(1) The main advantages of TPE applied to the adhesive coating
1 TPE elastomer soft glue is used for secondary injection molding, and is coated with glue and glued. Because TPE material has good skid resistance and good elastic touch, it can improve the touch feel of products and enhance the grip.
2 TPE elastomer soft adhesive can be adjusted to appropriate hardness (hardness range Shore 25-90A) and appropriate physical properties (such as abrasion resistance, scratch resistance, cohesiveness, melt index, etc.) according to the physical property requirements of the product. Various approximate material application plans are provided for different products.
TPE is coated with glue and shot-glued. Commonly used products such as handles, grips, electronic materials, etc. The material gives the product a comfortable touch, improves the grip, improves the product's beauty and the value attached to the product. Most of the products are exported to the United States, Japan, European Union and other developed countries and regions. Because TPE elastomer soft rubber is a green and environment-friendly raw material, the material does not contain phthalate, halogen and 38 SVHC substances of very high concern stipulated by REACH. It complies with RoHS, REACH, NP, EN71 and PAHs environmental protection testing standards, and completely meets the environmental protection requirements of developed countries and regions such as the United States, Japan and the European Union.
(2) The main mechanism of TPE-coated adhesive bonding
TPE coated adhesive has the distinction between real coated adhesive and fake coated adhesive. True encapsulation uses the compatibility of soft glue and hard glue during softening and melting (compatibility mainly depends on the solubility parameter SP of the material. The closer the solubility parameter is, the better the compatibility of the two materials. For details about SP, see Polymer Chemistry). A layer of adhesive layer is formed on the contact surface of hard glue and soft glue, which greatly improves the adhesion of TPE soft glue and hard plastic. False encapsulation almost does not involve the compatibility of the two materials. The encapsulation of the materials enables the soft adhesive and the hard adhesive to be bonded together through mechanical force, through the design of molds and products and the appearance cooking, and through the hoop embedding effect.
(3) TPE-coated glue injection bonding processing technology
TPE injection molding usually adopts a secondary injection molding process. Hard plastic parts that have already been molded are fixed on the molding tool, then soft TPE glue is injected and glued to the hard plastic parts at a suitable temperature, and the products are obtained after cooling. The injection temperature of glue coating is different according to the hard glue material. Due to the temperature, both hard rubber and TPE soft rubber should be softened, which can promote the compatibility of the two materials at the contact surface. In order to achieve the effect of true encapsulation, the injection temperature of TPE encapsulated PP material is usually about 170-190 degrees Celsius. The encapsulated ABS material is about 220-220 degrees Celsius. The temperature of encapsulated PC is slightly higher than the injection temperature of encapsulated ABS. If PA nylon is coated, the injection temperature should reach 240 degrees Celsius.
(4) Common TPE-coated and adhesive materials
TPE is used for adhesive coating and shot bonding. TPE soft adhesive is used as the outer coating of soft adhesive. Common hard materials that cooperate with each other are mainly plastic, metal and woven fabric. TPE and woven fabric are mainly applied to luggage products. Like metal encapsulation, TPE and woven fabric are generally fake encapsulation. True encapsulation is commonly found in secondary injection molding and two-color injection molding, that is, the main material of TPE encapsulation is plastic. TPE can be firmly bonded with common general plastics PP,GPPS,HIPS,ABS and engineering plastics PC, PC/ABS, PA and their modified materials.
The adhesion between TPE and POM polyoxymethylene is still a difficult problem in the elastomer industry. Because the solubility parameter SP(22.6) of POM and SP(7.2-7.6) of TPE are very different, the two materials do not have compatibility by themselves, and no suitable compatilizer has been found to promote the good adhesion between the two.
The advantages of the encapsulated products introduced by our company are as follows:
1. Broad application fields. The main application fields include: automobile industry, industrial products, shoe-making field, sports equipment, articles for daily use, tool handles, toy figures, medical care and polymer modification, etc.
2. The product is wear-resistant and easy to form.
3. Good hand feeling, easy processing and strong adhesion.
The TPE encapsulated products of Dechuang Chemical Co., Ltd. conform to the human skin test and will not cause allergy, variation and rejection to human tissues. They have passed FDA, REACH, Rohs and other environmental protection directive standards.
