That injection molding machines are not in the simulation is a problem we have to keep in mind. So there is the pressure loss in the nozzle. Some people create the nozzle in CAD to get this in the simulation. But what is with the quality of the injection molding machine. Old or new. Is the return valve working? Compression of the melt in the cylinder is not considered of simulation.

To increase the life expectancy of an injection mold, you need to do careful maintenance and avoid operation mistakes during molding plastic products. Water lines can be a major problem. Run treated water or build from stainless. Build the tool solid, large pins, support pins, locks etc. use the mold safety settings on the press. Chart the number of shots it takes for the mold to start to run less well, and set up a plan to pull, service and check it before it hits that number. Replace worn parts. Greasing the moving parts before they start to make noise. Blowing down the water lines when the plastic injection mold is pulled from the press, or using quick disconnects that seal the water lines when they are disconnected.

After we finish assembling a new mold, we need to launch it and do a mold tryout.

The mold designer and mold maker sometimes made mistakes, any small mistakes could lead to major damage of the injection mold, the purpose of mold tryout is to find out any potential defects and ensure the mold perform stable and efficiency during molding production. If the tryout process did not follow reasonable procedures and make the appropriate records, then we cannot guarantee smooth production, this could cause serious problem, it means much higher cost or even delay for mass production.

Multi-cavity molds produced parts in a much higher efficiency way, it's employed frequently on the occasion when the demands volume is high, the number of the cavities and mold construction depend on both economic and technical factors, quantity of parts to be molded at one cycle, required cycle time, and unit price are related with mold making cost. See below figure, mold cost and plastic parts cost need to be considered to achieved the best result of the project.


There are a few points need to be pay attention when we decide the numbers of cavity.

Plastic parts produced by the injection molding process are usually long lived consumer products. It's suitability depends on the properties of the finished part and surface quality, it required a lot of experiences of raw materials, processing condition, injection molding parameter to get optimum results. The reasons to cause problems could not be a certain answer as the processing condition is always different, on the basis of an individual case a decision has to be made as to whether simple and rapid fault correction is possible or whether intervention is the design of the parts or the layout of the mold and gating is necessary.

If the resin is in powder form then used high power magnets to remove them, and if it is in the form of granules then melt it in big volume in any bucket type (in this way metal parts will moved down in bottom) then in its molten state put it in extruder for re-granules or processing (molding).

Your Part size and Weight will also determine Press Size which will narrow the selection of manufactures, you will see that among your list of plastic injection molding machines, there are some that are very well suited for smaller parts whereas other excel in very large tonnage presses. The Resin used in your applications will also determine your choice of Barrel specified on your selection of the injection molding machines, this will relate to your part weight as it must be calculated to resident time in the barrel.

In general most feed throat temps are from 95 deg (f) to no more than 130 deg (f). There are some injection machines that have specific feed throat temperature specs. Husky PET machines are an example. However most injection machines do not. There are several things to avoid. Do not get any part of the feed throat cool enough to cause condensation. Do not let the feed throat get hot enough to let the material soften and clump. Outside these cautions you will usually find little effect of the process from FT temperature.