Silpak, Inc

Products

MEKP Ratio Chart

Polyester resin cures by an exothermic reaction created by promoters (cobalt & amine) and activator Methyl Ethel Ketone Peroxide (MEKP). The reaction of polyester will occur at the thickest cross section sending out a wave of heat, which cures resin to a solid glass-like hardness. Temperature and moisture content can affect the rate of cure and the drying of part’s surface. The resin’s reaction starts with the addition of MEKP at 0.5% to 1.5 % (2 % for thin laminates). The ratio is dependant on air temperature, resin thickness, temperature of resin and mold. Fillers are added to help control peak exotherm, shrinkage, and cure rate. Unfilled resin can heat up to 300F resulting in cracking. Resins that create uncontrolled peak exotherm can exhibit wrinkles or alligator skin. Using lower levels of MEKP, preheating the mold surface or both, can change this. In wet weather conditions, tacky surfaces may be exhibited by resin due to high humidity. Working in a controlled, dry-heated area should help resin to cure properly.

The information and data contained herein are based on information we believe reliable. Each user of the material should thoroughly test any application and independently conclude satisfactory performance before commercializing. Suggestions of uses should not be taken as inducements to infringe on any particular patent.