Newark, NJ
1. Mira Plastics Co., Inc.
Located in Newton, NJ (approximately 50 miles from Newark), serving Northern New Jersey and the NYC metro area
Address: 123 Fredon Springdale Road, Newton, NJ 07860
Phone: (973) 383-6380
Website: https://www.miraplastics.com/
Email: sales@miraplastics.com
Founded: 1955
Facility: 62,000 square feet
Services:
Custom thermoplastic injection molding, 3D CAD part design, 3D injection molding simulation analysis, 3D prototype printing, ultrasonic welding (up to 2,000 watts), hot stamping (up to 15 tons), heat transfer decal, threaded heat staking
Industries Served:
Medical, automotive, consumer products, electronics, industrial, packaging
Highlight:
Family-owned operation established in 1955 with nearly 70 years in the injection molding industry. Mira Plastics operates a 62,000 square foot facility powered entirely by solar energy, making them one of the few “green” plastic molding companies in the region. They are experts in two-plate, three-plate, runner-less, and hydraulic core pull molds, with robotics-enhanced parts removal systems. Their rheological expertise allows optimization of thermoplastic polymers, resins, colorants, and additives for any project.
2. Montrose Molders, Inc.
Address: 101 Harmich Road, South Plainfield, NJ 07080
Phone: (908) 561-6464
Website: https://www.montrosemolders.com/
Founded: 1970s (50+ years in operation)
Facility: 51 injection molding machines
Services:
Custom plastic injection molding (high and low volume), precision plastic components, tooling and die services, contract manufacturing
Industries Served:
Medical, consumer products, industrial, electronics, packaging
Highlight:
Over 50 years of experience as a custom plastics manufacturer with 51 injection molding machines ranging from 40 tons to 1,000 tons of clamp force. Montrose handles projects of any size, from prototype development to high-volume production runs. In 2023, the company joined Nelson Miller Group (NMG), a provider of custom engineering design and manufacturing services founded in 1937, expanding their value-added capabilities and strengthening their commitment to quality and customer care.
3. Madan Plastics, Inc.
Address: 7 South Avenue East, Cranford, NJ 07016
Phone: (908) 276-2600
Website: https://www.madanplastics.com/
Services:
High-tonnage injection molding, custom plastic injection molding, tool building, large part molding, mold making, engineering, secondary operations
Industries Served:
Industrial, automotive, consumer products, medical
Highlight:
Cranford-based manufacturer specializing in high-tonnage injection molding capabilities for large plastic parts. Madan Plastics provides comprehensive services from tool design and building through production, offering engineering support and secondary operations. Their location in Union County provides excellent logistics access to the greater New York metropolitan area and throughout the Northeast corridor.
Paterson, NJ
1. Bennett Plastics, Inc.
Address: 22 Kentucky Avenue, Paterson, NJ 07503
Phone: (973) 684-1501
Website: https://www.bennettplastics.com/
Founded: 1982
Facility: 36,000 square feet
Services:
Custom plastic injection molding, precision mold design, Fast-Track Mold Insert Program, design assistance, assembly, packaging
Industries Served:
Medical, consumer products, electronics, industrial, packaging
Highlight:
Family-owned and operated business manufacturing in Paterson since 1982, located just 15 minutes from New York City. Bennett Plastics produces millions of injection molded parts annually from their 36,000 square foot facility. Their Fast-Track Mold Insert Program delivers molded product samples in as little as 5 weeks, minimizing upfront tooling costs. The company emphasizes sustainability through eco-friendly materials, energy-efficient processes, and responsible manufacturing practices, with all products proudly made in the USA.
2. Injection Works
Address: 8000 Lincoln Drive West, Suite 100, Mount Laurel, NJ 08054
Phone: (856) 778-6206
Website: https://www.injectionworks.com/
Founded: 1994 (30+ years in operation)
Facility: 46,000 square feet
Services:
Custom thermoplastic injection molding, cleanroom molding (Class 100,000), engineering support, secondary operations, assembly
Industries Served:
Medical, pharmaceutical, consumer products, industrial, electronics, automotive
Highlight:
New Jersey-based injection molder celebrating over 30 years in business with 22 injection molding machines ranging from 22 to 720 tons of clamping force. Injection Works operates both traditional and Class 100,000 cleanroom environments, with extensive experience in commodity and engineered resins including ABS, polycarbonate, nylon, PEEK, and medical-grade materials. The company joined Nelson Miller Group (NMG) in 2023, expanding their custom thermoplastic injection molding capabilities and value-added services.
3. Inman Molding & MFG Co., Inc.
Address: 31 Church Street, Lodi, NJ 07644
Phone: (973) 473-5524
Website: https://inmanmolding.com/
Services:
Custom injection molding (50 to 300 ton presses, 30 oz shot size), insert molding (metal to plastic, plastic to plastic, ceramic to plastic), silicone rubber injection molding, mold design and fabrication, sonic welding, die cutting, hot stamping, assemblies
Industries Served:
Healthcare, defense, automotive, HVAC, electronics, industrial
Highlight:
Full-service custom injection molder specializing in diverse materials including olefins, PVC, ABS, polycarbonate, and engineering grades. Inman Molding offers proprietary silicone rubber injection molding processes and insert molding capabilities for specialty wire harnesses using horizontal and vertical shuttle equipment. Their in-house mold shop uses AutoCAD and SolidWorks for prototype development through full-scale production tooling.
Notes
New Jersey’s plastic injection molding industry benefits from strategic positioning between New York City and Philadelphia, two of the largest metropolitan markets in the United States. The state’s extensive highway network (I-78, I-80, I-95, NJ Turnpike) and proximity to major ports and airports creates ideal logistics for serving Northeast manufacturers and national distribution.
Northern New Jersey companies like Mira Plastics and Bennett Plastics demonstrate the region’s strength in family-owned manufacturing operations, with several firms maintaining 40+ years of continuous operation. The 2023 acquisitions by Nelson Miller Group of both Montrose Molders and Injection Works signal continued consolidation and investment in the New Jersey injection molding sector.
Notable capabilities in the region include cleanroom manufacturing for medical devices, high-tonnage presses for large industrial parts, and sustainable manufacturing practices. Mira Plastics’ solar-powered facility represents growing emphasis on environmental responsibility in plastics manufacturing.
Research conducted January 2026. Verify all information directly with companies before business engagement.