JEC COMPOSITES MAGAZINE - Issue #96 - April 2015 - 67

vacuum infusion

Membrane-assisted vacuum infusion:
a standard process all over the world
Over the past ten years, the VAP® membrane-assisted vacuum
infusion process has become the de facto standard in serial
production of high-quality fibre-reinforced polymer components.
Aviation, vehicle and shipbuilding component manufacturers,
along with global leaders in wind turbine rotor blades, in particular, have come to appreciate the high process stability delivered
by the process with the help of semi-permeable membranes.

he cornerstone for the global
advance of patented VAP® technology was laid in 2003, when it
underwent the first trials in the manufacture of wind turbine rotor blades.
Due to the advantages of the method
- which ensures full infusion and a
complete absence of dry spots with
the help of microporous membranes
that keep the resin in place yet allow
trapped air and reaction gases to escape
- leading manufacturers in the field
were quick to recognise its technological and economic potential and were
soon deploying it in serial production.

characteristics in heavy-duty elements
such as spars and root sections, and
reproducible process parameters are
additional advantages, also in further
work on the components. The method
also enables a precise definition of the
amount of resin required for infusion,
thus delivering considerable weight homogeneity within batches. This way, the
laminate is produced with thicknesses
within a tight range of tolerances, thus
permitting the precise and reproducible
joining of individual parts. Connecting
and mating surfaces are well defined,
meaning that less adhesive is required.

A cost-effective method
This huge increase in process stability over traditional infusion methods
explains why the VAP® method is so
cost-effective. Production risks are
significantly minimised, particularly
when large amounts of resin have to be
infused in a very short time or when
structural materials are concerned.
Outstanding component quality,
improved structural performance

Fig. 1: VAP® membrane systems reliably remove
trapped air and gases (diagram: Trans-Textil
GmbH)

Mag. Andreas Hänsch
VAP Marketing & Sales, Trans-Textil GmbH
Dipl.-Ing. Uwe Tiltmann, General Manager,
Stefan Utecht, General Manager,
Composyst GmbH

Fig. 2: Fabrication by Composyst GmbH of a wing
incorporating integral stringers for an ultralight
aircraft (photo: Composyst GmbH)

In traditional vacuum infusion processes, the entire lay-up has to be extensively flushed with the infusion medium
until it is assumed that no more air is
trapped, plus vacuum pressure has to be
reduced towards the end of infusion to
prevent the resin from boiling. In VAP®
lay-ups, the gas-permeable resin barrier
ensures an even vacuum action across
the entire area of the component,
allowing trapped air and volatiles to
escape during and after infusion without having to reduce vacuum pressure,
and thus preventing the matrix from
boiling. A track-tested tool is available
for determining the amount of resin the
finished part will require, which in turn

No96 April 2015 / jec

composites magazine 67

JEC COMPOSITES MAGAZINE - Issue #96 - April 2015

Table of Contents for the Digital Edition of JEC COMPOSITES MAGAZINE - Issue #96 - April 2015