The VARTM process consists of the following steps:
- A closed mold is used cnsisting of one rigid tool face and one flexible blanket (polymer film, rubber membrane, thin GRP, etc)
- Dry reinforcement (preform) and cores are inclosed between blanket and tool
- Liquid thermosetting resin is introduced under full or partial vacuum
- Various techniques are used to control and facilitatate resin distribution.
Typical VARTM Set Up:
RTM vs VARTM
| RTM | VARTM |
| Fixed mold cavity | Part thickness depends on compressibility of reinforcement |
| High
pressure injection (rapid flow rates) |
Maximum
1 bar injection pressure (slow flow rates) |
| Two molded faces | One molded surface |
| Sophisticated process control | Little potential for automation |
| High cost tooling | Reduced tooling costs |
| Few consumables | Significant consumables |
Special techniques are used for fabrication of transparent composites, thick composites, and nanocomposites: Details
