infusion through a 2 piece alum mould

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infusion through a 2 piece alum mould

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Fasta	Fasta posted 9 Years Ago HOT Post Details
Group: Forum Members Posts: 468, Visits: 3.5K	Will.Harris (24/08/2016) Fasta (19/08/2016) I don't imagine that applying 5 ton pressure will help with infusion. For infusion you need some degree of pathways for the resin to flow and move. Once you apply any significant pressure then there is no way the resin can move through the fibres. This isn't strictly true - with RTM, the cavity is fully defined by two closed mould surfaces. Assuming the top half of the mould doesn't deform under 5 tonnes of closing force, then the fibre stack can't be over compressed, and permeability shouldn't be an issue...as long as you have done your calculations correctly, and don't have too much fibre in the cavity in the first place! Have you considered injecting under positive pressure? I am working on a commercial project developing RTM injection of windsurf fins/foils. Sadly its hugely covered by NDAs, so cant share too much info, but I can say that what you are trying to achieve is definitely possible! RTM is with positive pressure isnt it? We are talking about vacuum infusion so far. In some recent samples I have done there was a thicker section of laminate sample with 10 layers of 450g uni carbon and the resin front near stopped in comparison to the rest of the laminate. So resin did not really flow and this just a regular vacuum bag job, about 14psi pressure. Uni fibres really nest/stack very well leaving almost no pathway for resin flow. I think jelly could try just filling the moulds with the carbon but do not over fill the moulds to avoid the pressure on the fibre stack. Then use the press he has to clamp the moulds and then infuse. This way the press holds the moulds really solid yet there is no significant pressure on the fibre and letting the resin move easier. The foil will still have heaps of fibre in it and be very stiff. Fastacraft Facebook page Edited 9 Years Ago by Fasta
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Will.Harris	Will.Harris posted 9 Years Ago HOT Post Details
Group: Forum Members Posts: 1, Visits: 288	Fasta (19/08/2016) I don't imagine that applying 5 ton pressure will help with infusion. For infusion you need some degree of pathways for the resin to flow and move. Once you apply any significant pressure then there is no way the resin can move through the fibres. This isn't strictly true - with RTM, the cavity is fully defined by two closed mould surfaces. Assuming the top half of the mould doesn't deform under 5 tonnes of closing force, then the fibre stack can't be over compressed, and permeability shouldn't be an issue...as long as you have done your calculations correctly, and don't have too much fibre in the cavity in the first place! Have you considered injecting under positive pressure? I am working on a commercial project developing RTM injection of windsurf fins/foils. Sadly its hugely covered by NDAs, so cant share too much info, but I can say that what you are trying to achieve is definitely possible!
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Fasta	Fasta posted 9 Years Ago HOT Post Details
Group: Forum Members Posts: 468, Visits: 3.5K	I don't imagine that applying 5 ton pressure will help with infusion. For infusion you need some degree of pathways for the resin to flow and move. Once you apply any significant pressure then there is no way the resin can move through the fibres. If you can make the infusion process work ok then I would suggest adding strips of flat pre preg uni carbon sandwiched within the laminate and this will make it really stiff. The flat pre preg strips are readily available and cheap too. 20mm x 1.5mm thick or so?? Fastacraft Facebook page Edited 9 Years Ago by Fasta
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jellyfishboards	jellyfishboards posted 9 Years Ago HOT Post Details
Group: Forum Members Posts: 2, Visits: 24	thanks for the reply I was thinking about making the inlet and out let ports sizing them up to 12mm straight carbon all the way through no core. need it as stiff as possible ( being only 11mm thick ) my press is has plates top and bottom and will be pressing in between them so warpage should be little to none.. ( proto types were pressed this way with MDF moulds) good idea about just doing a layup in a bag and seeing how it wets out and how much resin I will need. one friend suggested I do infusion on the 2 outer layers and once it is set ( but still green) do a wet prepreg on the inside just so I get the pretty layer on the out side. been trying to get my head around this for months now. the only thing that scares me is not having any fusion cloth in it so has to pull through carbon only.
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scottracing	scottracing posted 9 Years Ago HOT Post Details
Group: Forum Members Posts: 460, Visits: 5.2K	What you are effectively doing here is RTM, Im currently working on a lot of automotive tools in this area and we have a lot of issues with the resin front flow and the permeability of the materials. Are you using any core or is it a monolithic layup? You may need to increase the size of the inlet port and I would suggest that you do a couple of trials with the layup in a vac bag and check how well the material wets out with the resin, this will give you an identification of how much time you require to fully wet-out the complete part. As you have stated with the press you are using a little but of clamping pressure to keep the moulds in place, prior to giving it full compression and heating. Have you checked the CTE values for the aluminium you are using to make sure that you dont get any warpage?
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jellyfishboards	jellyfishboards posted 9 Years Ago HOT Topic Details
Group: Forum Members Posts: 2, Visits: 24	I have cnc a 2 piece alum mould and would like to do infusion through it... the part is 900mm long x 120mm x11 mm and will have 3 different kinds of carbon in it. Is it possible to pull through it I have cnc a place for a gasket around the rim of the mould , put placement for inlet port and outlet port. the way I have been doing it is a wet prepreg hand lay into moulds putting the two pieces together and pressing it in my heated press. Finish isn't there and needs too much hand work in the end. so my goal is to do a dry lay up in the alum moulds put them together , put them in the press under 5ton of pressure , pull resin , bump the press up to 40 ton and hit it with heat to cure the resin. I am using heat cured resin so the parts will not deform in the sun on the beach. Resin cures in I hr at 180 degrees. any advice would be great... thank in advance terrie Attachments 20160804_130022_resized.jpg (682 views, 347.00 KB) 20160804_162545_resized.jpg (570 views, 250.00 KB) 13592166_1577970309163984_156167130992915661_n.jpg (626 views, 117.00 KB)
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