SR640 Natural Rubber Lining
This natural gum rubber lining material provides impact abrasion and Hydrochloric (HCl) Acid resistance.
Lining Specifications
Lining Code: SR640
Type: Natural (Black)
Tie Gum: Without Tie Gum / (Available With Tie Gum upon request.)
Properties: Durometer 45 +/- 5 Shore A – Natural soft, black lining for impact abrasion and Hydrochloric (HCl) Acid resistance.
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) | 1 hr. @ 20psi 260°F (126°C) |
| Internal Steam Cure | 4 hrs @ 10psi 240°F (115°C) |
| Atmosphere Steam Cure | 24 hrs. @ 190°F-205°F (87°C-96°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 recommendations on lining thicknesses 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 | 2800 min |
| % Elongation at Break | ASTM D412 | 600 min |
| Durometer | ASTM D2240 | 45 +/- 5 |
| Specific Gravity | ASTM D297 | 1.34 |
| Adhesion to Metal | ASTM D429 | 30 pli min |
Skive: Open (Without Tie Gum), Closed (With Tie Gum)
Repair lining: Same or SR627C
Application Suggestions
- SR640 lining shows acceptable rubber to metal adhesion without or with Tie Gum.
- For gauges greater than ¼” plying up to desired thickness is recommended using a 45°/135° butt splice with offset seams on all but the top layer.
- When plying up, the first layer can be installed without or with Tie Gum. The Tie Gum on subsequent layers is not necessary, therefore the top layer may be lapped with an open skive.
- 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.
