Current Methods
Before vacuum infusion processing (VIP or resin infusion), there was vacuum bagging. With vacuum bagging, a laminate is first wet out through an open mold type process, then covered in plastic and sealed. A vacuum is then pulled, which helps consolidate the laminate and pull out air and excess resin.
From vacuum bagging came vacuum infusion. Here, a dry laminate is sealed, air is removed using a vacuum, and resin is "pulled" through the fabric creating a fully impregnated composite part.
Getting Started
Equipment needed for resin infusion include:
- Vacuum pump
- Inferred thermometer
- Resin collector / reservoir
- Clamps
- Hoses and connectors
- Vacuum gauges
- Flow media
- Peelply
- Bagging film
- Double sided sealant tape
If you are outfitting a larger shop, the majority of your cost will come from a quality vacuum system that includes:
- Two pumps
- Filter
- Reservoir
- Permanent vacuum lines throughout shop
Molds
Tooling for VIP may be exactly like that of standard open molds. One requirement for VIP is a perimeter flange needed to mount the vacuum bag. Perhaps the largest capital cost in converting an existing composite manufacturing operation to resin infusion is reconfiguring the plant, modifying the molds, and the lost production time during the transformation.
No special type of tooling is required for VIP, similar tooling from open molding is sufficient. Commonly, polyester molds with a polyester tooling gel coat are used. Other resin tooling systems work fine as well, including vinyl ester or epoxy tooling. In some instances metal molds or even coated wood have been used for resin infusion tooling. Obviously, a vacuum source is required, and for large processing a plant vacuum system is a must.
Just like how a shop will route compressed air around the factory with numerous port locations to hook into. Manufacturing plants using resin infusion will also route from a central vacuum to the entire factory.
Education
There are different avenues for learning VIP technology. You may choose to pay for a license and training or perform your own experiments in the shop. The duration of typical VIP base course is one week. However, two to three weeks is required for the average fiberglass worker to be trained and ready for manufacturing. The budget for training will vary. The technology can be acquired through licensing; it depends upon the chosen system.
Manufacturers of equipment and materials are eager to teach the basics of resin infusion and often will put on clinics. Additionally, composite material distributors, often will offer introductory trainings on site. To see VIP in first person, the ACMA annual conference, which is free to attend, has live demonstrations most every year.
Reinforcements for Resin Infusion
There are a handful of manufacturers of materials and accessories for resin infusion. Many of these materials are specific for vacuum infusion. Below are a list of some of the common North American manufacturers and suppliers of materials.
Chomarat
Chomarat creates knitted and woven products specific for infusion and RTM. Their trade names include Rovicore and Coreglass which have a thin layer of flow media that is sandwiched between the reinforcement. Because of this, and external flow media is not required.
OCV Reinforcements
OCV (Owens Corning Vetrotex) has a range of fiberglass, both standard e-glass and high-strength glass, that are either stitched or woven into fabrics for vacuum infusion.
Vectorply
Vectorply has a wide range of fiberglass, carbon fiber, aramid, or a hybrid combination of any mentioned. They can manufacture these with a flow media attached. Vectroply can help with the laminate design and recommend a particular fabric with a particular fiber type and orientation to fit the needed requirement.
Composites One
North America's largest distributor of composite reinforcements and associated products for resin infusion. Composites One carries all the materials mentioned above, and all the necessary resins, gel coats, VIP accessories, and related products.
