What are the differences between TPE, TPV and TPU?

　　Not familiar with TPE, TPV and TPU friends or just contact TPE, TPV and TPU soon friends of TPE, TPV and TPU are very confused, today, Shibu and you say what are the differences between TPE, TPV and TPU, compared with each other, can deepen the understanding of TPE, TPV and TPU three.

　　The comparison of TPE, TPV and TPU.

　　1, transparency, TPU is better than TPE, TPE is better than TPV, TPV in the market has not yet appeared completely transparent, but it is said that a large foreign company has developed this type of product.

　　2, weather resistance, TPV is better than TPE, TPE is better than TPU.

　　3, specific gravity, the specific gravity of TPE varies greatly, from 0.89 to 1.3, TPV in about 0.98, TPU in 1.0 to 1.4 between.

　　4, acid and alkali resistance (weak acid and alkali), TPV is better than TPE, TPU is not acid and alkali resistance.

　　5, temperature resistance, TPE is -60 degrees Celsius ~ 90 degrees Celsius, TPV is -60 degrees Celsius ~ 130 degrees Celsius, TPU is -60 degrees Celsius ~ 80 degrees Celsius.

　　6, abrasion resistance, TPU is better than TPV, TPV is better than TPE, there are also high wear-resistant TPE, but there is still a gap with TPU.

　　7, oil resistance, TPU (good) better than TPV (medium), TPE is not oil resistant.
The metal cladding has become a new application or potential application area for TPE/TPR and TPU in recent years. A layer of soft rubber material is encapsulated on the surface of the metal, which can play the role of anti-slip, shock absorption, corrosion prevention, etc. TPE/TPR, TPU used in the wrapping of metal, there are several common wrapping methods.

　　1. true overmolding: TPE and plastic, metal and other materials, through chemical action, such as molecular level penetration, polar group reaction link bonding or similar hydrogen bonding (van der Waals force), the bonding interface between the two materials to form a solid fusion or bonding effect, without the help of any mechanical physical action. The bonding with the metal is done directly by injection molding without the use of adhesives.

　　This type of processing, usually TPE and metal parts are the whole package, and TPE hardness as high as possible (70 ~ 80A and above), in order to achieve a certain package effect, because the TPE and metal package, there is no real sense (chemical and molecular level) on the bonding, completely with the TPE of a certain strength, the metal wrapped. In addition, the surface of the metal parts have grooves, holes (such as nuts, shanks), will be more conducive to TPE and metal parts to form a relatively strong bond.

　　2. Pseudo-covering: TPE and hard materials (plastic, metal or other materials) between the purely physical and mechanical bonding with the help of holes, grooves and other clips, rather than simply rely on the chemical level of the two materials bonding. There is no molecular-level penetration directly on the bonding surface of the two materials, the reaction of polar groups linked together or similar hydrogen bonding (van der Waals forces). Bonding by adhesives.

　　Sometimes some special products, the rubber material only partially covered the corresponding position of the metal parts, so that it is not conducive to TPE and metal parts to form a more solid bond. It is a common idea to apply a layer of adhesive on the metal surface where the adhesive is needed. But in fact, due to the different molding process of TPE and rubber, it has an important influence on the bonding strength of rubber parts and metal parts. The choice of adhesive type is very important for this type of metal products, in addition, the structure of the metal wrapped position and the hardness of the TPE is also a factor to be considered and evaluated.

　　3. Overall overmolding

　　The overall package, equivalent to injection molding a TPE / TPR, TPU plastic parts, the hardware products wrapped in it, there is no chemical sense of bonding, the package is still feasible. The general use of higher hardness TPE/TPR, TPU, hardness 80A or more, can be wrapped, but the wrapped hardware should be the whole package, if only part of the package, it is difficult to reach.

　　4. Partial encapsulation

　　Partial encapsulation, hardness is soft, not strong enough, difficult to adhere, through the hardware to do hole processing, can strengthen the physical and mechanical combination of TPE and hardware, so as to improve the solidity of encapsulation. This kind of cladding, many cases of vulcanized rubber parts cladding hardware, but the rubber is vulcanized. Such as the use of injection molding processing, TPE/TPR, TPU and hardware partially overmolded, it is very difficult. If the hardware is perforated, the TPE/TPR, TPU rubber injected into the hardware products inside, or can enhance the solidity of the package. Another customer tries to pre-coat the hardware with glue, and then inject the glue, but the effect is not good.