1. High Temperature Resistance
Silicone rubber features outstanding thermal stability. It can serve continuously at 250℃ to 300℃. With special fillers and high-temperature additives, its long-term working temperature can reach 375℃, and it can withstand instantaneous high temperature up to several thousand degrees.
Service life reference: 20 years at 120℃, and 5 years at 150℃, with excellent aging resistance.
2. Low-temperature Elasticity
Silicone maintains good flexibility at low temperatures. It normally stays elastic at -50℃ ~ -60℃, far better than natural rubber and other synthetic rubbers that tend to turn brittle in cold conditions.
3. Gas Permeability
Silicone film has excellent air permeability. At room temperature, its permeability to air, nitrogen, oxygen and carbon dioxide is 30–50 times higher than natural rubber.
4. Electrical Insulation Properties
Silicone boasts stable electrical performance. Its dielectric strength, power factor and insulation barely change with temperature and frequency over a wide range.
Key electrical indicators:
- Breakdown voltage: 20~25 kV/mm
- Dielectric constant: 3~3.2
- Dielectric loss tangent: 3~3.5×10⁻³
- Volume resistivity: 1×10¹⁶ Ω·cm
It also has good resistance to corona and electric arcs.
5. Mechanical Properties
- Hardness: 35~75 Shore A
- Tensile strength: up to 105 kg/cm²
- Elongation at break: within 1000%
All parameters can be customized according to product requirements.While its room-temperature strength is lower than general-purpose rubber, silicone retains stable mechanical performance at 150℃, greatly outperforming ordinary rubber. Its compression set stays between 7%~10% under heat.
6. Weather Resistance
Silicone is resistant to oxygen, ozone and UV radiation. It will not crack after long-term outdoor exposure.
7. Biological Inertness
The material is non-toxic, odorless and tasteless. It also has low surface activity and low moisture absorption.
Why do we use it?
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Lorem Ipsum is simply dummy text of the printing and typesetting industry.
Lorem Ipsum is simply dummy text of the printing and typesetting industry.
Lorem Ipsum is simply dummy text of the printing and typesetting industry.
Lorem Ipsum is simply dummy text of the printing and typesetting industry.
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LATEST NEWS
27 6 月
How to Select X-Rings | Professional X-Ring Sizing Guide
Choosing the proper X-Ring (star-shaped quad ring) for your sealing application follows these professional selection criteria:
1. Static Seals & Reciprocating Linear Motion
Bore-mounted (housing) seals
The inner diameter of the X-Ring should match the groove dimension, or be roughly 2% smaller than the outer diameter of the groove. The pre-compression creates stable pre-tension and effectively prevents X-Ring twisting during operation.
Shaft-mounted seals
The X-Ring inner diameter needs to equal or slightly exceed the shaft outer diameter by 0.2–0.3 mm, or 1% larger than the shaft OD. This design simplifies installation and extends the service life of the quad ring.
2. Rotary Shaft Sealing
For rotary applications, select an X-Ring whose inner diameter is 2%–5% larger than the shaft diameter.
Rubber X-Rings generate friction heat while rotating, which causes elastomer shrinkage. The enlarged inner diameter maintains proper lubrication and ensures reliable long-term sealing performance.
3. X-Ring Material & Standard Specifications
The most common material is NBR 70 Shore A (N70 nitrile rubber). You can also adopt other elastomer grades that match standard O-Ring material options.
X-Ring dimensions fully conform to universal O-Ring size standards.
27 6 月
NBR O-Ring Advantages & Disadvantages | Silicone Sealing Mold Manufacturing
When manufacturing silicone seal molds and rubber sealing products, NBR O-rings remain the most widely used sealing element. Let’s break down the main advantages and limitations of nitrile rubber O-rings.
Advantages of NBR O-Rings
- NBR O-rings deliver outstanding resistance to water, solvents and mineral oil, plus excellent air tightness for hydraulic and plumbing systems.
- Nitrile rubber features great wear resistance and reliable compression set performance under long-term clamping pressure.
Disadvantages of NBR O-Rings
- NBR seals cannot work well in polar chemical environments. They degrade quickly when exposed to ozone, ketones and other strong polar media.
About Our Precision Mold Factory
Since establishment, Dongguan Ouning Precision has adhered to the principle of premium quality and customer-oriented service, following ISO quality standards to continuously optimize mold precision. Our mold manufacturing has earned consistent recognition from global buyers.
We are equipped with imported CNC machining centers (Taiwan Dali 1020 / 860), KENT grinders, EDM machines, and Miyano (BNA-42C) CNC lathes from Japan. We also adopt Mitutoyo testing instruments and professional design software including UG, PROE, MASTERCAM and CAD. We provide one-stop service from product development to finished rubber seal mold fabrication.
Our core business covers custom molds for 45° X-rings & O-rings, oil shaft seals, valve stem seals, as well as Y-type, U-type, K-type, O-type and X-type high-precision silicone rubber sealing components.