Very informative Ann. I think the following statement says a tremendous Very informative Ann. I think the following statement says a tremendous amount about current technology and the use of that technology:
They used Moldflow to help optimize the process, and finite element analysis to optimize the design. RJG Inc.'s mold cavity pressure-sensing technology was used to get data on the pressures that were being exerted inside the cavity during over-molding.
"Old guys" like me had better get on the bandwagon, if we have not already, and realize previous methods of "cut-and-try" are out the window. I'm sure the methodology used above saved countless hours of design time and frustrating failures along the way. I'm still amazed at the capabilities of "plastic" parts relative to temperature and pressure. At GE, we would kill for a cost reduction of merely $1.00. That would be big. Promotions and salary increases would be in order.
One more thing; I had a 2003 Mercedes ML320. By sons borrowed it to go bowling with some friends. When they got home they "had terrible news". As they were pulling the bowling bag (a three ball bag) out of the back, they let it drop onto the rear bumper (dumb, for sure). What was "dumberer" was the almost perfectly round hole it had punched in the rear, plastic bumper, about 3" across. I took the bumper off (a single screw on either side and it slide right off) only to be confronted with "plastic welds", the kind you design into toys (I know, that's what I used to do) holding the inner bumper to the "shell".
When I was younger, I "always wanted" a Mercedes (of the day). So well built, just the sound of the door closing told you there was quality. When the day came that I could afford one, I got "tin can" doors and bumpers better suited for a golf cart. Was I glad the day that lease ran out...
I have a friend that owns an injection molding plastic company. He has a favorite saying "F*** it, do it in plastic". This is his response every single time anyone talks about a simple metal part that was subsequently replaced by a plastic part and failed, often miserably (a very small example - check out the difference between the window clips used in Volkswagon Passat's vs. the same part used in Audi's. Google it. I know of this one first hand). Having worked on cars of all kinds since I was a "kid", I see this kind of stuff and it makes my skin crawl. My son has a Ford Taurus that had a leaky gasket around the oil pan. No big deal; we can swap that out in a couple of hours. Wrong... It took the better part of 12 hours for this "simple" repair (which included dismantling the front end of the engine, as well as theoretically dropping the exhaust - something I found a work around for). This will, not might, turn into yet another manufacturer issue where it will crack, warp or simply disintegrate; despite the amount of FEA done and awards won. When it does happen, it won't be under warranty, leaving the owner with the decision to either pay a shop to replace ($$$$), or junk the vehicle. Cars today are designed to last the life of the loan; period. At the end of the loan, trade it in and get another. If not, suffer the consequences. As long as we have "engineers" designing engine parts in plastic, and billionaires coping attitude that demonstrated failures and bad design "could never really happen in real life" then the automotive business is on one big slope into the "recycle bin".
Any polymer -- let alone Biodegradable plastic -- will have a tough time in proving its worthiness, over time. Plastic Manifolds can certainly pass the FEA and FMEA analysis', but actual field conditions, over time will tell the real story. It will be interesting. I'll watch for the follow-ups!
Contrarian, thanks for sharing your experience. Maybe those problems are what was behind the redesign. At least Ford fixed it (apparently). Wish my bank could do as well with their unbelievably bad software problems.
Thanks Contrarian I thought there had been a problem with the Focus plastic intake manifold and was going to post something but I couldn't remember the specifics. Something about fins inside the manifold that were intended to swirl the mixture, but the fins were breaking off and were ingested into the intake valves.
GTOlover, thanks for pointing that out: the encapsulation, as it were, of metals inside plastic making it hard to recycle the entire manifold. One answer to your question is Ford's own programs for recycling its own materials, including collecting damaged parts from dealer-repaired vehicles and either remanufacturing them, or recycling them to recover raw materials, as we discuss here http://www.designnews.com/author.asp?section_id=1392&doc_id=266056 Another may be the growing infrastructure to support recycling plastics, which we've covered several times, for example http://www.designnews.com/author.asp?section_id=1392&doc_id=269499 http://www.designnews.com/author.asp?section_id=1392&doc_id=269232
far911, I totally agree with you about the importance of recyclability and reuse, and of sustainable materials in general. We have covered these topics many times in DN, especially in respect to plastics. Here's a story I did on Ford's efforts in this department, including their internal use of their own recycled and remanufactured car components: http://www.designnews.com/author.asp?section_id=1392&doc_id=266056 Ford has been a leader in this effort, and it's by no means a trivial one considering the nature of automotive manufacturing. The company is also doing its own internal research for making sustainable materials recyclable.
Maybe it's nice that car made with plastic parts can be easily recycled but I'd rather have a car that will last a while before it needs to be recycled. Seems upside down to be concerned about the recycleability of some minor percentage of the car, when that minor percentage can cause the entire car to be junked and likely prematurely.
My last car had an "exploding" plastic intake manifold that Ford was the subject of a class action and lost. It couldn't take the heat and/or pressure over time and Ford had to extend the warranty and labor for those failures. Something tells me they lost a whole lot more on that idea than they ever saved themselves or the customer using a plastic manifold.
I guess from a marketing standpoint, plastic used in critical applications is a great idea because you're creating cars that have no potential for longevity. Anyone that has worked on an old car (80's/90's) knows the joys of disintegrating and brittle plastic parts. As time goes on and materials advance that is sure to improve but for the most part this penny shaving is false economy. Per the article - saves a $1 per car. I'd have gladly given Ford $1 more when I bought my car and saved myself the headache of replacing that plastic part at great expense and trouble six years later. Reliability and cost of ownership extends well beyond the warranty period, and is a big factor in my mind.
Linear guides are one of the most important components required for the design of automated or computer-controlled equipment. Aluminum profile extrusions, used for these guides, can enable designed-in functional features.
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