Astlett Rubber Inc.


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Rubber Materials
Natural Rubber
Specialty NR Grades
Synthetic Rubber
Carbon Black

Titanium Dioxide

Zinc Oxide

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Natural Rubber

Key Properties and Characteristics
Durometer (Shore A)
  Tear Strength
Specific Gravity (Polymer)
  Flame Retardent Properties
Tensile Strength Max-psi (Mpa)
  Weathering Characteristics
Low Temperature Brittle Point (C/F)
  Oxidation Resistance
  Ozone Resistance
Compression Set
  Oil Resistance
Heat Aging
  Acid Resistance
F to G
Abrasion Resistance
  Resistance to Alkali Substances
F to G
CAS Number
Key Characteristics
Tensile strength and tear resistance.
Further Comments
The outstanding strength of natural rubber has maintained its position as the preferred material in many engineering applications. It has a long fatigue life and high strength, even without reinforcing fillers. Other than for thin sections, it can be used to approximately 100C, and sometimes above. It can maintain flexibility down to -60C if compounded for the purpose. It has good creep and stress relaxation resistance and is low cost. It's chief disadvantage is it's poor oil, oxygen and ozone resistance, although these latter disadvantages can be ameliorated by chemical protection.
Legend: P=Poor; F=Fair; G=Good; E=Excellent

This natural rubber page is provided to assist you with useful information on the basics of the various grades of standard natural rubber that are currently available. We can supply you with additional information such as common uses, technical variations and supply and price trends on request.

Astlett Rubber does regular trade in all the grades of natural rubber listed below. We would like to become a supplier to your company. Please contact us for more information.

Standard Grades
Most natural rubber produced today conforms to the TSR (Technically Specified Rubber) scheme developed over the last 20 years or so. This scheme requires standardized tests to be performed on each grade of rubber as well as a standardized packing of either 33 1/3 Kilo or 35 kilo bales wrapped in thin, dispersible polyethylene or thick, strippable polyethylene. TSR rubber is usually packed with 36 bales on a crated or shrink-wrapped standard size pallet. Crate size is 1200 or 1260 Kilos.

The TSR scheme consists of the following grades:

TSR CV: Constant viscosity from latex
TSR L: Light coloured from latex
TSR 5: Equivalent to 1 RSS from sheets
TSR 10: Field grade material
TSR 20: Base field grade material

Individual rubber producing countries are in charge of setting the acceptable limits for each grade of rubber they produce. The four main countries producing rubber have their own schemes patterned after the TSR scheme:

SIR: Standard Indonesian Rubber
SMR: Standard Malaysian Rubber
STR: Standard Thai Rubber
SVR: Standard Vietnamese Rubber

Astlett also has connections with producers in other countries, such as Cambodia, Sri Lanka, and several West African nations. Please call us for specific recommendations on the applications of these grades of rubber.

Safety Data Sheet for all grades of natural rubber Adobe PDF File
Download our GHS Safety Data Sheet in pdf format here. A French language version is available in pdf format here.

Visually Graded Types
Prior to the invention of the TSR (Technically Specified Rubber) scheme, Natural Rubber was collected from small holders in various forms and separated into specific grades based on a visual inspection. Rubber sheets were then compressed into various sized bales. These grades are still best for certain applications and are now available packed similar to TSR type packaging.

Ribbed Smoked Sheets (RSS)
This material consists of deliberately coagulated* rubber sheets, completely dried using smoke. These sheets are then graded into three main grades according to their color, consistency and observed impurities. The purest is 1RSS S/B, then 2RSS S/B then 3RSS S/B. RSS is sold in standard TSR pack (designated S/B for small bales) consisting of a compressed bale of 33 1/3 or 35 Kilos wrapped in dispersible polyethylene or thick, strippable polyethylene. Crate size is 1200 or 1260 Kilos.

RSS are used when extra tough (due to extensive cross linking) rubber is needed. Some applications are tires, tank liners, industrial products, etc. RSS is generally more difficult to process than TSR.

Pale Crepe
This material consists of carefully collected fresh liquid latex, deliberately coagulated* and (sometimes) bleached, milled to produce crepe of a thickness corresponding approximately to standardized thickness, either thin or thick. There are a number of grades available with the purest being 1X Thick Pale Crepe (1XTPC) while the most popular is 1 Thick Pale Crepe (1TPC). 2 Thick Pale Crepe is also available. Pale Crepe is usually sold in 25 Kilo bales with 32 bales packed onto a crated pallet of 800kgs, suitable for Ocean Container shipping.

Pale Crepe is used in FDA applications, medical sundries, footwear, cements and adhesives, and any application that requires light color, sweet smell and good properties.

* “cup lump” grades such as TSR10/20 are coagulated in the cup by natural processes.

Specialty Grades
There are many different types of natural rubber available for special uses that don’t conform to the standard schemes or are not easily available. Some of these grades are only produced by a few factories and only needed by a few customers while others are advanced or expensive variations on the standard types used in specialized applications.

For more information, please see our specialty grades page. If your recipe calls for a grade not listed on our website, please call or email us. We have been in this business a long time and know where to get what you need.

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