Silicone

Silicone Rubber Moulding Compounds

MOLDSIL - RTV SILICONE RUBBER
MOLDSIL is a high quality silicone moulding compound developed for the Fibrous Plaster industry and resin castin industry. Moulds made from MOLDSIL will give high quality reproduction and a long mould life with virtually no shrinkage and no risk of the plaster ever gripping to the mould surface. MOLDSIL has been designed to be easy to mix by hand with colour-coded components to offer a visual aid to ensure mixing is complete. The two components mix easily and because of it's low viscosity MOLDSIL can be used without the use of a vacuum chamber. MOLDSIL comes in three grades: slow, fast and very fast, giving you a choice in how quickly you wish to have a finished mould in production. MOLDSIL also has a thixotropic additive to enable you to make skin moulds or to mould on site.

A simple guide to using MOLDSIL :-

1. Apply release agent to the master model once you have removed any loose paint or dirt. Use a single brush coat of "PETROGEL" on bare plaster - wet or dry, never use shellac. Allow the "PETROGEL" to dry for about 20 minutes before pouring the MOLDSIL. If the model is made of wood, clay or is painted, use a wax spray as a release agent (DP 100/2 or similar).

2. Mixing MOLDSIL is easy, it is supplied in 5Kg, and 1Kg, kits so you don't have to use any scales (if you want to part-mix, the ratio is 100 parts of base to 10 parts catalyst, by weight). Simply pour the red catalyst on top of the white base and start by folding the two components together gently, as they become inter-mixed you can mix with more vigour until a uniform "strawberry-pink" colour is attained. Pay particular attention to the sides and base of the container. When you think it is mixed, pour the entire contents into another clean container and re-mix, this is the only way you can be sure the material is thoroughly mixed.

3. You can now either pour the MOLDSIL over the model as it is, or you can add the THIXO additive to turn it into a non-slumping paste which can be brushed onto the model (about 1 teaspoonful per 1Kg. of MOLDSIL is sufficient - add a bit more if you need to - it's not critical). The THIXO additive will go solid if it gets cold, a bit like lard, simply warm it up to get it liquid again. Mix in the THIXO additive for about 90 seconds or until the MOLDSIL starts to stiffen. It is better to use MOLDSIL F (fast) or MOLDSIL VF (very fast) if you are using it with THIXO, this means you can build up layers more quickly and if you're working on-site you can take the mould off within a few hours.

If you are pouring the MOLDSIL, pour in a long steady stream, which helps burst any air bubbles introduced while mixing. For most open-pour moulds MOLDSIL F is suitable, whereas when pouring through a long case using MOLDSIL S will give you a longer pour-time to ensure the materials fills the case. (All three grades can be used with other and will bond to each other).

Supplied by:
W.P. Notcutt Ltd, Homewood Farm, Newark Lane, Ripley, Surrey GU23 6DJ.
TELEPHONE: 01483 223311 TELEFAX: 01483 479594 e-mail: sales@notcutt.com

De-mould times will vary According to the grade of MOLDSIL used. As a general guide :-

MOLDSIL	Moldsil 'S' Slow	Moldsil 'F' Fast	Moldsil 'VF' V. Fast
De-mould Time or Skin time (Hrs).	20	10	3
Gel Time (Mins).	120	50	10
Hardness Shore A	22	23	22
Tensile Strength mPa	3.2	3.1	3.1
Elongation to Break %	350	360	310
Tear Strength KN/m	21	21	15
Relative Density	1.2	1.2	1.2
Linear Shrinkage %	0.3	0.3	0.3

For customers using large volumes of moulding materials MOLDSIL is also available in 22Kg
and 220Kg packs.

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MOLDSIL SOFT - RTV SILICONE RUBBER

MOLDSIL SOFT is a high quality silicone moulding compound developed for the Fibrous Plaster and resin casting industry. Moulds made from MOLDSIL SOFT will give high quality reproduction and a long mould life with virtually no shrinkage and no risk of the plaster ever gripping to the mould surface. MOLDSIL SOFT has been designed to be easy to mix by hand with colour-coded components to offer a visual aid to ensure mixing is complete. The two components mix easily and because of it's low viscosity MOLDSIL SOFT can be used without the use of a vacuum chamber. MOLDSIL SOFT comes in three grades: slow, fast and very fast, giving you a choice in how quickly you wish to have a finished mould in production. MOLDSIL SOFT also has a thixotropic additive to enable you to make skin moulds or to mould on site.

A simple guide to using MOLDSIL SOFT :-

1. Apply release agent to the master model once you have removed any loose paint or dirt. Use a single brush coat of "PETROGEL" on bare plaster - wet or dry, never use shellac. Allow the "PETROGEL" to dry for about 20 minutes before pouring the MOLDSIL SOFT. If the model is made of wood, clay or is painted, use a wax spray as a release agent (DP 100/2 or similar).

2. Mixing MOLDSIL SOFT is easy, it is supplied in 5Kg, and 1Kg, kits so you don't have to use any scales (if you want to part-mix, the ratio is 100 parts of base to 10 parts catalyst, by weight). Simply pour the red catalyst on top of the white base and start by folding the two components together gently, as they become inter-mixed you can mix with more vigour until a uniform "strawberry-pink" colour is attained. Pay particular attention to the sides and base of the container. When you think it is mixed, pour the entire contents into another clean container and re-mix, this is the only way you can be sure the material is thoroughly mixed.

3. You can now either pour the MOLDSIL SOFT over the model as it is, or you can add the THIXO additive to turn it into a non-slumping paste which can be brushed onto the model (about 1 teaspoonful per 1Kg. of MOLDSIL SOFT is sufficient - add a bit more if you need to - it's not critical). The THIXO additive will go solid if it gets cold, a bit like lard, simply warm it up to get it liquid again. Mix in the THIXO additive for about 90 seconds or until the MOLDSIL SOFT starts to stiffen. It is better to use MOLDSIL F (fast) or MOLDSIL VF (very fast) if you are using it with THIXO, this means you can build up layers more quickly and if you're working on-site you can take the mould off within a few hours.

If you are pouring the MOLDSIL SOFT, pour in a long steady stream, which helps burst any air bubbles introduced while mixing. For most open-pour moulds MOLDSIL F is suitable, whereas when pouring through a long case using MOLDSIL S will give you a longer pour-time to ensure the materials fills the case. (All three grades can be used with other and will bond to each other).

Supplied by:
W.P. Notcutt Ltd, Homewood Farm, Newark Lane, Ripley, Surrey GU23 6DJ.
TELEPHONE: 01483 223311 TELEFAX: 01483 479594 e-mail: sales@notcutt.com

De-mould times will vary According to the grade of MOLDSIL SOFT used. As a general guide:-

MOLDSIL SOFT	Moldsil 'S' Slow	Moldsil 'F' Fast	Moldsil 'VF' V. Fast
De-mould Time or Skin time (Hrs).	20	10	3
Gel Time (Mins).	120	50	10
Hardness Shore A	12	12	12
Tensile Strength mPa	3.2	3.2	3.2
Elongation to Break %	500	500	500
Tear Strength KN/m	21	21	15
Relative Density	1.15	1.15	1.15
Linear Shrinkage %	0.2-0.4	0.2-0.4	0.2-0.4

For customers using large volumes of moulding materials MOLDSIL SOFT is also available in 22Kg and 220Kg packs.

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MOLDSIL "T"- RTV SILICONE RUBBER

MOLDSIL "T" is a translucent, high strength, two component, tin cured, room temperature curing silicone rubber. It is designed as a 14 shore A. very pourable rubber providing excellent long library life and accurate detail reproduction. MOLDSIL "T" may be easily pigmented which makes it ideal for robotic animatronic skins, special effect skins and props for theme parks.

A simple guide to using MOLDSIL "T" :-

1. Stir the base (part A) well before use.

2. Shake the catalyst container (part B) well before use.

3. Weigh the desired amount of base into a clean mixing container. Tip the container and roll the base all the way around the side wall up to two inches from the top. This will prevent the catalyst from becoming absorbed into the container. It is recommended that the container be filled to not more than 1/3 the container depth to allow sufficient room for expansion under vacuum.

4. Weigh the proper amount of catalyst into the container. Mix the base and catalyst together by stirring with a stiff, flat ended metal spatula until a uniform mix is obtained. Scrape the container walls and bottom well to insure a thorough mix.

5. Place the container into a vacuum chamber and evacuate the entrapped air from the mixture using a vacuum pump capable of achieving 29 inches of vacuum. The mixture will rise, crest and then collapse in the container. Interruption (bumping) of the vacuum may be necessary to prevent overflowing the container. Keep the mixture under full vacuum for 2-3 minutes after the material has receded into the container.

6. Bleed air slowly into the vacuum chamber. When the vacuum chamber is at atmospheric equilibrium, remove the de-aired mixture.

7. Pour the de-aired material slowly into a steady stream from one end of the mould box so that the material flows evenly over the pattern. This should minimise entrapment of air bubbles under the flowing material. A "print" coat may be poured first over the pattern which will also help reduce the possibility of entrapping air on the pattern and in the cured rubber. A mould release (petroleum jelly) may be applied on the pattern first to improve release.

8. Allow the rubber to cure for 16-24 hours at 75°F (24 °C) before removing the cured rubber mould from the pattern. Heat acceleration is not recommended with this product.

9. For best results, allow the mould to air cure an additional 24 hours before using it in production.. Full cure is achieved in 3-7 days.

Supplied by:
W.P. Notcutt Ltd, Homewood Farm, Newark Lane, Ripley, Surrey GU23 6DJ.
TELEPHONE: 01483 223311 TELEFAX: 01483 479594 e-mail: sales@notcutt.com

PROCESSING INFORMATION

CATALYSED PROCESSING PROPERTIES ARE EFFECTED BY TEMPERATURE AND HUMIDITY VARIATIONS

1. For best results, mix and cure the material at 75°F (24°C) and 50% relative humidity.

2. Higher temperature and humidity will decrease the work life and pot life of the material. The faster cure will also cure affect the flow properties. Refrigeration of the base prior to use in hot environments has been shown to improve the handling properties of this material.

3. Lower temperatures and humidity will increase the work life and pot life of the material. The slower cure will increase the flow time. Cure temperature below 68°F (20°C) are not recommended and have been found to cause a reduction in final cure hardness and properties.

4. It is important that the catalyst containers are tightly closed after use. Catalyst exposed to air for extended periods of time will hydrolyses (cure). An indication of the hydrolysis is a film or crust formation on the surface of the catalyst. The use of hydrolyses catalyst is not recommended and may cause incomplete cure.

SAFETY PRECAUTIONS
USE MATERIAL IN ACCORDANCE WITH MATERIAL SAFETY DATA SHEET
This rubber system uses an organometallic tin catalyst which may irritate or burn skin and eyes upon contact. If eye contact occurs, flushing with water for at least 15 minutes will relieve discomfort. If irritation or discomfort persists, obtain medical attention.

MOLDSIL "T"

De-mould Time or Skin time (Hrs).	16
Gel Time (Mins)	60
Hardness Shore A	14
Tensile Strength mPa	3.1
Elongation to Break %	500
Tear Strength KN/m	20
Relative Density	1.10
Linear Shrinkage %	0.2

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RUBBER GLASS TM - RUBBER COMPOUND
Rubber Glass^TM is a silicone rubber product developed specifically for special effects and display applications. Two liquids (Parts A + B) are mixed together in equal amounts and poured into a container. The mixture cures overnight to a solid water clear rubber that can then be easily broken or "crumbled" into pieces that look exactly like broken glass, ice or diamonds. Vibrant colours are possible by adding liquid colour pigments. Rubber Glass^TM can be used to create a variety of display effects (i.e. encapsulate dried flower arrangements in vases for retail displays), special effects (i.e. simulated broken glass where human contact is required) and model effects (i.e. simulated ice or water).

TECHNICAL OVERVIEW

*Key Values:* *~Mixing Ratio:* 100A to 100B by weight or volume *~Shore A Hardness:* 32 ~ *Pot Life:* 90 minutes *~Cure Time/Demould:* 16-24 hrs. at room temperature *~Colour:* Clear
*Components*	*Viscosity*	*Cu.In./Lb.*	*Mix Ratio*
Mixed Part A+B	200 cps	28.5	100A:100B pbw or pbv

Mixing Pouring Curing
Mixing…Mixing containers and stirring sticks should be made of plastic and must be clean and dry. Dispense equal amounts of Parts A and B into mixing container. Mix thoroughly for at least three minutes, making absolutely sure that you scrape the sides and bottom of your container several times. Do not whip or agitate material as this may cause air bubbles. If completely bubble free castings are required, vacuum degassing material prior to pouring will eliminate all bubbles. Vacuum material for 2 – 3 minutes (29 inches of mercury), making sure that you leave enough room in container for product expansion.
Pouring…pour mixtures into a plastic container or mould (ice cube trays or plastic cups made of polyethylene work well). If pouring into or over other surface, be aware that cure inhibition is possible (see section below – "cure inhibition"). If casting into silicone moulds, a suitable release agent is required. If casting into a polyurethane mould, make sure that urethane mould is fully cured and clean of silicone release sprays that may have been previously applied.
Curing…Let cure overnight at room temperature (65 F/18 C). Colder temperatures will slow the curing process, while warmer temperatures will accelerate curing time. Cure time can be reduced by applying mild, constant heat (125^oF/51^oC) for 4 – 6 hours. Let cool to room temperature before removing cured rubber from mould.
Cure Inhibition – Silicone rubber may be inhibited by certain contaminants resulting in "tackiness" or a total lack of cure. If compatibility between the rubber and the surface is a concern, a small scale test is recommended. Materials found to cause cure inhibition include sulphur-based modelling clays, latex rubber and water. If casting Rubber Glass over a model surface that you think might cause inhibition, apply a "barrier coat" of clear acrylic lacquer sprayed directly over all surfaces that will come in contact with the Rubber Glass is usually effective.
Material Performance – Once material has fully cured, remove from container or mould. Cured Rubber Glass^TM is now ready to be displayed as is or broken/crumbled for your specific application.
Safety First
The Material Safety Data Sheet (MSDS) for this or any product should be read prior to use and is available upon request. Products are safe to use if directions are read and followed carefully.

Be careful. Use only with adequate ventilation. Contact with skin and eyes may cause irritation. Flush eyes with soap and water for 15 minutes and seek immediate medical attention. Remove from skin with waterless hand cleaner followed by soap and water.

Important: The information contained in this bulletin is considered accurate. However, no warranty is expressed or implied regarding the accuracy of the data, the results to be obtained from the use thereof or that any such use will not infringe upon a patent. User shall determine the suitability of the product for the intended application and assume all risk and liability whatsoever in connection therewith.
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