RESIN TRANSFER MOULDING: (RTM):
It is an adaptation of Marco process.
Reinforcing material used is commonly continuous strand, glass fiber mat.
The reinforcing mat is clamped between the two halves of a male and female mould. The room temperature cured and catalyzed resin is injected through the injection ports, displacing the air through the other ports. Usually the resin is injected at the bottom and the air is ejected (exits) through the top ports which have transparent tubing inserts. So that when resin is seen in the tubing, injection can be stopped.
COLD PRESS MOULDING: (Variation in RTM)
Here the reinforcement is placed in the female half and the catalyzed resin is poured into the reinforcement. The mould is then closed so that the resin is distributed. The male and the female mould tightly fits in each other. Most uniform resin distribution is determined empirically and then consistency is accomplished easily.
Advantage (of both RTM and cold press moulding):
a. Smooth surfaces on both sides of the part.
b. Fast cycles.
c. Lower part cost.
d. Uniform wall thickness.
e. Good dimensional control.
f. Low cost plastic moulds can be used because high pressures are not involved.
g. Process is particularly adaptable for moderate quantities of large parts.Up to 100 lb or ft2 in area.