During the production, storage, or use of TPE/TPR products, there are cases where the products are deformed. The five common TPE/TPR products are analyzed and the corresponding solutions are summarized!
1. Distortion of products during processing
Reasons: TPE and TPR are soft plastics. During the process of injection molding, extrusion, etc., they may be pulled out from the mold due to insufficient cooling of the products, resulting in deformation of the products.
Countermeasures: Attention should be paid to the cooling of the mold and the mold release treatment to reduce the tensile deformation of the product.
2, deformation caused by improper storage
Reasons: TPE and TPR are thermoplastic materials. For TPEs with higher hardness and TPR products, the material phase system has a strong tendency to crystallize, and it is squeezed due to gravity due to excessive stacking and storage of products. Restoring extrusion deformation.
Countermeasures: TPE, TPR products try not to stack too much too high.
3, TPE, TPR material problems caused by deformation
Reason: TPE, TPR material melt strength is not enough, such as tensile strength, flex resistance, resilience, anti-permanent deformation, etc. can not meet the requirements of the use of products, resulting in products in the process of use, due to the role of external forces (can not be Restoring) deformation.
Countermeasures: The melt strength of the material should be improved, starting from the substrate SEBS, SBS to solve, need to take into account the ratio of other components!
4, the product adhesion pull deformation
Reasons: Some TPEs and TPR products with lower hardness, due to TPE and TPR, are somewhat sticky on the surface (SBS system materials are particularly noticeable in summer), and they are stored improperly, causing the products to stick together, making it difficult to separate and forcibly pulling them apart. Pull deformation. This is strictly speaking another problem area, but the adhesion of materials or products may indeed cause the product to deform.
Countermeasures: The effective solution is to make adjustments to the TPE, TPR material formulas, or the manufacturer must pay attention to the cooling of the TPE, TPR particles packaged and stored. The expedient measure is to store the surface of the product with a layer of paper or film in isolation and not in direct contact.
5. Forming Shrinkage Warpage
Reasons: Some products with large size and thickness and high material hardness have large thickness and severe material shrinkage. During injection molding or extrusion, there is shrinkage stress, but the shrinkage stress is not completely released after molding, but After being placed for a period of time, it slowly appeared, showing that the edges of the product were warped and uneven. Sometimes the temperature fluctuations are large, and it is also a factor of warping deformation of products.
Solution: Keep the pressure in the molding process as long as possible. For extrusion products, try to cool them and then cut. Material formulations should pay attention to reduce the role of crystalline components.