Wood pulp cotton rag manufacturers produce thermoforming materials

The more important features of wood pulp cotton rag manufacturers producing thermoforming materials include the following two:
(1) Plastic memory
Plastic memory allows plastic to become rubbery when heated, and a tight fit on the mold is an important feature of the material. Thanks to this feature, a poorly formed product can be heated outside the mold to restore it to its original flat shape.
(2) Thermal strength and thermal extension
Hot strength and hot elongation are two characteristics related to plastic memory. Thermal strength is the strength remaining after the plastic is heated. Some plastics lose all their strength when heated and become soft and tacky, but some plastics still have strength rebound when heated. Plastics with high thermal strength can be stretched on a mold, but plastics with low thermal strength tear quickly when stretched. Therefore, a material with high hot strength is a material with high hot tear strength.
During the hot pressing process, the fibers are in close contact, and the interdiffusion motion between the lignin and hemicellulose macromolecular segments and the macromolecules themselves (in a constrained state) is gradually enhanced until the intermolecular attraction and hydrogen Make the interface disappear until the key works to complete the gluing process.

Special attention should be paid to plastic materials during hot pressing. Some of them create inherent plastic memory stress during the molding process and fail to achieve the desired product. Therefore, the molding temperature and pressure have certain ranges and limitations. Also, in thermoforming, a certain degree of elongation also occurs. Therefore, when selecting materials, attention must be paid to the molding temperature. When hot pressing, operate within a relatively small time and temperature range.
Hot press forming can sometimes be divided into vacuum forming, while compression forming has a different pressing method. Compression molding mostly involves putting plastic into a mold to heat and soften it, and then applying pressure to form it. The pressure source for vacuum forming can be a single-sided vacuum, or in addition to the vacuum on one side, a high pressure can be supplemented on the other side. Compared with other processing methods, hot pressing has the advantages of cheap mold and uniform thickness of the finished product. Its products range from early military map models and aircraft hoods to refrigerator doors, car fenders and linings for car chassis. , soft water cups, nameplates, packaging materials and other products of uniform thickness.