Hi-Rel Plastics & Molding Corp. is a custom plastic blow molding company and blow mold manufacturer in California providing complete engineering, tooling, molding, assembly, and secondary manufacturing solutions for OEMs throughout Los Angeles, Southern California, Northern California, and across the USA.
With more than 40 years of plastics manufacturing experience, Hi-Rel Plastics & Molding supports customers from initial product development and Design for Manufacturability (DFM) through blow mold design and mold & tool manufacturing, prototype and pilot production, full-scale plastic blow molding, secondary operations, assembly, custom packaging, and ongoing production.
Our comprehensive plastic blow molding services include:
Hi-Rel Plastics & Molding is ISO 9001:2015, ISO 13485:2016, and AS9100 Rev D certified, supporting demanding plastic manufacturing programs for the medical, pharmaceutical, aerospace & defense, food & beverage, packaging, consumer products, automotive & electric vehicles, industrial equipment, electronics, cosmetics & personal care, research & laboratory, and other major industries.
Blow molding is one of the most efficient manufacturing processes for producing hollow plastic products ranging from small bottles and containers to complex technical components and larger industrial products.
During blow molding, heated thermoplastic material is formed into a preform or parison and expanded against the internal surfaces of a mold using pressurized air. The specific process varies depending on whether extrusion blow molding, injection blow molding, or injection stretch blow molding is selected.
Choosing the correct blow molding process can affect dimensional accuracy, wall thickness, material selection, neck geometry, surface appearance, production rate, tooling investment, and overall part cost.
Hi-Rel Plastics & Molding’s engineering team works with customers to determine the appropriate combination of part design, blow molding process, plastic resin, mold construction, automation, secondary operations, and production strategy for each application.
Customers developing new products can also utilize Hi-Rel Plastics & Molding’s 3D printing and rapid prototyping services to evaluate form, fit, and function before committing to production tooling.
Processes designed to ensure uniform material distribution and structural integrity.
Ideal for creating strong yet lightweight hollow components.
Efficient manufacturing for large production runs with consistent quality.
Support for a wide range of shapes, sizes, and application requirements.
Hi-Rel Plastics & Molding provides custom extrusion blow molding services in California for bottles, containers, reservoirs, tanks, housings, ducts, and complex hollow plastic components.
During extrusion blow molding, molten thermoplastic is extruded vertically as a hollow tube known as a parison. The blow mold closes around the parison, compressed air expands the material against the mold cavity, and the molded component is cooled before removal and trimming.
Hi-Rel Plastics & Molding’s automated EBM equipment includes 200-point parison programming, providing precise control over material distribution and helping engineers optimize wall thickness throughout complex blow molded components.
Our extrusion blow molding capabilities support products ranging approximately from 1 mL through 7-gallon containers and components, allowing Hi-Rel Plastics & Molding to manufacture both small precision products and substantially larger hollow plastic parts.
Typical EBM applications can include:
Hi-Rel Plastics & Molding also supports multi-component and multi-layer blow molded products when applications require additional barrier properties, strength, durability, functionality, or material performance.
Hi-Rel Plastics & Molding offers injection blow molding services for applications requiring excellent neck definition, dimensional repeatability, surface finish, and consistent container geometry.
Injection blow molding combines injection molding and blow molding into a controlled manufacturing process. A plastic preform is initially injection molded around a core pin. The preform is subsequently transferred into the blow mold, where compressed air expands the plastic into the final product geometry.
IBM can be particularly effective for smaller bottles and containers where accurate neck finishes, consistent dimensions, clean appearance, and repeatable production are important.
Injection blow molding can be considered for:
Our engineering team evaluates product geometry, production quantity, resin requirements, tolerances, neck specifications, and application requirements when determining whether IBM is appropriate for a program.
Hi-Rel Plastics & Molding also provides injection stretch blow molding (ISBM) services for high-quality plastic bottles and containers requiring excellent clarity, strength, dimensional stability, and attractive surface appearance.
During ISBM, an injection molded preform is conditioned to the required processing temperature before being simultaneously stretched axially and expanded radially with compressed air inside the blow mold.
The biaxial orientation created during stretching can significantly improve the mechanical and physical properties of suitable materials.
ISBM is particularly well suited to PET and other compatible thermoplastics used for high-quality rigid packaging.
ISBM can be used for products such as:
By offering EBM, IBM, and ISBM, Hi-Rel Plastics & Molding can evaluate multiple manufacturing technologies rather than attempting to fit every hollow plastic product into a single blow molding process.
Successful blow molding begins with properly engineered tooling.
Hi-Rel Plastics & Molding provides complete custom mold and tool manufacturing services, supporting customers requiring new tooling, replacement molds, production molds, prototype tooling, mold modifications, or transferred blow molds.
Our blow mold manufacturing capabilities support tooling for:
Depending on product requirements, production volumes, expected mold life, cycle-time requirements, and project budget, blow molds can be engineered using appropriate aluminum, steel, and specialty tooling materials.
Hi-Rel Plastics & Molding’s broader mold and tool making capabilities can also support tooling for plastic injection molding, liquid silicone rubber molding, thermoforming and vacuum forming, and rotational molding.
Blow mold manufacturing requires more than machining the shape of a finished product.
Hi-Rel Plastics & Molding’s engineering team reviews product geometry and manufacturing requirements before tooling development to identify opportunities to improve manufacturability, material distribution, part quality, cycle time, tooling reliability, and production economics.
Engineering considerations can include:
Early engineering involvement helps reduce costly tooling revisions and creates a stronger foundation for consistent production.
For early-stage product development, rapid prototyping and 3D printing can also assist with design validation before production tooling is finalized.
Companies searching for a new blow molding manufacturer in California do not necessarily need to manufacture a new mold.
Hi-Rel Plastics & Molding can evaluate existing customer-owned blow molds for potential transfer into our manufacturing operation. Our engineering and tooling teams can review transferred molds for condition, compatibility, maintenance requirements, modifications, and readiness for production.
This provides OEMs with another option when experiencing challenges such as:
When modifications are required, our mold and tooling resources can support blow mold repair, engineering changes, mold refurbishment, maintenance, and production optimization.
Material selection plays an important role in the performance, appearance, processing, recyclability, and cost of a blow molded product.
Depending on the selected process and application requirements, Hi-Rel Plastics & Molding works with commonly used blow molding thermoplastics including:
Material selection can be based on requirements including chemical resistance, impact strength, rigidity, flexibility, clarity, temperature resistance, barrier properties, environmental exposure, regulatory requirements, appearance, and cost.
Customers interested in polymer selection can also review Hi-Rel Plastics & Molding’s thermoplastic material selection resource for additional information about engineering and high-performance thermoplastics.
Where appropriate, Hi-Rel Plastics & Molding can also evaluate PCR and other sustainable resin options based on product specifications and application requirements, including programs serving sustainability and renewable applications.
Hi-Rel Plastics & Molding provides much more than plastic blow molding.
Our secondary manufacturing and value-added services allow customers to consolidate multiple manufacturing steps with a single plastics contract manufacturing partner.
Secondary services for blow molded products include:
Integrating blow molding with secondary operations can help reduce transportation between suppliers, shorten the supply chain, simplify purchasing, improve quality accountability, and accelerate finished-product delivery.
Hi-Rel Plastics & Molding provides custom plastic bottle and container manufacturing services for OEM and packaging applications requiring specialized shapes, materials, capacities, colors, finishes, and performance characteristics.
Depending on the application, our EBM, IBM, and ISBM capabilities can support development of:
Customers can combine custom blow molding with mold manufacturing, pad printing, label application, assembly, filling & sealing, testing, and custom packaging to create a more complete turnkey manufacturing program.
Medical and pharmaceutical products require controlled processes, repeatability, traceability, and strong quality systems.
As an ISO 13485:2016 certified plastics manufacturer, Hi-Rel Plastics & Molding supports custom blow molded products and packaging for medical, healthcare, diagnostic, research and laboratory, and pharmaceutical applications.
Potential applications include:
Hi-Rel Plastics & Molding’s medical manufacturing experience allows customers to combine blow molding with medical device injection molding, ISO Class 7 and ISO Class 8 cleanroom medical molding, liquid silicone rubber molding, assembly, packaging, and other secondary-operation capabilities.
Hi-Rel Plastics & Molding is an AS9100 Rev D certified plastics manufacturer supporting demanding aerospace and defense programs.
Custom blow molding can provide lightweight, durable hollow components for aerospace applications while reducing component weight and allowing complex geometries to be manufactured efficiently.
Potential applications include:
Hi-Rel Plastics & Molding’s combination of AS9100 certified manufacturing, engineering support, custom mold manufacturing, plastics processing, inspection, assembly, and secondary operations provides aerospace OEMs and suppliers with a comprehensive manufacturing resource.
Blow molding is extensively used throughout the packaging industry because it enables efficient manufacturing of lightweight, durable plastic containers in high production volumes.
Hi-Rel Plastics & Molding provides custom blow molding and blow mold manufacturing solutions for the food and beverage industry, including:
Our engineering team can help evaluate container geometry, resin selection, wall distribution, neck design, decoration, labeling, filling & sealing, and custom packaging requirements during product development.
Not every blow molded product is a bottle.
Hi-Rel Plastics & Molding’s extrusion blow molding capabilities can manufacture complex hollow plastic components for consumer and household products, automotive & EV applications, industrial equipment, agricultural and farming equipment, electronics, pet care, and other markets.
Potential products include:
Our engineering team evaluates each project to determine whether extrusion blow molding or another Hi-Rel Plastics & Molding manufacturing technology provides the best manufacturing solution.
Alternative processes may include injection molding, thermoforming and vacuum forming, rotational molding, or 3D printing and rapid prototyping.
OEMs increasingly prefer manufacturing partners capable of managing more than an individual molding operation.
Hi-Rel Plastics & Molding provides a turnkey plastic blow molding contract manufacturing solution that can combine:
Product Development → DFM → 3D Printing / Rapid Prototyping → Material Selection → Blow Mold Design → Mold Manufacturing → Sampling → Blow Molding → Inspection → Secondary Operations → Assembly → Custom Packaging
Working with one manufacturing partner can improve communication, reduce supplier complexity, provide better control over tooling and manufacturing changes, and simplify supply-chain management.
Because Hi-Rel Plastics & Molding also offers plastic injection molding, LSR injection molding, cleanroom medical molding, thermoforming and vacuum forming, rotational molding, mold and tool manufacturing, engineering, assembly, and secondary operations, OEMs with multiple plastic manufacturing requirements can consolidate programs with a broader plastics contract manufacturing partner.
Quality is incorporated throughout the manufacturing process from engineering and tooling through final inspection.
Hi-Rel Plastics & Molding Corp. maintains:
These quality systems support customers requiring a qualified plastics manufacturer for commercial products as well as highly regulated medical, pharmaceutical, aerospace, and defense applications.
Process controls, inspection procedures, documented quality systems, experienced manufacturing personnel, and engineering support help Hi-Rel Plastics & Molding maintain repeatability throughout ongoing production.
Companies searching for a plastic blow molding company in Los Angeles, blow molding manufacturer in Southern California, custom blow molding company near Los Angeles, or California blow mold manufacturer can work with Hi-Rel Plastics & Molding for complete tooling and production support.
Hi-Rel Plastics & Molding serves OEMs throughout:
Our California manufacturing presence provides OEM customers with easier engineering communication, tooling support, quality coordination, production management, and domestic supply-chain options.
Hi-Rel Plastics & Molding also supports OEMs throughout Northern California, including companies searching for plastic blow molding and blow mold manufacturing services in:
Customers can access Hi-Rel Plastics & Molding’s complete combination of blow molding, custom blow mold manufacturing, engineering, secondary operations, assembly, and contract manufacturing from a single California manufacturing partner.
Hi-Rel Plastics & Molding supports customers throughout the United States that require reliable domestic plastic manufacturing.
Whether a customer needs a new product developed, an existing blow mold transferred, additional manufacturing capacity, a replacement tool, or a complete turnkey manufacturing program, our team can support programs from initial engineering through ongoing production.
We work with OEMs searching for:
Customers can also explore the Hi-Rel Plastics & Molding Resources Center for additional plastics manufacturing information and technical articles.
Hi-Rel Plastics & Molding provides customers with the advantage of combining multiple plastics manufacturing technologies, engineering expertise, tooling capabilities, secondary operations, and certified quality systems with one manufacturing partner.
Complete Blow Molding Capabilities
Access extrusion blow molding, injection blow molding, and injection stretch blow molding for a broad range of product requirements.
Blow Mold Manufacturing
Combine molding production with custom blow mold design and manufacturing, modification, repair, maintenance, and transferred-tool support.
Engineering & DFM Support
Experienced plastics engineers help optimize product designs for manufacturability, quality, performance, tooling reliability, and production cost.
Rapid Prototyping Support
Use 3D printing and rapid prototyping to evaluate concepts and product designs before full production tooling.
Advanced EBM Process Control
Automated extrusion blow molding equipment with 200-point parison programming helps provide precise wall-thickness control and consistent material distribution.
Broad Product Range
Manufacturing capabilities support products ranging from approximately 1 mL to 7 gallons, from precision bottles to larger hollow plastic components.
Certified Quality Systems
Hi-Rel Plastics & Molding is ISO 9001:2015, ISO 13485:2016, and AS9100 Rev D certified.
Multiple Industries
Our manufacturing capabilities support medical, pharmaceutical, aerospace & defense, food & beverage, packaging, consumer products, automotive & EV, industrial, electronics, cosmetics & personal care, research & laboratory, pet care, agriculture, and other industries.
Value-Added Secondary Operations
Integrate molding with pad printing, label application, hot stamping, adhesive bonding, heat insertion and heat staking, ultrasonic welding, assembly, filling & sealing, surface treatment and enhancements, CNC machining, and custom packaging.
Multiple Plastics Manufacturing Processes
Customers can access blow molding along with injection molding, cleanroom medical molding, liquid silicone rubber molding, thermoforming and vacuum forming, rotational molding, mold and tool manufacturing, and secondary operations.
California Manufacturing Partner
Hi-Rel Plastics & Molding serves OEM customers throughout Los Angeles, Southern California, Northern California, and nationwide.
Whether your project requires a custom blow molded component, plastic bottle, container, new blow mold, transferred mold, extrusion blow molding, injection blow molding, injection stretch blow molding, or complete turnkey plastics contract manufacturing, Hi-Rel Plastics & Molding Corp. can help take your project from concept through production.
Contact Hi-Rel Plastics & Molding to discuss your plastic blow molding and blow mold manufacturing requirements, request a quote, or submit project drawings and specifications.
What types of blow molding does Hi-Rel Plastics & Molding offer?
Hi-Rel Plastics & Molding provides extrusion blow molding (EBM), injection blow molding (IBM), and injection stretch blow molding (ISBM), allowing our engineering team to evaluate the appropriate manufacturing process based on part geometry, material, production volume, performance requirements, and cost.
Does Hi-Rel Plastics & Molding manufacture blow molds?
Yes. Hi-Rel Plastics & Molding provides custom mold and tool design and manufacturing services for extrusion blow molding, injection blow molding, and injection stretch blow molding applications, along with tooling modification, repair, maintenance, and transferred mold support.
What plastics are commonly used for blow molding?
Common blow molding materials include HDPE, LDPE, LLDPE, PP, PET, PETG, PC, ABS, TPE, TPU, and specialty thermoplastics. Material selection depends on the manufacturing process and the mechanical, chemical, appearance, regulatory, and environmental requirements of the finished product.
For additional technical information, visit the Hi-Rel Plastics & Molding Resources Center and thermoplastic material selection resource.
What industries use blow molded plastic products?
Blow molding is widely used for medical, pharmaceutical, food and beverage, packaging, consumer products, personal care, automotive, aerospace and defense, industrial, household, pet care, and agricultural applications.
Can Hi-Rel Plastics & Molding take over an existing blow mold?
Existing customer-owned tooling can be evaluated for potential transfer. Hi-Rel Plastics & Molding can review the mold’s condition, compatibility, maintenance requirements, modifications, and production readiness before beginning manufacturing.
Does Hi-Rel Plastics & Molding provide secondary operations?
Yes. Hi-Rel Plastics & Molding provides a broad range of secondary services, including trimming and deflashing, leak testing, pressure testing, pad printing, hot stamping, label application, heat insertion and heat staking, ultrasonic welding, adhesive bonding, assembly, filling & sealing, and custom packaging.
Does Hi-Rel Plastics & Molding serve customers outside California?
Yes. Hi-Rel Plastics & Molding supports OEMs throughout California and across the USA, including customers seeking domestic blow molding, custom tooling, plastics contract manufacturing, and supply-chain support.
Explore Related Hi-Rel Plastics & Molding Capabilities
Customers requiring additional plastic manufacturing processes can explore Plastic Injection Molding, Cleanroom Medical Molding, Liquid Silicone Rubber Molding, Thermoforming & Vacuum Forming, Rotational Molding, Mold & Tool Making, and 3D Printing & Rapid Prototyping.
Explore additional Secondary Services, Industries Served, and plastics manufacturing information in the Hi-Rel Plastics & Molding Resources Center.
Ready to discuss a new blow molding project, existing blow mold transfer, custom bottle or container, blow mold manufacturing program, or complete contract manufacturing requirement?
Contact Hi-Rel Plastics & Molding Corp. to request a quote and discuss your project with our engineering and manufacturing team.
