Knowde Enhanced TDS
Identification & Functionality
- Chemical Family
- Polymer Name
- CAS No.
- 68909-20-6
- Technologies
- Product Families
Features & Benefits
- Materials Features
- Product Highlights
- Two-part, ultra high properties silicone elastomer
- Cures with heat via addition-cure chemistry
- Has a non-tacky surface and no volatile by-products or peroxide residues
- Strained through a 400-mesh screen (minimum)
- 1:1 Mix Ratio (Part A: Part B)
Applications & Uses
- Markets
- Cure Method
- Plastics & Elastomers End Uses
- Plastics & Elastomers Processing Methods
- Applications
- For a wide variety of fabrication techniques for the healthcare industry including: molding, calendering and extruding
- For applications requiring high physical properties and fatigue and abrasion resistance
- Instructions for Use
Combine Part A and Part B in equal portions on a two-roll mill prior to use. Take care to work in a meticulously clean area with no organic rubbers used on the same equipment, as traces of foreign materials can poison the catalyst, thus inhibiting the cure. Thoroughly clean all equipment at the end of each use to avoid build-up of cured stock. The next material used on unclean equipment may pick-up residue, resulting in “gels” and imperfections.
Blending
First soften Part B on a cooled two-roll mill. Remove from the mill and soften Part A. Add an equal portion by weight of softened Part B and cross blend the components until thoroughly mixed. Keep the temperature of the blended material as low as possible to give maximum table life. Blend only sufficient material required for use in within 2 to 3 hours. Blended material may be stored in a freezer for at least 7 days if carefully wrapped. Warm material stored in a freezer to room temperature before unwrapping to avoid condensation on the elastomer, which may cause voids in molded or extruded parts.
Molding
This product can be formed into cured configurations by compression, transfer or injection molding processes. Molding cycle times are dependent on the mold temperature and crosssectional thickness of the part. It is best to use highly polished, chrome-plated or stainless steel molds for these operations. Other polished metals will normally require release agents to prevent sticking. If using release agents, clean the molded parts prior to use.
Calendering
Calender the elastomer into sheeting with or without reinforcement. Make sheeting by calendering onto a laminate such as Mylar™ or polyethylene, for vulcanized and unvulcanized sheeting, respectively. If using Mylar™, strip off the Mylar™ after vulcanization while the sheet is still hot. If using polyethylene, strip off the polyethylene before vulcanization. Long lengths of Mylar™ laminated sheeting can be calendered on a core and vulcanized in a hot air oven or steam autoclave.
Extrusion
For maximum uniformity, re-soften the elastomer on a two-roll mill at time of use. Extrude the elastomer through an unheated die to make rod, tubing and coated wire. Vulcanize after extrusion by passing the material through a horizontal or vertical heated chamber. The residence time will vary based on the temperature of the chamber and the size/thickness of the extrusion.
Vulcanization
Cure of the blended elastomer is accelerated by heat. The premeasured catalyst gives the stock a fixed cure rate. Do not attempt to change molding times by mixing the two components in any other than a 1:1 ratio, as this will change the properties of the elastomer. Only adjusting the temperature may vary the rate of cure.
Cure Inhibition
The cure may be inhibited by traces of amines, sulfur, nitrogen oxide, organotin compounds, and carbon monoxide. Because organic rubbers often contain these substances, they should not come in contact with the uncured elastomer. Catalyst residues from silicone RTV elastomers and peroxide-cured silicone elastomers may also inhibit the cure.
Post-Curing
Because these materials vulcanize via addition-cure, no residues are present and post-cure is not required for many applications. The user must confirm that press molding or short oven-cures are suitable for any specific application.
Properties
- Appearance
- Translucent
- Typical Properties
- Cured Properties
| Value | Units | Test Method / Conditions | |
| Durometer Type A | 55.0 | — | — |
| Tensile | 1,700 (11.72 ) | psi (MPa) | — |
| Elongat ion | 900.0 | % | — |
| Tear | 300 (52.91 ) | ppi (kN/m) | — |
| Mix Rat io | 0.042361111 | — | — |
| Special Feat ure | Ultra High Performance High Consistency Rubbers | — | — |
| Specific Gravity | 1.14 | — | — |
| Stress at Strain 200 % | 500 (3.45) | psi (MPa) | — |
| Work Time | 2.5 | hours | — |
| Value | Units | Test Method / Conditions | |
| Cure at 138 °C | 10.0 | minutes | — |
| Cure Rat e Scorch | 1.0 | minutes | — |
| Cure Rat e T90 | 2.85 | minutes | — |
| Cure System | Platinum | — | — |
| Post Cure at 177°C | 4.0 | hours | — |
Packaging & Availability
- Country Availability
- Regional Availability