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HordRT Overmolding Service

What is Overmolding?

Overmolding is a manufacturing process in which a substrate or base component is covered or encapsulated with a second material, usually a thermoplastic elastomer (TPE), to create a composite product. It involves injecting the second material onto or around the first component, bonding them together to form a single integrated part. Skilled professionals like those at HordRT offer swift and precise over-molding services to assist you in designing your project

The Over-molding Process

  • First, the substrate material is prepared and placed into a mold.
  • Then, the overmolding material is injected or molded over the substrate material.
  • The two materials are bonded during the molding process, creating a strong and durable bond between them.

Rules of Overmolding Design and Production

Rules of Overmolding Design and Production

  • The best bonding is generally achieved when wall thicknesses are within the range of 0.060" to 0.120" (1.5 mm-3 mm).
  • To minimize localized stresses, it is recommended to maintain radii of at least 0.020" or 0.5mm in corners.
  • If thick thermoplastic elastomer sections are necessary for the part, it is advisable to core them out to minimize shrinkage problems, reduce part weight, and lower cycle time.
  • It is recommended to avoid deep and blind pockets or ribs in your design.
  • To prevent flow issues such as backfills and gas traps, gradual transitions between wall thickness should be used.
  • To avoid warpage, especially for flat or long parts, the thermoplastic elastomer/thermoplastics vulcanizates should be less thick than the substrate.
  • Overmolding requires mechanical or chemical bonding to the substrate. Therefore, the choice of overmolding materials should allow for this.

Applications of Overmolding

Applications of Overmolding

Commercial merchandise
Overmolding injection molding is commonly used in the production of commercial merchandise such as household appliances, office equipment, and personal care products. For example, overmolding can be used to create comfortable and ergonomic handles for kitchen utensils or cosmetic tools, providing a better user experience.
Automotive industry
Overmolding is extensively used in the automotive industry to create high-quality and durable parts such as dashboards, door handles, and steering wheels. The process can provide additional functionality, such as improved grip, tactile response, and durability, resulting in a better driving experience.
Medical industry
Overmolding is used in the medical industry to create medical devices such as catheters, hearing aids, and surgical instruments. Overmolding can create a soft and comfortable exterior layer, while the interior layer provides the necessary stiffness and support, improving patient comfort and enhancing the functionality of the device.
Electronic industry
Overmolding is widely used in the production of electronic components such as connectors, switches, and sensors. Overmolding can provide additional features such as waterproofing, shock absorption, and thermal insulation, which improves the performance and reliability of electronic products.
Beauty industry
Overmolding is increasingly used in the beauty industry to create ergonomic and comfortable handles for cosmetic tools such as brushes and applicators. The process can provide a non-slip grip, making it easier to use the products and enhancing the overall aesthetic of the product.
Difference Between Insert Molding and Overmolding
Insert molding and overmolding are two distinct processes used in the manufacturing of plastic parts. Although both processes involve molding multiple materials together, they differ in several ways.
The key difference between insert molding and overmolding is the placement and purpose of the preformed component. In insert molding, the preformed component is typically rigid and used to add strength or functionality to the final product or to reduce the post-molding manufacturing and assembly operations. In overmolding, the substrate component is the functional component, and the overmolding material is used to add comfort or aesthetic appeal.
Additionally, insert molding typically involves a preformed component that is placed in a specific location and orientation, whereas overmolding involves the substrate component being placed in the mold and the overmolding material being molded around it.

Get the Perfect Parts with HordRT Overmolding Services

Work with a professional overmolding manufacturer like HordRT.

Get the Perfect Parts with HordRT Overmolding Services

Work with a professional overmolding manufacturer like HordRT.

Over-molding FAQs

The benefits of overmolding include enhanced functionality, improved aesthetics, increased durability, improved ergonomics, better sealing and waterproofing, simplified assembly, and customization opportunities.

Common materials used in overmolding include rigid plastics (such as ABS or polycarbonate) as the base material and flexible or elastomeric materials (such as TPE or silicone) as the overmolded material.

Design considerations for overmolding include material compatibility, part geometry, bonding between materials, proper gating and venting, and the specific requirements of the end-use application.

The cost implications of overmolding can vary depending on factors such as material selection, part complexity, tooling requirements, and production volume. Generally, overmolding can add complexity and cost to the manufacturing process compared to traditional molding techniques.

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