Product Description
HPM Corporation — historically known as the Hydraulic Press Manufacturing Company of Mt. Gilead, Ohio — was a major American manufacturer of plastic and phenolic injection molding machines from the 1930s through the 1980s. HPM presses were built in a broad capacity range, including 100-ton 12-ounce, 300-ton 36-ounce, and larger tonnage configurations, and supplied molders producing electrical components, automotive parts, household and consumer products, packaging, and industrial moldings.
Per publicly filed U.S. asbestos litigation, HPM injection molding presses incorporated asbestos in multiple components of the heated process system. HPM has appeared as a corporate defendant in asbestos personal-injury and wrongful-death actions.
Asbestos Content
Plaintiffs alleged that HPM injection molding presses incorporated asbestos in one or more of the structural roles common to hydraulic injection presses of the era:
Heating cylinder insulation — The heated injection cylinder operated at temperatures of 350°F to 600°F or higher. Plaintiffs alleged the cylinder was wrapped in asbestos-containing thermal insulation to retain heat and protect operators.
Band heater insulation and gaskets — The electric band heaters clamped around the cylinder were alleged to be insulated and gasketed with asbestos-bearing material.
Hot platen insulation — Heated mold platens were alleged to be insulated with asbestos in some HPM press configurations.
Hydraulic system gaskets and seals — High-pressure hydraulic flange connections and packing on the press hydraulic system were alleged to incorporate asbestos sealing material.
Mold transfer plate and nozzle insulation — Heated nozzle and transfer-plate assemblies were alleged to be wrapped or gasketed with asbestos-containing material.
How Workers Were Exposed
Workers were exposed during routine press operation and maintenance:
- Band heater replacement — A routine maintenance event that disturbed asbestos-containing cylinder insulation.
- Cylinder rewrap — Major rebuilds required stripping and replacing the entire asbestos-bearing cylinder insulation jacket.
- Mold changes — Required working at hot platens and nozzle assemblies where asbestos insulation was disturbed.
- Hydraulic system gasket and packing replacement — Plant pipefitters and millwrights cut and scraped asbestos sealing material from press hydraulic flanges.
- Heater wiring — Electrical maintenance on band heaters, thermocouples, and contactors required working in asbestos-insulated areas.
- Machine rebuilding — Used-equipment dealers and plant rebuild crews handled and replaced asbestos-bearing insulation during press refurbishment.
Plaintiffs alleged that plastic molding operators, machine setup workers, mold-change crews, plant maintenance mechanics, millwrights, pipefitters, plant electricians, and bystander workers were exposed to airborne asbestos fiber during these routine activities.
Plants Where HPM Presses Were Installed
HPM injection molding machines were installed across the U.S. plastics and phenolic-molding industries from the 1930s through the 1980s — supplying molders producing electrical switchgear components, automotive parts, household products, packaging, and industrial moldings.
This information reflects facility history, exposure pathways, and product documentation drawn from publicly filed asbestos litigation, federal regulatory records, and industry archives. It does not constitute a finding of fact or liability with respect to any specific manufacturer, supplier, or facility operator.
Documented End-User Plants and Worker Populations
HPM injection molding machines were installed across the U.S. plastics, phenolic-molding, and rubber-molding industries from the 1930s through the 1980s. HPM-related worker exposure occurred at:
Electrical Switchgear, Breaker, and Panelboard Manufacturers
- Square D Company, Westinghouse Electric Corporation, General Electric Company, Federal Pacific Electric Company, and other U.S. electrical switchgear, breaker, and panelboard molders that ran HPM hydraulic presses for phenolic-molding of arc chutes, barrier insulators, terminal blocks, and contactor housings
Automotive Plastic-Component Molders
- U.S. automotive plastic-component molders supplying instrument-panel, interior-trim, and under-hood molded components to U.S. automotive OEMs
Appliance and Consumer-Product Molders
- Small-appliance plastic-component molders supplying toaster, broiler, oven, and other small-appliance manufacturers (including McGraw-Edison Toastmaster facilities)
- Consumer-product, household-chemical, and packaging-component molders
Industrial Phenolic-Molding and Plastic-Component Molders
- Industrial phenolic-molding houses supplying asbestos-filled phenolic moldings to industrial OEMs
- Independent plastic-component molders nationwide
Worker Populations Across All End-User Plants
Plastic molding operators, machine setup workers, mold-change crews, plant maintenance mechanics, millwrights, plant electricians, and bystander workers at all of these end-user plants were exposed to airborne asbestos fiber from HPM cylinder insulation, band-heater insulation, platen insulation, and hydraulic-system gasket and packing materials during routine press operation, mold changes, band-heater replacement, and machine rebuild work throughout the asbestos era.
If You Worked at a Plastic-Molding Plant Running HPM Injection Molding Presses
If you operated, maintained, or rebuilt HPM injection molding presses during the asbestos era — and have since been diagnosed with mesothelioma, asbestosis, lung cancer, or another asbestos-related illness — you may have legal rights.
Free, confidential case evaluation: Speak with O’Brien Law Firm — (314) 936-2956
All consultations are free. No fee unless a financial recovery is made on your behalf.