Study On Influencing Factors Of Molding Technology Of All-water Polyurethane Foam

The chemical-blowing agents of All-water polyurethane foam is water, the reaction of wa- ter and isocyanate form CO2 ,as a gas filler, which fills to the melting liquid, the foaming pr -ocess is All- water polyurethane foam. It has the quality of low cost of producing,non-toxic characteristic, simple technique process. Recently, the application of the All-water polyureth- ane foam becomes broader. It plays the important role in the areas of the automotive,construc -tion, environmental protection and other fields. However, its foaming process request a pro- per viscosity of polyether. At the same time, an unstable CO2 generated by the unstable ther- mal conductivity, the generating cell walls thin, the framework is not strong, the bubbles pro -ne to collapse,, so the preparation of the All-water polyurethane foam and the research of v- arious parameters is an important topic.All over the world, there are a lot of studies about the All-water polyurethane foam, the ge -eneral analysis of the affection of the parameters is not exist. This article focused on this are -a, The influencing way of the technical parameter on the quality of the foam. including the water content, viscosity of polyether polyol, isocyanate index, catalyst, foam stabilizer, mol- ding temperature and so on. According to the molding principle of All-water polyurethane foam, the reaction of isocyanate and water is the foaming reaction, the reaction which forms urea and biuret bond is gel reaction. Too much water will increase the density of the polyure- thane foam, decrease the physical properties. The functionality of polyether and molecular affects the viscosity of polyether. In the reaction process, the disperse of fusibility affects the cross-linking of foam, then, affects the physical properties. The foaming stabilizer and catal- yst affect the degree of foaming reaction and gel reaction. The proper level will product reg- ular foam. Too fast or too slow all will make the foam have some defects, such as the half-b- aked foam. The other aids also play important role. The flaming retardant, opening agent, antistatic agent regulate the physical properties of the All-water polyurethane foam. Through the study of different packing structure of the cell, the mechanism enhances. The article anal- yzes the physical characteristic of the foam by different means and methods. The mechanism of building up the quality of the foam is discussed. Various photos of the micro-sample are analyzed, the different stage show the different situation. By studying the affection of the pa- rameters on the pore structure of the foam, finding out the mechanism and solving these qu- estions.