(2) For bulk dyes used for transfer printing, the molecular weight should not exceed 350 and 250-270. On the other hand, the sublimation points, transfer and diffusion properties of various dyes are close to the production requirements.
(3) The requirements for transfer printing paper: It has enough strength and can withstand high temperature of 220°C. The time should be more than 30 seconds. The surface should be clean and free of dust. Gas-phase dyes have a lower new force on paper. General use of rubber sheet, stamp paper or special transfer printing paper, the specifications for the 55-80g/m2.
(4) Printing ink is mainly composed of dyes and slurries. The dyes used should be purified without dispersants and other additives. They are insoluble in water or other organic solvents. Slurry mainly serves to attach the dye to the paper surface. At high temperatures, it should not hinder the dye gasification, commonly used slurry ethyl cellulose, sodium alginate and polyacrylate ester slurry.
three. Electrostatic flocking and screen printing combined printing method
As long as the screen printing technology is mastered, this method can be adopted, and screen printing machines can be converted into flocking machines. Tie-color printing is a very ideal flocking product, and its process is as follows:
Plate making, mixing - screen printing (printing flocking glue) - color flocking - drying - baking - finishing - finished
The process has three main points:
(1) The pattern must be screened and modified before the plate making, so that it can reflect the special effects of flocking.
(2) Adjust the flocking glue. If the viscosity is too high, filming will occur when the flocking has not been completed, which will be very unfavorable to the flocking process. If the viscosity is too low, it will penetrate into the fabric quickly and affect the planting. Wool fastness.
(3) When the color separation and flocking, the voltage level is high and low, the polar distance has a great influence on the flocking effect. It is necessary to test and adjust, select the best data, and the sequence before and after the color registration should be designed before the plate making and the sequence is improper. It is difficult to achieve the desired results, and the type of screen used depends on the specific pattern.
four. Transferring cashmere printing
Transferring cashmere printing, according to different preferences of consumers, pre-preparation of a variety of transplanted cashmere paper, and then put it on the appropriate part of the fabric that needs to be transferred, after high-temperature pressing, paper flocking The pattern is transferred to the fabric.
Transferring cashmere printing paper is the key to production. The paper requires coating with several different properties of adhesives, mainly flocking adhesives, printing adhesives and transfer adhesives.
The function of the flocking adhesive is to make the fluff at a proper density and temporarily planted on the base paper. When the flocking pattern is transferred to the fabric by pressing and ironing, the base paper is peeled off; the transferred fluff surface can not have the adhesive There are cellulose derivatives, natural rubber, and synthetic polymers that can be used as flocking binders.
The printing adhesive is water-soluble, requires stronger adhesion than the transfer adhesive, has good extensibility, soft hand feeling, and is relatively easy to formulate a suitable viscosity for printing and cleaning. Can be used as a printing adhesive natural or synthetic latex.
The function of the transfer adhesive is to transfer the pattern on the flocking paper to the fabric under heating conditions. When the fabric and the transfer adhesive are contacted under heat, the transfer adhesive softens and fuses with the fabric. In combination, hot melt powders such as polyester, nylon, and polyethylene are used as transfer adhesives.
The transfer velvet printing method utilizes the action of an electrostatic field to grow short piles onto paper coated with flocking adhesive, and then prints adhesive on the fluffy side, and sprinkles the hot melt powder to remove the non-adhered portions. Hot melt powder can be made into flocking transfer paper.
The flocking transfer pattern on the floral paper can be printed on the fabric by hot pressing machine (flower type available household electric iron). The temperature, time and pressure required for pressing are related to the properties of the hot-melt adhesive powder used. The general heating temperature is 80-170°C, the pressure is 0.001-0.05Mpa, and the time is 10-40 seconds. After the pattern is cooled, the flocking transfer bottom paper is peeled off, and a flocking pattern with strong three-dimensional effect appears on the fabric.
Fives. Printing network perspective <br> <br> flocking pigment is first added to the slurry, a color printing method by screen printing on fabric, and flocked base cloth colorless fluff. Due to the relatively low hiding power of the colorless fluff, the various colors of the bottom layer can still be revealed by the human eye. This method is also unique.
The process is as follows:
Screen-making version, coloring paste - screen printing printing - electrostatic flocking - baking - finishing - finished products
Technical points:
(1) It is better to select transparent and non-colored, short and thin villi.
(2) The base fabric is made of white fabric with a sparse and transparent structure.
(3) Due to the more color registration, when the last color is printed, the color paste of the first few colors may be dry and solidified, and the flocking difficulty is increased. Generally two-color flocking is easy to grasp.
Source: China Electrostatic Flocking Federation