Material
Silicone Rubber
Silicone elastomer contact material
Choose Silicone Rubber based on its stiffness, recovery, wear, wet-service, chemical, and temperature behavior. Stiffness is set by the complete filament specification, including material, diameter, free trim, density, grade, and service conditions.
Datasheet values
- Hardness
- 20–80 Shore A
- Density
- 1.1–1.3 g/cm³
- Use temperature
- -50–200°C
- Water absorption
- below 1%
- Compression set
- 5–30% by grade
Silicone rubber is an elastomer family valued for elastic recovery and weathering; standard and fluorosilicone grades have different fluid resistance.
What is Silicone Rubber, and where is it used?
In the silicone elastomer contact material family, Silicone Rubber is specified, supplied as rubber strip and silicone component, drawn in sheet, porous body and molded shape sections and set in straight rows, helical, staggered, zoned, wavy and random fill patterns.
Silicone Rubber is used in custom cleaning brushes for heat-tolerant soft contact, bottle cleaning and squeegee functions in kitchen, laboratory and wet-process tools.
It is usually weighed against Polypropylene PP, TPEE Elastomer Filament and Nylon PA, and the deciding difference is moisture uptake and working temperature rather than anything you can read off the name.
Compare Silicone Rubber with PP, TPE, Nylon. Change material when wet stiffness, temperature, chemical resistance, conductivity, particle shedding, or surface marking becomes the limiting factor.
What stiffness and contact pressure can I expect from Silicone Rubber?
Silicone Rubber is soft to medium elastomer; Shore A commonly about 30-80 depending on grade. Contact pressure here is set by Shore A hardness and by the section of the element and how far it is compressed. Silicone is chosen for temperature range or food contact at least as often as for the way it presses, so state the grade requirement and the hardness separately.
Material-level figures for this grade and the ones it is usually compared to. The brush built from it is rated lower: the backing and the adhesive give out before the material does.
| Property | Silicone Rubber | Polypropylene PP | TPEE Elastomer Filament | Nylon PA |
|---|---|---|---|---|
| Shore hardness | Soft to medium elastomer; Shore A commonly about 30-80 depending on grade. | Shore D 65–75 | Shore D 35–72 (Grade Range) | Medium to firm; filament diameter and trim length control bending force. |
| Continuous temperature (°C) | 200 | 80–100 | 100–120 | 93 |
| Peak temperature (°C) | 230 | 120–140 | 130–150 | 121 |
| Water absorption, 24 h | below 1% | ≤0.03% (24h, ISO 62/ASTM D570) | 0.20–0.80% (24h, ISO 62/ASTM D570) | 0.3–9% by PA grade and conditioning |
| Filament diameter (mm) | Not applicable (Sheet / Foam Structure) | 0.08–3.00 | 0.10–3.00 | 0.08–2.50 |
| Flexibility | Low to High Flexibility(Structure Dependent) | Medium Flexibility | High Flexibility | Medium to High Flexibility |
The part people get wrong: the same grade can feel soft or aggressive depending on diameter, trim and density. Specify that geometry before the material, or the sample will surprise you.
How does water affect Silicone Rubber performance?
Silicone Rubber takes up below 1%.
Non-absorbent elastic contact for wet cleaning, wiping and squeegee action.
What this means for your application: absorbed water swells the filament and drops contact pressure, so a brush that reached the far end of a bore when dry may stop short once it is wet.
A practical check: soak a sample for an hour and re-measure the trim. If it has moved enough to change the contact band, the grade is wrong for the duty.
What temperature limits apply to Silicone Rubber?
-50 to 200°C.
Where it stops working: A face that stays compressed after the load comes off means the answer is a different compound or foam grade, not more thickness.
The usable limit also moves with thickness, density and how hard the face is pressed. A thick low-density pad under light load tolerates more than a thin dense one under heavy pressure.
What chemicals attack Silicone Rubber?
It stands up to water and common detergents.
The same cleaner can be harmless or destructive depending on how strong it is, how hot it runs and how long it sits. Quote the concentration and the dwell time, not just the product name.
Before you commit to a quantity: Give the grade, the Shore A figure, and the section thickness. Then say which part is the working face, at what temperature it runs, and whether food-contact compliance is required.
What hardness and section should I specify for silicone rubber?
In this form silicone is supplied as sheet and moulded shapes, 3–100 mm thick, at Shore A 30–80 depending on grade. Specify the section thickness and the Shore figure together, and say which part is the working face — a wiping lip and a flat pad in the same compound behave nothing alike.
Silicone is usually chosen for temperature range or food contact rather than for the way it presses, with continuous service far above the other elastomers here. State that requirement separately from the hardness; the two are selected independently. Silicone supplied as moulded bristle is a separate entry and carries its own diameter.
Finishing available on this material: cutting, perforation and composite coating.
What applications typically use Silicone Rubber?
Heat-tolerant soft contact, bottle cleaning and squeegee functions in kitchen, laboratory and wet-process tools.
Where it turns up in practice:
- Bottle & Container Cleaning
- Cup & Mug Cleaning
- Hydration Bag Cleaning
- Laboratory Tube Cleaning
- Beverage Equipment Cleaning
- Hose Cleaning
It is normally set into these constructions:
- Custom Handheld Detail Brushes
- Custom Tube & Pipe Bore Brushes
- Custom Bottle & Container Brushes
- Custom Disc Brushes
If the sample comes back rejected: Not for aggressive scraping, rust removal or metal deburring.
How do I specify Silicone Rubber for a custom brush?
A usable specification carries the construction, the thickness and density or Shore figure, the cut shape and backing, and the service conditions: wet or dry, temperature, and what the cleaner actually is.
The mistakes that most often send a sample back:
- Selecting Silicone Rubber from the material name alone without setting thickness, density or Shore hardness, and the cut shape
- Using dry stiffness to predict wet behavior without checking moisture absorption or liquid exposure
- Ignoring trapped abrasive particles, chemical concentration, temperature, or contact motion when assessing surface risk
Reference standards behind the figures on this page: ISO 37; ASTM D412; ISO 48-4; ASTM D2240-15(2021); ISO 4892-3:2024; ASTM G154-23; UL 94.
Source: Dow — Silicone elastomers — LSR product technology. Silicone holds its hardness across a far wider temperature span than organic rubber, which is why it appears in hot and cold contact work. It is not the choice where the assembly has to resist tearing or abrasion.
What else does the datasheet specify for Silicone Rubber?
| Filament cross-section | Sheet / Porous Body / Molded Shape |
|---|---|
| Electrical behaviour | Insulating |
Questions this page is asked
How should silicone rubber be released for oils, solvents or repeated wash chemistry?
Test the exact compound in the actual fluid or blend at its concentration, temperature, dwell, mechanical strain, rinse and drying sequence, including peak and repeated exposure. Measure swelling, mass, hardness, tensile or tear change, compression recovery, tack, discoloration and transferable residue; broad water and weather resistance does not establish compatibility with hydrocarbons, oxidizers or every cleaner.
What should a heat-cycled silicone brush or squeegee assembly retain?
After combined temperature, fluid and contact cycles, measure permanent set, contact force, edge geometry, tear or abrasion, streaking or cleaning result, shedding or residue and bond, insert or core retention. Release the assembly only to the lowest qualified limit of the silicone, pigment, adhesive, base and joint, and set replacement by functional output rather than the absence of visible melting.
Where these figures come from
| Property | Published value | Source |
|---|---|---|
| Chemical resistance | Good resistance to water and common detergents; oil, solvent and chemical resistance follows the elastomer compound. | Dow Retrieved 2026-07-20 |
| Published datasheet figures |
|
Dow Retrieved 2026-07-20 |
| Hardness and stiffness | Soft to medium elastomer; Shore A commonly about 30-80 depending grade. | Dow Retrieved 2026-07-20 |
| Limitations | Not for aggressive scraping, rust removal or metal deburring. | Dow Retrieved 2026-07-20 |
| Temperature resistance | -50 to 200°C. | Dow Retrieved 2026-07-20 |
| Water resistance | Non-absorbent elastic contact for wet cleaning, wiping and squeegee action. | Dow Retrieved 2026-07-20 |
Guides that go deeper on this
We have not written a guide specific to this one yet. The material that covers selection, filament, dimensions, maintenance and sourcing is collected in the technical resources library.
No catalogue item for this yet
Every brush here is made to order, and this one has no catalogue entry so far. Send the working surface, the residue, the access opening and the quantity, and it is quoted through the same specification route as the rest of the range.
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