• Everything you need to know about hot runner mold for engineering polymers

    When injection moulding partially crystalline engineering thermoplastics, choice of the correct hot runner system determines the function of the plastic injection mould and moulded part quality. Here, the temperature must be controlled much more strictly than in the case of amorphous materials. The type of hot runner system used,  and its installation, decide the properties of the finished parts. This article deals with the most important points which have to be considered when choosing the most suitable hot runner system for POM (acetal), PA (nylon), PBT and PET (polyesters). Problems with hot runners Moisture in thegranules Feed system toosmall Wrong gateposition Hold time tooshort Wrong melttemperature Wrong tooltemperature Poor surfacefinish Problems with hotrunners Warpage Moulddeposit   What happens when an unsuitable hot runner system is used? Unsuitable hot runner systems usually cause high pressure losses; they should, if used at all, be operated only at very high temperatures. This will usually cause the polymer to degrade, with…

    Mold design, Mold making January 1, 2020
  • Everything that you need to know about plastic hor runner mold

    The hot runner is heated to ensure that the plastics of the runners and gates remain in molten condition. Why do we recommend it? If the plastic injection product is large without  using hot runner system, it is prone to occur the defect of shortage shot. Since there is heating rod and heating ring near or in the center of the runner, the entire flow path from the nozzle exit of the injection molding machine to the gate is kept in a high temperature state, so that the plastic through the whole path remains in a molten condition.  Therefore there is no need to take out the condensed resin after shutdown and just heat the runner to required temperature after restart.  In general, hot runner processes are sometimes referred to as hot manifold systems. Advantages and disadvantages of hot runner technologyAds.1. Save raw materials and reduce costs.2, shorten the molding cycle and improve machine efficiency3. Improve the surface quality and…

    Mold design, Mold making November 1, 2019


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