![]() Make your mold, heat and press/vacuum, and BAM, you have a part. The carbon fiber content can be 15% to 60% right off the shelf. There are tons of steps down from there as those can be expensive. PEAK and PIA are some of the top performing plastics and in their carbon fiber matrix form are replacing metal parts in aerospace. The strength, strength to weight, and temperature tolerance needed will all point you in the right direction. There are a bunch of polymer and even metal fiber combinations available. What's great about forged carbon (and steel) is you can leave the forging part to experts, then used the forged product for forming.īecause of the size, quantity of what you are making, and your ability to machine molds, you should looking into polymer/carbon fiber forged sheet products. Its called forged carbon because the chopped fibers mashed together resemble that of a steel grain structure in forged steels. IF you simply pour resin into a cup full of fibers, and put it in a vacuum pot/jar/bell.yes, sooner or later the air will pull out, and when the vacuum is released, the resin SHOULD ideally flow into all the voids. You need to inject it with vacuum, or pressure. But here goes the questioning of, what do you want to do? Pouring resin into a mass of chopped carbon will not infuse into the carbon. Some need it without a doubt, others will help. you'll have to play with both size and ratio to give you want you want to.Ħ: Degasing your resin helps. It will help with abrasion resistance for sure. ![]() I think you said 6sq inches? If it's a plate of any thickness, and you are doing a charge, you'd need enough pressure to close the molds together.ĥ: yes, adding kevlar will help, but can hurt. Compression molding? Well, depends on your mold shape, and how your vents are set up. RTM? Enough clamping so the pressure injection doesn't blow it out. VARTM? Enough pressure to seal the mold from leaking. Metal will need sealing and releases.ĥ: poressure all depends on everything you are doing. You will have to deal with stiction, but resins come right off. Using chopped strand SMC/BMC will need a press and a metal mold.Ĥ: yes, HDPE and PP will allow you to forego mold release. RTM uses higher pressures, so metal is a better choice. Using Vacuum, make sure the material will not deform. you want a solid object that is 3x1x.75?ģ: how do you want to do it? Resin and chopped fibers can be infused in any sort of mold. Forging is banging metal into shape.Ģ: you want compression molding, from what it sounds. I would highly recommend his course if you are at all interested, as far as I know it’s the only place you can go to get a professional crash course in carbon.ġ: CHOPPED FIBER. You can easily mess this up if you don’t have all the specifics and know how. That’s a very abbreviated explanation, he obviously knew the time & temperature to put it at, we had to prep the molds before by hand cleaning them with a compound and then coating it multiple times in release agent. We packed the chopped/forged carbon in both sides of the cavity of the mold, the resin was already mixed with it btw, and then we bolted it together and threw it in the oven. The course is 2 weeks for the advanced and ~$6500, but I’ve have a really decent understanding of how to work with carbon now.įor the forged carbon dropouts we used steel blocks that were obviously machined for the drop outs. Not sure if you have the time or $$, but I just took David Bohm’s Carbon Fiber Framebuilding course in Tucson, and we made forged carbon dropouts for my frame. How do I determine what size of chopped fibers I need and where do I source them? Would adding chopped aramid fibers give me a more resilient part than carbon alone?ĭo I need to vacuum pump my resin mix before pouring it? What kind of pressure do I need to exert on my molds? Are we talking 4 or 5 good quality c clamps or will I need to build a hydraulic press to get appropriate pressure? Will a slippery plastic like HDPE allow me to forego mold release? If I make plastic molds should I affix them to some steel or aluminum backers? I can machine anything from delrin or HDPE to A2 tool steel. 75" x 1" and I would love to be able to make 6 or so at a time. What should I make the molds out of? The part is about 3" x. I just have a few questions about the process. My research has led me to believe that so called "forged composites" may be the way to go. I have never laid carbon and the part is pretty small, with some fiddly features. I'm a hobby machinist and I recently designed and prototyped a part in aluminum that I believe would be best manufactured in a composite, perhaps a carbon/aramid blend.
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