At SIMTEC, we work with our customers in the early phases of a project in order to gain a more thorough understanding of the project requirements. This allows us to provide a customized solution that will best meet customers’ functional and performance objectives. When customers need LSR components that combine two different materials or substrates with secondary operations choosing the best process requires a careful evaluation.
How SIMTEC Determines the Best Solution
Proprietary Part Evaluation Tool
SIMTEC has been supplying precision LSR injection molded components for two decades. Our team of experts has a combined 50 years of LSR material performance and LSR injection molding experience.
To help determine the best option for producing multi-material components that offer the greatest value, SIMTEC and the RICO Group have developed a proprietary tool used to evaluate the customer’s multi-material component.
This tool takes into consideration part geometries, materials, performance requirements, and other factors in order to analyze, calculate, and surmise the manufacturing option best suited.
With this information, SIMTEC experts then apply their in-depth knowledge, experience, and understanding of the customer’s specific needs to provide a customized solution that will meet the exact requirements.
Manufacturing Options for Multiple-Material Components:
Two-Shot Molding: The two-shot (2k) injection molding process combines LSR with a second LSR material or with another polymer-based substrate in the same molding process and press.
During the 2k process, the surface energy is elevated allowing for LSR (injected second) to chemically bond to the first shot, providing a superior bond between the two material substrates. This two-shot process is a superior process compared to overmolding because it prevents oxidation of the substrate surface; and offers accurate cavity-to-cavity designation and precision shut-offs for a stable, high yield process.
Examples of 2-Shot Components: Integrated seals for housings, weathering covers, expandable bladders, flexible buttons, dispensing/dosing valves, pressure sensing diaphragms, and pumping bladders
Multi-Shot Molding: In the multi-shot injection molding process three or more polymers/substrates are combined.
This could include two or more LSRs, an LSR combined with other polymer-based materials, or LSR with a polymer material and non-polymer substrate.
The multiple materials and substrate are molded together in the same molding cell producing a fully-integrated multi-material component with superior bonding. Molds for each of the materials are housed in a specialized multi-injection molding machine and requires an experienced molder for precision alignment and full integration.
Examples of multi-shot components: Parts containing seals, flexible buttons, handles, caps, enclosures
LSR Overmolding: In the overmolding injection molding process, a finished molded component or a non-polymer substrate is covered, bonded or encapsulated with liquid silicone rubber during the molding process.
Overmolding is the manufacturing option chosen when LSR is added to a non-moldable metal substrate such as aluminum, stainless steel, titanium, or to a finished plastic component.
In the overmolding injection molding process, a finished molded component or a non-polymer substrate is covered, bonded or encapsulated with liquid silicone rubber during the molding process. Overmolding is the manufacturing option chosen when LSR is added to a non-moldable metal substrate such as aluminum, stainless steel, titanium, or to a finished plastic component.
goes beyond typical injection molding by covering, bonding or encapsulating a substrate or molded component with liquid silicone rubber during the molding process. In other words, overmolding is the manufacturing option when you are looking to mold an LSR component to aluminum, stainless steel, or plastic part.
Examples of overmolded components: Rimmed metal enclosures, medical instruments and devices, baby bottles and pacifiers, consumer electronics
Post-Molding Substrate Integration
In the case that it is not the best option to combine an LSR component with other components or substrates within a molding operation- due to the parts’ design features, dissimilar weight/volume, molding temperatures or other factors – a post-molding secondary process is chosen (adhesion bonding, ultrasonic welding, etc.).
- Traditionally, secondary joining or assembly processes use manual or semi-automated operations, and require working with multiple suppliers. The use of manual or semi-automated processes can result in inconsistent part alignment and quality issues. Working with multiple suppliers can present additional challenges including logistics and quality tracing issues between suppliers and increased handling that can result in an increased opportunity for errors.
- Value-Added Inline Post-Molding Process: Alternatively, if the secondary process can be automated and performed inline within the same manufacturing cell as the molding, the supply chain is trimmed, and quality and consistency challenges mitigated. With robotic automation, the process is more efficient and provides consistent exact part positioning for precision accuracy and enhanced quality.
If you have a multi-material component need, contact us today to discuss manufacturing options with a SIMTEC expert.
Partnerships Built on Mutual Collaboration & Learning
Early involvement and collaboration are key to acquiring a thorough understanding of a project and customers’ needs.
SIMTEC gets involved early– providing design support, material selection, prototype and pilot production, simulations, and FEA calculations.
SIMTEC offers interactive Lunch-and-Learn meetings to allow SIMTEC’s and customers’ engineering teams to collaborate and share knowledge.
These technical discussions are tailored for part-specific, customer-specific topics and add great value to projects. Whether onsite at SIMTEC’s state-of-the-art facility in Miramar, Florida; at customers’ facilities; or virtually with personalized webinars, these meetings allow for the exchange of valuable technical information.
Discussion topics include technical information about LSR, LIM and Quality Systems as well as design guidelines for optimizing part designs and manufacturability based on each customer’s unique parts.
To request a customized lunch and learn for your team or for more information, contact our team today!