What Are The Reasons Why TPE Transparent Materials Are Not Transparent Enough And How To Improve Them?

If you make TPE pellets, you will definitely encounter customers who ask for transparent TPE materials to make some transparent toys or transparent parts. However, they often encounter such a problem: they use transparent TPE materials to produce test molds, but the transparency of the TPE products produced is not satisfactory. What is the reason for this?

1. Material selection

The transparency of the material itself is not good enough. The rubber base material, operating oil, resin additives, etc. of the material mixing system will affect the transparency of the blended TPE material, and then affect the transparency of subsequent TPE products.

2. Screw cleaning

Before injection molding transparent TPE products, be sure to clean the machine several times with lower hardness transparent TPE material. Impurities in the screw barrel will affect the transparency of TPE products. In severe cases, black spots, white spots, etc. will appear.

3. Plasticizing effect

Poor plasticizing of materials will cause the products to be whitish and opaque. TPE is a blended material. Different models may have different plasticizing temperatures. Generally, the plasticizing temperature of transparent TPE may be in a large range of 130~230℃. Hardness (oil filling multiples), molecular weight of rubber substrate, etc. are the main factors affecting the plasticizing temperature.

Highly transparent TPE material is a functional material with a high demand in the thermoplastic elastomer system. The requirements for highly transparent products are very strict. The product must have uniform color and no pores, streaks, or black spots. Therefore, TPE manufacturers and processing and molding manufacturers need to cooperate. Some TPE products that require visibility, such as infusion tubes, luminous soft rubber toys, etc., have rigid requirements for the transparency of TPE materials.

In order to improve the strength of TPE and TPR materials, a certain amount of PS or PP plastic is usually added to the compounding system. In order to maintain the transparency of the material as much as possible, the specifications and origin of PS and PP need to be considered. In addition, the amount of plastic added is also an important factor affecting the transparency of TPE and TPR. Generally speaking, as the amount of plastic (PS, PP) added increases, the hardness of the compounded TPE and TPR increases, and the transparency of the material gradually decreases. In addition, the transparency of SEBS-based TPE decreases more significantly than that of SBS-based TPR.

Regarding the transparency of elastomers TPE and TPR, from the perspective of the selection of the components of the compounding system, as long as the appropriate SEBS and SBS substrates and the appropriate plastic (such as PP, PS) grades are selected, and no fillers, colorants, flame retardants or other functional additives are added, transparent TPE and TPR particles can be mixed and synthesized. However, the differences in the specific brand and specifications of the components of the compounding system and the different proportions of the components will affect the transparency of TPE and TPR materials.

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