IPDB › China Industry › Manufacturing & Processing Machinery
China, Chinese Hot Runner Systems of Injection Moulding1 Industrial Products Supplier Manufacturer Details, price list catalog:
China Industrial Products Supplier Manufacturer List Catalog
Other MouldsMouldMold
Shenzhen Meibang Precision Technology Co., Ltd.
Preview:
Product Description OverviewThe ideal injection molding system delivers molded parts of uniform density, and freefrom all runners, flash, and gate stubs. To achieve this, a hot runner system, in contrastto a cold runner system, is employed. The material in the hot runners is maintained in amolten state and is not ejected with the molded part. Hot runner systems are also referredto as hot-manifold systems, or runnerless molding.Types of hot runner systemsThere are two types of hot runner systems:Insulated runnersInsulated runner molds have oversized passages formed in the mold plate. The passages are ofsufficient size that, under conditions of operation, the insulated effect of the plastic (frozen on therunner wall) combined with the heat applied with each shot maintains an open, molten flow path.Heated runnersFor heated runner systems, there are two designs: internally heated and externally heated. The firstis characterized by internally heated, annulus flow passages, with the heat being furnished by aprobe and torpedo located in the passages. This system takes advantage of the insulating effect ofthe plastic melt to reduce heat transfer (loss) to the rest of the mold. The second consists of acartridge-heated manifold with interior flow passages. The manifold is designed with variousinsulating features to separate it from the rest of the mold, thus reducing heat transfer (loss).Table 1 lists advantages and disadvantages of the three hot runner systems, which are sketched inFigure 1.TABLE 1. Advantages and disadvantages of hot-runner systemsHot Runner Type Advantages DisadvantagesInsulateLess complicated design.Less costly to build.Undesired freeze-up at the gate.Requires fast cycle to maintain melt state.Long start-up periods to stabilize melttemperature.Problems in uniform mold filling.Internally Heated Improved distribution of heat.Higher cost and complicated design.Requires careful balancing and sophisticatedheat control.Should take into account thermal expansion ofvarious mold components.Hot Runner SystemsFIGURE 1. Hot runner system types: (a) the insulated hot runner, (b) the internally heated hot-runnersystem, and (c) the externally heated hot-runner system.
Purchasing Request
Note: Send your purchase request, and we will screen suppliers or manufacturers for you free of charge...