What Is Liquid Silicone Rubber Molding (LSR) ?

What Is Liquid Silicone Rubber Molding (LSR) ?

Liquid Silicone Rubber Molding (LSR)  is a high-performance two-part thermoset elastomer with organic and inorganic properties (watch this video). Silicone elastomers have typical viscosities of 500,000 – 2,000,000 cps. They are used due to their process versatility, high-temperature stability, low-temperature flexibility, excellent weather resistance, long service life, excellent sealing properties, ease of coloration, and inertness. Due to its proven application performance, LSR is commonly used in aerospace, automotive, consumer goods, healthcare, and textiles.


Made of silicon, a nonmetal found in the earth’s crust that does not occur freely in nature but is a major component of clay, quartz, rock, and sand. Manufactured in an internal planetary mixer with methyl vinyl polymer, silica filler, and additives. The orbital motion creates high shear forces to provide a homogeneous mixture of the polyvinylsiloxane matrix. After a relatively long mixing time, the base is divided into equal amounts of different additives to form “A” and “B” components:


Component A:

Platinum catalyst

Component B:

hydride crosslinking agent, the inhibitor
Material volumes are then filled into batch-matched containers, 200L (55gal) or 20L (5gal)

Advantages of LSRs:

Automated process, fast cure cycle – excellent productivity, multi-cavity molds, very low flash tolerance, high strength product, low viscosity = low injection pressure. Overmolding and two-shot capability make liquid silicone rubber one of the fastest-growing technologies in the industry.

LSR molding process:

The LSR molding process is always called the “opposite case” of the thermoplastic molding process, where the mold is hot, and the screw/barrel is cooled. When mixed in a 1:1 ratio, LSR will begin to cure at room temperature. Adding heat to the equation produces a faster curing profile, so a proper chilled water system is required to delay the curing cycle after introducing these two components. The approximate cooling temperature for the unit is 70°F. This is a 30,000 ft view, as many differences from the LSR process must be correctly specified to succeed.




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Frequently Asked Questions

Daoben has the SOP (Standard Operation Procedure) and all the production steps must follow up this SOP. Every machine needs at least automatic running over 72 hours and must be inspected carefully before shipment.

Actually, the delivery time of the machines is depended on the machine options. Normally, the delivery time of a standard machine could be within 1-2 months.

12 months warranty after shipment for mechanical parts, hydraulic parts, and electric components excluding the screw and barrel 6 months (not including use for recycled material or reclaimed material).

Yes, Daoben will provide one set of standard spare parts to the customer including a heater, filter, screw head, screw washer, checking ring, sealings, etc.

Surely, we have experienced technical engineers for oversea service, they would help you install machines and support training to workers also. Currently, we provide visits online by video call for COVID-19.

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