Properties and Characteristics
Brittle Point (C/F)
F to G
||Resistance to Alkali
F to G
Tensile strength and tear resistance.
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 100°C, and sometimes above.
It can maintain flexibility down to -60°C 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.
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.
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
CV: Constant viscosity from latex
TSR L: Light coloured from latex
TSR 5: Equivalent to 1 RSS from
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:
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
Download our GHS Safety Data Sheet in pdf format here. A French language version is available in pdf format here.
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.
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.
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
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.