The hottest leather printing opens the digital cha

Leather printing opens a digital chapter

leather, as a practical and beautiful natural raw material, has considerable market value in clothing, luggage, shoes, jewelry and other industries. The exquisite patterns printed on leather can further improve the application of leather and increase the added value of leather. Therefore, it has been said that the application of printing technology has set off another storm in the development of leather. Prepress processing

rawhide is mainly divided into three layers: the upper layer is the epidermis, the lower layer is the subcutaneous tissue, and the dermis between the epidermis and subcutaneous tissue is also the main object of printing. Based on the observation of tissue structure, we will find that the dermis of rawhide has the characteristics of dye penetration, diffusion and adhesion, which is the material basis of leather printing

in leather production, in order to improve the use performance and aesthetic effect of leather, it is generally necessary to carry out surface modification, degreasing, lustering and mildew proof treatment on leather. Common leather surface treatment technologies include flame treatment, corona treatment and plasma surface treatment, each of which has its own characteristics. ① Flame treatment uses flame to heat air to a certain high temperature, activate oxygen molecules, form polar plasma on the surface of materials, and increase the adsorption of materials on inks. This method has high requirements on equipment and environment, has certain potential safety hazards, and the process is not easy to control, so it is not common in practical applications; ② Corona treatment, by increasing the voltage on the needle electrode to obtain a large amount of plasma, so as to activate the material surface and increase the adhesion ability. This method has poor treatment time and intensity, so it is also less used in practical operation; ③ Plasma surface treatment technology uses jet plasma treatment system to send plasma to play the role of cleaning and activation. This method has good treatment effect and is widely used

the irregularity and high price of traditional craft

leather determine its difference from ordinary textile printing. At present, the traditional leather printing process includes direct printing and transfer printing, and direct printing can be divided into dye printing and pigment printing

1. Dye printing: dye printing is a process based on the principle of interfacial colloidal chemical surface tension and free energy to affinity soluble dyes on the surface of leather fibers (usually on the surface of white or light colored leather), so as to obtain specific patterns. The pattern obtained by this method has good hand feel, but does not have hiding power. Dye printing has high requirements for surface quality, which is suitable for leather with smooth surface, no defects, good softness and uniform color. Coupled with its disadvantages of high temperature resistance, the application of dye printing in practice is greatly limited

2. Pigment printing: pigment printing is based on the principle of coating. The paint used is composed of pigments that can give special visual effects to printing products, accounting for about 54% of the world, such as beads, foaming agents, fluorescent pigments, luminous pigments and other insoluble material particles and adhesives. This will ensure the rapid use of Raymond's low-cost carbon fiber. The printing method of coating and printing on the leather surface can effectively cover the defects of the leather itself or the defects of uneven dyeing and printing. However, the rough feel and poor adhesion of the paint have always been an important factor limiting its wide application

the processes of dye printing and pigment printing are very similar. Spray (brush) platen, glue shop, leather silk printing, peeling, hanging, baking, softening, grading, measuring and warehousing. In the printing process, both methods need to use tableboard adhesive, and chemical materials such as emulsifier, defoamer and various additives are also needed when configuring dyes, so there is a great pressure on environmental protection. In addition, the cumbersome process and strict process requirements are also a great challenge for the printing cost. Therefore, in my opinion, both dye printing and pigment printing are destined not to become the most suitable process for leather printing in the future, and will eventually be replaced

3. Transfer printing: transfer printing is an indirect printing method. In practice, the patterns to be printed should be pre printed on specific paper or film through silk screen printing, offset printing, gravure printing and other printing methods, and then the transfer printing paper and leather materials are composite hot pressed, and the patterns on the transfer film are transferred to the leather surface through external force conditions to form color patterns. The method is suitable for suede garment leather, bag leather, shoe upper leather and other leather. Digital printing

digital leather printing process is a high-tech gradually formed with the development of computer technology, which integrates machinery, computer electronic information technology as an instrument to restore to its original state. It carries out process control through computer management system to ensure product quality and production stability, while printing patterns with popular fashion elements. The production process of digital leather printing process is actually very simple, that is, through the spray printing system, various special dyes are directly sprayed onto the leather according to the digital pattern, and then after simple processing, various high-precision printing products can be obtained. In addition, the process introduces the concept of environmental protection, and uses non-toxic water-soluble materials (resins, pigments) in the printing process, so it can meet the increasing requirements of the market for green environmental protection. Through the PK of traditional leather printing and digital leather printing in Table 1, it is not difficult to see that digital leather printing technology has greater development potential than traditional leather printing technology, whether it is technology, materials, or social effects

throughout the digital leather printing In the dangerous process of high-temperature hot gas rushing out of the box, inkjet ink and nozzle are still the core technology, which is the key to ensure the formation of clear, non feathering and friction resistant patterns on leather. In addition, in the process of practical application, the consistency of ink should not lead to nozzle blockage, but also stable and high-speed ejection

leather printing machine is habitually called universal printer. It applies the concept of digital printing. It is an inkjet printing device that can directly print on leather. It saves the process of film and plate making, and can print full-color images with high precision and anti fading. With higher printing quality, simple operating procedures and stable performance, leather printing machine can replace the traditional silk screen printing brush machine, pad printing and transfer equipment. While reducing printing costs and leading fashion color printing, it is in line with the development trend of green printing

the application of inkjet printing technology in leather makes leather printing enter a fast era. It brings not only the production advantages of low cost, zero waste, high profit and simple process to the leather printing industry, but also the continuation and even improvement of the theme of green. At present, leather printing has set off a digital chapter

(the author is Tianjin University of science and Technology)