We have a passion for chemistry.

Interplastic Corporation has been an industry leader in thermoset resin, gel coat, colorant, and putty research, design, and development since 1959. We have remained with a stable ownership over that time allowing us to consistently focus on long term results and invest in the industry. Our chemists and engineers work closely with Interplastic customers and suppliers to develop innovative solutions for product, manufacturing, and marketplace challenges. Our goal is to help composites and cast polymer manufacturers build better, longer-lasting products.

Interplastic has strategically placed itself to meet the diversified needs of its customers by expanding its manufacturing capabilities and by investing in product research. Our three full-service product development laboratories are located in Minneapolis and St. Paul, Minnesota; and Fort Wright, Kentucky. In addition, all of our manufacturing facilities and research and development laboratories are ISO 9001:2015 certified through ABS Quality Evaluations, Inc. Interplastic manufacturing facilities also have ISO 14001:2015 registered environmental management systems also certified through ABS Quality Evaluations, Inc..

Interplastic is the leading manufacturer of unsaturated polyester, vinyl ester and specialty resins, gel coats, colorants and putties under the CoREZYN®, and Silmar® brand names for the composites, cast polymer, and solid surface industries. All CoREZYN, Silmar and marine products are sold direct and through our extensive network of distributors in North America and around the world.

Interplastic has been manufacturing CoREZYN® thermoset resins, gel coats, and colorants for the composites and cast polymer industries since 1959. The division introduced CoREZYN epoxy-based vinyl esters in 1978. Today, they produce the most extensive line of vinyl ester resins in the marketplace. CoREZYN vinyl esters have become the resin of choice, for specialized high-performance, high-corrosion applications within the marine, transportation, and construction industries.

Interplastic acquired Silmar® brand resins from an affiliate of British Petroleum in 1993. They then became one of the world’s largest casting and solid surface resin producers with facilities in California and Kentucky. When manufacturers are looking for low color (clear) resins for filled and clear castings, Silmar is the world’s premier brand. With its 45-year history of quality and reproducibility, Silmar is able to meet the toughest customer demands. Interplastic introduced its line of Silmar clear gel coats in 2004.

The marine high performance gel coats were developed in 2011 for use above and below the waterline in marine applications. Our gel coats stand for consistent quality and color from batch-to-batch giving our customers superior application and repair performance.