At Composite Advantage, we’re proud to specialize in vacuum infusion, the most cost-effective method for molding large structural parts. This is a closed mold process which is more environmentally friendly than traditional composite molding processes. It makes use of vacuum pressure to create a quality part ready for finishing.
Vacuum infusion offers a range of unique benefits, but first, let’s address what the vacuum infusion process actually is.
The Vacuum Infusion Process
There are five main steps to the vacuum infusion process:
- Lay down fiberglass — First, technicians lay down dry fiberglass fabrics, which are similar to textiles. These fabrics are layered and oriented according to specific design requirements in order to create a facesheet laminate.
- Place internal core — This is placed on the bottom facesheet. The vertical fiberglass in the core will become the shear webs. Closed cell foam offers shape until the part is completely molded. The desired amount of fiberglass can be placed on the foam to increase the structural properties of the webs.
- Seal bag — To achieve a vacuum and infuse polymer resin into the part, a bagging sheet is sealed to the molding tool.
- Heat and remove — Once the resin is infused, a chemical reaction creates heat, curing the resin into a solid part. The part is then removed.
- Apply finishes — To complete the part, a number of finishing operations are performed, such as sanding, drilling, applying the nonslip overlay, adding drainage scuppers, and applying coatings for extra protection or added aesthetics.
The vacuum comes into play to drive resin throughout the fiberglass reinforcements. Materials start out in a dry environment, and once a resin is introduced, then atmospheric pressure pushes the resin through the vacuum cavity to create the product.
Benefits of the Vacuum Infusion Process
With the vacuum infusion process, resulting products are both stronger and lighter thanks to the improved fiber-to-resin ratio.
Other key benefits include:
- Consistent resin usage
- Less wasted resin
- Huge range of possible part sizes
- Unlimited setup time
- High consistency and repeatability
- Cleaner process than traditional FRP processing
- Minimized styrene emissions (due to resin curing in a closed environment)
- Minimal to no voids in the finished laminate
- Strong end product due to minimal voids
- Better working environment (especially compared to an open molding alternative)
- Ability to use standard composite tooling (as long as it holds a vacuum and the flange is wide enough to seal the bag)
Vacuum infusion is also highly controllable, as only three variables affect the resin flow: the permeability of the laminate, the pressure differential in the cavity in relation to atmospheric pressure; and the viscosity of the resin.
The only drawbacks compared to other closed mold techniques, is vacuum infusion involves higher consumable costs and slower cycle times. But when compared to other molding methods, the advantages are clear.
To learn more about our vacuum infusion services and discuss how they can help with your specific manufacturing needs, reach out to the team today. Our experts are on hand to answer any questions you may have.