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To find out the injection molded products' true manufacturing cost, I factor all the following in:
  • Part weight
  • Number of impressions
  • Runner weight (if applicable)
  • Material cost include masterbatch etc.
  • Cycle time.
  • Machine set/shakedown time
  • Full time or part time machine minder
  • Assembly/printing/trimming
  • Injection molding machine cost/hour
  • Floor space cost/hour
  • Packaging
  • Delivery charges.
I'm evaluating some ideas for manufacturing a mold, and I was wondering if anyone had tried "printing" a mold on a 3D printer with the metallic media that's available. I know some of the printers are capable of producing injection molds with the plastic material (specifically, the Stratasys machines,) which can be used for to check to see if the mold works as intended and for making a short run of test-shots (50-100.)

But, I was wondering if the metal media molds had been attempted and if so, how they hold up for a longer production run? Not necessarily in the millions of pieces, but for small runs of product.

So, my two questions are:
1. Has anyone tried it?
2. Has anyone seen any research on the matter?
Quality is a much abused term nowadays. Nobody would ever admit to or promote the fact that they make junk. Therefore, it's more a question of horses for courses. If the injection mold runs trouble free with a good cycle time and a contribution is made for the duration of the product and maintenance is low, then it could be described as a quality injection mold.

In an ideal world there are only the best customers and suppliers. In the real world we have customers who don't know anything about tooling and then injection mold manufacturers as a customer which use other manufacturers for contracting. One can't suppose that the customer always knows what's the best for them. This leaves a big responsibility for the supplier. Injection molding tools are often unique pieces, therefore they can't be treated as car in manufacture.
Plastic injection mold life is decided for a particular grade of RM, before an injection mold is born & the mold is designed accordingly. If I need only 1000 plastic parts, I will never go for a high quality class 101 mold. I will never be able to meet customer cost & delivery time. Requirements like, 'how an injection mold is run', 'care & maintenance of the injection mold', 'sturdy machine' & processing with mold safety, are valid for any type of plastic injection mold. Failure due to these external factors can not be considered as short life of injection mold or poor mold design.

When I am thinking about making an injection mold, I will first of all take into consideration commercial factors such as Schedules (Orders), Component cost, Machine Tonnage, Mode of transportation. Financial viability alone will decide those inputs into plastic injection molds. One can't plan an injection mold for 50Mn life if the orders are not even for 2 Mn plastic parts! This is as simple as that.
I don't think you will be very successful in making a good serial troubleshooting guide, however, I do recommend you develop some level of organized method, a DOE, to guide a resolution. Developing that is a job in itself.

When the injection mold was brought up was a complete decoupled (scientific) molding DOE performed? If so then this should have data defining the processing parameter relationships and, from there, you can see how moving settings will affect the plastic part. This also reveals injection mold performance issues as well as press issues. Not doing this often leads to discussions and answers like these, it's all over the place. The answers are not wrong but also are not aligned with the problem. Let's be honest with this, you can't solve a problem in a general sense only in a specific sense so tossing ideas around is interesting but let's not kid ourselves that this necessarily is helpful.

One thing I always do with my injection molds is provide for instrumentation. This means have thermocouples and pressure transducers in the first injection mold of any new design. While I don't always install the pressure transducers I always have locations ready for them. However, you can never have too much thermal information so I always have a lot of thermocouples where I feel I can get the most useful data from.
The design of the injection mold cooling system is very important. The cooling time takes up 70% to 80% of injection molding cycle, a well-designed cooling system can shorten the molding time and improve the productivity magnificently. Poor design of cooling system will extend molding time, increase production cost, and the injection mold temperature has great influence to the mold shrinkage, dimensional stability, deformation, internal stress and surface quality.

If possible, the number of cooling channels should be as many as possible, diameter of the cooling channel should be design as large as possible, cooling speed of A is faster than B as figure below. Diameter of cooling channel usually are 6-12mm.
Injection mold cooling channel
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