Hi AeroGarage, VRTM processes are fine using other fabric types such as Carbon, Aramids (Kevlar), Hemp etc. You are absolutely correct that factors like permeability need to be considered, understanding this before you construct you VRTM mould is crucial in order to manufacture components without defects. Permeability of the fibre and resin viscosity are just a couple of the factors we consider when designing our injection/ venting strategy. Thank you for your comment.

Hi Ubedulla J, The bag in the video was manufactured using our 2 part platinum cure silicone system. We used reinforcement cloth in areas that needed some additional support. The resin runner and and vents are products that we can provide and have a few different configurations available. For further information please contact us directly at [email protected] . Thank you for your comment.

Hi Max, It is difficult to predict an exact number of cycles as this will depend on the type of resin being used, the complexity of the shape and the general care taken by the operator. However, we have many customers using this technique successfully and several hundred cycles are possible (using polyester resin) Have a look at this case study on our website. Between 250 and 300 are achieved in this application. siliconecomposites.com/production-success-with-silicone/

We're interested to know why you think this technique is so limited. We have customers using it very successfully at various levels of complexity and at different scales.

@@Compositeinteg1 It would be great to see a more complex shape, Love the product already

How come? The silicone bag follows the complicated shape and wringkles, so it fits much much better than conventional nylon plastic vacuum bag. It saves time, and material.

@@ericww1993 you clearly didnt work with any complicated shapes

@@RePlayBoy101 So just explain it why? We need explanation and proof instead of statement

Thanks Khaled!

Hi Masoud, from your description it sounds like there must be a vacuum leak into your mould somewhere. If the mould is fully vacuum-tight the flow of resin into the catch pot will stop when you stop feeding the inlet with resin. Some flow may continue while the mould relaxes but it certainly shouldn't empty the cavity.

I'm not sure that I understand your question. I'm happy to help if you can explain a little more.

Hi, If you don't like the look of this process you would really hate the traditional hand-laminating process! Maybe you're safest staying on the beach!!

We use a 'release agent' to protect the mould and to stop the resin and gelcoat from sticking to the mould. In this application we used material from Marbocote (www.marbocote.co.uk/)

I'm sorry that you feel this is a waste of time but, with respect, I think that you have missed the point. We have used this small hull to demonstrate the principal of infusing large composite structures. Our customers are successfully using this principal to infuse laminates which consume up to 8 tons of resin (boat hulls, turbine blades etc) Hand laminating on this scale is not an attractive proposition! Regarding the lack of stringers- the structure of this hull is irrelevant as it is not a commercial product- however, the final product includes an internal seat/floor moulding which is bonded in place and which provides rigidity. Spray gelcoating would of course be preferable in a 'production' situation. Anyway, thanks for watching!

An 'infusion' type process (either with a reusable silicone bag or a conventional disposable vacuum bag) could result in a thinner laminate with a higher fibre content but this would depend on the type of fibre being used and the other process parameters. With a vacuum bag one can use flow-mesh to accelerate the resin over the compacted fibre so you're not depending entirely on lateral flow. However, the laminate achievable in this type of RTM process is perfectly adequate for this application and, as you point out, the smooth inner surface is a big advantage!

Hi- you can see our contact details at the end of the video. Please feel free to get in touch.

Hi- please feel free to contact us using the details at the end of the video. We'll be happy to help.

Thanks for the feedback Therese- I'm glad that you enjoyed the video.

You can purchase all the rubber seals (and other components) from Composite Integration Ltd Have a look at www.composite-integration.co.uk

It's hard to say exactly how long it would take to inject this mould as this will depend on the resin viscosity and the fibre type and content. However, an injection rate of approximately kg per minute is generally achievable. The size is no problem and we have experience of building and using moulds much bigger than this.

Compositeinteg1 thanks alot I need your phone num.

No problem- the main office number is +44(0)1752849998

The resin that is injected into the finished mould is a standard polyester injection grade resin.

I can understand your comment! However, this type of mould is often used to make rather 'special' small flat panels that are used to generate test coupons for structural analysis of composite laminates. The processing parameters and dimensional tolerances must be controlled to a very strict tolerance. Most of these moulds go into laboratory environments.

Approximately 18kg of resin was used in this hull infusion.

Obshy weight of the boat and Width laminate?

I'm not sure that I understand your question but the total weight of the Hull (glass and resin) is approximately 36kg

ОК

The gap between the central plate and the outer flange is sealed with 'O' rings. These seals allow the central plate to slide up and down but maintain the necessary vacuum/pressure integrity.

Thanks! I have thought about that but was not sure. Very nice technical design of the whole form.

The hull laminate is formed with multiple layers of glass fibre reinforcement which are all infused at the same time. I hope this answers your question.

질문에 답변해주셔서 감사합니다!! 그러면 여러장을 적층할시에 섬유 한장 붙이고 수지바르는 식을 반복해서 성형하는 것인가요??

No, all the layers are moulded (infused with resin) at the same time.

Yes, both sides of the mould are coated with a 'semi-permanent' release agent which prevents the resin from adhering to the surfaces and maintains a good finish. We generally use the release system from Marbocote (www.marbocote.co.uk)

Hi Samuel, Thanks for your positive comments. if you contact us via our company email ([email protected]) we can send details and pricing.

The green mould is a conventional 'composite' laminate. It's made with vinylester resin and glass fibre. The green surface is the vinylester gel-coat.

+Compositeinteg1 does it have to be a composite? Is that the reason you added the gel coat into the mold so there wouldn't be a problem when to other resin was injected to the fiber?

The white gelcoat was added simply to provide a good surface finish to the final moulded hull. The mould is coated with a release agent so this gelcoat (or the injected resin) doesn't bond to (or damage) the green mould surface.

Hi, we use heat-toughened (tempered) glass for the upper half.

Yes, you are absolutely correct. The gap between the resin channel and the top mould is 1mm and so this is taken into account when adjusting the cavity thickness.

Hi Stefano, Yes, this type of mould can potentially be used with a PU system. The type of equipment necessary would depend on the material specification but feel free to contact us if you'd like us to look at this in more detail. Actually I have just uploaded a video that shows a similar mould but with a variable/adjustable cavity and a higher pressure rating that could also be of interest. Follow this link: kzbin.info/www/bejne/jn2pm2eJgdySfLs

+Александр Ненахов Thanks!

+Puertas y Decoracion The Air is injected via an 'Air-Ejector' valve built into the lower mould half. You can see the end of this valve (black circle) in the centre of the lower mould at the start of the video. The resin is injected into the mould through an 'Injection Valve' and this valve is cleaned (flushed with solvent) as part of the cleaning cycle of the Ciject injection machine at the end of the process.

Hi Jack I could provide some photos of the inside surface if you can send an email address. We used a standard Scott Bader injection grade polyester and it was left in the mould for about 45 minutes after the end of the injection to cure. (by the way, are you the ex-Falmouth student who designed the hull??)

+Compositeinteg1 I am the Ex-Falmouth student! I am working at Solent University now. My email is [email protected] Glad to see the progression of the project. Thanks againJack

No problem- I'll send you some photos when I get a minute. The project has been very useful and we use it as a way to compare traditional infusion with the VRTM process. The VRTM hull is certainly a far more 'finished' moulding as it includes a foam core around the gunwale and has a nice smooth surface inside. We will be working on a mould to make the internal seat/floor structure and aim to have some of these on the water in 2016! Feel free to come and have a look if you're passing.

Michael Eliot Hi Michael, RTM stands for Resin Transfer Moulding. VRTM stands for Vacuum Resin Transfer Moulding and so implies that the mould is held closed solely by atmospheric pressure (vacuum)

+Michael Eliot Resin Transfer Molding

Koen Klijnsmit The machine is controlling the pressure of the resin at the inlet (small level of positive pressure). Without the machine the process would still work but it would be slower.

Thank you, i can not afford the RTM machione but i have a small vacuum pump. The 2 hard shells instead of 1 and a flexible bag just seems more accurate to me (if you calculated your tolerances correctly). That is why i was wondering if it would still work without a pushing force on the resin... To make it even more complicated, i need a mold that can become 100 degrees C, so i am thinking of putting Carbo e -therm between layers ( i can not find a more advances solution), then i don`t even need an oven anymore.

Koen Klijnsmit Yes, your process could potentially still work with only vacuum providing the transfer pressure.You might also look at the Fibretemp mould heating system from Germany- it could be relevant. www.speautomotive.com/SPEA_CD/SPEA2009/pdf/ET/ET-09.pdf

Thank you, that looks interresting. ^_^

Koen Klijnsmit All the seals and 'formers' used in the mould making stages are available from Composite Integration Ltd.Vacuum is connected to the perimeter flange as well as to the main mould cavity.

Compositeinteg1 Thank you, i can`t find the seperate products on the site...