Large projects can easily approach the 2-hour mark, and even small, seemingly simple projects can quickly turn frantic when a pesky leak in the vacuum seal cannot be found. Even so, that time limit is extremely critical in vacuum bagging applications. Many resins have a pot-life of about 30 minutes, though there are certainly some (such as our System 4500 Infusion Epoxy Resin or System 4600 High Temp Infusion Epoxy Resin) that offer work times of up to 90 minutes. A frequent problem that can arise in vacuum bagging is the time factor. Vacuum infusion provides another valuable benefit: time.

This results in less wasted resin, and more importantly, less wasted money. Even when creating a large product, resin usage will be predictably similar upon repeated attempts. While a standard lay-up varies in resin content due to the human variable, VIP is remarkably consistent. Parts constructed using VIP can approach prepreg levels of resin content.Дue to the nature of VIP, resin usage becomes very predictable. This lowers weight, increases strength, and maximizes the properties of fiber and resin. As a result, only the minimum amount of resin is introduced. Ideally, any excess resin that is introduced will eventually be sucked out into the vacuum line. Rather than starting with excess and drawing resin out, VIP starts with none and pushes resin in. From that point, resin is infused using vacuum pressure. Vacuum infusion takes a different approach, in that a vacuum is drawn while the materials are still dry. This includes reinforcement material, resin, time factors, as well as others. Vacuum pressure will remove much of the excess resin, but the amount removed still depends on the variety of variables. Because of this, the laminate will always begin in an oversaturated state. While vacuum bagging certainly improves on the hand lay-up, there is still a hand lay-up involved. Vacuum bagging can reduce this number significantly however, it is still not ideal and can lead to additional problems. Resin alone is very brittle, so any excess will actually weaken the part. A typical hand lay-up usually results in excess of 100% fabric weight by resin. VIP offers a better fiber-to-resin ratio than vacuum bagging. Vacuum infusion provides a number of improvements over traditionally vacuum bagged parts. Vacuum infusion builds upon these principles, providing further improvements to the lamination process. If you are unfamiliar with vacuum bagging, we recommend reading our guide, Vacuum Bagging Equipment and Techniques for Room-Temperature Applications, as VIP requires experience in this area and uses many of the same principles. Vacuum bagging greatly improves the fiber-to-resin ratio, and results in a stronger and lighter product. An improvement on that method is to use a vacuum bag to suck excess resin out of the laminate. In a typical hand lay-up, reinforcements are laid into a mold and manually wet out using brushes, rollers, or through other means. This process is aided by an assortment of supplies and materials. Once a complete vacuum is achieved, resin is literally sucked into the laminate via carefully placed tubing. Dry materials are laid into the mold and the vacuum is applied before resin is introduced.

The Vacuum Infusion Process (VIP) is a technique that uses vacuum pressure to drive resin into a laminate.

Г— Introduction Photo credit IStock Photo.

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