sandwich structures

[Barry1492]

Does anyone know of a good method to control flow in a sandwich structure (VARTM)?? I'm mainly concerned with the bottom flow either being too slow and not finshing before the top flow reaches the vent OR the bottom flow being too fast and closing off the vent before the top flow reaches it.

I've seen some use multiple vents and injection ports, but not sure exactly how they set it up and how they know when to clamp which vent.

Thanx - Barry

 

[ZEB31]

If your application can stand the extra weight, you can machine small holes through the core. This allows the flow fronts to be linked and usually prevents uneven flow. If you have a very low viscosity and long pot life you may be fine anyway - unless the fabric stacks are significantly different on both faces. I have also seen the core channeling technique used, where small grooves are machined along the surfaces of the core to allow flow - this encourages through thickness infiltration also; or you could use the RIFT technique where open mesh is placed on one or both surfaces.

Hope this helps

 

[Barry1492]

Thanks for the reply. Unfortunately, for reasons I cannot tell (I'd hate to lose my job giving proprietary info over the internet) that will not be possible.

I think we've found a solution. I just started working here and found out that previous attempt had some serious problems using distribution medium. We pretty much fixed everything.