MVS Microporous Vacuum Strip

MVS is a flat format version of the MTI and MVL Hose, it is used in resin infusion to maintain vacuum along its full length throughout the process, this greatly reduces the risk of dry areas in more complex infusions, typically the strip is used on the laminate itself to maintain vacuum in central areas of the part without causing 'print-through'.

Its working principle is like that of breathable waterproof clothing, in that it will allow air to pass through the membrane but effectively seals off when it is reached by the resin front, the breather mesh that is in the core of the strip will maintain the vacuum to any uninfused areas that would normally have become isolated in a traditional infusion stack.

For perimeter vacuum lines generally the hose formats of the MTI or MVL would be preferable as they can easily follow shapes and contours, however the flat format of the MVS strip allows it to be use on the part without the risk of print-through like you would expect with the MTI or MVL.

Due to its resin brake function it allows a minimal amount of resin to enter. The Membrane usually keeps resin out for ~30 min and allows it to enter slowly. This brings the advantage that in an outside-in or reverse infusion the flow front might cut off the lower plies or central areas of the moulding that can result in pinholes or dry areas in the component. Due to its open pores after infusion these problems can be minimized by maintaining vacuum for a while after the main infusion flow has completed which will continue to extract entrapped air.

How to Buy

The MVS Hose is available in 2 widths, 100mm and 300mm, and can be purchased by the metre or in wholesale coils of 100m. Prices shown are per meter, volume discounts are automatically calculated.

Volume Pricing

We believe we offer unbeatable prices on vac bagging consumables. To make comparisons easy, select the different pack/roll sizes from the drop-down menu above:

Further Information

Increasing Reliability

MVS Strip will increase the reliability of infusions particularly of new and complex infusions where the precise flow path has not been established, this will reduce the likelihood of scrappage and defects which could offer huge cost savings in production.

Self-Regulating

As the resin flow is almost entirely halted by the MVS strip the timing for clamping the vacuum line is no longer a critical factor in the process meaning that is does not need to be continuously monitored, Unlike the MTI Hose the MVL can allow a very slow leak-past of resin so we would not suggest leaving this under permanent vacuum but instead clamp the lines like you would in a traditional infusion, albeit in a much less critical time window. Although we would always recommend the use of a catch-pot as a precautionary measure, MVS Strip will generally render a catch-pot redundant so it would be possible to run a direct connection to the vacuum pump.

Typical Use

Typically, the MVS Strip is laid over the laminate of the moulding wherever vacuum needs to be maintained. The ends of the MVS Strip seal easily and effectively using conventional vacuum bagging sealant tape in combination with duct-tape, alternatively the strip can be sealed using hotmelt adhesive or heat-sealed with an impulse sealer. The vacuum hose connection is typically made using a conventional resin infusion connector placed inside the strip. Although the strip will still allow for full vacuum to be achieved it will slow the initial pull down time so take care to ensure to bag generally conforms well to the mould before closing to reduce the pull-down time.

Leak Fixing

It is a common misconception that microporous products eliminate the need to ensure that the vacuum bag is perfectly sealed, the (incorrect) theory being that as the vacuum can be maintained through the cure that the bag can be held down even with a leak, although it is true that a microporous vacuum line might be able to help to hold a bag and material roughly in place in the event of a leak it will not do this effectively enough for the part not to be severely compromised. The reason for this is that once the membrane has become ‘wetted’ with resin it is no longer permeable to air and so you should consider it to be sealed, with this in mind once the part has infused fully the MVL hose will be fully covered in resin and sealed therefore no longer able to draw out the air caused by a leak.

Related Products

MTI Hose - Microporous Vacuum Line

MTI Hose would be used where the vacuum needs to be maintained around the perimeter of the part, the hose format allows it to follow the corners and contours typically found on the perimeter of a mould more easily than the MVS Strip. MTI hose is the premium version of the MVL Hose, the MTI in the most part serves the same role as the MVL hose however the membrane used is superior and will completely prevent resin ingress over prolonged periods and end-sealing is easier and can be effectively achieved using only sealant tape.

MVL Economy Microporous Vacuum Line

MVL is a lower-cost alternative to the MTI Hose; MVL in the most part serves the same role as the MTI hose however the membrane used does not completely prevent resin ingress over prolonged periods and end-sealing is slightly more difficult and requires either heat-sealing or a combination of sealant tape and duct tape.

MTI Valve - Resin Inlet Regulator

The MTI Valve can be used in conjunction with microporous vacuum lines/strips, its purpose is to create a regulated back pressure on the resin inlet which ensures that the part does not become over-saturated with resin and in turn increases the consistency of infused parts.