Nonwoven fabrics and PE film composite of several ways

With the maturity of the primary processing of nonwoven fabrics, more and more enterprises are turning their attention to the deep processing of nonwoven fabrics, in order to maximize the value-added of the products and the profits of the enterprises. In the domestic, hot melt adhesive coating equipment applications are therefore constantly expanding, medical, health materials production sector is the most widely used in this type of equipment industry, the rapid development of the automotive industry in China has also stimulated the spare parts manufacturers on the demand for hot melt adhesive coating equipment, the relevant information shows that the domestic geotextile industry not long ago, also introduced the first production line of hot melt adhesive so far. As a mature and evolving process, hot melt adhesive coating technology in the nonwoven deep processing industry will have a better and better future. With that is discarded medical supplies (such as surgical gowns, surgical sheets, hole towels, gloves, shoes, hats, etc.), industrial protective products, personal care products are mainly based on non-woven composite film products, the requirements of these industries for the product is almost the same, i.e., waterproof, breathability and comfort. This paper will analyze and compare the current medical and health materials composite of several major process characteristics, based on the introduction of a new non-woven fabrics and film composite technology: Existing technology ◆ Lamination: This technology is the most used by the domestic enterprises of a method, features: process is simple, mature, and faster production speed (about 100m/min). Disadvantages: Cannot make products with breathable requirements; hard handfeel, poor comfort; high requirements for nonwoven fabrics. Low grammage (below 18gsm) and low coated nonwoven fabric (below 15gsm) are not ideal for lamination, because the unevenness of the web surface makes the lamination process easy to produce leakage points. ◆Hot Rolling: It is the standard process for manufacturing composite nonwoven fabrics by two-step method, and some enterprises in China use this process for composite manufacturing of film and cloth. Characteristics: Ready-made equipment and process can be used. Disadvantages: the composition of the film is PE, and the composition of the nonwoven fabric is polypropylene, the melting point of the two is different so that the temperature of the hot rolling rolls can not be taken into account at the same time; the heat capacity of the hot rolling rolls makes the composite strength of the product poorer under the same temperature with different speeds of production; the machining accuracy of the hot rolling rolls is also a factor affecting the quality of the product; the hot rolling method has a higher rate of loss of air permeability of permeable film materials (between 30-40%); the production speed is slower. Hot rolling method has high air permeability loss rate (between 30-40%) for breathable film material; production speed is slow. ◆ Cloth powder lamination: A method of evenly sprinkling hot melt adhesive powder on nonwoven fabric or film, and then laminating by heat. Characteristics: Thermal pressure rollers use rubber band rollers and glossy rollers to cause little damage to the material. Disadvantages: slower production speed, low production efficiency; hot melt adhesive powder sprinkling uniformity is the key to product quality, but the hot melt adhesive powder hygroscopicity makes uniform sprinkling becomes quite difficult, sprinkling amount is not good control; hot melt adhesive powder melting temperature is higher, the melting temperature of the permeable film is lower, the hot melt adhesive powder can not be completely melted in the composite, which produces the peeling strength is not enough, the composite film surface flatness is not good. ◆Hot melt adhesive breathable coating composite: Characteristics: faster production speed, low breathable loss rate of breathable film material (between 20-30%). Disadvantages: large investment in equipment (a set of 1600mm effective width of hot melt adhesive breathable coating composite hot melt adhesive system costs more than 400,000 U.S. dollars); high grams of coated adhesive (to the angle of 180 о, the strength of the composite requirements of the 3.0N / inch, for example, the amount of adhesive used to reach 4gsm or more); coated when the coating head needs to be in contact with the coated material, the stability of the winding and unwinding of the equipment, the smoothness of the high requirements; coating process on the material to impose the material to contact, the stability and flatness of the requirements. High; coating process on the material to impose a greater tension, and non-woven fabrics and films are required to run under very low tension, otherwise it is easy to cause material stretching and deformation, composite products wrinkled, thus affecting the quality of the product; operation is more complex to adjust: non-woven fabrics and films can not be resistant to high temperatures, while the use of hot melt adhesive temperature basically in 150 degrees Celsius or more, low-speed operation is easy to cause the material of the scalded off, causing production stoppages, waste products, and the production of the product. The low-speed operation is easy to cause the material to be burned off, which will cause the production to stop and increase the scrap. The new process proposed in order to provide a more effective solution, the U.S. ITW DYNAFIBER (Dynatec) company recently launched a patented product DYNAFIBER (tm) hot melt adhesive fiber (UFD) spray adhesive composite technology. The fiber-type spray adhesive process using high-tech, high-precision airflow high-frequency oscillation technology and stacked nozzle structure design, so that the liquid flow distribution is more uniform, the diameter of the adhesive fibers have been well controlled, the fiber thickness is consistent and continuous, eliminated due to the defects caused by the broken wire particles of adhesive spots, within a certain range of controllable frequency of oscillation and swing of the adhesive filaments, the first industry-wide filtering function effectively eliminates the design of the nozzle blockage! The industry's first internal filter design effectively eliminates nozzle clogging problems. In addition, the process also has: glue saving: in the same composite strength than the traditional composite way to save glue up to 40% above; spray glue uniformity: unique patented design of the liquid flow pressure, fiber glue filament control has been improved, the composite product left, right, front and back on the amount of glue is more uniform and accurate, so that the composite nonwovens to maintain a superior permeability and softness; maintenance-free nozzle: unique gasket nozzle design and filtration function, the nozzle does not need to dismantle and wash the nozzle. Filter function, the nozzle does not need to be dismantled and washed, which greatly reduces the defective products caused by nozzle clogging and reduces the maintenance cost; high hardness special stainless steel design: greatly improves the service life and maintenance cycle; non-contact glue spraying: eliminates the influence of traditional coating on the quality of the composite product such as the flatness of the equipment and the material, the tension, the heat resistance, the production speed, etc., and reduces the permeability loss rate of breathable film to a minimum; Easy installation and adjustment: simple operation, no need to adjust each nozzle, very low air consumption; spray adhesive width: 4mm-7000mm are available; production line laminating speed: up to 900m/min; hot melt adhesive fiber filament thickness can be controlled from 2-50um.