What is screen printing

Among the common fabric printing (screen printing, roller printing, transfer printing), screen printing is a process derived from template printing. It can be divided into platen type (including manual operation type and automatic transfer printing type) and automatic type (including flat screen printing and rotary screen printing). It began to be operated manually. With the development of technology, it has gradually formed a semi-automatic, Fully automatic mechanical printing. Among them, rotary screen printing and flat screen printing have become the main printing methods at present. The vast majority of fabric printing uses these two printing processes.

The flat screen is stretched on a metal or wooden rectangular frame, and the round screen is made of nickel circular metal mesh. Carve patterns and patterns on the Internet, and cut out the mesh where there are patterns. In printing, the color paste transfers the pattern to the textile through the mesh. Flat screen printing is different from manual and mechanical, while rotary screen printing is a continuous mechanical operation. Flat screen and rotary screen printing are currently widely used printing methods. They are characterized by a large number of printing sets, low tension on the textile, low deformation, bright colors, full color, and less defective fabrics. It is especially suitable for small batches and multiple varieties. Production.

Flat screen printing

There are three types of flat screen printing: manual platen type, semi-automatic plate and automatic plate. Although the output of flat screen printing is low, its plate making is convenient, the length of the flower back is large, the color registration is more, it can print fine patterns, does not transmit color, prints a large amount of paste, and has a three-dimensional effect. Suitable for printing on cotton, silk, chemical fiber and other woven fabrics and knitted fabrics, and more suitable for printing on small batches of high-end fabrics with multiple varieties.

The principle of flat screen printing is the same as that of manual screen, but its process is automated, so the speed is faster. The printed fabric is transported to the screen through a wide rubber belt, instead of being placed on a long table (like manual screen printing). Like manual screen printing, automatic screen printing is also an intermittent process. In this process, the fabric is moved under the screen and then stopped, and the squeegee on the sun screen automatically scrapes and prints. After scraping, the fabric continues to move under the next screen frame. The production speed is about 500 yards/h.

Rotary screen printing

Rotary screen printing is a printing method in which the color paste in the rotary screen is printed on the fabric under pressure by a scraper, and it is currently the most widely used screen printing method. Rotary screen printing is a continuous process in which the printed fabric is transported to the continuously moving rotary screen through a wide rubber belt. Rotary screen printing is suitable for mass production, and its speed is currently the fastest in screen printing, up to 3500 yards/h, but it is not suitable for small batch printing. Rotary screen printing uses seamless perforated metal net or plastic net, the largest circle net circumference is greater than 40 feet, and the largest flower back size at a time is also greater than 40 feet.

The rotary screen printing machine is composed of cloth feeding, printing, drying and cloth discharging devices. The mechanical composition of the printing part can be divided into printing rubber guide belt, rotary screen drive device, rotary screen and printing scraper frame, registration device, rubber guide belt washing and wiping device, and printing fabric paste and slurry pump system. When printing, when the printed fabric is in contact with the rubber guide belt, the rubber guide belt is pre-coated with a layer of cloth glue, so that the printed fabric sticks to it and does not move. When the fabric enters the drying device after printing, the rubber guide belt is transferred to the machine in a reciprocating loop for washing and scraping off water droplets. The drying and cloth discharging device adopts loose hot air drying. The printed fabric is separated from the rubber belt. It relies on the polyester belt that rotates by the active roller, and uses the pressure of the hot air nozzle to make the fabric stick to the polyester belt and enter the drying room for drying. After being dried by hot air, the fabric will be sent out from the drying part at a certain speed and with proper tension. Fold or roll the fabric after printing.