Views: 0 Author: Site Editor Publish Time: 2025-08-21 Origin: Site
High-transparent TPR (Thermoplastic Rubber) is widely used in transparent toys (such as luminous toys, bouncing balls, figurines), footwear (children’s shoes, casual shoes), and even adult products due to its soft touch, easy coloring, and excellent processability. Achieving high transparency in TPR pelletizing requires careful control of formulation, processing, and raw material selection.
1. Optimized Formulation Design
Additives: Use liquid antioxidants instead of solid ones to prevent uneven dispersion, which may create light scattering points and reduce transparency.
Fillers: Avoid fillers whenever possible since they negatively impact transparency. Instead, control oil content to adjust TPR hardness.
Polymer Compatibility:
For standard applications, GPPS (General Purpose Polystyrene) is ideal due to its excellent transparency and high compatibility with SBS.
For improved chemical resistance, switch to SAN (Styrene-Acrylonitrile Copolymer).
For high gloss and weather resistance, MS (Styrene-Methyl Methacrylate Copolymer) is the best choice.
All three blend well with SBS, forming a uniform system that reduces phase separation and prevents transparency loss.
2. Processing Technology Control
Mixing & Extrusion Parameters: Precisely adjust mixing time, processing temperature, and screw shear force to ensure uniform dispersion of components. Avoid high temperatures or prolonged processing, which may cause SBS degradation, chain scission, or oxidation. Inadequate or excessive shear can also reduce transparency by damaging polymer chains.
Equipment Cleaning: Thoroughly clean screws and barrels before TPR pelletizing to eliminate residue, impurities, or color contamination. A clean system ensures maximum transparency of the final pellets.
3. Raw Material Selection
Choose linear, low-molecular-weight, and impurity-free SBS (e.g., YH-188E, 988). These grades offer excellent chain regularity, high purity, and natural transparency.
They also provide strong oil compatibility, allowing oil content up to 80–90%, enabling flexibility in hardness adjustment.
Particularly, SBS 988 offers a drier surface, reducing oil separation and haze, making it ideal for producing ultra-transparent TPR pellets.
Conclusion
Producing high-transparency TPR pellets requires a balance of optimized formulation, precise processing, and careful selection of raw materials. By using liquid additives, avoiding fillers, maintaining clean extrusion equipment, and selecting high-purity SBS, manufacturers can achieve TPR granules with superior clarity, gloss, and stability.
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