Efficient bonding and connecting of silicone components
A process technology for creating strong and durable connections between silicone regions or parts is presented, which involves a specific combination of vacuum ultraviolet irradiation and tailored application of mechanical pressure.
Challenge
Silicone (also known as polysiloxane) is a synthetic polymer and is known for its relatively high temperature resistance, UV resistance, inert properties and chemical resistance. Silicone components such as tubes and hoses are typically connected to each other with mechanical elements (e.g. clamps) by force or mechanical connection. However, this can cause the material to be crushed and severely damaged, which can mean premature wear. Likewise, such connections are often not (air) tight enough. Alternative joining or connections methods are therefore in great demand. VUV (vacuum ultraviolet) radiation can be used for the (photochemical) activation and modification of silicone surfaces. Depending on the type of material and VUV radiation, surface properties can be changed in a targeted manner, with the aim to activate materials, achieve superior adhesion or provide functional surfaces with dirt repellency.
Our Solution
The core of the present process technology involves exposing silicone surfaces to VUV rays, combined with simultaneous or subsequent mechanical pressure in order to press the connection regions against each other and to form a strong bond. The key components of this process involve material transparency and the deformation of silicone to optimize the adhesion between two silicone components. The first and a second connecting region of the silicone objects are exposed to VUV rays, which are used to modify and activated the surface of the silicone, making it more receptive to bonding. The silicone parts are then pressed against each other. The pressure ensures the silicone surfaces come into contact and form a bond. During or after the exposure to VUV rays, the silicone undergoes elastic or plastic deformation, making the surfaces more compatible for bonding by improving surface contact. A key feature of this method is the use of a force introduction body that facilitates elastic or plastic deformation of the silicone by applying pressure. The force introduction body has a material region that is transparent to VUV rays, enabling the exposure of the silicone surfaces to the rays even through this body. The method includes bonding strategies for silicone components, whereby the first and the second connecting region are opposing inner surface areas of a silicon hose and an adhesive, lanyard or connecting body is introduced into the interstitial space between the opposite inner surface regions of the silicone hose.
Schematic representation of the silicone bonding technology using VUV radiation and mechanical pressure.
Advantages
- Efficient bonding and connecting of silicone components without clamping elements
- Enhanced bond strength between silicone components
- Versatility in silicone geometries
- Improved surface compatibility
- Efficiency in mass production
- Controlled environment (reduced impact of oxygen for high-quality connections)
Applications
- Medical device manufacturing
- Fluid handling systems
- Sealent technology
- Packaging
- Materials processing
- Process technology
- Automation technology
Development Status
Functionality has been successfully tested. Design drawings available. Prototype available.
Patent Status
European patent application: EP4574402A1
International patent application: WO2025132178A1
Patent holders:
University of Applied Sciences and Art Hildesheim/Holzminden/
Göttingen (Germany)
Sartorius Stedim FMT (France)
Contact
Dr. Mirza Mačković
Patent & Innovation Manager Technology
E-Mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
Tel.: +49 551 30724 153
Reference: CPA-2391-HAWK
Tags: Synthesis and Process Technology, Physics and Technology & Software, Medical technology
