Manufacturers across industries from automotive, consumer goods, and healthcare, use a liquid injection molding (LIM) process to create silicone rubber parts that are durable and easy-to-mold.
The current LIM process utilizes a two-part liquid silicone rubber system. Typically, the Part A base polymer contains a catalyst to begin the crosslinking process. The Part B polymer usually has the inhibitor blended in to control the rate of cure. Once The two parts are blended 1:1 through the dosing unit the chemical reaction starts, and the final molded part is produced. In this process the cure kinetics are built into the two-part system, with limited variation that can be made by adjusting temperature of the mold.
It is most common to use liquid silicone rubber for injection molding, especially in the healthcare industry, due to its superior characteristics:
- Hypoallergenic and biocompatibility
- Chemical inertness, resistant to oils, solvents, and stain
- Dielectric and insulating properties
Manufacturers require easy-to-process materials that can produce parts efficiently and cost-effectively while giving them the flexibility to experiment with different blends to find the ideal functioning product.
Liquid Injection Molding of Silbione® LSR SELECT™
The medical grade LSR SELECT™ product range, Silbione® LSR SELECT™, is a patented, advanced system of materials designed to enhance the operation, control, flexibility, and productivity of liquid silicone rubber injection molding processes for healthcare and medical applications. Unlike the traditional two-component LSR system for injection molding, Silbione® LSR SELECT™ is a single component base polymer that cures when mixed with the LSR SELECT™ CONTROL and CATA using a specific dosing system. Molders can select the amount of additives in the mixing process, giving them control over the cure kinetics if the material. This allows them to speed up or slow down the cure for their part.
This new process for injection molding gives the molder more freedom of design and processing of parts. They can achieve multiple capabilities all in one solution:
- Optimized cure kinetics that can result in cycle time improvements in the 15–50% range
- The ability to select a custom blend of LSR SELECT™ to obtain desired durometer performance from 20 to 70
- Achieve cure temperatures with LSR SELECT™ as low as 80 °C
This system provides:
- Improved productivity through controlled cure initiation resulting in efficiency and productivity gains
- Better process control to improve part appearance and increase part acceptance rate
- Optimized capital investments with shorter cycle times resulting in increased part making capacity per press and increased profitability
With the dosing system, molders can use two different base durometers and blend them together to achieve a precise hardness to fit their product requirements. This ability of material blending allows for:
- Better control over unique and precision hardness requirements
- Customized durometer blends to control end product performance
Low Temperature Cure
LSR SELECT™ products can cure at temperatures as low as 80oC and possibly at lower temperatures. This ability can expand the range of applications and substrates in injection over molding. Many current thermoplastics used in the healthcare industry cannot withstand the higher curing temperatures required of LSRs. Over-molding of sensitive electronics can also be achieved using the lower cure temperature offered by Silbione® LSR SELECT™.
Discover the possibilities of Silbione® LSR SELECT™ for healthcare devices and applications, backed by the Elkem Silicones Silbione® brand including clean manufacturing and biocompatibility support. We offer innovative solutions, expertise and services to improve your performance, competitiveness and profitability.
Discover the possibilities of LSR SELECT™ for healthcare, backed by Elkem’s Silbione® brand for high quality, clean manufacturing and biocompatibility support. Contact us through our website or call 866-474-6342 to learn more about how Silbione® LSR SELECT™ can help you improve your productivity performance, competitiveness and expand your range of applications.
Elkem Silicones is one of the world’s leading fully integrated silicone suppliers, operating 9 multi-functional manufacturing sites and 11 R&D centers around the globe. The company has more than 3,100 employees worldwide dedicated to providing high quality silicone solutions with a personal touch to deliver your potential. www.silicones.elkem.com