The gate is a narrow intersection between the main runner and the mould cavity, and the intersection is also the shortest part on the whole mold. Its function is to make the molten plastic enter into the mould cavity quickly, which is beneficial to the rapid filling of the cavity. After filling, the gate is condensed …
In order to understand the various designs of undercut mould, we must first understand the definition of what a moulded undercut really is. In its most simplistic form，an undercut can be described as any feature on the moulding which resists the line of the draw or inhibits the ejection of the moulding from the mould. …
The choice of mould steel is of great importance if the mould is to function effectively. The prime function of any mould steel must be that of meeting the service requirements imposed upon it. Moulding requirements vary，e.g. from simple prototype work undertaken on soft aluminium construction moulds, to fully hardened alloy steel volume production moulds …
A runnerless or hot-runner mould system could be considered as an extension of the moulding machine injection unit. In this case，the polymer is kept molten right up to the cavity gate by means of additional heating elements controlled by thermocouples. The working temperature of the hot-runner system is not dissimilar to that of the molten …
How to avoid contamination and waste in injectionmolding shop? Keeping material clean The importance of cleanliness in the plastic mould injection shop is nowhere more apparent than in the making of mouldings free from contamination. Safeguarding the material in the sack is an obvious matter， but is often ignored. Partially used sacks or containers should …
Most injection moulding organizations cannot go to the expense of having a complete reprocessing plant consisting of granulator, mixer/extruder, and die- face or lace cutter. The general arrangement is to have a room in a fairly remote corner of the building where material can be granulated using an ordinary masson-type cutter. Although this produces re-work …
Thermoplastic materials flow when they are heated to the proper temperature (which varies with each plastic). This ability can be verified by test, using a melt index unit per ASTM Test #D-1238. This ability to flow also determines how far a plastic can be injected through a specific wall thickness of a product. If the …
Tooling costs are extremely hard to estimate because of the variety of designs and steel types available. Tools can range from a thousand dollars to many hundreds of thousands of dollars depending on these factors, as well as the size of the part being molded and how many cavities are being molded at one time …
A parting line can be defined as any part of the mold that parts, and forms part of the part. There is usually only a single parting line, but there can be two or three or more, depending on the complexity of the mold. Items that determine the number of parting lines include: the geometry …