High-performance natural dry solid rubber

Yulex is the first company to produce dry solid natural rubber from refined, purified and concentrated latex emulsion sourced only from FSC certified plantations and recognized processing facilities.

Yulex Pure® dry solid is produced by coagulating Yulex Pure latex emulsion in specially developed batch coagulation equipment using the Yulex weak acid process which causes a change to the rubber particle’s electrical charge; forcing the rubber particles together to form soft clumps.

These wet clumps are rinsed and milled into smaller pieces, washed with clean water and oven dried to remove all traces of moisture. Once fully dried, the material is compressed into small bales, wrapped in protective plastic, and readied for transport. Each production run of Yulex Pure Dry Solid is laboratory tested, certified, and guaranteed FSC 100%.

Yulex Pure FSC 100% dry solid natural rubber is a direct drop-in replacement for traditional crude hevea solid rubber as well as many synthetic elastomers and can be used in compounded hot cavity molding, extruding, rolled processes, closed cell foams, and thousands of other uses and applications.

Yulex Pure dry solid specifications and packaging options are available from Yulex customer service.


Yulex Pure dry solid is an industry first and available in traditional 25-30/kg bales and come protected in a compound-ready plastic wrap. Special dry solid versions are available upon request in addition to custom bale sizes. Bales are package for transport on export-safe shipping pallets.

The Advantages of Yulex Pure Dry Solid Rubber

  • Non-detectable protein levels reduced product sensitization – helping to improve product safety
  • Light brown color – reduces need for color blocking fillers, especially in bright colored products
  • Purity improves compounding efficiency – saving time and production costs
  • Purity increases green strength – improving stability of process build-up
  • Purity eliminates common foul odor found in smoked ribbed sheet crude hevea
  • FSC ensures ongoing sustainability of vital forested lands globally


download spec sheet

Yulex Pure is a GRAS material and meets ASTM D1076 Category 4 material for the total protein content. It is a high performance cis-1,4-polyisoprene plant based backbone material. Yulex Pure is ultra-high purity with over 99.9% of impurities removed. It can be stabilized and compounded with a variety of formulas depending on the end user application:

  • plus ammonia
  • plus ammonia and K laurate
  • plus ammonia and K oleate
  • plus ammonia, surfactant and flame suppressant

Potential applications include dip formed, sheeted, coated, sprayed, foamed, and adhesive products. Lexcell Pure emulsion achieves high tensile strengths in combination of high elongations and low modulus. Typical compounding techniques such as sulfur vulcanization and peroxide cure can be used. Material readily accepts common compounding additives used in both natural and synthetic polyisoprene systems such as: mineral fillers, process fluids, antidegradants, colorants, fragrances and physical property modifiers.


Yulex Pure is available for purchase in 5-gallon pails, 55 gallon coated steel drums, 1 MT (wet) IBC, or 20 MT (wet) bladders.


Store Lexcell Pure in original unopened container at 20°C ± 5°C (59-77°F) and out of direct sunlight. Product should not be frozen. Storage conditions, changes in pH, and contamination can all have a significant impact on the actual shelf life of material. Once opened it is recommended to monitor material through visual inspection and pH readings to help determine impact of storage. For IBC loads, the material should be stirred at low speeds every three to five days for one hour. Drums should be fully inverted once a week. Refrigerated storage can help maximize shelf life once opened.

* Storage conditions, changes in pH, and contamination can all have a significant impact on the actual shelf life of material.

Physical Properties & Performance Characteristics

Property Typical Values
Total Solids Content 60% to 63%
Dry Rubber Content 60% to 63%
Non-rubber Content < 0.1% difference between %TSC and %DRC
pH 10 to 12
Alkalinity (as ammonia, % Latex) 0.4 to 0.6
Total Protein Content ≤ 100 ug/ g Latex
Coagulum ≤ 0.03%
MST (@55% TSC)** >700 sec
Color Bright White for Lexcell Pure and Light to Medium Gray for Lexcell Pure FS
Odor Slight Ammonia
Elongation %* 50 to 1550
Tensile* 10 – 40 MPa
Modulus* 1.2 to > 10
Foam Density* 0.05 to 0.3 for Lexcell Pure FS; and 0.1 to 0.5 for Lexcell Pure FS
Compression Set* Good to Excellent
UV/ Ozone* Fair to Excellent
Tear* Good to Excellent
Abrasion* Good to Excellent
Chemical Resistance* Good to Excellent
Water Absorbency Good to Excellent

* Features are compound and process dependent

** MST can be modified by additions of surfactants by the preference of the end user


  • Plant Based
  • Ultra Pure
  • GRAS Approved
  • FDA Compliant Material
  • Overall Performance Properties
  • Ash
  • Dirt
  • Volatiles
  • Material Purity Level
  • Material Consistency
  • Mooney (UML 1+4, 100°C)
  • Color
  • Raw Material Biodegradable
  • Odor

Yulex Pure

  • Excellent
  • <0.5%
  • Non Detect to 0.01%
  • ≤ 0.2%
  • Excellent
  • Excellent
  • >85
  • Cream
  • Neutral

Commercial Hevea

  • Good
  • Grade L: ≤ 0.6%; Grade 20: ≤ 1.0%
  • Grade L: ≤ 0.05%; Grade 20: ≤ 0.2%
  • Grade L: ≤ 0.8%; Grade 20: ≤ 0.8%
  • Poor-Fair
  • Seasonal
  • Varies
  • Solid Yellow to Dark Brown
  • Smoky Rancid

Synthetic Polyisoprene

  • Varies
  • Varies
  • Varies
  • Varies
  • Varies
  • Excellent
  • Brand Dependent
  • Depends on Grade
  • Light Yellow
  • Chemical

The following information is supplied as general guidelines for the proper disposal of unused Yulex emulsions orsolids which have not been further compounded or processed. All un‐compounded Yulex emulsions and solids are made from a natural polymer (polyisoprene), and are GRAS and non‐hazardous. Since State and local guidelines vary on regulations for disposal of various materials, it is extremely important that a local waste service provider be consulted on the proper disposal of any material.

Yulex emulsions: Any non‐compounded emulsion material should be coagulated before disposal. This can be done by simply placing the material in a container in a freezer until all the emulsion has turned into a solid block. The time frame for this will depend on the amount of material being coagulated. Dispose of the material following all local regulations for the disposal of non‐hazardous waste.

Yulex solids: Any un‐compounded solid material can simply be bagged and disposed of following all local regulations for the disposal of non‐hazardous waste.

Compounded materials: Both emulsions and solids which have had compounding chemicals added must be handled in accordance to all local regulations for waste disposal. It is the responsibility of the disposer to contact a local waste service to help determine if the materials added are considered potentially hazardous.

If in doubt, always contact a local waste service for consulting on the proper procedures for handling of waste following all local regulations.

Solid Rubber Results

ASTM D5712 tests for the total aqueous extractable protein and ASTM D6499 is the immunological measurement of antigenic protein.

Material ASTM D5712
(Total Protein Typical Values)
μg/g Latex
ASTM D6499
(Antigenic Protein Typical Values)
μg/g Latex
Yulex Pure Solid* ≤10 < 0.3
Yulex Pure Solid** < 41.5 not tested

* In-house testing; ** Third party testing

Effective Date: 8/28/15