Several ways of compounding non-woven fabric and PE film

Release time:

2018-03-29

With the maturity of the primary processing technology of non-woven fabrics, more and more enterprises turn their attention to the deep processing of non-woven fabrics, so as to enhance the added value of products and the profits of enterprises as much as possible. The application field of hot melt adhesive coating equipment in China has also been continuously expanded. The medical and sanitary material production departments are the most widely used industries of this kind of equipment. The rapid development of the automobile industry in China has also stimulated the demand of spare parts manufacturers for hot melt adhesive coating equipment. Relevant data show that the domestic geotextile industry has also introduced the first hot melt adhesive production line so far not long ago. As a mature and developing process, hot melt adhesive

in the domestic

The application field of hot melt adhesive coating equipment has also been continuously expanded. The medical and sanitary material production departments are the most widely used industries for this kind of equipment. The rapid development of the automobile industry in China has also driven the demand for hot melt adhesive coating equipment from spare parts manufacturers. Relevant data show that the domestic geotextile industry has also introduced the first hot melt adhesive production line so far not long ago. As a mature and developing process, the prospect of hot melt adhesive coating technology in the non-woven deep processing industry will be better and better.

Disposable medical supplies (such as surgical gowns, surgical sheets, hole towels, gloves, shoes, hats, etc.), industrial protective products, personal care products are mainly non-woven composite film products, these industries for products The requirements are almost the same, that is, waterproof, breathable and comfortable.

Based on the analysis and comparison of several main process characteristics of the current medical and sanitary materials composite, this paper introduces a new type of non-woven fabric and film composite technology: existing technology ◆ coating: this technology is the most used method by domestic enterprises, and its characteristics are: simple process, mature, and fast production speed (about 100 m/min). Disadvantages: Do not make breathable products; feel hard, poor comfort; higher requirements for non-woven fabrics. The coating effect of non-woven fabrics with low gram weight (below 18gsm) and low coating amount (below 15gsm) is not ideal, because the unevenness of the coil surface makes the coating process prone to leakage.

Hot rolling: is the standard process of two-step manufacturing composite non-woven fabrics, some domestic enterprises use this process for film, cloth composite manufacturing. Features: ready-made equipment and technology can be used. Disadvantages: the composition of the film is PE, while the composition of the non-woven fabric is polypropylene. The different melting points of the two make the temperature of the hot roll unable to be taken into account at the same time. The heat capacity of the hot roll makes the composite strength uniformity of the product poor at different production speeds at the same temperature. The processing accuracy of hot rolled patterned rolls is also a factor affecting the quality of the product. Hot rolling method has a higher air permeability loss rate (between 30 and 40%); production is slower.

◆ Cloth powder compounding: a method of evenly spreading hot melt adhesive powder on non-woven fabrics or films, and then compounding by heat. Features: thermal pressure roller rubber roller and smooth roller on the material damage is very small. Disadvantages: slow production speed and low production efficiency; Uniform spreading of hot melt adhesive powder is the key to product quality, but the easy hygroscopicity of hot melt adhesive powder makes uniform spreading difficult and the spreading amount is not well controlled. The melting temperature of hot melt adhesive powder is relatively high, and the melting temperature of breathable film is relatively low. The hot melt adhesive powder cannot be completely melted during compounding, resulting in insufficient strength and poor surface peeling of composite film.

Hot melt adhesive breathable coating composite: features: faster production speed, breathable film material breathable loss rate is low (between 20-30%). Disadvantages: large investment in equipment (the cost of a 1600mm effective width hot melt adhesive breathable composite hot melt adhesive coating system is more than US $400000); The gram weight of gluing is high (taking the composite requirement of angle 180 о and strength 3.0N/inch as an example, the amount of glue used reaches 4gsm or more); During coating, the coating head needs to be in contact with the coating material, which requires high stability and flatness of the winding equipment; the coating process exerts a large tension on the material, while the non-woven fabric and the film are required to operate under a small tension, otherwise it is easy to cause tensile deformation of the material and wrinkle the product after compounding, thus affecting the quality of the product. The operation adjustment is relatively complicated: neither the non-woven fabric nor the film can withstand high temperature, while the use temperature of the hot melt adhesive is basically 150 degrees Celsius or above, and low speed operation is easy to cause hot break of the material, cause production pause, waste increased.

The proposal of a new type of process

In order to provide a more effective solution, the United States ITW hawknat (Dynatec) company recently launched a patented product DYNAFIBER(tm) hot melt adhesive fiber (UFD) spray compound technology.

The fiber-type glue spraying process adopts high-tech, high-precision airflow high-frequency oscillation technology and laminated nozzle structure design, which makes the liquid flow distribution more uniform, the diameter of the glue fiber is well controlled, the fiber thickness is consistent and continuous, and the defects of particle glue points caused by broken wires are eliminated. In addition, the process also has:

Save glue: in the same composite strength than the traditional way to save glue up to 40%;

Uniform glue spraying: the unique patented design improves the control of liquid flow pressure and fiber glue, and the glue amount on the left, right, front and back of the composite product is more uniform and accurate, so that the composite non-woven fabric maintains superior air permeability and softness;

Maintenance-free nozzle: unique gasket nozzle structure design and filtering function, the nozzle does not need to be disassembled and washed, which greatly reduces the generation of defective products caused by nozzle blockage and reduces maintenance costs;

High hardness special stainless steel design: greatly improve the service life and maintenance cycle;

Non-contact spray glue: eliminates the influence of equipment and material flatness, tension, heat resistance and production speed on the quality of composite products in traditional coating, and minimizes the loss rate of permeability of breathable film;

Easy installation and adjustment: simple operation, no need to adjust each nozzle, very low gas consumption;

Spray width: 4mm-7000mm can be;

Production line compound speed: up to 900 m/min;

The thickness of hot melt adhesive fiber can be controlled from 2-50um.

Waterproof breathable membrane

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Global Medical Nonwovens Market Expected to Reach $10.05 billion by 2020

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