When OEMs, engineers, sourcing teams and product developers search for a local plastic injection molding manufacturer in Southern California, they need more than a molding press. They need a manufacturing partner that can help with part design, material selection, tooling, process development, precision molding, quality control, secondary operations, assembly and long-term production support.
Hi-Rel Plastics & Molding Corp. is a Riverside, California-based custom plastics manufacturer serving Los Angeles, Orange County, Riverside, the Inland Empire, San Bernardino, San Diego, Ventura and other Southern California communities, as well as customers throughout California and the USA. With more than 40 years of plastics manufacturing experience, Hi-Rel Plastics combines local accessibility with a broad range of in-house and integrated manufacturing capabilities.
For companies searching for “plastic injection molding near me,” “injection molding Southern California,” “plastic injection molding Los Angeles,” “injection molding Orange County,” “injection molding Riverside CA,” “Inland Empire injection molding,” or “plastic injection molding San Diego,” Hi-Rel Plastics provides a regional manufacturing resource focused on custom plastic components, precision tooling and complete production support.
At the center of Hi-Rel Plastics’ manufacturing capabilities is custom plastic injection molding. The company supports prototype, low-, medium- and high-volume programs for OEMs requiring consistent, repeatable molded components.
Capabilities include conventional injection molding, single-shot and multi-shot molding, insert molding, overmolding, vertical injection molding, micro molding, multi-cavity molding, clean room molding, automation and robotic part handling. Injection molding presses extend up to 900 tons, giving customers access to a broad processing range for custom thermoplastic components.
For appropriate applications, Hi-Rel Plastics supports tight-tolerance molding requirements down to approximately ±0.001 inch, depending on geometry, resin, tooling, process capability and inspection requirements.
A local or regional molding supplier can make product development and ongoing production easier to manage. Engineering reviews, mold trials, first-article inspections, tooling changes, supplier audits and production meetings can be coordinated without the communication and logistics challenges associated with a distant supplier.
Companies searching for a plastic injection molding manufacturer near Los Angeles can use Hi-Rel Plastics for projects ranging from new product development to established production programs. The Riverside manufacturing location provides access to the greater Los Angeles market while supporting demanding medical, aerospace and defense, electronics, automotive, industrial and consumer applications.
Los Angeles-area customers can combine injection molding with tooling, DFM, prototyping, secondary operations and assembly, helping reduce the number of vendors involved in a program.
Orange County is a major Southern California center for medical devices, electronics, aerospace, technology and consumer products. Customers searching for injection molding near Orange County, Anaheim, Irvine, Costa Mesa, Santa Ana, Huntington Beach or surrounding communities can work with Hi Rel Plastics for precision plastic component manufacturing.
For regulated healthcare programs, customers can also review Hi-Rel Plastics’ medical device injection molding capabilities, which support medical devices, diagnostics, laboratory equipment and other precision applications.
Hi-Rel Plastics is headquartered in Riverside, California, placing its manufacturing operation directly within one of Southern California’s most important industrial and logistics regions. This location is especially convenient for companies searching for an injection molding company in Riverside, Corona, Moreno Valley, Norco, Jurupa Valley or surrounding Riverside County communities.
Customers can work with a local team for part evaluation, DFM, material selection, tooling, molding, troubleshooting, inspection and downstream manufacturing support.
The Inland Empire includes major manufacturing and distribution corridors across Riverside and San Bernardino counties. Hi-Rel Plastics serves companies throughout Riverside, Corona, Ontario, Rancho Cucamonga, Fontana, San Bernardino, Redlands, Chino, Moreno Valley and nearby communities.
For OEMs searching for an Inland Empire injection molding manufacturer, proximity can simplify tooling coordination, production scheduling and local logistics while still providing access to advanced engineering materials and certified quality systems.
San Diego and North San Diego County contain significant medical device, biotechnology, diagnostics, defense, aerospace and electronics activity. Hi-Rel Plastics supports customers searching for plastic injection molding near San Diego, Carlsbad, Oceanside, Escondido and other Southern California locations.
Medical and life-science companies can combine precision molding with medical injection molding and controlled clean room manufacturing for qualifying applications.
Hi-Rel Plastics also supports OEMs throughout San Bernardino County, Ventura County and other Southern California areas. The goal is not simply geographic coverage; it is to provide regional customers with a plastics manufacturing partner that can remain involved from development through production.
Hi-Rel Plastics’ manufacturing history dates to 1984. Over more than four decades, the company has developed practical experience with molds, machinery, engineering resins, colorants, additives, processing parameters, secondary operations and the interaction among these variables.
That experience matters because injection molding quality depends on the complete system: part design + material + mold design + machine selection + processing + cooling + automation + inspection. Difficult programs often require problem solving across several of these areas rather than changing one processing parameter.
Successful injection molding begins before steel is cut. Hi-Rel Plastics works with customers on Design for Manufacturability (DFM), Mold Flow Analysis and material selection to identify potential manufacturing issues before production tooling is finalized.
Customers evaluating resin options can also review Hi-Rel Plastics’ thermoplastic injection molding material selection resource for additional information about material performance and processing considerations.
Prototype development can help engineering teams evaluate form, fit, assembly and design intent before committing to full production tooling. Hi-Rel Plastics supports product development from initial part evaluation and rapid prototyping through tooling, sampling and production.
A typical development path can follow: CAD design → DFM → Mold Flow → prototype → design review → mold manufacturing → mold sampling → validation → production.
Tooling is one of the most important investments in an injection molding program. Hi-Rel Plastics supports mold design and manufacturing, tooling optimization, transferred-tool evaluation, mold maintenance and refurbishment.
Companies moving production from another molder or an overseas source can have existing customer owned tooling evaluated for machine compatibility, mold condition, maintenance needs and production readiness. This makes Hi-Rel Plastics relevant for reshoring, dual-sourcing and supplier-change programs in Southern California.
Complex products may require metal inserts, threaded components, electrical contacts or multiple polymer materials. Hi-Rel Plastics supports insert molding, overmolding and vertical molding for appropriate applications.
These processes can reduce downstream assembly, improve component integration and create features such as soft-touch surfaces, seals, grips or encapsulated inserts.
Hi-Rel Plastics processes a broad range of commodity, engineering and high-performance thermoplastics. Material selection should be based on mechanical strength, temperature resistance, chemical exposure, electrical performance, dimensional stability, appearance, regulatory requirements and total product cost.
Common materials include PP, ABS, nylon, glass-filled nylon, polycarbonate, acetal, PBT, TPE/TPU, HDPE, LDPE, acrylic, PVC and high-performance resins such as PEEK, PEI/ULTEM, PVDF, LCP and PPS. For a deeper technical overview, visit the material selection guide.
Southern California’s medical-device and life-science companies often require more controlled manufacturing environments and documented quality systems. Hi-Rel Plastics provides medical device injection molding and supports qualifying programs requiring clean room molding, assembly and packaging.
Hi-Rel Plastics offers Class 10,000 / ISO Class 7 and Class 100,000 / ISO Class 8 clean room environments. Medical capabilities can include injection molding, LSR injection molding, insert molding, overmolding, clean room molding, assembly, packaging and secondary operations.
Hi-Rel Plastics maintains ISO 9001:2015, ISO 13485:2016 and AS9100 Rev D certifications. These quality-management systems support commercial programs as well as demanding medical, aerospace and defense manufacturing requirements.
For customers comparing local injection molding companies, certifications, documented processes, inspection capability, traceability and experience with regulated markets can be as important as molding machine capacity.
Hi-Rel Plastics supports OEMs across a broad range of markets. Its capabilities can be combined differently depending on the product, resin, regulatory requirements and production volume.
Additional examples of cross-process applications are available on Hi-Rel Plastics’ agricultural and farming equipment page, pet-care industry page and sustainability and renewable manufacturing page.
Some OEMs require several plastic manufacturing processes across one product family. In addition to injection molding, Hi-Rel Plastics provides plastic blow molding for hollow components, bottles, containers, reservoirs and other products. Blow molding capabilities include extrusion blow molding (EBM), injection blow molding (IBM) and injection stretch blow molding (ISBM).
This broader manufacturing approach can help customers consolidate programs that include both injection molded and blow molded components with one plastics manufacturing organization. Hi-Rel Plastics also supports other plastics processes and development needs described throughout its main website and resources library.
A molded part is not always a finished product. Hi-Rel Plastics supports value-added operations that can reduce outside vendor handoffs and help customers receive more complete components or assemblies.
For decorative applications, Hi-Rel Plastics also provides hot stamping and foil services for suitable plastic components.
Production needs change over a product’s life cycle. A program may begin with prototypes or limited quantities and later scale into medium- or high-volume manufacturing. Hi-Rel Plastics supports programs across these stages, allowing tooling, automation, production strategy and secondary operations to evolve with customer demand.
Automation and 3-axis servo robotics can be integrated where appropriate to improve consistency, reduce handling and support efficient production.
Many OEMs are evaluating domestic manufacturing to reduce long supply chains, simplify communication and create additional sourcing options. Hi-Rel Plastics can evaluate new programs as well as existing customer-owned molds being transferred from another supplier.
For Southern California customers, a Riverside manufacturing location can make plant visits, tool reviews, sampling and engineering coordination more practical. For customers outside the region, Hi-Rel Plastics also supports programs throughout California and across the USA.
Customers comparing local injection molding manufacturers should evaluate the complete manufacturing fit rather than relying on a single factor such as hourly rate or machine tonnage. Hi-Rel Plastics combines:
Hi-Rel Plastics & Molding Corp. is located at 7575 Jurupa Avenue in Riverside, California 92504.
Yes. Hi-Rel Plastics supports customers throughout the Los Angeles metropolitan area and greater Southern California market.
Yes. Orange County customers can use Hi-Rel Plastics for custom injection molding, tooling, engineering, medical molding and related manufacturing services.
Yes. Hi-Rel Plastics supports San Diego and North San Diego County customers as part of its Southern California service area.
Yes. Hi-Rel Plastics is based in Riverside and serves Riverside County, San Bernardino County and communities throughout the Inland Empire.
Existing customer-owned tooling can be evaluated for transfer, condition, compatibility, maintenance, repairs, modifications and production readiness.
Yes. Hi-Rel Plastics supports prototype, low-, medium- and high-volume production depending on project requirements.
Yes. Hi-Rel Plastics supports medical device injection molding and qualifying clean room molding, assembly and packaging programs under ISO 13485-certified quality systems.
Material capabilities include common commodity and engineering thermoplastics as well as high performance resins. Material selection depends on the application, design and performance requirements.
Yes. Available services include CNC machining, bonding, welding, insertion, heat staking, printing, labeling, finishing, assembly, packaging and other value-added operations.
If your company is searching for a plastic injection molding service provider near Los Angeles, Orange County, Riverside, Inland Empire, San Bernardino, San Diego, Ventura or another Southern California location, Hi-Rel Plastics can evaluate your project from engineering and tooling through molding, secondary operations and production.
Whether you need a new injection mold, an existing mold transferred, a difficult molded component troubleshot, a medical clean room program, prototype production or scalable high-volume manufacturing, Hi-Rel Plastics offers a broad manufacturing platform backed by more than 40 years of plastics experience.
Contact Hi-Rel Plastics & Molding Corp. to discuss your CAD files, drawings, material requirements, estimated annual quantities, tooling status and quality requirements.
