Rubber has excellent damping properties, widely used in the manufacture of shock absorption shock reduction or isolation of vibration damping products. With the rapid development of modern science and technology and social progress, as well as people's attention to seismic hazards, rubber shock absorbing products are increasingly wide range of uses, its performance requirements are increasingly high.
Compressor vibration damping pad is placed at the bottom of the compressor, supporting the compressor's key parts, general requirements for the service life of about 10 years and in the life of the requirements of the height of the pad, hardness, size change is small, because the compressor hangs in the outdoor, so the rubber pad weather resistance requirements are high, and requires the hardness of the pad with the temperature change is low.
Rubber cushion performance directly affects the compressor vibration damping effect and noise, so that, vibration damping rubber cushion is inevitably air-conditioning compressor "green and environmentally friendly an important part of the". Based on the work of the rubber shock pad is the use of rubber's high elasticity and high viscosity set in one, effectively converting mechanical energy into kinetic energy of molecular movement, with the rubber molecules of the deformation and restoration of the mechanical energy consumption, and will reduce vibration and noise. Vibration-damping rubber cushion long-term work in the outdoors, it is required to have dimensional stability, weather resistance and hardness with the temperature change is not obvious characteristics.
Chloroprene rubber (CR) has excellent weather resistance, and good workmanship and inexpensive. Many developed countries give priority to its use as a compressor vibration damping cushion rubber, such as the Japanese compressor factory's vibration damping cushion specifications (equivalent to the domestic technical standards), which provides for the use of chloroprene rubber. The purpose of this research and development is to select the appropriate grade of neoprene rubber and softening agent, and examine its mechanical properties, aging properties and dimensional stability.
1. The effect of different types of CR on the performance of the rubber material
Shock absorbing pads on the aging resistance and low temperature performance requirements, and must take into account the cost, the selection of DCR2131, CR3221 and CR2321 three kinds of grades. The same with the rubber, CR2321 rubber under normal physical and mechanical properties are better, but the aging resistance is slightly worse, did not meet the technical specifications; DCR2131 rubber performance to reach the required indicators, but the mixing process is not good, the rubber is too soft, thin through the very difficult, easy to lead to uneven mixing phenomenon. Due to the low viscosity of the mixing rubber Mooney, the rubber in the vulcanization is difficult to exclude the air, resulting in product surface bubbles, affecting the product's qualification rate; and CR3221 rubber performance indicators to meet the requirements of the technical specifications.
2. The influence of different softeners on the performance of the rubber material
Due to the compressor on the vibration damping cushion hardness special, shall be lower hardness (Shore A40 degrees), so the requirements of the softener is more demanding and the amount is also relatively large, with the system has a great impact on the performance of the rubber and the product. At the same time to consider the cost and source, selected a representative DOTP, aromatics oil, epoxy soybean oil softener in CR3221 rubber material for comparative experiments, due to the use of aromatics oil rubber material hardness is high, in the aromatics oil formula used in 39, the results of the use of DOTP or aromatics oil vulcanized rubber performance can meet the requirements of the technical indicators, mixing found that the use of DOTP rubber material is not easy to stick rollers, easier mixing, and the results of the use of DOTP or aromatics oil curing rubber performance can meet the requirements of technical specifications. It is easier to mix, and consider the compressor plant to RosH certification "Restriction of the use of certain hazardous substances in electrical and electronic equipment directive" and REACH certification "on the registration, evaluation, authorization and restriction of chemicals system" environmental requirements, so DOTP is the best choice!
