1.4 Test method 1.4.1 Tensile strength test According to the provisions of GB/T528-1998 vulcanized rubber or thermoplastic rubber tensile stress and strain properties.
1.4.2 The elongation at break test shall be carried out according to the provisions of GB/T528-1998 for the determination of the tensile stress-strain properties of vulcanized rubber or thermoplastic rubber.
1.4.3 Tear strength test According to the CB/T529-1999 vulcanized rubber or thermoplastic rubber tear strength determination requirements (take a rectangular sample).
1.4.4 Falling ball rebound rate test shall be carried out according to the provisions of GB/T1681-1991 vulcanized rubber rebound resilience.
1.4.5 Hardness test shall be carried out according to the CB/T3903l4 General Test Method for Hardness of Footwear.
1.4.6 Density test According to the K/T2872-1997 rubber-plastic shoes microporous material visual density test method.
1.4.7 Peel strength test shall be carried out according to the CB/T532-1997 vulcanized rubber or thermoplastic rubber and the determination of the bond strength of the fabric.
1.4.8 Determination of expansion ratio: After foaming a square material with a side length of 10 cm in the mold, place it at room temperature for 24 hours, measure the change of its side length (in cm); divide the measured value by 10 cm. The value is the expansion ratio.
2 Results and discussion 2.1 The effect of different SIS addition on the mechanical properties of foamed materials Thermoplastic elastomer styrene-isoprene-styrene block copolymer (SIS) has both rubber and plastic properties, at room temperature It has good elasticity. When adding SIS to EVA foaming material, it can effectively improve the elasticity of foaming material. The resilience increases with the increase of SIS dosage, but with the increase of SIS dosage, some mechanical properties of the material (such as pulling The tensile strength and peel strength are decreasing (see Table 1). It can be seen that the elastic energy of the foamed material is 55-60 (PHR) and the elastic material can reach the high elastic material requirement (elasticity! 50%). Can also reach the standard.
2.2 The effect of different foaming agent AC3000H on the mechanical properties of foaming materials The amount of foaming agent A3000H is the main factor to control the performance of foaming materials, which directly affects the expansion ratio of materials and the physical and mechanical properties of foamed materials. It can be seen from Table 2 that the density, hardness, tensile force and peel strength rebound rate of the foaming ratio material all decrease. According to the hardness requirement of the midsole of sports shoes (50% degree), it is suitable to control the amount of foaming agent generally between 2 8-30, and the expansion ratio is L55-160. 2.3 Crosslinking agent (PCP for foaming material) Influence of mechanical properties The degree of cross-linking of crosslinked foamed materials has an important influence on the foaming, mechanical properties and resilience of the materials. The amount of controlled cross-linking agent (DCP) is the key to the production of high-elastic EVA sole materials. Table 3 can be found that if the amount of cross-linking agent (DCP) is lower than that of Q4PHR material, the cross-linking is insufficient, and the sticking phenomenon occurs. Foaming failure If the amount of cross-linking agent (DCP) is higher than that of L5PHR material, Table 1 Effect on mechanical properties Test item Standard value Elastic flexural resistance) Equivalent compression deformation) Peel strength (N/cn) Tensile strength (MPa) Elongation at break Hardness Shore) Table 2 Different amounts of foaming agent AC3000H Effect of mechanical properties of foaming materials Test item Standard value Elastic resistance to bending (secondary) Compression deformation Peeling strength cm) Tensile strength (MPa) Elongation at break Hardness (Shore) Cross-linked excessively produced turtle during foaming The cracking material is brittle and has no practical value. It can be seen from the table that as the amount of the crosslinking agent increases, the rebound rate of the tensile force and the peel strength both increase first and then decrease. The rebound rate is increased with the amount of crosslinker. According to the requirements of the sports sole, the amount of the crosslinking agent is preferably controlled at 0L7-a9PHR.
Table 3 Crosslinking agent (the effect of the amount of PCP on the mechanical properties of the foamed material) Peel strength (kN/n) rebound rate Cross-linked excessive bubbling, brittleness can not be tested. Cross-linking insufficient mold can not be removed.
2.4 Influence of the amount of ZnO on the mechanical properties of foamed materials ZnO is an alkaline oxide, which can effectively reduce the decomposition temperature of AC foaming agent, adjust the crosslinking speed and match the decomposition speed of foaming agent to obtain uniform pore structure. Fine foaming material. At the same time, it can neutralize the acidity of the whole system to prevent the acidity of the system from being too strong, causing acidosis of the crosslinking agent, causing the active radicals to be transferred, thereby delaying the crosslinking and adversely affecting the elasticity and compression deformation. It can be seen from Table 4 that as the amount of ZnO increases, the density and mechanical properties of the material decrease. This is mainly because when the amount of ZnO is small, the crosslinking speed of the system is higher than the decomposition rate of the blowing agent, the expansion ratio is small, and the mechanical properties of the material are obtained. Higher, when the amount of ZnO is large, the crosslinking speed of the system is lower than the decomposition rate of the foaming agent. The expansion ratio of the material is larger. The experimental results show that the ZnO dosage of the system is controlled at 0l8-L0 (PHR), the crosslinking speed and The decomposition rate of the blowing agent is matched to obtain a more desirable foaming material.
Table 4 Effect of different ZnO dosage on mechanical properties Test item standard value ZnO dosagezhou) Elasticity (flexibility (secondary) qualified compression deformation peel strength (N/cn) tensile strength (MPa) elongation at break hardness (Shore Degree) The effect of 2.5 molding foaming process conditions on the expansion ratio The molding foaming process conditions (time and temperature) have a great influence on the foaming process of the material. The direct characterization is the expansion ratio of the material, which can be obtained from Table 5. It can be seen that if the temperature is constant, it increases with time, and the final expansion ratio tends to be stable, but the foaming time is too long, the production efficiency decreases, and the anti-time is certain. As the temperature increases, the final expansion ratio also tends to increase. In the case of stability, steam heating is generally used to increase the demand for equipment with increasing temperature, equipment investment increases and the safety of production decreases. According to the principle of maximizing benefits, the production process conditions are controlled at 500-900 S degrees of 165-170! .
Table 5 The effect of foaming time and temperature on the expansion ratio The foaming temperature is 172!
Foaming time is foaming time (S) Foaming ratio Foaming temperature is (!) Foaming ratio Note: 1 bubble sticking mold; 2 sheet distortion; 3 bubble sticking; 4 sheet twisting deformation.
3 Conclusion The addition of thermoplastic elastomer styrene-isoprene-styrene block copolymer (SIS) to EVA foaming material can effectively improve the elastic SIS dosage of foaming material controlled at 5560 (PHR). The amount of the coupling agent is controlled at 0l75-Q90 (PHR), and the amount of the blowing agent is controlled at 280-3Q. The amount of ZnO is controlled at 0 8-10 (PHR). The foaming condition is controlled at a temperature of 165-170! The time is 800-900S, and the rebound rate can be obtained!
50% high-elastic EVA foam material.
(Finish)
Rolling Mill Parts,Rolling Mill Spare Parts,Rolling Mill Gear Box,Rolling Mill Parts For Sale
Taiyaun JDS Machinery And Equipment Co., Ltd. , https://www.ccagoods.com