Finding a plastic injection molding manufacturer that can meet strict quality standards while delivering consistent results is no easy task. Many companies struggle to balance precision requirements with production timelines, especially when regulatory compliance is non-negotiable. These challenges become even more complex when working with specialized industries like medical devices or aerospace components.
Seaway Plastics is a plastic injection molding manufacturer that provides precision molding services backed by comprehensive certifications and decades of manufacturing expertise. Our five facilities throughout the U.S. combine advanced tooling capabilities with rigorous quality control systems to support projects from prototype through full production.
Read on to learn more about our services, certifications, and the industries we serve.
ISO 13485 Certified Medical Injection Molder
Seaway Plastics is an ISO 13485 Certified injection molder that understands the complexities of producing components that meet stringent regulatory standards. Seaway Plastics maintains ISO 13485 certification across all five facilities, which demonstrates our commitment to quality systems specific to the medical device industry. This certification ensures that every part we produce follows documented procedures designed to protect patients and end-users.
Our facilities, located throughout the country, provide full turn-key solutions from design for manufacturability and engineering through production, assembly, kitting, packaging, and distribution. We leverage vertical integration to deliver efficiency, cost savings, reduced risk, and faster time to market for medical OEMs. This approach allows us to scale and support complex projects across multiple regulated industries.
Seaway Plastics offers the following services:
In-House Tooling
The in-house tool shops at each of our locations build molds ranging from Class 105 to Class 101. All our tools are designed and manufactured entirely in the United States. We produce aluminum molds, steel molds, and combination materials tailored to your resin selection, shot volume, and expected tool life. Our tooling team also handles mold transfers and stores hundreds of tools in climate-controlled warehouses for customers transitioning from other manufacturers.
Plastic and LSR Injection Molding
Our facilities support multiple molding processes, including traditional thermoplastic injection molding, two-shot molding, overmolding, and liquid silicone rubber molding. Two-shot molding creates molecular bonds between materials in a single cycle for high-volume production, while overmolding provides a cost-effective alternative for lower volumes. Liquid silicone rubber molding produces water-resistant parts ideal for seals, membranes, and electrical connectors across medical and industrial applications.
Cleanroom Injection Molding & Assembly
Our cleanroom operations span more than 25,000 square feet across ISO Class 7 and 8 certified spaces equipped with HEPA filtration systems that remove airborne particles as small as 0.3 microns. Class 7 cleanrooms exchange air 30 to 60 times per hour to control contaminants during the production of medical devices, surgical instruments, and pharmaceutical packaging. Equipment ranges from 44 to 180-ton machines with capabilities including specialized sterile packaging, material traceability, and complete cleanroom kit assembly.
Low-Volume Injection Molding
Low-volume injection molding is a versatile process for creating 100 to 10,000 units of complex and precise parts. This production method is suitable for a variety of industries, including aerospace, defense, and medical, that require rapid prototypes or limited quantities. With over 700 available resins and various mold materials, parts can be customized to meet specific project requirements and tested for functionality before large-scale production.
Post Molding Operations
A range of secondary services is available to complete the manufacturing process for plastic parts. These offerings include sonic welding and additional CNC machining when required. Seaway Plastics can also complete final assembly and provide a finished product ready for market.
Injection Molder with Medical-Grade Resins
We provide access to a wide range of state-of-the-art thermoplastic and thermoset materials. Our team helps select the ideal resin based on the performance characteristics required by the finished parts. This process ensures the final product will meet all necessary specifications and functional requirements.
Seaway customers have the opportunity to choose from a wide range of highly engineered materials.
Medical Injection Molding Materials Comparison Table
| Resin Type | Key Properties in Medical Injection Molding | Common Medical Applications |
| PEEK (Polyetheretherketone) | High strength, chemical and heat resistance, excellent sterilization compatibility (autoclave, gamma, ETO), biocompatible. | Surgical implants, dental components, orthopedic devices. |
| PC (Polycarbonate) | Impact-resistant, transparent, stable under sterilization, and good electrical insulation. | Surgical instruments, housings, IV components, and safety eyewear. |
| ABS (Acrylonitrile Butadiene Styrene) | Tough, rigid, dimensionally stable, easy to mold and finish; not ideal for repeated sterilization. | Device housings, diagnostic equipment, and disposable handles. |
| PA (Nylon) | Strong, wear-resistant, chemical-resistant; may absorb moisture unless stabilized. | Catheter components, mechanical connectors, surgical fasteners. |
| LSR (Liquid Silicone Rubber) | Flexible, biocompatible, high-purity, resistant to heat and cold, excellent for overmolding. | Seals, valves, baby care products, implantables. |
| EI (Ultem / Polyetherimide) | High heat resistance, flame retardant, transparent, autoclavable, and good dielectric strength. | Sterilizable medical trays, connectors, and diagnostic housings. |
| LCP (Liquid Crystal Polymer) | Very high flow for thin-wall molding, chemical and radiation resistant, low moisture absorption. | Micro-molded components, surgical instrument connectors. |
| PMMA (Acrylic) | Optical clarity, UV stability, rigid, biocompatible, but brittle; limited chemical resistance. | Transparent housings, lenses, and diagnostic cuvettes. |
| POM (Acetal / Delrin) | Low friction, high stiffness, excellent dimensional stability; not ideal for repeated sterilization. | Drug delivery systems, gears, snap fits, moving parts. |
| PBT (Polybutylene Terephthalate) | Good mechanical strength, electrical properties, and chemical resistance; moderate heat tolerance. | Connectors, sensor housings, diagnostic components. |
| PET (Polyethylene Terephthalate) | Strong, lightweight, clear, moisture and chemical-resistant, stable for single-use devices. | IV bags, bottles, lab containers, suture spools. |
| PUR (Polyurethane) | Highly flexible, abrasion-resistant, excellent biocompatibility, and can be soft or rigid. | Tubing, catheters, wound dressings. |
| TPU/TPE (Thermoplastic Polyurethane / Elastomer) | Flexible, durable, chemical-resistant, transparent, and easy to overmold with rigid plastics. | Medical tubing, seals, and wearable device straps. |
| PPE+PS (Polyphenylene Ether / Noryl) | High dimensional stability, good electrical and hydrolytic stability, moderate heat resistance. | Enclosures, connectors, and sterilizable device housings. |
ITAR & FDA-Registered Plastic Injection Molding Manufacturer
Industry certifications validate a manufacturer’s quality management systems and production capabilities. Holding these credentials demonstrates a commitment to meeting rigorous standards for safety, quality, and reliability.
Seaway Plastics holds the following certifications:
ISO 9001: Both of our Florida facilities hold ISO 9001 certification, which validates our comprehensive quality management system. This system ensures a uniform structure throughout the manufacturing process and a strong commitment to meeting customer needs.
ISO 13485: All five of our facilities are certified to the ISO 13485 standard for medical devices. This certification protects patients and end-users through quality assurance requirements that exceed ISO 9001 standards:
- Â Maintaining comprehensive documentation for all medical device files.
- Â Implementing strict contamination and cleanliness controls throughout production.
- Â Ensuring quality control systems are in place for sterile medical device manufacturing.
- Â Defining clear procedures for reporting to regulatory authorities.
International Traffic in Arms (ITAR): Our registration with the International Traffic in Arms Regulations (ITAR) allows us to manufacture defense articles for the U.S. military and its allies. This compliance ensures we adhere to the strict security protocols required to handle and export sensitive defense-related technology and data.
FDA: Three of our five facilities are registered with the U.S. Food and Drug Administration. This registration allows the agency to monitor medical devices and ensure manufacturers are meeting stringent quality requirements. The extensive review process is renewed every year, helping the FDA manage public health emergencies and ensure patient safety.
Precision Medical & Industrial Injection Molding
Choosing the right partner is critical for successful precision medical and industrial injection molding projects. Key considerations include production capabilities, material selection, and a proven commitment to quality through industry certifications.
At Seaway Plastics, we provide comprehensive injection molding solutions tailored to meet your specific requirements. Our team is dedicated to delivering high-quality components that adhere to the most stringent industry standards.
Click below for a quote and to learn more about our injection molding services.