What Interplastic Corporation does

Interplastic Corporation is a US specialty chemical manufacturer founded in 1959 and headquartered in St. Paul, Minnesota. The company is a wholly owned subsidiary of IP Corporation, a composite-industry holding company that also oversees HK Research Corporation, North American Composites Company (NAC), and Molding Products LLC. Interplastic produces unsaturated polyester resins, vinyl ester resins, gel coats, colorants, and adhesives/bonding compounds, organized primarily under the CoREZYN and Silmar brands. The Silmar business was acquired from a British Petroleum affiliate in 1993 and remains one of the largest casting and solid-surface resin operations globally.

The product portfolio spans more than 500 SKUs across process technologies (open mold/laminating, RTM/infusion, pultrusion, SMC/BMC, casting, CIPP) and end-markets including marine, bath/pool/spa and cast polymer, CIPP pipe rehabilitation, corrosion and fire-retardant industrial, transportation, wind energy, infrastructure (road, bridges, rebar, pilings), architectural/theme park, and surfboard manufacturing. Technology differentiation rests on the most extensive vinyl ester line in the marketplace, the patented ONEstep CIPP single-initiator resin system (US Patent 10,131,766), a pultrusion test laboratory, and three full-service product development laboratories (Minneapolis MN, St. Paul MN, Fort Wright KY), all ISO 9001:2015 and ISO 14001:2015 certified with extensive regulatory qualifications (EPA 40 CFR Part 63, FDA 21 CFR 177.2420, ASTM E84/E162/E662, MIL-R-21607E/QPL, UL 94V, ISO 12215-1, SCAQMD Rule 1162).

Revenue is generated through one-time unit sales of resins, gel coats, colorants, and adhesives via a hybrid direct/distributor model. Direct sales are managed by Regional Sales Managers and a VP of Sales (Kevin Casey, joined April 2025), targeting enterprise accounts in marine, transportation, mining, and infrastructure. The bulk of volume flows through an entrenched distribution network including Composites One, NAC, Univar Solutions (including Eastern Canada since June 2019), Resiglass, and other regional composite-material distributors supporting mid-market customers. Technical services and custom formulation are delivered through the three R&D labs, functioning as a professional services overlay. Pricing is quote-based and not publicly disclosed; the company announced a price increase of up to $0.23 per pound on Silmar and CoREZYN polyester resins in March 2026, and trade events (CAMX, IBEX, No-Dig Show, Polycon, UIC Conference) remain a core demand-generation channel alongside association leadership in ACMA, ICPA, NACE, NASTT, and ASTM.

Name

Interplastic Corporation

Legal name

Interplastic Corporation

Website

https://interplastic.com

Company type

Private

Founded year

1959

Operating status

Operating

Headcount range

251–500 employees

Short description

Interplastic Corporation is a US specialty chemical manufacturer, founded in 1959 and headquartered in St. Paul, Minnesota, that produces unsaturated polyester resins, vinyl ester resins, gel coats, colorants, and bonding compounds under the CoREZYN and Silmar brands for composites and cast polymer industries including marine, bath/pool/spa, CIPP, and corrosion-resistant applications.

Ownership category

akta.pro rank

Product category

Specialty Chemicals (Thermoset Composite Resins and Gel Coats)

NAICS

Chemical Manufacturing (325), Resin and Synthetic Rubber Manufacturing (32521), Custom Compounding of Purchased Resins (325991)

SIC

Industrial Organic Chemicals (2860), Miscellaneous Chemical Products (2890), Chemicals & Allied Products (2800)

akta.pro primary industry

Specialty Polymers & Resins (Engineered Materials) (IMAEABAK)

Keywords

• Unsaturated polyester resins
• Vinyl ester resins
• Gel coats manufacturing
• Composite materials chemistry
• Thermoset resin chemistry

Headquarters

HQ city

Saint Paul

HQ country

United States

HQ region

North America

Offices4 records

Markets served

GTM type

B2B

Offering type

Hardware or Manufacturing

Cost components

Supply Chain, Operations, Personnel, Technology or R&D, Marketing or Sales, Infrastructure

Revenue model

1. Resin Sales: Sale of unsaturated polyester resins, vinyl ester resins, and specialty resins under CoREZYN and Silmar brands. Products are sold direct and through distributors to composites and cast polymer manufacturers.
2. Gel Coat Sales: Sale of gel coats including general purpose, tooling, vinyl ester barrier, and specialty gel coats for marine, bath, pool, spa, and industrial applications.
3. Colorant and Additive Sales: Sale of colorants, putties, bonding compounds, and COR-Grip product line for structural bonding, gap filling, and surface finishing.
4. Technical Services: Product development support and technical assistance provided through three full-service product development laboratories to help customers develop customized resin solutions.

Pricing tiers

Go-to-market motion3 records

Distribution channels4 records

Marketing channels5 records

Core offering

Interplastic Corporation manufactures and distributes specialty chemical products—unsaturated polyester resins, vinyl ester resins, gel coats, colorants, putties, and adhesives—for the composites and cast polymer industries. These products are sold under the company's two flagship brands, CoREZYN and Silmar, to manufacturers in marine, bath/pool/spa, CIPP, corrosion-resistant, fire-retardant, transportation, wind energy, and infrastructure applications.

Product overview

Interplastic Corporation offers a diversified portfolio of thermoset resins and related chemical products primarily organized under two core brands: CoREZYN® and Silmar®. CoREZYN® encompasses vinyl ester resins (including the extensive CORVE series), polyester resins (COR series), gel coats, colorants, and the COR-Grip adhesives/compounds line, serving the composites industry for marine, transportation, corrosion-resistant, wind energy, infrastructure/CIPP, and general industrial applications. Silmar® focuses on casting and solid surface resins (SIL series) for cultured marble, onyx, and solid surface manufacturing. The company also offers the patented ONEstep CIPP resin system. Products are sold through an extensive North American distribution network and direct sales, with manufacturing facilities in the US certified to ISO 9001:2015 and ISO 14001:2015 standards.

Differentiator

Problem solved

Functional benefit

Brands

• CoREZYN: Leading manufacturer of unsaturated polyester, vinyl ester and specialty resins, gel coats, colorants and putties for the composites, cast polymer, and solid surface industries. Introduced epoxy-based vinyl esters in 1978 and now produces the most extensive line of vinyl ester resins in the marketplace.
• Silmar
• CoREZYN Marine
• COR-Grip
• ONEstep
• CoREZYN Vinyl Ester Barrier Gel Coats

Products and services

• ONEstep CIPP Resin System Patented single-step resin system for cured-in-place pipe (CIPP) rehabilitation, sold to pipeline rehabilitation contractors and municipal water/wastewater authorities to reline buried pipelines with resin-impregnated composite liners.
• CORVE Series Vinyl Ester Resins Vinyl ester resin series engineered for corrosion-resistant and fire-retardant composites fabrication, targeted at industrial fabricators producing chemical processing equipment, tanks, ducts, and fire-rated structures.
• MVR Series Modified Vinyl Ester Resins Modified vinyl ester resin series targeted at demanding corrosion-resistant and fire-retardant composites applications where enhanced chemical resistance, thermal performance, or fire, smoke, and toxicity compliance is required.
• SIL Series Silmar Resins Polyester resin series under the Silmar brand used by composites manufacturers in marine, bath/pool/spa, transportation, and general composites applications.
• COR Series Polyester Resins Polyester resin series under the CoREZYN brand for general composites fabrication across marine, bath/pool/spa, cast polymer, transportation, wind energy, and infrastructure applications.
• Marine High Performance Gel Coats High-performance gel coat product line designed for marine composites applications, sold to boatbuilders and marine fabricators requiring durable, weatherable, and UV-resistant surface finishes.
• CoREZYN Vacuum Infusion Resins Specialty polyester and vinyl ester resin systems formulated for vacuum infusion molding, sold to composites manufacturers producing large structural parts such as wind turbine blades and marine structures.
• CoREZYN Pultrusion Resins Specialty resin systems formulated for pultrusion processes, sold to composites manufacturers producing structural profiles, rebar, pilings, and other reinforced infrastructure components.
• COR-Grip Adhesives Structural adhesives and putties used by composites manufacturers for bonding and repair applications across marine, transportation, and general composites fabrication.

Quantifiable outcome

• 15-year immersion study demonstrates CoREZYN vinyl ester resin creates barrier impervious to water preventing osmotic blistering and retains original physical properties (flexural strength, flexural modulus, Izod impact strength)
• +2 more outcomes

Named customers10 records

Segments8 records

Ideal customer profiles5 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature5 records

Partnerships

Seven partnerships are on record, tiered core and flagship.

• Univar SolutionscoreChannel Partner/ Reseller/ Distributor · 19 June 2019Interplastic named Univar Solutions as a new distribution partner for its unsaturated polyester and vinyl ester resins, gel coats, colorants and bonding compounds in Eastern Canada. The partnership extends reach in Manitoba, Ontario, Quebec and points further east with local product inventory and delivery service.
• Structural Composites IncorporatedflagshipStrategic or Co-development Partner · 27 September 2018Partnership to market Advanced Marine Coatings using Structural Composites' CoCure technology. This brings the functionality of urethane chemistry to gel coats, allowing a higher performing product with regard to flexibility, weatherability and durability for the marine industry.
• Composites OnecoreChannel Partner/ Reseller/ DistributorMajor North American distribution partner for composite materials including Interplastic's resin products.
• NAC - North American CompositescoreChannel Partner/ Reseller/ DistributorNorth American distribution partner for composite materials and Interplastic products.
• HK Research CorporationflagshipStrategic or Co-development PartnerStrategic integration announced between Interplastic and HK Research Corporation for advanced marine coatings and gel coat technology development.
• American Composites Manufacturers Association (ACMA)coreGTM or Marketing PartnerIndustry association partnership for the Scholars Award program, co-sponsored by Interplastic Corporation in affiliation with ACMA to support education in the composites industry.
• International Cast Polymer Association (ICPA)coreGTM or Marketing PartnerIndustry association partnership for the Scholars Award program, co-sponsored by Interplastic Corporation in affiliation with ICPA to support education in the cast polymer industry.

Scale indicators4 records

Recent moves6 records

Expansion highlights6 records

Market position

Competitive moat6 records

Key risks6 records

Key highlights5 records

Customer concentration

Compliance12 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles14 records

Subsidiaries1 record

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Interplastic Corporation