SR690 Natural Rubber Lining
This natural gum rubber lining material is meant for general purpose use and water demineralization. It is FDA Compliant.
Lining Specifications
Lining Code: SR690
Type: Natural – Semi-hard (Black)
Tie Gum: With Tie Gum
Properties: 90 +/-5 Shore A – Natural, Semi-hard lining for general purpose and water demineralization. FDA Compliant.
Primers and Adhesive System:
- One coat Chemlok® 289 on Metal
- One coat Chemlok® 290 on Metal
- One coat Chemlok® 286 on Metal
- One coat Chemlok® 286 on Lining
Cure time and Temperature:
Cure for thickness up to ¼”
| Pressure, Saturated Steam (Autoclave) | Slowly rise to (15psi) 250°F (121°C) Hold 2 hrs. @ (15psi) 250°F (121°C) |
| Internal Steam Cure | Slowly rise to (15psi) 250°F (121°C) Hold 5 hrs. @ (15psi) 250°F (121°C) |
| Atmosphere Steam Cure | 24 hrs @ 212°F (100°C) |
Note: All reference to cure psi represents gauge pressure.
**Cure times may require tunings to compensate for low temperatures, heavy metal thicknesses, and other anomalies. Contact SRR Technical Department for recommendation on thickness over ¼“.
Storage
Ideal storage temperature is 50°F not to exceed 85°F and shelf life is 180 to 45 day range respectively.
Depending on storage conditions it may be possible to use rubber linings beyond shelf life. Please contact Salem-Republic Rubber Company for technical advisement before usage.
Designed Physical Properties
| Tensile Strength PSI | ASTM D412 | 1800 min |
| % Elongation at Break | ASTM D412 | 125 min |
| Durometer | ASTM D2240 | 90 +/- 5 |
| Specific Gravity | ASTM D297 | 1.29 |
| Adhesion to Metal | ASTM D429 | 30 pli min |
Skive: Closed
Repair lining: Same or SR669 Chemical Cure
Application Suggestions
- Plying up lining thicker than 1/4″ is not recommended due to sagging during cure process.
- Warming rubber to approximately 120°F will aide in applying and is recommended.
- SR690 is a hard rubber compound, over-cure may cause brittleness.
- Experienced applicators may have techniques which produce equal or superior results and by no means are SRR’s application suggestions meant to replace these proven techniques. As long as those procedures fall within industry standard lining application guidelines.
Standard Dimensions
Roll Standard Gauge Tolerance Roll Gauge Standard Roll Maximum
A Roll .120 +/-.05 A Roll 90ft 96
B Roll .180
+/-.010 B Roll 60ft 66
C Roll .240
+.010 or -.020 C Roll 45ft 51
3/8” Roll .360
+/-.015 3/8” Roll 30ft 33
½“ Roll .480
+/-.015 ½“ Roll 23ft 27
*Customer specific gauges and widths, other than standard, are available upon request. Please call Salem-Republic Rubber Company at 1-877-425-5079 with any questions or more information about our Custom Elastomeric Linings.
