Latex that befits the gloves sector

latexACCORDING to the latest report from Indian market research firm Konsept Analytics (KA), the rubber gloves sector remained unperturbed in 2012, despite the Eurozone crisis. There were some regions that were previously reported to have low penetration for gloves but with health and safety regulations being imposed on the healthcare and food industries, use of gloves has become imperative.

The research firm says that other key factors that generated demand for gloves were increasing healthcare reforms that are adopting more stringent regulations in the light of emerging diseases like the H1N1 as well as decreasing material costs. With natural rubber having posted significant price increases over the last two years, manufacturers have turned to the use of nitrile rubber, says KA.

The report cites Malaysia as still dominating the global glove market, with the presence of the four top rubber gloves manufacturers globally namely Top Glove, Supermax, Kossan and Hartalega. The report says that the country, being one of the largest producers of natural rubber, affords these manufacturers an advantage in terms of raw material availability as well as access to R&D capabilities as part of the support given by the government. Meanwhile according to AmResearch, in
2012, Malaysia exported 100 billion pieces of rubber gloves, around 63% of the world’s supply to 180 countries, and the industry is expected to hit US$3 trillion by 2015. But things are not all that rosy according to market analysts. Malaysian research house RHB Research is giving Malaysia’s glove sector an optimistic review, citing that the market conditions are favourable. It says that Hartalega’s next generation integrated glove complex (NGC) will commence in August 2014, with an expected increase in total capacity to 43 billion pieces/year by 2020. Meanwhile, Supermax has also posted a healthy second quarter financial result and has two new plants that will be fully commissioned by 2014 to further boost its sales.

Nonetheless, there are major bottlenecks the manufacturers have to deal with, including labour shortage, fluctuating rubber prices and the imposition of minimum wage levels in the country. Meanwhile, Thailand and Indonesia, which are two top rubber producers, are also catching up in the manufacture of rubber gloves. Recently, the Public Health Minister of Thailand, Pradit Sintawanarong, was quoted as having said that gloves exports will ramp up from 20 billion baht to 50 billion baht over the next five years, making the country a close contender to Malaysia.

Since more than 12 billion gloves of capacity has been added in the last 10 months in Asia (with several new projects currently are under way and expected to come online soon), the sector will experience an overcapacity situation. This is further affirmed by the largest maker of gloves in the world, Top Glove, that said recently it is consolidating its operations in China where it has two vinyl factories.
According to Chairman Tan Sri Lim Wee Chai, the firm will be more cautious about expanding its business and would instead focus on improving the quality of its products and mix rather than ramping up production capacity in the 2014 financial year. The company’s current utilisation rates are 90% for nitrile gloves, 80% for latex gloves and 50% for vinyl gloves. It will also readjust its high surgical glove production volume as it has fulfilled a supply contract to Africa. Nitrile gloves continue to be the growth driver, though the firm had a 40% growth volume this year, slower than last year’s 65% growth.

Latex improvements offer opportunities
Though natural rubber latex (NRL) has long been used to manufacture rubber gloves, the risks for allergy in gloves have become more of a concern now.

David Hill of UK-based international latex consultancy David Hill & Associates, who is an experienced latex scientist and technical manager with over 26 years of work experience in companies within the latex segment, says the greatest concern in the glove market would be major health scares on rubber accelerators or latex proteins. He was speaking during the recent Latex and Synthetic Polymer Dispersions conference held in Kuala Lumpur, Malaysia.

He says the industry has evolved from the development of powder-free surgical gloves and the availability of de-proteinised NRL to the development of soft nitrile latex exam gloves and the development of synthetic polyisoprene latex as a viable glove material. But yet, NRL is still a growing material in glove production, he says. Another speaker at the conference Hardi Tamm,

Founder/CEO of Korymbos in Estonia pointed out that the changes in allergy risks are in line with the development of rubber gloves. Highlighting that the role of gloves is to protect, he says that allergy risks need to be eradicated. He explained in his presentation that the allergenic factor of rubber gloves is rooted in the protein content of raw latex, adding that in a small portion (1%) of raw latex, proteins are responsible for allergic reactions. “The rubber tree uses proteins to protect itself against bacteria and fungi, as well as to heal the wounds caused by tapping,” he explained, countering that majority of these proteins are, however, “harmless to us”.

He affirmed, “Raw latex contains about 200 different proteins, 50 to 60 of which have been named as potentially allergenic. The WHO/IUIS Allergen Nomenclature Sub-Committee currently (2013) lists only 14 natural rubber latex (NRL) proteins as allergens (that are characterised at the molecular level). Only four of them are clinically relevant (major allergens).”

There are two important thresholds (NRL allergens, Type I sensitivity), according to Tamm. “When the sum of four allergens is below 0.15 microgram/g, the latex product is more likely to be safe. Products with allergen content higher than 1.15 microgram/g have a high allergy potential.”

He also mentions that the shift to synthetic rubber has increased risks for Type IV allergy. While there are currently testing methods for allergenicity of NRL and synthetic rubber gloves as well as regulations and standardisations in place (such as the ASTM, CEN, ISO), few safety thresholds have been established, says Tamm.

He also says that there is no definitive method of finding out what material is used or how much NRL is contained in the glove being used.

Other options for glove makers Tamm also says that studies relating to
allergies in NRL-based products indicate that it is imperative to use safer materials, adding that ongoing developments in using guayule (a potential commercial source of high quality yet hypoallergenic latex), Russian dandelion and other natural sources of rubber are indicative that the shift to new materials is slowly taking place. One such alternative comes from Vystar Corporation, the exclusive creator of the multipatented Vytex Natural Rubber Latex (NRL).

Vytex NRL is said to result in a more translucent and cleaner latex following the removal of proteins and non-rubbers. For manufacturers, Vytex NRL cuts production costs due to less chemicals and water used and processing involved in removing proteins, says the firm that only this year received a patent from the European Union.

Latest developments add value to gloves Meanwhile, Australian glove maker Ansell says it is committed to reducing glove allergenicity at every stage of the manufacturing process by refining the use of chemical accelerators, like Diphenylguanidine (DPG), reducing residual protein levels throughout the production process and on-going investment in R&D. Ansell says it has developed a DPG-free polyisoprene formulation that provides relief for healthcare workers suffering from latex allergies and Type IV allergies caused by DPG.

Compatriot Zeon Corporation has also started marketing its new polyisoprene rubber, which is incorporated with polyisoprene emulsion using the company’s proprietary emulsion production technology. The Nipol ME Series is suitable for highly pliant, tight-fitting products that require tensile strength and tear strength equivalent to natural rubber, says the Japanese firm. It adds that the Nipol ME Series does not contain the proteins found in NRL, making it a suitable material for surgical gloves.

Effective barriers against pathogens From minimising risks to causing allergies, the latex in gloves has to be an effective barrier device. This was emphasised by Professor Ho Chee Cheong, an adjunct professor at the University Tunku Abdul Rahman, Malaysia, in his presentation at the latex conference.

He says that the latex material has to form a continuous film for protection against pathogens (barrier property); be mechanically strong and elastic; hydrophilic (compatible with damp skin); and should be soft and conform to the contour of the hand. He added that when the latex glove is worn, it has to exhibit low surface friction against skin, with minimal surface contact with the skin. “The Initial contact between latex particles achieved by gelation (chemical means) is followed by inter-particle diffusion of rubber molecules. Cross-linking of rubber molecules – network formation and mechanical strength development is enabled. A complete fusion/coalescence of latex particles gives a continuous, coherent film without any residual structures,” he says in his presentation at the conference.

Meanwhile, Ho describes the prerequisites for coalescing of the latex particles and film formation. “There is a minimum film forming temperature (corresponding to Tg) and also above 0°C to be observed and applied. Sufficient adhesion between adjacent latex particles for inter-particles fusion to occur and film to develop mechanical and barrier properties is needed. The rate of coalescence of latex particles depends on rate of inter-diffusion of polymer molecules across interface (molecular size, chemical) nature of the polymer and thermal energy of the ambient and the process drying rate.”

Latex dipping, while it is a rather sophisticated method that requires “lots of engineering innovation for sophisticated high-speed dipping machine”, is likewise presented as a measure to improve a glove’s efficiency as a barrier device. Ho adds that the latex’s surface treatment by coating polymeric lubricating layer could improve lubricity for donning. The coating should not delaminate from surface upon stretching and usage, he stresses.

Meanwhile, Aik Hwee Eng, from Ansell Malaysia said that the firm has innovated its first antibacterial infection protection medical glove. He said that medical gloves with an anti-bacterial coating on the outside surface will be playing a big role in the healthcare setting.

“This proprietary anti-bacterial coating is fast-acting, capable of reducing the bacterial load when in contact with contaminated surface such as a dirty hand during dispensing or any surface during use. The relevance of this glove in the healthcare setting is vital in reducing the transmission of pathogens by gloved hands that could cause the healthcare-associated infections,” he explained.