Hi guys,

quite a while ago I came across the MTI hose, developed in Germany. A regular spiral tube (albeit a larger diameter) covered in an air-permeable membrane that is impervious to resins.

Question is, are any of you familiar with this product? They promise cosmetic, pinhole-free surface, without the need for catchpot and continuous vacuum. Was just curious if easycomposites or some of the other pros out there have any experience and if its worth giving a try, looks interesting.

Cheers

surely as soon as the resin reaches the hose, the pores will block and any trapped air will stay in the laminate?? ie resin flow will stop as will vacuum pull.

Surely this will lead to resin rich parts??

As we all know, during infusion, the vacuum on the resin feed side of the mould plummets as its only the viscosity of the resin stopping the vacuum going completely back to ambient pressure.

So you are going to have to be very careful in timing when you clamp off the resin feed to ensure there is enough vacuum head on the resin to pull a vacuum again by the resin feed and even out the laminate before it gets to the hose all the way round.

Sure it might give pin hole free parts and might be useful if the resin isnt flowing right to edges far from vacuum port, but surely it does nothing that cant be achieved with proper planning and placement of resin feed, spiral, mesh and vacuum ports. 

Have you actually tried this product or is this just theory?
I've received a sample a few month ago and have ordered more since.
Never had any problems with pinholes or resin rich areas. It's a truly remarkable product, such a shame easycomposites.com don't sell it (the guy I spoke to actually said that he tried to contact these guys but never got any answers)

I don't agree. If you look at that membrane and compare it to the behaviour of a paint filter for example. You can pour water through it easily. (think of the water as the Vacuum) Now pour in a hand full of wet sand.(representing the resin ) You can still pour water through the filter no problem as it will flow through and around the sand) just as the air will.

Fred 

Here are some interesting videos about MTI, its benefits and proper use:http://www.youtube.com/user/GAComposites