Liquid silicone sealing ring is a high-performance sealing component, which is not made from traditional solid silicone rubber raw materials (such as rubber compound) through molding or cutting, but is manufactured from liquid silicone rubber through injection molding process. This gives it significant advantages in both performance and appearance.

What is liquid silicone rubber?

Liquid silicone rubber is a high-purity two-component silicone material, divided into component A (base rubber) and component B (crosslinking agent catalyst). Before injection molding, the two components are mixed in a 1:1 ratio using a precision metering pump and injected into the mold for rapid vulcanization molding under heating conditions.

Main characteristics and advantages of liquid silicone sealing rings

Excellent high and low temperature resistance

The usual operating temperature range is between -60 ℃ and+200 ℃, and it can withstand higher temperatures in the short term. This makes it suitable for high-temperature environments such as hot water, steam, and car engine compartments, as well as low-temperature environments for refrigeration equipment.

Extremely high chemical and physiological inertness

Has good resistance to water, ozone, alcohol, various chemicals, and solvents.

Non toxic and odorless, compliant with FDA (US Food and Drug Administration), LFGB (EU Food Contact Materials Regulation) and other certifications, widely used in the fields of food, mother and baby, and medical care.

Excellent elasticity and compression permanent deformation

Even after prolonged compression, it can quickly restore its original state, maintain long-lasting and effective sealing force, and prevent leakage. This is a key indicator for measuring the performance of sealing rings.

High precision and ability to form complex structures

LSR has low viscosity and good fluidity, and can fill extremely fine and structurally complex mold cavities.

Sealing rings with side holes, inverted buckles, and irregular structures can be injection molded in one go, which is difficult to achieve with traditional O-rings.

Excellent appearance and consistency

The injection molding process has a high degree of automation, with almost no burrs in the production process. The product size stability is excellent, and the batch difference is very small, ensuring the high quality and consistency of each product.

Good electrical insulation performance

It is an excellent insulation material suitable for sealing electronic and electrical products, such as waterproof connectors, charging interfaces, etc.

Transparency and Coloribility

The base material can be transparent and easy to dye into various bright and durable colors, making it convenient for product identification and classification.

Liquid silicone vs. solid silicone (traditional molded silicone) sealing ring

Characteristics: Liquid silicone sealing ring, solid silicone sealing ring

Raw material form liquid, two-component solid, mixed rubber (raw rubber+filler)

Production process: Injection molding, fully automatic compression molding, semi-automatic

Extremely high production efficiency, short vulcanization time (several seconds to tens of seconds), can be produced in multiple cavity molds with lower efficiency, long vulcanization time, limited number of cavities

The product has extremely high precision, stable dimensions, and no or very few burrs. There may be burrs, which require subsequent trimming

The structural complexity is extremely strong, and the ability to form complex three-dimensional structures is weak, usually simple two-dimensional structures (such as O-rings)

The production cost of molds is high, and the cost per piece is low (suitable for large quantities). The mold cost is low, and the cost per piece is high (suitable for small and medium-sized batches)

Transparency can achieve high transparency, but transparency is usually low

Main application areas

Medical and health: respiratory masks, infusion tube fittings, medical device housing seals, implantable devices, pacifiers.

Food and catering: sealing rings for rice cookers, wall breaking machines, hot water kettles, coffee machines, and baking molds.

Automotive industry: engine ECU seals, headlight seals, various sensor seals.

Consumer electronics: waterproof sealing for smartphones/watches (such as SIM card holders, earphones, buttons), waterproof sealing for drones, and sealing for outdoor audio systems.

Industry and Energy: Valve Sealing, Connector Sealing, Solar Module Sealing.

Production Process Overview

Feeding: The LSR raw materials of components A and B are stored in the material bucket.

Measurement mixing: Extract and mix in a 1:1 ratio using a precision metering pump.

Injection: The mixed rubber material is thoroughly and uniformly mixed by a static mixer and injected into a heated mold.

Vulcanization molding: The rubber material undergoes rapid cross-linking reaction in the mold when heated (usually 170-200 ° C), and solidifies into shape.

Demoulding and retrieval: The mold is opened and the robotic arm automatically retrieves the finished product. Due to the good demolding properties of LSR, no demoulding agent is usually required.

summary

Liquid silicone sealing rings represent the high-end direction of silicone seals. With high precision, high efficiency, high complexity, excellent physical and chemical properties, and unparalleled consistency, they occupy an irreplaceable position in the demanding modern industry. When your project has extremely high requirements for sealing performance, safety and hygiene, production efficiency, and product appearance, liquid silicone sealing rings are usually the preferred solution.