RTV 1320 Silicone Elastomer

Applications

The RTV1300 series has been formulated for use in skin/block mouldings, resin and plaster figurine castings, fibrous moulding, and general purpose mouldmaking where reproduction of fine detail is required. Selection of the appropriate part B catalyst allows the most suitable pot-life and demould time to be obtained.

Specifications

Using medium Yellow catalyst:
Pot life, minutes 100g @ 20ºC: min 55 max 65
Demould time, hours 100g @ 20ºC min 4 max 10
Hardness at full cure shore A: min 19 max 22
 

Mix Ratios

The catalysts are added at the following levels based on the part A component, regardless of the hardness grade.
Medium yellow or Fast red: 2%



Typical properties
 

Property	Units	Catalyst	RTV1320
mixed viscosity	MPa,s	any	<50,000
S.G.	-	any	1.18
pot life 100g 20ºc	minutes	medium (yellow)	60
demould 100g 20ºc	hours	medium (yellow)	8
pot life 100g 20ºc	minutes	fast (red)	30
demould 100g 20ºc	hours	fast (red)	4
hardness at full cure	shore A	any	20
tensile strength	MPa	medium (yellow)	3.5
elongation at break	%	medium (yellow)	450
tear strength	KN/m	medium (yellow)	23
linear shrinkage (max)	%	medium (yellow)	0.50

The above data were measured on samples cured as described in the sections below and at room temperature for 7 days. Note: demould times are approximate and depend partly upon atmospheric conditions.

Preparation of components

The RTV1300 series part A component requires only thorough mixing prior to removal of product from container.

The RTY1300 series part B components must be thoroughly mixed where they are coloured, in order to evenly disperse pigment, prior to removal from container. This is especially important after storage.

Details for pre- warming moulds are given in the preparation of mould section. Details of postcure conditions are given in the method of use section.


Preparation of moulds

Mould and patterns should be clean and dry and generally a good quality relaese agent should be used and allowed to dry fully.

Moulds should require no pre-warming, though if ambient conditions are particularly cold then warming to a temperature of 15-20ºc will assist the cure of material and avoid differential shrinkage between the core and edges of the moulding. Be aware that cold temperatures will result in longer cure and demould times.

Method of use.

Weighing
The components should be weighed on equipment capable of an accuracy of 2% or better. The larger quantity (usually part A component) should be weighed into a vessel of sufficient capacity to accommodate the entire mix and allow room for mixing, and degassing if required.

All components should be weighed directly into one vessel. Do not weigh each component into separate vessels and combine them, as this will not give the desired mix ratio due to losses and wastage in each container. In turn this will lead to cure problems such as incorrect cure time and hardness.

Mixing.
The components should be mixed thoroughly together by hand, use a flat blade such as pallet knife use a jiffy type mixer if using a drill. The mixing should be carried out with care to avoid the inclusion of air and also to ensure that material on the sides and bottom of the vessel is removed and mixed in.

To avoid patches of unmixed component in the finished product the mixed material may then be transferred to a second container and mixed again.

Degassing.
If degassing is required it should be done immediately after mixing. It is important to remember that degassing is only possible if the material has a sufficiently long pot life or gel time to allow for mixing, degassing and pouring.
The degassing chamber should be large enough to accommodate the mixing vessel, and the vacuum pump should ideally be able to create sufficient vacuum in the chamber to start degassing within one minute. Once the violent bubbling ceases degassing is complete for most applications. Further degassing removes only a tiny proportions of air and is only necessary in critical applications.
Please note that increasing the quantity of mix or working at higher ambient temperatures (e.g. in the summer) can reduce the pot life of the material. Where possible trials should be carried out to establish these parameters.

Pouring.
Care during pouring is essential to avoid entrapped air. Pour the material slowly allowing it to flow gently over the mould surface and to fill cavities and channels from the bottom up.

Take care not to scrape the sides of the mixing vessel to remove the last of the product. This very frequently results in an under-cured or soft area in the finished casting.

Postcure.
This material will cure satisfactorily at ambient room temperatures. Whilst the material can be de-moulded after 24 hours depending on section cast, full strength and hardness will develop over 2-4 days.


Handling and storage.
The relevant safety data sheets should be read carefully before using this material.
Good housekeeping is important with this material as with all chemicals. Spillages should be wiped up immediately and containers wiped clean after use.
The components should be stored in their original containers in a dry place at 5-30ºC.
RTV1300 series part A components have a minimum shelf life of 12 months from date of manufacture when stored correctly in unopened containers.
RTV1300 series part B components have a minimum shelf life of 6 months from the date of manufacture when stored correctly in unopened containers.

Health & Safety.
The safety data sheet provides information on the health and safety aspects of this material.

The RTV1300 series part A components are not classified according to the requirements of the CHIP regulations. However care should be taken to minimise contact and gloves, goggles impervious overalls should be worn.
RTV1300 series part A component are not classified as hazardous according to the requirement of CHIP regulations.
RTV1300 series part B components are classified as FLAMMABLE and HARMFUL by inhalation. Refer to the safety data sheet for more information.

Suitability for use.
The information in this datasheet is given to the best of our knowledge and belief but without warranty or liability.
The user must establish the suitability of the material for the intended application by carrying out any appropriate tests.
Finished products produced from any batch of our materials must be subjected to comprehensive standards of quality control by the user.

Additional information.
The product has not been tested for all applications and it is strongly recommended that customers carry out adequate trials to determine the suitability of this material for the intended use.
No liability will be accepted for direct or consequential losses arising from the use of this material. However any comment or suggestions relating to improving the processing or characteristics of this material will be very welcome.