Why Crude Rubber Needs Refinement

Crude rubber needs to be purified to remove impurities including excess proteins, bacteria and allergens to improve its quality for optimal product performance.

For more than a century natural rubber, whether crude latex or crude solid, has been harvested, packaged, and used in its unrefined, contaminated, and crude form; essentially as it comes from the rubber tree.

Unrefined, crude rubber contains lots of impurities and excess proteins (including bacteria) that detract from its manufacturability, physical properties, pungent odors, short term stability, and performance. Unfortunately, manufacturers did not have much choice in the matter and as a result learned to deal with these impurities through chemical additions, compounding techniques and manufacturing methods; many of which can add significant cost to production and the finished product. When crude hevea allergies become prominent in the late 1980s and early 1990s, producers of medical gloves for example added extra post manufacturing processes to helped to remove some of the excess proteins, although did nothing about performance issues caused by impurities. Many glove manufacturers moved away from natural rubber altogether, switching to synthetic elastomers which offered lower physical performance but were contaminate and protein free. Today, however, the purity of natural rubber remains essentially unchanged, remaining a challenge to product designers and manufacturers alike. A few companies tried to develop processing methods to chemically reduce protein content by either masking proteins with harsh additives or chemically neutralize proteins yet did nothing to address the contaminants and impurities. All these products focus on adding chemicals to the rubber rather than removing them through purification; often leading to significantly reduced product performance.

Refining an Idea

Yulex was the first company to rethink how crude hevea rubber could be purified without the use of harsh chemicals or loss of physical performance properties. After years of research, development and testing, Yulex created the industry’s first purification and refinement process that utilized safe, clean water to strip away unwanted impurities and water-soluble proteins while improving physical performance of both latex emulsion and dry solid materials: The Yulex Pure® process was perfected at the company’s technology campus and has established the gold-standard for purity, performance and extremely low protein content, and is the only commercially available portfolio of FSC 100% certified and purified natural rubber on the market today.

Yulex’s commitment drove the technical team to develop a completely new process technique called liquid-to-liquid dilution chemistry which isolates impurities, pollutants and detaches soluble proteins from the rubber particles without damaging the molecular weight or polymer chain structure; all the while maintaining the correct alkalinity level. Once the reaction is complete, the process excludes the impurities, contaminants, and soluble proteins from the colloidal suspension without damaging the distribution of rubber particles. As excess liquid is removed from the colloidal suspension the Yulex Pure process concentrates rubber content, forming a highly concentrated latex emulsion. The Yulex Pure process improves elongation, green strength, pot-life, tear resistance, and modulus while producing a bright white, odor-free latex emulsion that enhances and improves your products.