Resin infusion technology is available on the Impact Rigid Inflatable boats 24' and above. Optimized resin-to-fiberglass ratio minimizes excess weight, achieving over 30% reduction in final boat weight compared to traditional open-molded technique.
Some additional benefits also include:
– Weight savings results in better performance on lower horsepower, ability to carry heavier loads, and improved fuel economy.
– Improved laminate consistency and quality.
– A viable alternative to more expensive carbon fiber or Kevlar.
– Laminate strength is equal to or better than the traditional open-molded technique.
Overview:Brunswick Commercial and Government Products incorporates the SCRIMP (Seemann Composites Resin Infusion Molding Process) method, which was initially developed in order to reduce the emission of volatile organic compounds (VOC's). The first patent was awarded in 1990 to Bill Seemann, a former boat builder and founder of Seeman Composites, Inc. The patent was subsequently purchased by Brunswick Corporation, and the technology was put to use in the construction of luxury yachts.
When resin is introduced to dry glass under vacuum, the process yields a significantly higher glass to resin ratio over traditional open-molding techniques. Excess resin in the final part is minimized, achieving weight savings of up to 35%. An additional benefit to using resin infusion technology is consistency. By removing the variables of the ambient conditions and individual laminating styles during molding, the resin infusion process yields a repeatable and consistent part.
Since the part is sealed under vacuum, the only condition variable is temperature. The entire fiberglass part is laid up in dry form and essentially gives the user the ability to have an even higher level of quality control before resin is introduced into the part. This is compared to traditional open molding methods, in which the resin is catalyzed as it is applied, and makes it next to impossible to make changes or adjustments to the part during the actual construction. Typically, infusible stacked laminate material is selected to maximize the flow of resin through the part under vacuum, assuring that the user will saturate the part completely. The laminate and core usually consist of coarse materials that will serve as "resin highways" to flow resin through the part when put under vacuum. This is seen firsthand with the increased demand of grooved cores and infusion-specific fiberglass mats that resist full compression under vacuum, thus creating a void through which resin can travel. The rate of failure is reduced, giving boat builders the confidence to implement the resin infusion process.
Knowing that the driving force for the implementation of infusion technology was customer demand for significant weight savings, the engineers at BCGP took a slightly different approach, starting with the selection of their laminates. They abandoned the use of "resin highways" to flow resin through a part, since they become brittle and serve a minimal structural purpose once the part has fully cured. Whereas most laminates are typically selected to easily flow resin, BCGP engineers selected laminates to yield the lightest part possible without sacrificing strength. The effect of this material selection would mean that the part would be more difficult to infuse and require significantly more resin inlet ports, but would yield an even lighter part with the absence of cured resin channels inside the finished part.
Prebag - A deck mold just prior to the bagging stage, showing resin inlet ports, feed lines, peel ply and flow media.
Infusion - Part during infusion, nearing the final stages, feed lines and part are filled with resin.
Final Part - After resin has cured, bag and flow media are removed. Complete part is approximately 30% lighter than parts built with open-mold methods.