Knowde Enhanced TDS
Identification & Functionality
- Chemical Family
- Polymer Name
- CAS No.
- 133-14-2
- EC No.
- 205-094-9
- Technologies
- Product Families
Features & Benefits
- Materials Features
- Product Highlights
- Pre-catalyzed, high consistency elastomer (HCR)
- Strained through a 400-mesh screen (minimum) to ensure freedom from particulate contamination
Applications & Uses
- Markets
- Plastics & Elastomers Processing Methods
- Applications
- Applications requiring solvent resistance
- Transfer and compression molding parts such as: o-rings, gaskets, stoppers and seals
- Calendering and extruding
- Instructions for Use
The unvulcanized elastomer is a soft material that typically will crepe-harden with time. This phenomenon is reversible by “resoftening” the material on a two-roll mill. In general, freshly softened elastomers have better processing characteristics; therefore, milling to a smooth consistency before use is advised regardless of the elastomer’s age. Minimize heating the material when milling to prevent premature partial curing. Also accomplish addition of fillers and pigments on the mill.
Caution
Avoid foreign organic material absorption through contact or vapor and contamination from handling or processing equipment. During vulcanization, oven-curing, and post-curing, vapors containing polychlorinated biphenyl (PCB), and other residual volatile byproducts of vulcanization may be released in small amounts, which may be harmful. Work areas must be well ventilated, and workers should avoid inhalation of vapors. Review the Material Safety Data Sheets for specific information.
Molding
Mold by standard techniques of compression, transfer or injection molding. Molding cycle times depend on the mold temperature and cross-sectional 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 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 autoclaved.
Extrusion
Extrude the elastomer through an unheated die to make rod, tubing and coated wire. Accomplish vulcanization with this fabricating technique by passing the extrusion through a horizontal or vertical heated chamber. The residence time in the chamber varies with the size of the extrusion. For maximum uniformity, re-soften the elastomer on a two-roll mill the same day it is extruded.
Post-curing
The peroxide vulcanized elastomer contains 2,4-dichlorobenzoyl peroxide. The post-cure serves two purposes: post-curing removes the volatile components and other residuals generated from the decomposition of the peroxide during vulcanization, and post-curing stabilizes and enhances the physical properties of the elastomers. Accomplish post-curing by heating the vulcanized material in a hot air circulating oven to a predetermined temperature for the required length of time. The oven must have an exhaust system of sufficient capacity to prevent volatiles from reaching an explosive level. The exhaust system should be vented so as to prevent worker exposure. The time required for post-curing at a given temperature depends upon the rate at which the volatiles can escape from the elastomer, which in turn depends upon the thickness of the part, the exposed surface area and the oven loading.
Properties
- Appearance
- Translucent
- Typical Properties
- Cured Properties
| Value | Units | Test Method / Conditions | |
| Durometer Type A | 30.0 | — | — |
| Tensile | 850 (5.86 ) | psi (MPa) | — |
| Elongat ion | 300.0 | % | — |
| Tear | 40 (7.05 ) | ppi (kN/m) | — |
| Specific Gravity | 1.33 | — | — |
| Value | Units | Test Method / Conditions | |
| Cure System | Peroxide | — | — |
| Cure at 120 °C | 30.0 | minutes | — |
| Post Cure at 150°C | 1.0 | minutes | — |
Packaging & Availability
- Country Availability
- Regional Availability