Hi-Rel Plastics & Molding Corp. provides automotive and electric vehicle plastic injection molding, mold and tooling manufacturing, engineering, prototyping, custom plastic and metal component manufacturing, assembly, and secondary services for automotive OEMs, electric vehicle manufacturers, Tier 1 and Tier 2 suppliers, aftermarket manufacturers, mobility companies, and automotive product developers throughout California and across the USA.
With more than 40 years of manufacturing experience, Hi-Rel Plastics & Molding combines advanced manufacturing processes with comprehensive engineering and quality systems to support automotive programs from initial product development and prototype evaluation through tooling, production, secondary operations, assembly, and delivery.
Our manufacturing capabilities include plastic injection molding, blow molding, LSR (liquid silicone rubber) injection molding, thermoforming, vacuum forming, rotational molding, mold and tool manufacturing, 3D printing and rapid prototyping, custom plastic and metal component manufacturing, mechanical and cable assembly, ultrasonic welding, pad printing, and a broad range of value-added secondary services.
Hi-Rel Plastics & Molding serves automotive and EV customers throughout Southern California, Northern California, Los Angeles, Orange County, San Diego, Riverside, the Inland Empire and throughout the United States.
Modern vehicles increasingly rely on engineered plastic components to reduce weight, integrate complex features, provide electrical insulation, resist chemicals and corrosion, and support efficient high-volume manufacturing.
Hi-Rel Plastics & Molding provides custom plastic injection molding for complex and tight tolerance automotive and electric vehicle components. Our capabilities support prototype, low-, medium- and high-volume manufacturing programs using commodity and engineering-grade thermoplastics selected according to the mechanical, thermal, chemical, electrical and cosmetic requirements of the application.
Automotive injection molding applications can include:
Our engineering team can assist with material selection, part geometry, moldability, tolerance requirements and manufacturing efficiency to help customers transition from concept to repeatable production.
Components engineered to withstand heat, vibration, and mechanical stress in automotive environments.
Experience with resins designed for strength, impact resistance, and long-term reliability.
Efficient manufacturing processes to support high-volume automotive production demands.
Precision molding ensures uniform, repeatable parts across every production run.
The transition toward electric vehicles is creating new manufacturing requirements for lightweight structures, battery systems, charging infrastructure, electrical connectors, thermal-management systems, electronic controls and high-performance plastic components.
Hi-Rel Plastics & Molding provides custom manufacturing support for electric vehicles, EV charging equipment, battery-related systems, e-mobility products and automotive electronics.
Potential EV applications include battery-system plastic components, battery module housings and covers, electrical connector housings, busbar and terminal protection components, cable-management components, sensor enclosures, charging connector components, charging-station housings, insulating components, electronics enclosures and thermal-management components.
Our combination of plastic molding, tooling, custom metal manufacturing and assembly capabilities allows Hi-Rel Plastics & Molding to support projects involving both individual components and more complex subassemblies.
A reliable production program begins with properly engineered tooling.
Hi-Rel Plastics & Molding provides automotive injection mold manufacturing and tooling support for new automotive and EV programs as well as existing production programs requiring transferred, repaired, modified or replacement tooling.
Our tooling capabilities can support injection molding, LSR molding, blow molding, thermoforming, vacuum forming and rotational molding applications.
Automotive tooling services can include:
Combining mold and tool manufacturing with production molding helps customers simplify supplier management and establish a more efficient transition from product development to production.
Manufacturing involvement during the early stages of product development can help identify potential molding and tooling problems before production tooling is released.
Hi-Rel Plastics & Molding supports automotive engineers and product-development teams with engineering assistance, material selection, DFM evaluation, mold flow analysis, tooling development, 3D printing and rapid prototyping and production planning.
Our prototype-to-production approach can help customers evaluate:
This integrated approach can help reduce development risk, minimize costly tooling revisions and accelerate the transition from prototype to production.
Hi-Rel Plastics & Molding also provides plastic blow molding for automotive and electric vehicle applications requiring hollow plastic components.
Our blow molding capabilities include extrusion blow molding (EBM), injection blow molding (IBM), and injection stretch blow molding (ISBM).
Automotive blow molding applications can include fluid reservoirs, washer-fluid containers, expansion tanks, air ducts, intake components, protective hollow components, custom containers and other lightweight hollow plastic products.
Blow molding provides manufacturers with an efficient method of producing lightweight, durable and chemically resistant hollow components with complex geometries.
For applications requiring flexibility, sealing, temperature resistance or environmental durability, Hi-Rel Plastics & Molding offers LSR (liquid silicone rubber) injection molding.
Potential automotive and EV LSR applications include seals, gaskets, electrical protection components, connector seals, vibration-control components, flexible covers and other custom silicone components.
LSR molding can be combined with insert molding and overmolding techniques to create multi-material components and integrated assemblies.
Hi-Rel Plastics & Molding provides thermoforming and vacuum forming for larger or relatively thin-walled automotive plastic components where injection molding may not provide the most economical manufacturing approach.
Potential applications include interior panels, protective covers, equipment enclosures, trays, liners, housings and other formed plastic components.
Offering multiple plastic manufacturing processes enables our engineering team to help determine a practical manufacturing method based on component geometry, material, tooling requirements and expected production volume.
Our rotational molding capabilities provide another manufacturing option for large, hollow or complex plastic products.
Potential applications include specialty tanks, protective housings, equipment enclosures, fluid-handling products and custom mobility components.
Rotational molding can provide durable seamless components with relatively uniform wall thickness while accommodating larger geometries and lower tooling investment for suitable applications.
Custom Plastic & Metal Automotive Component Manufacturing Automotive assemblies frequently incorporate both plastic and metal components.
Hi-Rel Plastics & Molding offers custom plastic and metal parts manufacturing to help customers consolidate manufacturing operations and reduce the number of suppliers required for complex programs.
Depending on project requirements, capabilities can support molded plastic parts, CNC machined plastic and metal components, inserts, brackets, hardware and other custom manufactured components used within automotive and EV products.
Hi-Rel Plastics & Molding provides mechanical assembly and cable assembly services for customers that require more than individual molded components.
Assembly capabilities can support plastic and metal components, fasteners, inserts, electrical components, cables, connectors and other supplied or manufactured parts.
Providing component manufacturing and assembly through a single manufacturing partner can help automotive customers reduce supply-chain complexity, transportation requirements, work-in-process inventory and overall program management.
Hi-Rel Plastics & Molding provides a wide range of secondary manufacturing services to transform molded components into finished or assembly-ready products.
Available operations can include:
These services enable customers to consolidate molding, finishing, assembly and packaging with one manufacturing partner.
Material selection is critical for automotive components exposed to heat, vibration, chemicals, fuels, UV exposure, mechanical loading or demanding electrical environments.
Depending on application requirements, Hi-Rel Plastics & Molding can process a broad range of thermoplastics and engineering-grade materials, including:
ABS • Polycarbonate (PC) • PC/ABS • Polypropylene (PP) • HDPE • LDPE • Nylon (PA) • Glass-Filled Nylon • Acetal (POM) • PBT • PPS • PEEK • PEI / ULTEM® • LCP • PVDF • TPE • TPU • Acrylic and other engineered resin systems
Material selection should be based on the individual component’s mechanical, thermal, electrical, chemical, dimensional and regulatory requirements.
Hi-Rel Plastics & Molding can support components for instrument panels, controls, HVAC systems, trim assemblies, electronic housings, clips, brackets and other functional or cosmetic interior applications.
Manufacturing capabilities can support protective housings, covers, brackets, clips and specialty components requiring durability, dimensional consistency and resistance to environmental exposure.
High-performance engineering thermoplastics can be used for selected under-hood components requiring resistance to heat, chemicals, vibration and mechanical stress.
As vehicles incorporate increasingly sophisticated electronics, plastic components are widely used for sensor housings, connector systems, electronic enclosures, insulating components, cable management and control-system components.
Electric vehicles create additional applications for plastic components within battery systems, electrical distribution, thermal management, cable routing and charging equipment.
Hi-Rel Plastics & Molding Corp. maintains ISO 9001:2015, AS9100 Rev D and ISO 13485:2016 certifications, providing a quality-management foundation for customers requiring documented and repeatable manufacturing processes.
Quality processes can incorporate production documentation, in-process inspections, dimensional verification, traceability, process control and final inspection according to individual customer and program requirements.
Our experience serving highly demanding medical, aerospace, defense and industrial applications strengthens our ability to support automotive and electric vehicle programs where consistency, documentation and manufacturing discipline are important.
Automotive and electric vehicle manufacturers increasingly need suppliers capable of supporting more than a single manufacturing process. Hi-Rel Plastics & Molding provides an integrated manufacturing platform covering product development through finished component and assembly production.
Key capabilities include:
By bringing engineering, tooling, molding, secondary operations and assembly together, Hi-Rel Plastics & Molding can help OEMs and suppliers streamline sourcing and establish a more efficient manufacturing supply chain.
Located in Riverside, California, Hi-Rel Plastics & Molding supports automotive and electric vehicle companies throughout Los Angeles, Orange County, San Diego, Riverside, San Bernardino, the Inland Empire, Southern California, Northern California and across the United States.
Whether your project involves a new EV product, an existing automotive production program, transferred tooling, an engineering change, prototype components or high volume manufacturing, our team can evaluate the requirements and develop a manufacturing solution around your program.
Looking for an automotive plastic injection molding company, EV component manufacturer, automotive mold manufacturer or turnkey contract manufacturing partner in California?
Hi-Rel Plastics & Molding Corp. can support your project from engineering and prototyping through tooling, molding, secondary operations, assembly and production.
Contact Hi-Rel Plastics & Molding to discuss your automotive or electric vehicle manufacturing requirements and request a quote.
Automotive, EV, and charging system components require exceptional precision, consistency, and reliability. Hi-Rel produces tight-tolerance molded parts designed to perform in demanding automotive and electrification environments where durability, thermal resistance, chemical resistance, electrical insulation, and dimensional stability are critical to long-term performance.
With experience in advanced engineering resins and a focus on quality-driven manufacturing, we help automotive OEMs and Tier 1 suppliers achieve reliable performance while meeting critical design and production requirements.
Injection Molding
Blow Molding
Liquid Silicone Rubber (LSR) Molding
Thermoforming / Vacuum Forming
Rotational Molding
Components engineered to withstand heat, vibration, and mechanical stress in automotive environments.
Experience with resins designed for strength, impact resistance, and long-term reliability.
Efficient manufacturing processes to support high-volume automotive production demands.
Precision molding ensures uniform, repeatable parts across every production run.
