To reduce the noise of the punch press during the punching process, the polyurethane elastomer is used as the damping material. The experiments of reducing noise were made by means of adding the polyurethane elastomer...To reduce the noise of the punch press during the punching process, the polyurethane elastomer is used as the damping material. The experiments of reducing noise were made by means of adding the polyurethane elastomer at different positions on the 100 kN and 1 000 kN punch presses. The better effect of reducing noise was obtained. After researching and analyzing a large number of test data, the ″equivalent damping hypothesis″ is put forward. The hypothesis makes the experiment of reducing noise simpler and also more economical. It is estimated that there is a vast application in the research area of vibration control and noise reduction.展开更多
The flame retardants containing organophosphorus compounds have extensively been used in the flame retarding of polymer materials. Among others, dimethyl methyl phosphate (DMMP) was applied in flame retarding of polyu...The flame retardants containing organophosphorus compounds have extensively been used in the flame retarding of polymer materials. Among others, dimethyl methyl phosphate (DMMP) was applied in flame retarding of polyurethane owing to its so much merit. However, the water-soluble property of DMMP restricted its application in textile fabric. The flame retarding system containing DMMP will be microencapsulated to form a novel flame retardant that could be used in textiles. We have studied the built–up effect of DMMP with some inorganic compounds to improve the afterflame and afterglow suppression in the flame retarding system. The experimental data indicated that inorganic compounds containing various non-metal elements P, N, B and metal ions Mg2+, Al3+, Ca2+, Zn2+, Cu2+, Mn4+ could be applied in flame retarding systems as additives to effectively suppress afterflame or afterglow.展开更多
文摘To reduce the noise of the punch press during the punching process, the polyurethane elastomer is used as the damping material. The experiments of reducing noise were made by means of adding the polyurethane elastomer at different positions on the 100 kN and 1 000 kN punch presses. The better effect of reducing noise was obtained. After researching and analyzing a large number of test data, the ″equivalent damping hypothesis″ is put forward. The hypothesis makes the experiment of reducing noise simpler and also more economical. It is estimated that there is a vast application in the research area of vibration control and noise reduction.
文摘The flame retardants containing organophosphorus compounds have extensively been used in the flame retarding of polymer materials. Among others, dimethyl methyl phosphate (DMMP) was applied in flame retarding of polyurethane owing to its so much merit. However, the water-soluble property of DMMP restricted its application in textile fabric. The flame retarding system containing DMMP will be microencapsulated to form a novel flame retardant that could be used in textiles. We have studied the built–up effect of DMMP with some inorganic compounds to improve the afterflame and afterglow suppression in the flame retarding system. The experimental data indicated that inorganic compounds containing various non-metal elements P, N, B and metal ions Mg2+, Al3+, Ca2+, Zn2+, Cu2+, Mn4+ could be applied in flame retarding systems as additives to effectively suppress afterflame or afterglow.
