Helvoet also specializes in precision products made in LSR Liquid Silicone Rubber. This processing technology allows short cycle times for high volume production of sealings, membranes, valves etc.  Clean surroundings and a precise process control are essential for the quality of the parts. We also produce hybrid parts (2k or k+k) combining LSR with other materials.

Controlled processes

Constant quality over millions of parts

Clean environment

Production and handling in prepared facilities

2 component products

Hybrid parts possible

Support in part design

Our engineers assist you with developing your product

Our offer for you in Liquid Silicone Rubber



Our process technologies for LSR products

Injection Moulding

LSR Moulding uses two componentes that are mixed at precise levels before injection into the mould. These liquid rubber components have characteristics of other processed rubber compounds, with the main benefit to you as a reduced cycle time and nearly no waste material. That translates to higher efficiency and more capacity.

2k Moulding

Combining two materials in one mould, such as LSR and PPP, is an efficient way to provide high volume components. 2K moulding processes save handling, improve alignment, and offer higher quality finished goods.

Transfer Moulding (K+K)

A hard component (plastic part) is produced separately and is then inserted precisely by a robot into the mould and overmoulded with the soft component LSR (self bonding LSR). With this technology it is possible to get e.g. structural products with an integrated sealing without the high investment for a 2k process.

Engineering / Development

We can develop LSR parts from scratch, employing state of the art CAD software and engineering software for FEA and moldflow studies. During development all engineers (development, material, process and application) are involved to ensure a smooth transition to production including the validation of the products.



Our processed Liquid Silicone materials can be grouped in four categories

Standard LSR

Standard LSR is available in post cure and Non-post cure types and is suitable for a lot of different applications, including products for the food tech industry.

Resistand LSR

There are a lot of different resistant LSR types developed. Examples are oil resistant and coolant resistant types, but also fluoridated LSR has been developed for a good resistance to fuels.

Functional LSR

LSR types in this category have been designed for a specific function. Examples are self-lubrication, oil sweating, ultra transparent silicone types and grades that have a low coefficient of friction.

Self-adhesive LSR

Self-adhesive LSR can be used for direct bonding to many different substrates. These materials include metal and many plastic types like PBT or PA.



Post-processing you products after moulding to finetune them


LSR compounds offer challenges removing flash as the material has a very high viscosity and does not easily come off. Helvoet uses techniques such as cryogenic deflashing, tear and dreher to remove the flash that is inherent in the process.


Like a lot of rubber components, also many LSR products can be stamped to separate them from each other or even to form them. Sometimes geometry limits moulding the final shape and in such cases stamping of parts, can be the best and most competitive alternative.

Testing / Measuring

The testing and measuring of LSR parts has to be very precise and controlled as parts are often very flexible or highly transparent. Automatical vision inspection by cameras or automated leakage tests can be essential to assure the zero-defect-quality of your product.



We offer various methods to assemble different components to a final functional product which can be used directly

Manual Assembly

Some assembly products need to be assembled by hand. Most of these components are clicked together. These products can be a combination of plastic, rubber, lsr and metal parts and are often used in the Automotive , Food and Beverage industries. If required we can offer the assembly of several parts in one of our best-cost-locations and help to reduce the total manufacturing cost for our partners.

Semi-Automated Assembly

Semi-automated assembly is done on a turn table or transfer system. In this case employees are picking and placing products in a carrier for an automatic handling like ultrasonic welding, pressing and clicking, leakage testing, laser coding or vision control. The controls on the product are made both by man and machine.

Automated Assembly

On an automated dedicated assembly line the products are transported by a bowl feeder and linear feeder. Hereby the component is transported, separated, picked and placed in a carrier on a LCS (Linear Conveyor System) and after placing, the LCS transports the product to the next station. At the end of every assembly step there is an automatic control by a sensor, vision camera, leakage test or a laser coding step. These automated assembly lines are used for ourhigh quantity products to ensure a very high efficiency and quality level.

Flexline Technology

Using over 40-years of experience in assembly of precision components, Helvoet has developed an own Flex-Line Technology. By utilizing interchangeable modules for each assembly step, Helvoet offers the quality of a fully automated line while it is a flexible and cost effective solution due to lower investment and changeover times. Contact us to get more information about the Flexline.

Product cases

Membranes and Sealings

We manufacture a wide range of rubber and LSR membranes and sealings, adapting the material to the application requirements. It is also possible to integrate a sealing function in a structural part by k+k technology.

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Dosing Systems

Accurate dosing systems are build up of accurate parts. We produce dosing devices for several customers in the food and beverage markets and integrate functional testing methods to secure nothing but the best quality.

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Medical Devices

Helvoet is able to manufacture your medical device with all its different molded parts and bought in components. If required we also handle sterilization and packaging in its final individual packaging.

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Do you want to know more?

To best help you, we have a different contact person for each part of the world.

Europe Europe
Herman Koks Key Acc. Manager Health Tech

Asia Asia
Nandan Prabhu Key Account Manager

We understand the requirements of our customers