1, The effect of TPU moisture content

Although the water absorption of TPU and PET, unlike Nylon, PC particles come high, but because the TPU itself polar bond and absorb moisture in the higher hardness specifications of water more serious.TPU in the process, the temperature usually are between 180~230C, in such a high temperature under.PU molecular bond will produce reverse reaction and release R-NCO functional group, if not fully dry particles, R-NCO functional groups react with water to produce carbon dioxide, will be in addition to the original TPU molecular chain scission, resulting in the decline, will also cause the appearance of the molding processing is bad, and the gas pressure will affect the operation of processing. The following is the Rainthane TPU particles in the moisture condition of the outside world, caused by the adverse effects of particles and not dried in the injection of material.

The moisture content of particles has a great influence on the physical properties of the molded products. Based on this, the filling of the particles is absolutely necessary. It is better to be below 0.03%. We strongly recommend the drying effect.

2, back to the reference material and join it kind of material processing and return material

TPU either injection or extrusion grade. Recovery can be added to the material processing. As of recycled materials and decide, generally not more than 25% of the total principle, whether injection or extrusion processing, recycled prior sufficient drying and mixing with new material evenly, is the necessary condition, in addition to in addition, recycled material and new material in the barrel, the temperature and shear force, to obtain a uniform mixing homogeneous melt, the processing of finished products can be the ideal, generally speaking, the processing of finished products and recycled materials made of new material, if not recycled in bad quality fully dry, the biggest reason is that new materials and recycled materials in the sleeve is not homogeneous, based on this, the time of injection molding can be recycled back to the reference number, because the particles in the sleeve can be retained for a long time.

3, add it kind of material processing

In order to improve the machining molding rigidity, shorten the injection molding time and improve the liquidity of the rainbow melt overflow TPU can be added to ABS injection in order to reduce the hardness of TPU, such as A to 65-Shore so as to reduce the forming time and release the problems in the process, you can add a PVC injection, but the addition of ABS.PVC a particle with not more than 15% principles. In addition TPU can also be mixed with TPU particles it label use. Note that the hardness or high viscosity of the particles must occupy more proportion, such as 7:3 or 6:4, or if the hardness of the high viscosity of the particle, absolute minority, may not happen melting situation, in order to maintain the smooth appearance of the extrusion molding especially made, should be especially careful operation.