The award-winning Ford Escape instrument panel design has a complex geometry with changing wall thicknesses, making it difficult to meet required mechanical properties using solid injection molding processes. Creating the panel in the MuCell microcellular foam process reduced weight by more than 1 lb, improved mechanical properties, reduced cycle time, and lowered the part’s cost by $3 per car.
How else can you design a part to be manufactured without understanding the capabilities and limitations of the manufacturing process? Evidently it has been done, but it doesn't make sense. It seems that others have thought differently over the years, which is probably the basis for the whole "DFM" group of consultants who try to solve problems for those designing hard to manufacture parts.
Injection molding has been one of those areas where the first step of part design has been to determine the capabilities needed to produce the part features while designing those same features. That would determine which supplier was selected as well as what features of the part could be included. An analogy is deciding what one would ,ake for dinner based on what food was on hand and what was available to cook it with.
Theoption of including secondary operation types of actions while the part is molded is quite interesting, and it would allow a number of additional options for the initial design process.
The use of Scientific Molding is a great way to produce repeatable parts on multiple machines. Documentation of separation of pack and hold as well as a documented gate seal study helps to produce parts consistently on different machines.
In regards to aluminum tooling, what is the effect of glass filled reins on the aluminum mold? Often times, it is necessary to use glass filled resins for metal replacement projects.
Ann, I assume your statement regarding aluminum or steel in the first paragraph is incorrect considering the text of the rest of the article. It is an interesting one, by the way. Recently there was an article on this site on Metal Injection Molding (MIM), which had a poor reputaiton, but has seen great improvements.
One observation is about the statement about increased pressure on manufacturing. This is a common statement, so my comment is not aimed at your article, particularly. There would be no increased pressure without advances in science and engineering. The statemnt seems to imply that these industries are standing still and being pushed by someone else. In reality US industry is among, if not the most , efficient in the world.
Another interesting point in your article is about the Scientific Molding process. I once worked for a company that made simulators, primarily for training. These included flight, military as well as industrial simulators. In general, the simulators were very accurate. They could often be driven faster than real-time. A secondard market was found for the industrial simulators in plant control. The simulator could run many scenarios with different feed stocks, etc. This would allow adjustment to the process before acutally consuming anything.
Finally, your article points out the need for design for manufacturing. Before the move toward outsourcing, there was a move toward integration. If you could design a part to be more easily manufactured, and you did it in the design phase, it was a very inexpensive change. If this had to be addressed later, it would be very costly. Perhaps we are moving back.
I heard an example of this recently. A manufacturer of space heaters, I think it was, brought their manufacturing back to the US. By a small redesign, one that eliminated a lot of fasteners, they were able to lower the time to manufacture. Since their market was mostly here, and since they could make changes to respond to market conditions more quickly, they have improved their competitiveness. A god example, I think.
NIST's new five-year strategic plan for its Material Measurement Laboratory lists additive manufacturing materials development as one of the main areas it will support by developing measurements, data, techniques, and models.
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