Why should the model that note model install exhaust system

The exhaust of the model that note model is one of mould design serious problem, it is especially in fast Injection Molding, more strict to noting the exhaust of model model to ask. 1, the origin of the gas in the model that note model. (1) some air are put in gating system and mould antrum. (2) some raw material are contained not by dry the moisture that remove, they become vapor in the aerification below high temperature. (3) because note the temperature when model exorbitant, what certain property does not stabilize is plastic produce the gas that decomposes a generation. (4) the gas that the certain additive in plastic raw material volatilizes or mutual and chemical reaction makes. 2, the compromises the standard that note model exhaust with undesirable exhaust is undesirable, will give model a lot of respect such as quality is brought a series of harm. Main show is as follows: (1) in noting model procedure, fuse-element will be replaced model the gas in antrum, if aeriform eduction is not seasonable, it is difficult to will cause fuse-element to fill up, cause shot to be not worth and cannot be full of model antrum. (2) eliminate not the gas experience of free is in model high pressure is formed inside antrum, the compression with be in certain the infiltration below degree is plastic and in-house, cause stomatic, empty, organize the quality blemish such as loose, crazing. (3) be compressed by height as a result of gas, make model the temperature inside antrum rises quickly, cause then all round fuse-element is decomposed, burn, make model appear local carbonization and scorch phenomenon. It basically appears in the confluent place of two fuse-element, * horn and runner flange are in. (4) of gas eliminate not free, make enter each model the fuse-element speed of antrum is different, because this is easy,form mark of going from place to place and fusion mark, make model mechanical function is reduced. (5) as a result of model the block up of the gas in antrum, can lower rate full a pattern, the influence shapes periodic, reduce manufacturing efficiency. 3, model in of bleb distributing model the origin of the gas in antrum basically is divided kind, model the air of the stockpile in antrum; The gas of generation is decomposed in raw material; The vapor that water evaporates remains in raw material, because the different place of origin produces the position of angry bubble,also differ. (1) the bubble that place of air of the stockpile in modular antrum generates, often distributing to go up in as relative as runner position. (2) the bubble that the place in plastic raw material is decomposed or chemical reaction generates criterion edge model ply distributings. (3) the bubble that aerification of water of the remaining in plastic raw material generates, distributing irregularly in whole model on from afore-mentioned model in the distributinging state of bleb looks, can judge the quality of bleb not only, and the exhaust place that can judge a mould is reliable. CNC Milling