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SILISIL RTV MF-Ultra 45

SILISIL RTV MF-Ultra 45

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SILISIL RTV MF-Ultra 45 — 2K high-strength silicone Shore A 45, translucent — demanding tool shapes, available from Swiss stock.

2K addition silicone Shore A 45 (translucent, mixing ratio 1:1) — demanding tool shapes.

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
  • Certificates
  • Shore hardness A (cured)
  • Elongation at break (%)
  • Container

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Mold making SILISIL silicone RTV-2 Swiss bearing addition platinum prototyping Shore A 45 Swiss brand 2K 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-Ultra 45
SILISIL RTV MF-Ultra 45
SILISIL ·

SILISIL RTV MF-Ultra 45 is a room temperature vulcanizing 2-component addition silicone (platinum crosslinking, RTV-2) of the MF-Mold & Form series — 2K high-strength silicone Shore A 45, translucent — for demanding tool shapes.

The mixture is prepared in a 1:1 ratio by weight (tolerance ±5%). Pot life at 23 °C is approximately 10–12 minutes, demolding after approximately 60–90 minutes, and complete curing after 24 hours. Temperature resistant from -40 °C to +200 °C.

Key property

Translucent + Shore A 45 — unusual combination of visual inspection (air bubbles, mold filling, embedded original) and high-strength final shape, ideal for tool and industrial molds.

SILISIL RTV MF-Ultra 45 in figures
A 45
Shore Hardness
8'000
mPa·s viscosity
10–12 min
Pot life @23 °C
370 %
Elongation at break

What makes SILISIL RTV MF-Ultra 45 stand out

High final hardness Shore A 45
High final hardness for demanding tool shapes with high loads and long service life.
Translucent for visible pouring
Air inclusions, mold filling, and the embedded original are visible during processing and demolding.
Tear resistance 19 N/mm
High tear resistance — robust against mechanical stress when demolding abrasive materials.
Fast processing with a pot life of 10-12 minutes
Reproducible processing time — precise planning of mold production is possible.
Mixing ratio 1:1 by weight
Simple 1:1 ratio — hand-mixable without a precision scale, ideal for workshops and hobbyists.
Elongation at break 370%
Solid elongation at break — suitable for moderate undercuts with higher form stiffness.

What is SILISIL RTV MF-Ultra 45 used for?

High-stress tool molds
Shore A 45 with tensile strength 19 N/mm — suitable for industrial molds with high mechanical stress and wear.
Industrial serial molding
Hundreds of castings with consistent detail sharpness — an economical choice for medium series in stone, resin and synthetic resin processing.
Tool and fixture construction
Master models for injection molds, vacuum forming negatives and fixtures — dimensionally stable with high final hardness.
Translucent visual inspection of premium tools
During demolding, damage, air inclusions and material residues are immediately detected — best quality control.
High-strength jewelry and wax molds
More wax castings per mold than with lower hardness — economical for goldsmiths with higher throughput.
Aggressive resin and polyester casting
Release agent reliably protects against aggressive resins — ideal for designer and artist studios with frequent mold changes.

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 approximately 60–90 minutes; complete curing takes 24 hours. A 24-hour "maturation phase" is required before the first casting to ensure 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
Addition systems like MF-Ultra 45 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, 25 kg + 25 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-Ultra 45 in direct comparison with related MF products in our range (MF = Mold & Form).

MF-Ultra 45
Current Product 		MF-Ultra 50 →MF-Ultra 60 →MF-Ultra 70 →
Shore hardness A45506067
Mixed viscosity8'0005'000230'000230'000
ColorTranslucentOrangeBlueBlue
Pot life @23 °C10–12156060
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 45 Swiss brand 2K mold making

Technical data for SILISIL RTV MF-Ultra 45

All 17 Product Information 4 Physical Properties 4 Electrical Properties 1 Curing Values 3 Product Approvals 3 Mechanical Properties 2
Product Information
Brand SILISIL
Mixing Ratio 1:1
Curing type Addition (Platinum)
Container 500g+500g, 1kg+1kg, 5kg+5kg, 10kg+10kg, 25kg+25kg, 200kg+200kg
Physical Properties
Cured Color Translucent
Self-leveling Yes
Density (g/cm³) 1.1
Uncrosslinked viscosity (mPa·s) 8000
Electrical Properties
Electrical Insulation Yes
Curing values
Pot life (min) 10
Demolding time (min) 60
Full cure (h) 24
Product Approvals
Food contact No
Medical grade No
Certificates RoHS, REACH
Mechanical properties
Shore hardness A (cured) A 45
Elongation at break (%) 370

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-Ultra 45 - Technical Data Sheet DE.pdf
126 KB
SILISIL RTV MF-Ultra 45 - Technical Data Sheet EN.pdf
126 KB
SILISIL RTV MF-Ultra 45 - Fiche Technique FR.pdf
126 KB

Frequently asked questions about SILISIL RTV MF-Ultra 45

Practical application and design questions — answered by SILITECH.

SILISIL RTV MF-Ultra 45 is a two-component (Shore A 45, translucent) addition silicone for highly stressed tool molds and related applications. Two-component high-strength silicone, Shore A 45, translucent — demanding tool molds

At 23 °C, the pot life is approximately 10–12 minutes and the demolding time approximately 60–90 minutes. Complete curing is achieved after 24 hours. Lower temperatures extend, higher temperatures shorten these times.

As an addition system, SILISIL RTV MF-Ultra 45 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-Ultra 45 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-Ultra 45 achieves a Shore A hardness of 45 (ASTM D 2240), a tensile strength of >3.5 N/mm² (ASTM D 412), an elongation at break of approximately 370% and a tensile strength of 19 N/mm (ASTM D 624).

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Product Specifications

Product Information
Container 500g + 500g or 1kg + 1kg or 5kg + 5kg or 10kg + 10kg or 25kg + 25kg or 200kg + 200kg
Brand SILISIL
Mixing Ratio 1:1
Curing type Addition (Platinum)
Physical Properties
Cured Color Translucent
Self-leveling Yes
Density (g/cm³) 1.1
Uncrosslinked viscosity (mPa·s) 8000
Electrical Properties
Electrical Insulation Yes
Curing values
Pot life (min) 10
Demolding time (min) 60
Full cure (h) 24
Product Approvals
Certificates RoHS or REACH
Food contact No
Medical grade No
Mechanical properties
Shore hardness A (cured) A 45
Elongation at break (%) 370
Keywords
Keywords
Mold making SILISIL silicone RTV-2 Swiss bearing addition platinum prototyping Shore A 45 Swiss brand 2K mold making

Documents and data sheets

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