Buffer Capacity Of The Impact Of Tapping Of Polymer Materials

There are a large amount of impact in engineering problems. Apart from its useful aspacts, it can bring about serious loss. Cushion materials can be used to relax impact, and it is a imperative problem to research the cushion properties of cushion materials.Impact tapping is one of tap methods that rises recently. Its rise make the produce of screw thread upgrade, and its abroad application can bring important economic benefits. But there is an important problemxushion is needed to relax the acute impact. The cushion helps to the protection and comeback of the system. The properties of the cushion have a direct relation with the running of the system. The need of cushion material is strong and tough. The important function of the cushion and the importance of the cushion material choice are nailed down in the paper..According to the need of cushion material, choice is made on cushion materials. Among cushion materials, macromolecule possesses outstanding cushion properties, so it is choosed. Among macromolecule materials, the cushion properties of polyurethane elastomers are outstanding very much, for example the higher rigidity, better elasticity and less remnent, and so on. Polythylenes possesses higher impact rigidity and excellent toughness, and polyvinyls possesses the higher rigidity. They can meet the cushion material's needs. Then one kind of polyurethane elastomers, polythylenes and polyvinyls that made in China are choosed, then they are compressed statically with the other two polyurethane elastomers that made abroad.According to macromolecular theories, chemical compose and physical structure, explain the mechanics properties with molecule viewpoint, the relations between molecule sructure and properties of polyurethane elastomers are analyzed in detail. And the mechanics properties are analyzed with macroscopical describe in the paper.The properties are tested, and from the results of the test some useful strain-stress curves, cushion coefficient-stress curves are atained. According to the experiment tests and analyses of test matterials, the superiority of polyurethane elastomers in the cushion application aspact is discussed comparing with polythylene and polyvinyl in the paper.The mechanics properties of the three kinds of polyurethane elastomers are contrasted, their application states on the impact tapping system are analyzed:PUl is more easier to be distorted, and its life is the shortest; PU2 is suited to the impacttapping, and its cushion properties are better than PU1; PU3 can not only meet the impact tapping's needs, but can be applied on the higher impact conditions. The cushion properties of polythylene and polyvinyl are discussed. According to the results, a conclusion is gained that they are unsuitable for the impact tapping, and their characteristics and applications are analyzed.Based on the distortion phenomenon of samples when beening compressed, the distortion regularity of cushion's shape and dimension are analyzed. An advice are suggested that the shape and dimension of cushion should be adjusted to improve the mechanics properties and life.In the end, the aspacts should be discussed in the future are prospected in this paper..