沙伯基础PC3412R---3412R是一种高粘度，20%玻璃钢等级。它具有优异的阻燃性能，特别适用于要求高硬度和高热的应用场合。
Due to the high rigidity of molecular chain, high viscosity ofmelt, low fluidity and fast cooling speed of PC, there are usuallyinternal stresses in the products, so the re for moldingprocess conditions and the design of products and molds are strict.In order to reduce the internal stress of products, the productsare usually heat treated immediately after molding. PC hasexcellent molding performance, which can be processed by injectionmolding, extrusion and other methods. PC is in high elastic stateat 170 ~ 220 ℃, which can be processed by blow molding and rollpressing. At room temperature, PC has a considerable ability offorced high elastic deformation and high impact toughness, whichcan be used for cold forming such as cold pressing, cold drawingand cold rolling. Among them, injection molding is the most widelyused and occupies an extremely important position
Adding glass fiber, carbon fiber, boron fiber and asbestos fiberinto PC can significantly improve its fatigue strength, tensilestrength, elastic modulus, bending strength, compressive strength,mechanical properties such as stress cracking and heat resistance.The molding shrinkage can also be further reduced, but the impactstrength is reduced. At the same time, the product will lose itstransparency. At present, the reinforced PC is mainly reinforced byglass fiber. The effect of glass fiber content on the properties ofreinforced PC: the mechanical properties of reinforced PC increasewith the increase of glass fiber content, but the effect is notsignificant when the glass fiber content is less than 10%; When thecontent is more than 40%, the brittleness of the product is toolarge, and the melt fluidity is poor, which brings somedifficulties to the forming process. Generally, the glass fibercontent in the range of 20 ~ 40% is more appropriate
Although PC has good comprehensive properties, some defects,such as easy to produce stress cracking, sensitive to notch, poorwear resistance and poor processing fluidity, need to be furtherimproved. With the extension of aging time, Tg of PC appears asmall peak similar to the first-order transformation, which isusually called abnormal specific heat peak. There are two possiblereasons for the appearance of abnormal specific heat peak: (1) thestress relaxation occurs when the frozen strain PC reaches TG（ 2)PC is annealed near TG, so the free volume of PC varies greatlynear TG. PC is a very sensitive material to micro notches, so oncethese micro cracks are formed, the notched impact strength andelongation at break of PC samples will be greatly reduced, and thetoughness of PC will be seriously damaged, which may be the mainreason for the sharp decline of notched impact strength andelongation at break of PC after aging.
