Silicone Over Molding
- LSR Over Molding Technology
- HCR Over Molding Technology
- Custom Over-molding Service
Overmolding Introduction
Silicone over molding is a cost-effective method for precise silicone parts manufacturing with two different materials. This technology is applied in various application, such as waterproof, air-proof, aesthetics and comfort.
Since different properties of LSR and HCR, we apply these two materials in different applications. LSR overmolding can create high precise gasket for waterproof or air-proof. Meanwhile, LSR flashing requires professional removal procedure to ensure waterproof level of IP86, and soft-touch of gaming keypads.
HCR overmolding has advantages of low cost and high production capability, we normally apply this technology to produce conductive silicone keypads. These over-molded parts also have characteristic of tactile feedback, chemical resistance and long-lasting quality.
Silicone Overmolding Technology
Silicone over-molding is the technology to mold silicone rubber onto thermoplastics, metals or other substrates. These over-molded silicone can absorb shock, act sealing, separate internal component. The most critical issue in silicone over-molding is protecting the insert or substrate. The mold should be designed carefully to keep the insert and substrate in place, in order to withstand injection pressure and avoid insert crushing in tight clearances.
Another important aspect of silicone over-molding is to achieve adhesion between silicone and plastic or metal substrate. This adhesion can be achieved by several ways, mechanical interlocking, primer, self-adhesive silicone. Furthermore, we should keep inserts or substrates clean, pre-heat plastic and metal inserts. In order to avoid any chemical inhibition of silicone curing, and achieve stronger adhesive bond.
Adhesion Bond Method
- Mechanical Interlocking: We can adjust the design structure of insert or substrate, add undercut features to lock and hold silicone rubber in place.
- Primer: Primer is another option for excellent adhesion bond. Normally, we need 30 minutes to 2 hours to dry off primers. Then over-mold the inserts with silicone rubber by good bond.
- Surface Treatment: Liquid silicone (LSR) can resist water, oxidation and other chemical solutions like acids and alkali.
- Self Adhesive LSR: Several LSR materials have self adhesion characteristics, these LSR can bond to plastics without primers and surface treatments. Liquid silicone rubber can bond well with Polycarbonate (PC), PolyEthylene Terepthalate (PET), PolyButylene Terepthalate (PBT), PolyPhenylene Sulfide (PPS), PolyEther Ether Ketone (PEEK) and Nylons (PA).
Silicone Over-molding Materials
HCR (high-consistency-rubber) and LSR (liquid silicone rubber) are two common silicone materials to overmold with the substrates by compression molding or injection molding. Because of different vulcanizing agent in HCR and LSR. Normally, LSR has low molding temperature then HCR in over-molding process.
| Silicone Materials | LSR (Platinum Vulcanization) | HCR (Platinum Vulcanization) | HCR (Peroxide Vulcanization) |
| Molding Temperature | 120℃-150℃ | 130℃-140℃ | 170℃-180℃ |
LSR Over-molding
Miwo is the leading manufacturer of LSR over-molding in China. Our company has advanced production capability, outstanding quality control, more than 20 years of exclusive experience in LSR over molding. We are the ideal partner for your liquid silicone rubber parts project.
LSR over-molding is a cost-effective manufacturing technology for complicated assemblies with gasket, seal or fragile silicone rubber parts. This technique also provides LSR parts for applications with high tolerance and reliable performance. Regardless of parts performance enhancement, LSR over-molding also result in significant cost saving in assembly. The chemical and mechanical bond LSR to thermoplastic in LSR over-molding is a popular solution, this process also applied to create durable bond of metals and LSR with integrated adhesive or mechanical bonding.
We provide value-added service in every stage of LSR over-molding, from design, prototyping to packing, delivery. Our engineering team will assist you to finish your silicone projects faster with less cost. Based in China, we can easily fulfill global order from Asia, Europe, America, Oceania and Africa.
HCR Over-molding
Miwo is the leading manufacturer of HCR over-molding in China. Our company has advanced production capability, outstanding quality control, more than 20 years of exclusive experience in HCR over molding. We are the ideal partner for your liquid silicone rubber parts project.
HCR over-molding is a cost-effective manufacturing technology for complicated assemblies with gasket, seal or fragile silicone rubber parts. This technique also provides HCR parts for applications with high tolerance and reliable performance.
Silicone Over-Molding Benefits
LSR over molding is a cost-effective and versatile technology, which is applied in various industries and applications. Over-molding with liquid silicone injection enable us to produce aesthetic products with a wider range of colors and styles.
In addition, designing products with liquid silicone rubber (LSR) over-molding can improve products safety to against electric shocks, protect sharp or delicate areas, optimize products shape for comfortable usage. For repetitive usage medical instruments, LSR over-molded products are autoclavable, Liquid silicone rubber (LSR) formulations are ISO 10993 implantable grade and USP class 6 compliant for FDA requirement. From LSR over molded handles to complex electronic assemblies, there are multiple benefits of LSR over molding.
- Saving Cost and Time: Complex manual assembly will be eliminated by molding silicone directly onto the metal or plastic substrate. This will reduce manufacturing costs and turnaround time dramatically, and encourage our LSR part to a more economical level. It will also eliminate the risk and cost in secondary assembly.
- Design Flexibility: LSR over molding is excellent for complex design requirements in automotive and medical industries. Our LSR over-molding parts have properties of waterproof, airtight, shock and vibration resistance.
- High Quality Control: Miwo Silicone has high tolerance and strict quality control in LSR over-molding process, our LSR parts are suitable for any application with high precision. We can produce over molded silicone parts with your specifications, including Class Ⅶ or Class Ⅷ cleaning room manufacturing.
- Extend Product’s Life Span: Silicone over-molding can add waterproofing, shock and scratch resistance features on final over-molded products, in order to extend products or tools life span.
- Reduce Vibrations and Noise: Silicone as an elastomer has excellent elongation properties, it can absorb shocks efficiently, and reduce vibrations and noise in device assembly.
Custom Silicone Over-molding
Miwo has concentrated on silicone molding for 20 years, we are the most experienced manufacturer of silicone over-molding technologies. Our expertise encourage us to tailor the entire process for your specific demands, take your custom innovation into a new level.
We are the leading silicone parts manufacturer in China, we are able to serve all enterprise and companies in worldwide. Our advanced capability can encompass every aspect from design to production. We can assist you to select the perfect LSR grade, optimize design manufacturability (DFM), provide premium-quality tooling, high-volume production and packing solutions. Our high-quality LSR parts are widely applied in automotive, medical,