Gloves unsupported

Styrene—butadiene, acrylonitrile—butadiene, and butyl latices have also been prevulcanised, but this usually results in a lower wet gel strength. Where the mbber is to be deposited onto a fabric substrate, as in manufacture of fabric-lined gloves, the lower gel strength is not a problem. For unsupported dipped synthetic mbber products, however, the use of post-vulcanised compounds is more common. 

Dipped Goods. Gloves with and without cloth support are a typical example. Unsupported appUcations involve specialty medical gloves and weather balloons. Eor CR to compete with less expensive natural mbber, it must provide added value. Natural mbber medical examination gloves contain proteins that can cause an allergic reaction in both patients and medical personnel. Polychloroprene gloves avoid the problem for those individuals, but are too expensive for general use. Natural mbber weather balloons have less lift than CR balloons and are rapidly attacked by ozone in the upper atmosphere. 

Chem. Descrip. Carboxylated butadiene-acrylonitrile copolymer Uses Provid good flexibility, soft hand for supported/unsupported gloves, textile coatings... 

Some gloves are manufactured for specific applications, and some are for a broad spectrum of chemicals. Gloves are manufactured as supported (e g., cotton flannel lining) and unsupported. Unsupported gloves are usually made of thicker film (30 mils) (supported have film coated on support material). There are some gloves from very thin laminate such as Safety4 4H (2.7 mils thick, 5 ply laminate). 

Figure 2.4 Gloves. Clockwise from the top neoprene gauntlet, PVC, butyl rubber, vinyl, latex, unsupported nitrile NBR, nylon-polyolefin fiber (for cryogenic work), nitrile, natural rubber, texturized silica (Zetex).

Where chemical hazards exist, employers should read the Material Safety Data Sheet (MSDS) for each chemical and determine if employees will have incidental or extended contact with the hazardous materials. Disposable gloves are often selected for incidental contact whereas unsupported and supported chemical- or liquid-resistant styles are used for extended contact or where immersion is required. Unsupported gloves provide enhanced dexterity and tactile sensitivity. Supported styles are constructed of base fabrics for added physical strength. 

Disposable and unsupported gloves consist of a film of a chosen polymer with a thickness appropriate to the end use. Fabric-supported gloves are made by pulling a woven fabric liner on to a former, and applying a polymer coating to the fabric by dipping. 

Synthetic polymers have found their main use in light industrial, unsupported industrial and fabric supported gloves. The reasons have been associated with specific technical benefits, as described in the next section. 

Obviously the main requirement of a former for unsupported glove production, is to provide the shape of the desired final product In addition, however, the mix or coag-... 

Fig. 15-1 Former designs for (left) thin multi-purpose gloves (ambidextrous) (center) for fabric supported gloves (hand specific) and (right) for industrial unsupported gloves (hand specific).

The production of fabric supported gloves requires special formers. Since these gloves are relatively difficult to stretch, the former is often designed with a moveable joint at the base of the thumb (or even a detachable thumb) to ease the task of removing the final product Clearly, many of the features required by formers for unsupported gloves are unnecessary for fabric supported work, where only the fabric Hner should contact the dipping mix. 

Polyacrylates Unsupported, heavier weight gloves Polyacrylates are often supplied as an emulsion, becoming effective on raising their pH. They usually give a pseudoplastic rheology. 

Casein Unsupported gloves Expensive. Casein also acts as a colloid stabilizer. It is susceptible to infection problems. 

A schematic diagram of the batch process for thicker unsupported gloves is given in Fig. 15-3. 

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