/ep_edm/en/contect_501.html SHINI PLASTICS TECHNOLOGIES, INC.

Special Reports

2011 Quarter 3 Issue 8

Application Occasions for Hot Runner System

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Hot runner mold is a new-type constitution which is capable of replacing the traditional mold or three-plate mold runner with heating runners of constant temperature, thus it is no need to take runner out after each molding finishes. We are going to discuss application occasions of hot runner:

 

 

 

Diversity of mold structure

Molding for extra large products. Only by using hot runner can flow of plastics be balanced, such as car lining plate, balance bar. And runner flows should be processed concurrently.

Side direction flow with deviation the center of injection molding. The flow of hot runner way can make the structure of mold as simple, molding as easy, and accelerate the molding speed and reduce molding stub bars. That indeed serves several purposes.

 

Shortcoming of three-plate mold

During each injection in three-plate way, heavy mother model must glide on the guide pin, which is even under use during new launch period. The lifespan of moulds can not last long.

During each ejection in three-plate way, the movement amount of hot runner material taken out of moulds is more than that of necessary models taken from dies.

 

Conditions for using hot runner

Application of a long vertical hot runner during the flow into side of ejection.

Problems resulting from too long stub bars can be eliminated.

Application to products of large-scale or injecting plastics by the center.

Mother template should be moved to take out stub bar during the use of three plate mold. By using hot runner molding, mould opening movement can shorten the necessary movement of unloading stub bar, thus the mould thickness could be increased. For the traditional application with large scale molding machine, it is possible to use small scale machine by means of hot runner system.

Application on complicated molding: Hot runner system can solve problems like high viscosity, low viscosity and high molding temperature. Specific cases include injection of metal powder, injection of ceramic powder, injection of plastic magnet, injection of plastic bearing and thermoplastic rubber (TPE), etc.

 

Saving in plastic material

Costing of cold stub bar:

For instance, if cold stub bar takes the rate of 68% in waste, then 320g product would be produced among 1 kilogram of material but the rest is 680g for cold stub bars. Although cold stub bar is recyclable, there always stores of stub bars to maintain the normal machine operation due to personnel factors and the proportion mixture of recyclable material. Finally, it causes the problem of funds retaining.

 

Application on high speed injection molding:

High speed injection not just aims to raise molding efficiency, but also control thickness for such products as cup or container.

 

Application on stack mold:

As to injection molding of thin products with great number like CD shell, granule goods, 15% clamping force should be added with the same injection time to advance 80% output of production.

 

Eco-friendly and efficiency

Because hot runner does not produce "waste", hot runner systems seldom handle problems about "waste". And the accurate meaning of "waste" refers to the waste of resources. Hot runner system belongs to low carbon products and hardly harms environment.

 

Taking little store space of stub bar; no granulating noise and metamorphism

Stub bars would be stored up due to the multiple varieties and colors of plastics. And the assortment of dehumidified drying and storage is necessary. Also the granulating noise would make environment less tranquil for workers.

 

Below are advantages of applying hot runner to three-plate mold:

Easy to pick out stub bar and reduce the route.
An even material flow during injection, controlling operating conditions of injection points to make smooth injection.Saving in material, costs and expense of labor.