RTV 2 silicon rubber molds making materials for
casting Artificial Stone industry
&resin crafts molds making
Mouldmaking Materials HM-M-920
Product Information
FEATURES:
Outstanding release properties
Room temperature vulcanizing and suitable for high-temperature casting
Low shrinkage and good dimension stability
Low hardness with flexibility and toughness
TYPICAL PROPERITIES
Test | Result | |
| A | B |
Coulor | transparent | Transparent |
Mixed Ratio | 10 | 1 |
Curing time/h | 24 | |
Hardness /ShaoA | 20 | |
Tensile strength /Mpa | 2.7 | |
Elongation at break /% | 400 | |
Tear strength /kN/m | more than 13 | |
Shrinkage/% | 0.15 | |
Description
HM-M-920 is a two-component material consist base A, which when mixed with curing agent B cures at room temperature by addition reaction.
How to use
Substrate preparation
Surface of the original should be clean and free of loose material. If necessary, use suitable release agent.
Mixing
Weight 10parts of base A and 1 parts curing agent B in a clean container, then mix together until the curing agent is completely dispersed in the base. But do not mix for a extended period. Entrapped aid should be removes in a vacuum chamber, allowing the mix to completely expand and then collapse. A volume increase of three to five times when occur on vacuum deairing the mixture, so a suitably large container should be used.
Pouring the mixture and curing
Pour the mixture onto the original as soon as possible, avoid air entrapment the catalyzed material would cure to a flexible rubber within 24 hour at room temperature and then the mould can be removed. If the work temperature is significantly low, the cure time would be longer. Heat accelerating the cure is possible, but this will produce some apparent shrinkage of the mould due to the difference in volume contraction on cooling between the silicone rubber and original.
Inhibition of cure
All addition-cured silicone elastomers are suspect to cure inhibition when contact with certain materials and chemicals. Inhibition has occurs if the elastomer is only partly cured after 24 hours or has a sticky suface in contact with another material. Amines and sulphur-containing materials are strong inhibitors, as are organotin salts used in condensation cure silicone elastomers. Mixing containers, originals and release agents should be checked for any inhibition effect before use.
Usable life and storage
Base A and curing agent B has a shelf life of 3 months from the date of manufacture.
