Insert molding is a unique manufacturing method that allows manufacturers to integrate plastic or metal inserts into a molded component. Insert molding supports a range of design options while offering enhanced functionality and superior durability.
RD Rubber Technology Corporation is a leading rubber insert molding service provider with over 35 years of experience delivering engineered-quality products for a wide range of industries including aerospace, space, defense, food and dairy processing, and other demanding regulatory industries. We offer custom solutions for critical-to-function applications, leveraging sophisticated technology and deep expertise to realize engineered-quality products. We are known for delivering superior solutions and customer service.
What Is Rubber Insert Molding?
Rubber insert molding (also known as rubber-to-metal bonding) is a process where a pre-formed substrate-typically made of brass, stainless steel, aluminum, or high-temperature plastic is placed into a mold cavity. High-performance elastomer material is then injected or compressed around the insert, creating a permanent, seamless bond.
At RD Rubber, we utilize advanced rubber injection molding, transfer molding, and compression molding techniques to ensure every part meets the exacting tolerances required by mission-critical industries.
The Rubber Insert Molding Process
Rubber insert molding process follows several steps, including:
- Engineering & Material Selection: We consult on elastomer compatibility (Silicone, Viton™, EPDM, Nitrile) and substrate preparation to ensure maximum bond strength.
- Substrate Preparation: To achieve a bond stronger than the rubber itself, we use specialized primers and surface treatments (mechanical or chemical) before the molding cycle.
- Insert Placement: Inserts are precisely loaded into custom-engineered tooling.
- Vulcanization & Bonding: Under controlled heat and pressure, the rubber flows around the insert and vulcanizes, creating a chemical bond.
- Quality Inspection: Parts undergo rigorous testing, including pull-tests and visual inspections in our ISO 9001:2015 and AS 9100:2016 certified facility.
Key Benefits of Rubber Insert Molding
Rubber insert molding delivers several notable benefits, including:
- Improved product durability and strength (due to its integration with different materials) for a robust and solid finished product
- Lowered manufacturing labor costs with rapid assembly time and reduced additional component requirements
- Increased flexibility, which can be leveraged to create multifunctional parts and complex geometries for various project requirements
- Enhanced assembly process that produces a single integrated product, increasing efficiency while reducing labor costs
Rubber Insert Molding vs. Overmolding: What’s the Difference?
While both processes combine materials, rubber insert molding involves placing a pre-manufactured component into the mold before the rubber is added. Rubber overmolding typically involves molding one material over another in a multi-shot process.
Each process also has its unique advantages:
- Rubber insert molding is the preferred choice for incorporating threaded fasteners, electrical contacts, and structural reinforcements.
- Rubber insert molding delivers superior durability and strength by integrating the insert with the injected rubber or plastic material.
- Rubber overmolding is a superior solution for introducing secondary features to a component, offering a flexible option for a breadth of manufacturing projects.
High-Performance Materials & Industry Applications
Common materials used to produce parts with the rubber insert molding process include elastomers such as:
- Liquid Silicone Rubber (LSR)
- Fluorocarbon (Viton™)
- EPDM
- Neoprene
- Nitrile (NBR)
Rubber insert molding is used to produce parts for many different applications in many industries:
- Aerospace & Defense: Bonded seals, poppet assemblies, and vibration mounts.
- Medical Devices: Biocompatible overmolded handles and internal valve components.
- Electronics: Encapsulated connectors and weather-proof housings.
Advantages of Choosing RD Rubber
When you choose RD Rubber for your rubber insert molding project, you will benefit from our expertise and extensive industry knowledge. We meet your project deadlines and maintain rapid lead times.
Our team delivers comprehensive support from the initial design phase and prototyping to final production, ensuring seamless delivery of the final product.
Get Started With RD Rubber’s Insert Molding Services
Rubber insert molding delivers superior product functionality and durability by encapsulating metal or plastic inserts in injected rubber. Insert molding can be rapidly completed with fewer processes than conventional assembly options to produce a single component with enhanced structural integrity.
RD Rubber Technology Corporation is ready to improve your product’s reliability and performance with our custom molding services. Contact us or request a quote to speak with an expert about our full capabilities.
Frequently Asked Questions (FAQs)
Q: Can you bond rubber to any metal?
A: Most metals like steel, brass, and aluminum can be bonded using specialized primers. We also offer rubber-to-plastic bonding for high-performance thermoplastics.
Q: What tolerances can be achieved with insert molding?
A: We work to precision tolerances tailored to your application. Our engineering team provides manufacturing and process engineering to ensure consistent results.
Q: Does RD Rubber provide prototyping for insert molded parts?
A: Yes, we offer prototyping services to help you validate designs and bond strength before moving into full-scale production.
