Nitrile Gloves, Latex-Free Gloves, Disposable Gloves

Disposable Nitrile Gloves

• The History of Nitrile Gloves
• Why Use Nitrile Gloves?
• What's In Nitrile Gloves?
• All About Nitrile Gloves
• The Problem With Nitrile Gloves
• Powder Free Nitrile Gloves
• Nitrile Gloves and Fingerprints

Nitrile Butadiene Rubber, also known as Buna-N and more commonly known as "Synthetic Rubber".

There are trade names for nitrile rubber: Krynac, Europrene and Nipol are some of the most common. Perhaps because of the low startup production cost for nitrile rubber, it is produced mainly in Taiwan and China. Recently (2008), the European Union levied a very significant price-fixing tariff against most nitrile rubber producers, but this has not resulted in any significant price reductions for glove manufacturers.

For those who paid attention in college chemistry:
Emulsifier (actually, soap), propenenitrile, various butadiene monomers, activators (to generate radicals), and a time-saving catalyst are added to polymerization vessels during production of "hot" nitrile rubber. Water (distilled water is preferable, but not absolutely necessary) is used as the reaction medium inside the PVs (polymerization vessels). The PVs are heated to 36 degrees celcius to initiate the polymerization reaction and to encourage polymer branches.

Monomers are usually permitted to react for 6 to 15 hours, depending upon the mixture and the desired properties. Polymerization is permitted to continue until about 70% conversion is achieved. At 70% (or sometimes a little higher) conversion, the "shortstop" (such as dimethyldithioarbamate and diethyl hydroxylamine) is fed into the PVs to react with all remaining free radicals. When the resultant slurry has "shortstopped", all the unreacted monomers (as a percentage, less than 1% at this point) are removed using a slurry steam-stripping process.

It is important to recover close to 100% of the unreacted monomers for products which will come into contact with human skin, for many reasons. The steam process accomplishes this well, but the waste from this process has been problematic; sometimes requiring additional processes in order to meet environmental standards.

After monomer recovery, the synthetic latex is sent through a series of filters to remove coagulated solids. Then the liquid is blended with an antioxidant in order to further stabilize the product. The liquid polymenr is then purposely coagulated using calcium nitrate and aluminium sulfate in a special aluminium holding tank. The coagulated synthetic rubber is washed and dried into crumbs and the crumbs are carried into large cylindrical containers for shipment to glove manufacturers (among others).

The process may sound complicated, but when this process is contrasted with what is required to produce natural rubber (inclding the collecting of the sap), it's not so bad. The process is actually quite forgiving of inaccuracies and temperature control does not need the precision required by so many other industrial processes. Given recent developments, nitrile rubber is probably going to become less expensive during the next few years, but there will always be demand for this product, because of it's resistance to oils, solvents and it's special ability to resist punctures.