This is an attempt to summarize the big MTI hose thread from the “Products Talk” Sub-Forum, since it has grown to a size of about 25 pages.
MTI hose (Membrane Tube Infusion) is a cutting edge production aide developed by the German-based company DD-Compound to optimize the VARTM process with the lowest possible effort. The functionality of MTI is based on a microporous membrane hose which is permeable to gas but impermeable to resin. An integrated spiral hose ensures a smooth handling and provides an effective airflow channel for maximum evacuation performance even under adverse conditions. The self-regulating MTI process improves the reliability, reproducibility, and overall quality of products manufactured using any vacuum-assisted resin infusion process while reducing the material and labor costs.
After the product launch in Europe by DD-Compound the MTI hose is now also available in the Americas through German Advanced Composites.
With its product launch in the USA in January 2013 the[COLOR=Black] MTI hose[/COLOR] was honoured by the experts of the American Composites Manufacturers Association (ACMA) with the “Equipment and Tooling Innovation Award”
The physics behind the membrane hose and its application is visualized through the animation film [ame=“http://www.youtube.com/watch?v=R7OuvO1jZf4&feature=share&list=UUsPC12VbgXA3VP_quU7pgjQ”]“MTI How it Works”[/ame]
See what kind of glossy surface quality is possible right out of the mould. MTI Unboxing Experience
The proper application is visualized by the MTI Instruction Manual
[b][u]
Vacuum infusion with the use of MTI offers benefits through:[/u][/b]
[ul]
[li]Pinhole-free finish and production in one shot which leads to reduced overall cost by avoiding post treatment (sanding, primer, paint, etc).[/li][/ul]
[ul]
[li]Risks, such as dry spots, are minimized which enhanced the reliability of VARTM processes significantly.[/li][/ul]
[ul]
[li]The low-pressure process which leads to minimization of entrapped air bubbles. [/li][/ul]
[ul]
[li]The self-regulating process which supports a homogenous resin content across the entire component cross-section and offers flexible positioning of the resin feed lines.[/li][/ul]
[ul]
[li]Exact resin consumption can be calculated to achieve optimum fiber volume fraction. A resin trap is no longer necessary. No more waste of resin.[/li][/ul]
[ul]
[li]Since resin is not required to reach vacuum source uniformly, there is no need for complex calculations of resin flow. [/li][/ul]
[ul]
[li]The integrated spiral hose provides an effective airflow channel for maximum evacuation performance such as extremely large or complex designed moulds. Even molds such as hulls or wind turbine blades are simple with MTI. [/li][/ul]
[ul]
[li]The MTI hose is flexible and pliable so it can be routed along the profile of very complex parts. The outer membrane shell provides a high-quality tactile feature which protects the vacuum film against damage and ensures a pleasant working.[/li][/ul]
[ul]
[li]Very low initial investment: no autoclave or resin catch pot required.[/li][/ul]
To achieve excellent results the observance of the following is crucial:
[ul]
[li]A good vacuum level. The better the vacuum level (below 0,29 "HG absolute pressure recommended) the better the results.[/li][li]An accurate sealing of the open end of the hose and the coupling to the vacuum line with sealant tape.[/li][li]A 100% airtight vacuum system. An airtight system keeps the vacuum easily even without the help of the vacuum pump. Use a digital vacuum gauge for monitoring the success.[/li][li]Resin that has been degassed for at least 15 min.[/li]
[/ul]
Find the whole MTI thread here: http://www.compositescentral.com/showthread.php?t=6530