Kunshan Weite Packing Products Co., Ltd.
Add: No. 1353, Changjiang North Road, Kunshan City, Jiangsu Province
Contact: Di Zong
Mail box: [email protected]
The single or multi-layer composite plastic sheet (sheet) used for Kunshan plastic processing must have the following process properties.
First, plastic memory
When the sheets (sheets) are stretched mechanically or pneumatically, they have both a tendency to tighten against tensile forces and a tendency to stretch as uniformly as possible. These properties allow plastic sheets (sheets) to be formed on molds commonly used in many thermoforming processes.
The finished product is reheated to the original molding temperature. Then it produces a "plastic memory" and returns it to its original shape (ie, becomes a flat sheet). Therefore, the shape error of the molded part can often be corrected by reshaping.
Second, hot stretching
All thermoplastic sheets (sheets) can be stretched when heated, a property that has a large effect on the shape and quality of the product. Some plastics can be stretched by 15% to 20%, while others can even be stretched to between 500% and 600%.
Third, the heat intensity
Some plastics are only slightly stressed, whether pneumatic or mechanical. A clear outline is formed on the mold. Conversely, other panels (sheets) show strong resistance and therefore require heavy equipment and molds. The limited pressure differential provided by the most common vacuum forming of thermoforming may not be sufficient to show a subtle pattern on some products. Therefore, the plastic sheet (sheet) for thermoforming must have the heat strength required to meet the quality requirements of equipment and products.
Fourth, molding temperature
Suitable for plastic sheet (sheet) for thermoforming, it is required to have a suitable processing temperature range. It is easy to form at its heat-softening temperature, and has a certain distance from its melting temperature. It has a wide range of high elastic state; it can not be stretched well in a certain temperature range, but it is high or low when molding. Easy to tear and other phenomena. Therefore, the molding temperature is one of the most important process parameters for thermoforming.
Generally, the thermoplastic amorphous plastic is heated to a high elastic state above the glass transition temperature Tg, and the deformation ability is remarkably increased. In the high elastic state close to the viscous flow temperature, vacuum, pressure forming, calender forming and bending forming can be performed due to high viscosity.