Hot manifold

Some of the tests and criterion used to define fire resistance may be found in the Hterature (9). Additionally, the compression—ignition and hot manifold tests as defined in MIL-H-19457 and MIL-H-5606, respectively the Wick test as defined by Federal Standards 791, Method 352 flash point and fire point as defined in ASTM D92 autoignition temperature as defined in ASTM D2155 and linear flame propagation rate are defined in ASTM D5306 are used. 

Residence time too long] machine provides shot size that is too large/dead spots in hot manifold/temperature too hot/poorly designed manifold system/[contam-ination]. ... 

Fig. 2-7b. Types of injection molds illustrated here are insulated runner, hot manifold, and stacked (1).

These materials have been successfully molded in all types of mold, for example, 2-plate, 3-plate, insulated runner, stack and hot runner, en using the hot manifold type of runnerless mold, the runner channel must be streamlined so that there are no dead spots (nil flow areas) which are likely to cause degradation accurate temperature control of the manifold is essential. To maintain the sparkling clarity of this material, use vacuum smelted steel as this can take a very high polish and is non-porous. 

Hot-manifold mold n. An injection mold equipped with an internal heater located in the center of the melt stream in the manifold and nozzle system. This type of mold was developed for thermally sensitive resins to provide gentler heating and avoid the decomposition problems experienced with external heating techniques because of excessive temperature differences. 

Figure 7-5. Multiple Isothermal Bushings in a Hot Manifold Mold ...

Figure 7-14. Commonly Used Gating for Hot Manifold Molding "...

Figure 7-15. Suggested Design for Side or Edge Gating of a Hot Manifold Mold (Essentially a straight-through gate perpendicular to torpedo) "...

Figure 7-16. Partial Cross Section of a Hot Manifold Mdd Equipped With a Mechanically Actuated Valve-Gating Mechanism "...

Louis Temesvary, Injection Molding-Planning Hot-Manifold Systems , Plastics Engineering (December 1974). 

In comparison to the surrounding components, the manifold is insulated using an all-around air gap. Experience shows that the gap width should be between 8 and 10 mm because this is the optimum concerning the minimum amount of heat loss. Shiny surfaces can minimize the radiation losses of the hot manifold. A nickel coating is recommended to reduce radiation. The amount of radiation heat loss is less than 10%. Measures reducing contact heat promise greater effectiveness. 

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