Precision Insert Molding for Thermoset Plastics

MCM Composites delivers industry-leading precision with tolerances as tight as ±0.0015 inches, backed by our ISO 9001:2015 certification that ensures consistent quality throughout every project. Our precision manufacturing capabilities extend across an impressive range of part sizes, accommodating injection molded components weighing from just 0.1 grams up to 10 pounds, while our compression molding services can handle even larger parts weighing up to 80 pounds.

This exceptional precision is made possible through our advanced quality control systems and experienced engineering team who understand the critical importance of dimensional accuracy in insert molding applications. Whether you’re manufacturing delicate electronic components or robust automotive parts, our precision manufacturing processes ensure that every insert is perfectly positioned and every tolerance is maintained throughout production runs ranging from single prototypes to millions of parts annually.

±0.0015″ tolerances with ISO 9001:2015 certification

Part Weight Range:

• Injection molding: 0.1 grams to 10 lbs
• Compression molding: up to 80 lbs

MCM’s manufacturing facility houses state-of-the-art injection molding presses ranging from 75 to 500 tons, complemented by compression molding equipment spanning 50 to 800 tons of clamping force. This extensive range of tonnage capabilities allows us to handle everything from intricate small parts requiring precise insert placement to large structural components demanding significant molding force.

Our thermoset injection molding systems feature specialized capabilities that set us apart from typical molding operations. The degas sequence removes trapped air and volatiles from the molding compound, ensuring void-free parts with superior mechanical properties. Gate cut sequence technology provides clean part ejection without manual finishing, while core pull mechanisms enable complex geometries with undercuts and internal features that would be impossible with conventional molding.

Perhaps most importantly for insert molding applications, our runnerless injection compression systems deliver exceptional material flow around inserts while minimizing stress concentrations. This technology ensures that the thermoset material completely encapsulates inserts without creating weak points or air pockets that could lead to premature failure. The combination of precise temperature control, consistent pressure application, and automated cycle monitoring means every part meets the exacting standards required for demanding applications in automotive, aerospace, and electrical industries.

75-500 ton injection presses
50-800 ton compression presses

Specialized systems with degas sequence, gate cut sequence, core pull, and runnerless injection compression capabilities.

When your components must perform reliably in extreme environments, MCM’s thermoset insert molding solutions deliver superior mechanical performance at operating temperatures up to 204°C (400°F). This exceptional heat resistance stems from the fundamental chemistry of thermoset materials, which undergo irreversible cross-linking during the curing process to create a three-dimensional molecular network that maintains its structural integrity even under prolonged thermal stress.

Beyond temperature resistance, our thermoset materials exhibit outstanding chemical resistance to oils, automotive fluids, hydraulic fluids, and corrosive environments that would quickly degrade traditional thermoplastic components. This chemical stability makes our insert molded parts ideal for under-hood automotive applications, industrial equipment exposed to harsh chemicals, and electrical components that must maintain their insulating properties in challenging environments.

The combination of high-temperature performance and chemical resistance means that components molded from our thermoset materials won’t soften, warp, or lose their dimensional stability even when exposed to temperature cycling, chemical exposure, and mechanical stress simultaneously. This reliability is particularly crucial in insert molded assemblies where the integrity of the bond between the insert and the molded material determines the overall performance and lifespan of the finished component.

Our materials maintain their mechanical properties across their entire operating temperature range, ensuring that critical characteristics like tensile strength, impact resistance, and dimensional stability remain consistent whether the component is operating at room temperature or approaching its maximum service temperature.

Up to 204°C (400°F) operating temperature

Superior mechanical performance under extreme conditions with excellent chemical resistance to oils, fluids, and corrosive environments.

Thermoset Resins We Work With: (please verify and cut if you dont use one)We use all

• Phenolics: Our phenolic materials offer exceptional heat resistance and dimensional stability, making them perfect for electrical applications where thermal cycling and electrical insulation are critical requirements.
• Alkyds: Alkyd resins provide excellent surface finish and chemical resistance, particularly valuable in applications requiring both aesthetic appeal and functional performance.
• Polyester: Our polyester thermosets, available in both bulk molding compound (BMC) and sheet molding compound (SMC) formats, deliver outstanding strength-to-weight ratios with excellent chemical resistance, making them ideal for automotive and industrial applications.
• Epoxies & Melamine Phenolics: Epoxy-based materials in our portfolio offer superior adhesion to metal inserts and exceptional mechanical properties, while melamine and melamine-phenolic compounds provide outstanding arc resistance and flame retardancy for electrical applications.
• Carbon Fiber Compounds:  Carbon fiber compounds represent the pinnacle of performance, offering exceptional strength and stiffness while maintaining the processing advantages of thermoset materials.
• Vinyl Ester: Vinyl ester resins complete our material range with superior corrosion resistance and excellent mechanical properties, particularly in applications involving exposure to acids, bases, and organic solvents. The availability of these materials in both BMC and SMC formats provides additional flexibility in part design and manufacturing optimization.

Available in multiple formats: Bulk Molding Compound (BMC) and Sheet Molding Compound (SMC) for polyester and vinyl ester resins.

MCM’s technical capabilities span the complete range of mold configurations and production requirements that modern insert molding demands. Our single-cavity molds excel in prototype development and low-volume production where design flexibility and quick iterations are paramount. Multi-cavity tooling maximizes production efficiency for high-volume applications while maintaining the precision and consistency that insert molding requires.

Family molds allow us to produce multiple related parts in a single molding cycle, optimizing material usage and reducing per-part costs for assemblies requiring several different components. Our specialized insert molding capabilities accommodate complex geometries where inserts must be precisely positioned and permanently bonded within the finished part.

Our platen size range from 18.7″ x 20.7″ to 67.0″ x 63.0″ provides the flexibility to handle both compact precision components and large structural parts within the same manufacturing facility. This range ensures optimal material utilization and cycle times regardless of part size, while our experienced tooling engineers design each mold to maximize both part quality and production efficiency.

Production volume flexibility is a cornerstone of our service offering, with capabilities spanning from single prototype parts for design validation through annual production runs exceeding one million parts. This scalability means that customers can rely on MCM throughout their entire product lifecycle, from initial concept development through high-volume manufacturing, without needing to change suppliers or re-qualify processes.

Mold Capabilities: Single-cavity, Multi-cavity, Family, and Insert molding
Platen Size Range: 18.7″ x 20.7″ to 67.0″ x 63.0″
Production Volumes: 1 piece to over 1,000,000 parts annually