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  1. All Products
  2. SILISIL RTV MF-Flex 20
SILISIL RTV MF-Flex 20

SILISIL RTV MF-Flex 20

https://www.silitech.ch/web/image/product.template/3553/image_1920?unique=8ac25b8

SILISIL RTV MF-Flex 20 — 2K-Flex silicone Shore A 22, blue — very good flowability for sanitary and artificial stone molds, available from Swiss stock.

2K addition silicone Shore A 22 (blue, mixing ratio 1:1) — very good flowability for sanitary and artificial stone molds.

Price on request

  • Brand
  • Mixing Ratio
  • Curing type
  • Cured Color
  • Self-leveling
  • Density (g/cm³)
  • Uncrosslinked viscosity (mPa·s)
  • Electrical Insulation
  • Pot life (min)
  • Demolding time (min)
  • Full cure (h)
  • Food contact
  • Medical grade
  • Shore hardness A (cured)
  • Tensile strength (MPa)
  • Elongation at break (%)
  • Tear strength (N/mm)
  • Container

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Mold making SILISIL silicone RTV-2 Swiss Bearing Addition Platinum Prototyping Shore A 20 Swiss Brand 2K Moulding / Mold making

 
General Terms and Conditions

Shipping usually within 1 to 3 business days
(Availability confirmed after order)

Express logistics. Fast and reliable within Switzerland & Europe

From Swiss stock Dispatch within 24h Batch certificate Invoice 30 days (B2B) Technical advice
Shipping & Delivery

Usually 1 to 3 business days

Availability is confirmed after order receipt.

Express logistics within Switzerland & Europe.

Terms and Conditions →

Product data

HS Code: 3910.0000

HS Code: 3910.0000

SILISIL RTV MF-Flex 20
SILISIL RTV MF-Flex 20
SILISIL ·

SILISIL RTV MF-Flex 20 is a room temperature vulcanizing 2-component addition silicone (platinum cross-linking, RTV-2) of the MF-Mold & Form series — 2K-Flex silicone Shore A 22, blue — very good flowability for sanitary and artificial stone molds.

The mixture is prepared in a 1:1 ratio by weight (tolerance ±5%). Pot life at 23°C is approximately 15 minutes, demolding after approximately 90 minutes, and complete curing after 24 hours. Temperature resistant from -40°C to +200°C.

Key property

Highly flexible molding material (Shore A 22) with low viscosity — easy to pour, without shrinkage, excellent resistance to plasters, polyester and PU resins.

SILISIL RTV MF-Flex 20 in figures
A 22
Shore Hardness
4'500
mPa·s viscosity
15 min
Pot life @23 °C
480 %
Elongation at break

What distinguishes SILISIL RTV MF-Flex 20

Very good flowability
Excellent flowability — suitable for detailed models and microstructures.
Fast and shrink-free curing at 23 °C
Rapid vulcanization at room temperature — the mold is quickly ready for production.
Low Shore A hardness for flexible molds
Highly flexible — suitable for undercuts, soft-touch surfaces and sensitive originals.
High elongation at break 480%
High elasticity — reliable demolding of complex geometries without damaging the mold or the original.
Resistant to gypsum, casting resins and coatings
Highly compatible with common casting materials — plaster, polyester, epoxy, PU.
Tear resistance 20 N/mm
Very high tear resistance — the mold withstands hundreds of cycles with abrasive materials without wear.

What is SILISIL RTV MF-Flex 20 used for?

Master models for sanitary ceramics
Silicone master models for the production of plaster molds in the sanitary industry (sinks, bidets, toilets) — shrink-free and dimensionally accurate reproduction.
Artificial stone and concrete blocks
Paving stones, kerbstones, concrete sculptures — the high elongation at break (480%) allows the demolding of abrasive mixtures without cracking.
Master model reproduction
Low-shrinkage molding of architectural and industrial master models — compatible with common casting resins and coatings.
Sculpture and restoration casting
Excellent detail reproduction for art replicas, monument preservation and museum objects without mechanical stress on the original.
Wax and candle molds
Low viscosity (4,500 mPa·s) for highly detailed shapes — pot, antique, and designer candles in small and medium series.
Polyurethane foam and resin molds
Resistant to aggressive PU and polyester resins (with release agent) — suitable for furniture and design studio reproductions.

Processing

1
Prepare the original
The surface to be reproduced must be clean, dry, and free of dust. The ideal processing temperature is 23 °C — cooler environments significantly extend pot life and curing time.
2
Homogenize and mix components
Stir base and catalyst thoroughly before use. Weigh out 1:1 by weight (tolerance ±5%). When mixing, thoroughly incorporate the walls and bottom of the container.
3
Vacuum degassing
For pore-free molds, briefly degas the mixture under vacuum — entrapped air bubbles are removed, ensuring a smooth mold surface.
4
Pour slowly into the mold
Pour from a height of approx. 30 cm in a thin stream into the deepest point — the silicone displaces air independently and reaches all undercuts.
5
Vulcanize and demold
At 23 °C, demolding is possible after approx. 90 minutes, with complete curing after 24 hours. Before the first pour, allow a 24 h "maturation phase" for maximum strength.
Data Sheets & Safety Data Sheet
Complete TDS and SDS in DE, EN, FR — view or download directly.
To the documents →

Important Notes

Avoid crosslinking inhibitors
Additive systems like MF-Flex 20 are sensitive to sulfur, amine, tin, and phosphorus compounds—especially latex gloves, modeling clay, adhesive tapes, and some paints. If in doubt, make a small test cast before use.
Storage and Shelf Life
Shelf life of at least 12 months in unopened original container when stored in a dry, cool place (10–25 °C). Consult the Safety Data Sheet (SDS) before opening.
Available containers
1 kg + 1 kg, 5 kg + 5 kg. Other container sizes available on request.
Compatibility
Compatible with polyurethane, epoxy, and polyester casting resins. For aggressive resins, apply a release agent to protect the mold.

Recommended accessories

SILISIL white petroleum jelly release paste
Universal release agent for polyester, epoxy, and polyurethane casts — protects the silicone mold from aggressive resins and extends mold service life.
To the product →
SILISIL Delayer PA
Retarder for addition-curing silicones — extends pot life and setting time for more complex multi-part builds and relaxed processing.
To the product →
SILISIL Silicone Remover
Cleaning agent for silicone residues on tools, models, and work surfaces — gentle and effective.
To the product →

Which MF silicone for which application?

SILISIL RTV MF-Flex 20 in direct comparison with related MF products in our range (MF = Mold & Form).

MF-Flex 20
Current Product 		MF-Flex 25 →MF-Soft 12 →MF-Soft 13 TP →
Shore hardness A22241213
Mixed viscosity4'5004'5003'5004'500
ColorBlueTransparentBlueTranslucent
Pot life @23 °C15202045
Topics & Application Fields
Key terms related to this product. Also useful for our search and filters.
Mold making SILISIL Silicone RTV-2 Swiss Bearing Addition Platinum Prototyping Shore A 20 Swiss Brand 2K Moulding / Mold Making Range Review 2026

Technical data for SILISIL RTV MF-Flex 20

All 18 product information 4 Physical properties 4 Electrical properties 1 Curing values ​​3 Product approvals 2 Mechanical properties 4
Product Information
Brand SILISIL
Mixing Ratio 1:1
Curing type Addition (Platinum)
Container 1 kg + 1 kg, 5 kg + 5 kg, 10 kg + 10 kg, 25 kg + 25 kg
Physical Properties
Cured Color Blue
Self-leveling Yes
Density (g/cm³) 1.13
Uncrosslinked viscosity (mPa·s) 4500
Electrical Properties
Electrical Insulation Yes
Curing values
Pot life (min) 15
Demolding time (min) 90
Full cure (h) 24
Product Approvals
Food contact No
Medical grade No
Mechanical properties
Shore hardness A (cured) A 20
Tensile strength (MPa) 4.5
Elongation at break (%) 480
Tear strength (N/mm) 20

Please refer to the technical data sheet (TDS) in the "Documents" tab for binding values.

Documents and data sheets

Click on a document for the preview or the download icon for direct download.

Technical Data Sheets (TDS) 3
SILISIL RTV MF-Flex 20 - Technical Data Sheet DE.pdf
151 KB
SILISIL RTV MF-Flex 20 - Technical Data Sheet EN.pdf
156 KB
SILISIL RTV MF-Flex 20 - Fiche Technique FR.pdf
157 KB
Safety Data Sheets (SDS) 3
SILISIL RTV MF-Flex 20 - Safety Data Sheet DE.pdf
319 KB
SILISIL RTV MF-Flex 20 - Safety Data Sheet EN.pdf
340 KB
SILISIL RTV MF-Flex 20 - Fiche de Sécurité FR.pdf
346 KB

Frequently asked questions about SILISIL RTV MF-Flex 20

Practical application and design questions — answered by SILITECH.

SILISIL RTV MF-Flex 20 is a two-component (Shore A 22, blue) additive silicone for molds used in sanitary ware and related applications. This two-component flexible silicone (Shore A 22, blue) offers excellent flowability for sanitary and artificial stone molds

At 23 °C, the pot life is approximately 15 minutes and the demolding time approximately 90 minutes. Complete curing is achieved after 24 hours. Lower temperatures extend, higher temperatures shorten these times.

As an addition system, SILISIL RTV MF-Flex 20 is sensitive to crosslinking inhibitors: sulfur, amine, tin, and phosphorus compounds can locally halt vulcanization. Avoid latex gloves, sulfur-containing modeling clays, some adhesive tapes, and PVC plasticizers in the immediate vicinity of the mold. If in doubt, make a small test cast.

SILISIL RTV MF-Flex 20 is mixed in a 1:1 ratio by weight (base to catalyst), with a maximum tolerance of ±5%. Homogenize both components separately before mixing, then thoroughly incorporate them – including the container walls and bottom. Brief vacuum degassing of the mixture is recommended for non-porous molds.

SILISIL RTV MF-Flex 20 achieves a Shore A hardness of 22 (ASTM D 2240), a tensile strength of 4.5 N/mm² (ASTM D 412), an elongation at break of approximately 480 % and a tensile strength of 20 N/mm (ASTM D 624).

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Product Specifications

Product Information
Container 1 kg + 1 kg or 5 kg + 5 kg or 10 kg + 10 kg or 25 kg + 25 kg
Brand SILISIL
Mixing Ratio 1:1
Curing type Addition (Platinum)
Physical Properties
Cured Color Blue
Self-leveling Yes
Density (g/cm³) 1.13
Uncrosslinked viscosity (mPa·s) 4500
Electrical Properties
Electrical Insulation Yes
Curing values
Pot life (min) 15
Demolding time (min) 90
Full cure (h) 24
Product Approvals
Food contact No
Medical grade No
Mechanical properties
Shore hardness A (cured) A 20
Tensile strength (MPa) 4.5
Elongation at break (%) 480
Tear strength (N/mm) 20
Keywords
Keywords
Mold making SILISIL silicone RTV-2 Swiss Bearing Addition Platinum Prototyping Shore A 20 Swiss Brand 2K Moulding / Mold making

Documents and data sheets

Safety Data Sheets (SDS) and Technical Data Sheets (TDS) for download: