To truly understand the technical connotation of extruding liquid silicone rubber, one must start from the molecular level. The basic polymer of liquid silicone rubber is linear polydimethylsiloxane with moderate polymerization degree. According to the position of functional groups in the molecular structure, it can be divided into two categories: "remote claw type" and "non remote claw type". The functional groups of remote claw type liquid silicone rubber are located at both ends of the molecular chain, while non remote claw type active functional groups are randomly distributed in the main chain. This molecular level difference directly determines the rheological behavior, vulcanization rate, and mechanical properties of the material during extrusion.

Additive formed liquid silicone rubber is the absolute protagonist in the extrusion field. It is based on vinyl containing polydimethylsiloxane as the base adhesive, with hydrogen containing silicone oil as the crosslinking agent, and undergoes addition reaction under the action of platinum catalyst. This process releases no by-products, has uniform cross-linking density, and excellent mechanical properties, making it particularly suitable for precision extrusion molding. The typical processing flow is as follows: components A and B are usually mixed in a 1:1 or 10:1 ratio through a static mixer, controlled by a cold runner system to delay curing, and then injected into an extruder for continuous extrusion and heating curing at 120 to 180 degrees Celsius and 50 to 150 megapascals. Advanced cold runner molding technology, including closed system switch pin or needle valve control, as well as open system contraction nozzle and valve channel control, can achieve efficient molding without burrs and waste, greatly reducing production cycles.

On the other hand, although condensed liquid silicone rubber has lower cost and can be operated at room temperature, the curing process releases small molecule by-products, which may affect dimensional accuracy and weather resistance. It is mostly used in scenarios such as mold manufacturing and low-end seals where precision requirements are not so strict. In extrusion applications, additive molding clearly dominates.

Looking ahead to the future, the technological evolution of extruding liquid silicone rubber is advancing in parallel along four main lines: LSR high-speed extrusion to increase production capacity, co extrusion of multi-layer composites to achieve functional integration, online diameter measurement and closed-loop control to ensure quality consistency, and intelligent production line to reduce manual dependence. At the same time, the research and development of bio based liquid silicone rubber and high-temperature and corrosion-resistant functional products is accelerating, and cutting-edge applications such as new energy lithium battery soft pack sealing, hydrogen fuel cell electrode plate coating, and degradable tissue engineering scaffolds have begun to emerge. The global liquid silicone rubber market is expected to reach approximately 3.2 billion US dollars in 2026 and continue to expand at a compound annual growth rate of 9.1%. In this technological river from molecules to pipelines, China has transformed from a follower to an important force that cannot be ignored, and those enterprises that master core processes and can provide whole line solutions will eventually stand at the forefront of this industrial upgrading.

Regarding liquid silicone rubber, please refer to our website for details: IOTA Liquid Silicone Rubber