Quick adjustment of TPE package adhesive ABS.PC.PA bond
Time：2019-06-26Hits：2425
TPE coated ABS, as its name implies, is the TPE soft rubber material coated onto ABS raw materials. The general processing methods used are two-color injection molding machines for one molding, or general injection molding machines for the use of plastic mold, divided into two injection molding. TPE plastic molding products, generally some handles, handlebars products. TPE soft adhesive material has a special comfortable touch. The introduction of TPE material has improved the grip and touch feel of the product. However, there are often problems such as cracking and adhesion during use. TPE package ABS cracking, adhesion is not strong? The styrene elastomer TPE coated ABS has been relatively mature technically, but some have always encountered customer consultation, TPE coated ABS is not sticky enough or coated cracking. The author believes that there are two main reasons for the problem of glue in both of them: 1) Soft adhesive material 1. The poor quality of the material and the lack of physical properties(such as tensile properties and tear resistance) lead to cracking of TPE coated ABS products during use. As a solution, we should choose the TPE brand with good physical properties. 2. Soft rubber materials are not enough to resist aging. They are used outdoors(outdoors) for a long time and aging cracking occurs. As a response, TPE suppliers can improve their aging resistance. 2) Forming process problems TPE and ABS soft and hard materials are not firmly bonded, and TPE is stripped or cracked from the surface of ABS components. 1. It may be a stress cracking(crack) due to stress during the molding process. This cracking occurs within hours or days after the product is formed. As a solution, we should strengthen the cooling and compressive effects. 2. The adhesion effect is not good. It may be that the TPE injection molding temperature is low at the time of secondary molding, which affects the bonding effect with ABS. It is recommended to increase the injection molding temperature appropriately. The above is only TPE coated ABS products, the possible reasons and analysis of cracking and adhesion. The actual situation, if the user can judge best according to the author's analysis, if it can not be determined, then the problem model should be provided to the raw material supplier, so as to facilitate the analysis of symptoms and give a solution. Except for TPE coated ABS cracking, other TPE/TPR products are cracked for similar reasons. Why does TPE pack glue PC rupture? "Why does TPE pack glue PC break?" This is a search request from a good search engine user. This topic itself has a different understanding. Is it the part of the TPE package that ruptures or the part of the PC that ruptures. The author believes that the user's problem should refer to the majority of cracks in PC components. 1. A crack in a PC piece The problem of cracking of PCs(polycarbonate) is very common. PC parts are prone to cracks, mainly due to the internal stress of the parts. PC materials undergo forced molecular orientation at the time of molding, but after molding and cooling, the molecular orientation is very difficult due to the existence of a weak benzene ring structure. Therefore, when the PC part is formed, the solution orientation measures are not properly handled. For example, the mold temperature is set low, the cooling and holding time is insufficient, and the molecule can not be fully relaxed and reconciled. Then the formed product will have internal stress. When the internal stress reaches a certain degree(greater than when the cracking force), the PC component will break. When TPE, TPR secondary injection plastic coated PCs, due to the large internal stress of the PCs, the damage of this internal stress happens to appear when the TPE is coated, or when TPE is coated, TPE The adhesive part has a large area. At the time of coating molding, the TPE coating contract, and the thickness of the PC is thin. The contraction of the coating of TPE will contribute to the effect of internal stress, resulting in cracking of the PC component. Solution: high die temperature is used as far as possible when making PC parts, and the compression and cooling time are extended appropriately, and the internal stress is minimized or eliminated. 2. Cracking of TPE/TPR cladding TPE, TPR cladding PC, TPE cladding rupture(crack), this situation occurs, usually after the cladding has been formed for a period of time. The reasons for the cracks in TPE and TPR are mainly due to the poor aging resistance of TPE and TPR, and the time has elapsed. The aging cracking of TPE materials results. Solution: Using TPE, TPR products with excellent aging resistance to improve the aging cracking performance of the material. III. How to improve TPE coated PA adhesion? TPE coated nylon PA, to bond very strong, this is difficult in the industry. To improve the problem of poor adhesion, we need to start from the following aspects. 1. Material aspects The polarity of the TPE mixing system needs to be improved(currently more use of grafting agents to achieve), so that the polarity is close to PA, so as to facilitate adhesion. It is said that the TPU of some production models is good with PA, but the hardness is limited, and the TPU hardness is usually above 70A. If you need a less rigid TPE, you still need to solve the problem by improving the polarity of the SEBS system. 2. Appropriate cladding temperature TPE's coating forming temperature needs to be high enough. It is best to form a certain degree of fusion on the nylon coating surface. The adhesion will be greatly improved. If the forming temperature is low, it will be unfavorable for bonding. 3. Attention should be paid to the design of mold flow channels and adhesive ports For products that cover large areas and many locations, open as many as possible to reduce the melt time in the mold. The longer the running time and the running rubber path, the lower the melt temperature of the glue, which is unfavorable to the bonding. The key to glue is:(hot) quickly coated adhesive. 4. Pre-heat baking of nylon pieces For the use of ordinary plastic mold secondary injection molding, instead of two-color machine composite molding, it is recommended to Preheat or bake nylon pieces first, baking time of about 1 to 2 hours, baking temperature of 120 ~ 130 °C. This provides more energy for the adhesion of TPE to nylon, which facilitates the coating. 5. Nilon parts for grooves, fine holes, coated surface for grinding and other treatment It will be beneficial for the combination of TPE and nylon. But this is achieved by physical mechanical force, not chemical bonding. Dongguan Dechuang Chemical Co., Ltd. is committed to the development and production of TPE, TPR coated materials, and PP, PC, ABS, PA, PS, PE coated materials are solid, and can be customized according to the sample. With its unique performance, outstanding quality has been selected through the rigorous confirmation of major manufacturers. We believe that our TPE material plan will bring you more possibilities to increase your value.
