#20Ultra-Soft
Ultra-Soft
Ultra-low stress, soft conformance, low-pressure sealing & cushioning.
- Stress levelUltra-low
- OrientationSoft · low-pressure seal
- Typical dutyBattery cushion · display seal
Siminkey · Porous silicone foam series · 6 models
THERMOSIL PADS™ Silicone FoamPorous silicone foam · skin + core
A dense, non-porous skin over an open-cell honeycomb core — one material that seals, cushions, dampens vibration and insulates heat. Continuous operating range -55°C to 200°C, flame rating UL94 V-0, thicknesses 0.8~30mm, six models positioned by stress level and structure, covering electronics, aerospace, automotive and industrial applications.
−55~200°C wide range
UL94 V-0 flame rating
Skin + core construction
Thickness 0.8~30mm
Roll widths 500 / 600 / 950mm · Black / Gray · Cutting, die-cutting, punching & adhesive backing available
THERMOSIL PADS™ porous silicone foam · black sheet
−55°C ~ 200°C
Continuous operating range
UL94 V-0
Flame rating · self-extinguishing
0.8–13 mm
Thickness range
500 / 600 / 950 mm
Three roll widths
6 models
Positioned by stress & structure
Low compression set
Low density · stable seal force
01 · Structure
Skin + core.
Two jobs, one material.
THERMOSIL PADS™ is not a homogeneous foam: the dense skin does the sealing, the honeycomb core does the cushioning. You no longer trade one against the other.
Surface — dense silicone skin
Flat, dense and non-porous. It provides surface sealing and dust/liquid resistance, conforms smoothly at low pressure to establish a reliable seal, and shields the foam core from wear and ingress.
Core — open-cell honeycomb
A three-dimensional open-cell structure: low density, high resilience. Under load the cell walls buckle progressively and absorb energy; on release they recover quickly — the structural source of low compression set and vibration dampening.
Result — sealing and cushioning, uncompromised
The open cell structure lowers overall firmness and stress: in low-pressure duties like battery cushioning and display sealing, it fills tolerance stacks without pushing structures apart.
Macro view: the open-cell honeycomb core beneath the dense skin
02 · Wide range & flame rating
−55°C to 200°C.
Elastic across the range.
From sub-arctic outdoor exposure to engine-bay thermal cycling, the silicone matrix stays flexible — no embrittlement, no softening, no loss of resilience. The full series passes UL94 V-0 vertical burning, meeting typical flame-retardancy requirements of electrical, electronic and transportation equipment.
−55°C
Cold limit
25°C
Ambient
200°C
Sustained high temp
UL94 V-0: in vertical burning tests, specimens self-extinguish within 10 seconds after flame removal, with no flaming drips that ignite the cotton below — the baseline for flame-retardant applications.
Wide-range sealing and dampening: one material spans the extremes
The full 0.8~30mm thickness lineup — choose by tolerance and stress
03 · Properties
Low stress. Long life.
Four core properties.
Every property points at the same outcome: after assembly, sealing and cushioning stay on duty for the long haul.
Low compression set
High recovery after long-term compression, with slow seal-force decay — right for permanent assemblies and long-service gaskets.
Vibration dampening
The open-cell structure absorbs shock and vibration energy, protecting battery modules, displays and precision parts while improving NVH.
Thermal insulation
A low-conductivity silicone matrix plus entrapped air in the cells forms an insulating barrier — a lightweight pick for thermal-management layers.
Aging & weather resistance
Resists UV, ozone and heat/humidity aging; performance holds steady outdoors and in engine bays, cutting lifecycle maintenance.
04 · Model matrix
Six models, positioned by stress and structure
From ultra-soft to the high-resilience high-performance: every model shares the −55~200°C range, UL94 V-0 rating and 0.8~30mm thickness lineup — they differ in stress level and structural orientation. Open a card for its full spec page.
Pointer drag with momentum · interrupt and reverse at any time
05 · Specifications
Full technical specifications
Series-level specs at a glance; model-level differences (stress, structure, density) are in each datasheet.
- Material
- Porous silicone (silicone foam), skin + core construction: flat dense non-porous skin over an open-cell honeycomb core
- Operating temperature
- −55°C ~ 200°C (continuous)
- Flame rating
- UL94 V-0
- Thickness range
- 0.8~30mm
- Roll widths
- 500mm / 600mm / 950mm
- Colors
- Black / Gray (product images show black)
- Series models
- #20 Ultra-Soft · #21 High-Performance · #23 Low Stress Honeycomb · #24 Medium Stress · #27 High Performance · #28 High Performance (high-performance)
- Key properties
- Low density · low compression set · aging & weather resistance · vibration dampening · thermal insulation
- Typical uses
- Sealing · cushioning · vibration dampening · thermal insulation (electronics / aerospace / automotive / industrial)
* Figures are typical series specifications; refer to the model datasheet. Custom cutting, die-cutting, punching and adhesive backing — confirm with an engineer.
06 · Applications
Four industries, one material logic
Wherever there is a tolerance to fill, a vibration to absorb or heat to block — that is where THERMOSIL PADS™ belongs.
Electronics
- Battery-module cushioning & expansion uptake
- Display and module sealing
- Speaker dust- & water-resistant seals
- PCB & precision-part shock mounting
Aerospace
- Wide-temperature cabin & panel seals
- Vibration-isolated avionics mounting
- Insulation layers & thermal spacing
- Lightweight cushioning for large panels & composites
Automotive
- Interior cushioning & NVH treatment
- Battery-pack sealing & thermal spacing
- Harness & tubing fixings with cushioning
- Lamp and ECU sealing
Industrial
- Equipment-cabinet dust sealing
- Pipe insulation & clamping cushioning
- Precision-instrument transport cushioning
- Assembly-gap filling & anti-vibration pads
07 · FAQ
Frequently asked questions about THERMOSIL PADS™
THERMOSIL PADS™ porous silicone foam operates continuously from -55°C to 200°C. Across this wide range the material keeps its elasticity and sealing performance, making it suitable for sub-arctic outdoor exposure and engine-bay thermal cycling.
UL94 V-0 is a high flame rating in the UL94 vertical burning test: specimens self-extinguish within 10 seconds after removal of the flame, with no flaming drips that ignite the cotton placed below. The THERMOSIL PADS™ series meets UL94 V-0, satisfying typical flame-retardancy requirements for electrical and electronic equipment and rail/transport applications.
THERMOSIL PADS™ use a surface-plus-core construction: a flat, dense, non-porous silicone skin over an open-cell honeycomb core. Compared with foams whose surface is open-cell, the dense skin provides better surface sealing, dust and liquid resistance; compared with EPDM or PU foams, the silicone matrix stays elastic across the full -55~200°C range, with lower long-term compression set and superior aging and weathering resistance.
THERMOSIL PADS™ come in three standard roll widths — 500mm, 600mm and 950mm — with thicknesses from 0.8~30mm. Material can be cut, die-cut or punched to drawings, and secondary processing such as adhesive backing is supported. Confirm specific dimensions with a Siminkey engineer.
For battery-module cushioning and low-pressure sealing we recommend the ultra-low-stress #20 Ultra-Soft; for large panels and lightweight builds, the honeycomb #23 Low Stress Honeycomb; for balanced support, #24 Medium Stress; and #28 High Performance combines low density with high resilience for high-performance applications.
Contact Siminkey via the "Get a Quote" entry at the bottom of the page or in the navigation. Tell us the target application, model (or required stress level), thickness, width and volume — samples and volume quotes typically follow within one business day.
08 · Selection & inquiry
Match the right THERMOSIL PADS™
to your application.
Tell us the application, stress requirement, thickness and width — Siminkey engineers help with model selection and fast samples. Volume supply and custom converting (cutting / die-cutting / punching / adhesive backing) are all supported.
Typically answered within one business day · samples & volume inquiries welcome