| Application areas: |
| TPR material products are prone to cracking or cracking | |
| 2019/11/6 11:46:59 | |
| Soft toys made of TPR materials, artificial craft products, blown out with cold wind after injection, or placed for a few days, the products are prone to cracking or cracking (cracking), which are divided into aging cracks and stress cracking. The following is a brief analysis of the reasons and solutions. 1. Aging crack Reason analysis: the aging resistance of TPE and TPR compounds is not good enough, the TPR of SBS system is easy to be aging, and the quality of the operating oil will also affect the aging resistance of TPE and TPR compounds (according to the analysis of senior industry analysts) , The higher the hydrogenation degree of the operating oil, the better the aging resistance of the material). Solution: Use SEBS base material; use oil with high hydrogenation degree; add antioxidant to compounding system. 2. Stress crack Reason analysis: When the polymer material is in the molten state, it will produce stress orientation along the flow direction. The faster the flow rate, the more obvious the molecular orientation effect. The molecule will produce orientation stress when the orientation occurs. If the injection molded or extruded product is not properly processed , The stress in the product may not be completely eliminated, and the stress on the surface of the product is more obvious. In severe cases, it will cause the product to crack or crack. Solution: injection molding products are pressure-retained, and the mold is removed after the stress is removed; annealing treatment: using a spark spray gun or (hot air) to perform a short heat treatment on the product to eliminate residual stress, reduce and eliminate stress cracking (cracks) ). Some thicker soft TPE and TPR products are more prone to stress cracking. Generally speaking, stress cracking occurs within half an hour to a few days after the product is processed. Aging cracking occurs within a few days to a month. |
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