TPX release film has the best resistance among transparent resins. Transparent materials are generally non crystalline (such as glass, PS) or fully crystalline (such as diamonds, ice). The TPX release film is a crystalline polymer with a crystallinity of 20-70%, making it highly transparent due to its almost identical density between the crystalline and amorphous parts, demonstrating optical homogeneity.

The difference in mechanical properties between amorphous materials and crystalline materials is that amorphous materials lose strength above the Tg point, but crystalline materials retain mechanical strength before the far crystallization melting point, and do not lose strength above the Tg point. The Tg point of TPX release film is 16-30 ℃, and the melting point of crystallization is 220-240 ℃.

Due to the fact that TPX release film is also a type of polyolefin, its PE and PP, like others, also have excellent electrical properties and drug resistance. It is the only material in transparent resin that will not cause cracking due to lubricants or drugs.

1. Physical properties

a. Physical characteristics

The Tg value of TPX release film is only 10-30 ℃, much lower than the 190 ℃ of Psu and 155 ℃ of PC, but the melting point is as high as 220-240 ℃. Due to the fact that crystalline resins can still maintain rigidity near the melting point, they still have sufficient rigidity and maintain shape in the temperature range above Tg point.

The specific heat is very high at 0.47 cal/g. ℃, and the specific gravity is very small at 0.83, making it the lightest material among plastics. The crystallinity varies depending on the molding conditions, generally ranging from 30% to 45%, and can reach over 70% under conditions that promote crystallization. Extremely low water absorption.

b. Density

Among commercially produced plastic materials, TPX has the smallest density. The density of polyolefins is influenced by their side chains, and the larger the side chains, the greater the steric barrier, resulting in a decrease in density. After measurement, the specific gravity of the crystalline part of the TPX release film is 0.828 ± 0.002, while the non crystalline part is 0.838. The density of the crystalline part is equivalent to that of ice.

2. Mechanical properties

a. Tensile strength

In terms of the relationship between tensile strength and temperature, the mechanical strength of TPX release film is similar to that of PE release film and PP, and the absolute value of strength is smaller than that of PSu, PC or PMMA. However, due to the characteristics of crystalline resin, it can maintain strength before crystallization and melting (220-230).

b. Bending characteristics

Support a test piece with a thickness of 2mm, a width of 20mm, and a length of 120mm on one side, and measure the relationship between deformation and time at a certain temperature and without load. PMMA undergoes rapid deformation above 80 ℃, while PC and PSU undergo significant deformation at 140 ℃ and 160 ℃, respectively, making them unable to withstand their own weight. Due to the characteristic of crystalline resin, TPX release film has only a deformation of 10mm at 200 ℃, and can be used at a temperature of 180 ℃ without external force. Through finished product design, the practical temperature can be further increased.

c. Impact strength

The impact strength of TPX release film rapidly increases above the Tg value, while the impact strength at room temperature or low temperature is significantly inferior to PC, equivalent to PMMA, but superior to PS. As for the drop hammer impact strength, it increases with increasing thickness.