Ge-Shen Group’s LSR Demo Product

There is a learning curve in understanding and adopting new technology. There is also no shortcut to experience. We believe that learning through the development of our own demo product is the best way for the team to get hands-on experience and to also demonstrate our readiness to our customers. I’ll walk you through the process of how we designed our LSR product and manufactured it in time for the K Fair.

In earlier posts, we talked about adding this new capability and why people would choose to use silicone rubber. LSR is a versatile material useful for making parts that are suitable for a wide variety of applications in the medical, automotive, industrial or consumer industries. However, it is a little tricky to work with. We started the process of understanding the material properties a year ago leveraging our partnerships with key material suppliers. It is key to have a good network of material suppliers with the knowledge and experience with LSR processing as we work hand in hand in developing solutions for our customers.

Designing the part

Once we had a good understanding of the material properties and how it would affect our design, we started on the project of designing our part. In choosing what to make, we wanted something useful to hand out as a demonstration item. We want our customers to think of us when they use this item. With some consideration, the team decided to design a drinking glass. Kumar – an assistant manager at Ge-Shen Plastic was brought on board to lead the design of it. We picked through 3 designs and chose one that we would go forward with.

Part design and material information in hand, we utilised our CAE flow simulation software Moldex3D to simulate the processing (link here for a brief video on LSR simulation capabilities). CAE is important in our process as it helps to identify any manufacturability issues before we get started on the tool. Any changes after a tool has been fabricated means hefty expenses and a significant delay to the project timeline.

Good tools mean fewer problems in production. Our team has many years of specialist knowledge, successfully managing many projects from diverse industries. Having an in house tool team is also vital to support any repairs, modifications or last-minute changes to tools. We have found that this is invaluable to our customers

Manufacturing the part

From a plastic injection standpoint, typical processing parameters must be reversed. LSR is a thermoset silicone rubber that vulcanises (cures) in heat. This means that instead of heating the material through the barrel and cooling it down in the mould, you must keep the material cool through the machine and heat it up in the mould.

LSR material comes in two parts, an “A” part and a “B” part. The first step is to mix them together. This happens in our specialist 2KM dosing unit. Each pail is loaded on their respective sides and careful setting of the machine ensures that they are mixed in an exact 1:1 ratio.

Whilst the material is being loaded, the team simultaneously sets up the tools and connects the heaters and thermocouples to our Arburg 520 A injection moulding machine. With the set up of the tool complete, the next step is to trial the production parameters. Based on the material specification and the simulation results. We start by establishing the processing window. The lower and upper limits should be established through calculating the theoretical processing parameters and then lowering or increasing a single parameter until failure.

The tool trial often results in some interesting events such as below where the ejector pin goes straight through the part!

After production, we laser mark to demonstrate how we can mark clear transparent LSR parts and get a bit of marketing in.

The end result

It takes a lot of work to get even a simple part designed and manufactured. Much work and effort goes into making sure that each project is a success. Thank you for following me through the manufacturing process. Hopefully you will agree with me that the result is a beautiful part with some tasteful marketing thrown in!


Contact us to find out more!