Glove Manufacturing Terminology
ASTM
The American Society for Testing and Materials. established in 1898, The ASTM is a not-for-profit organization that provides a forum for the development and publication of voluntary consensus standards for materials, products, systems and services in various industries. The FDA uses some of the standards and specifications developed by the ASTM to establish its requirements for examination gloves.
AQL
This is a quality standard set to control the pinhole defects in gloves and is based on the findings of random sampling procedures for any particular batch/lot being produced.
All gloves are tested to determine the Acceptable Quality Level. This involves the sample testing of each batch of gloves to determine the number of non-conformities per 100 units.
A certain quantity from the batch of manufactured products is removed for random testing in accordance with accurately defined procedure. These random samples are then tested in accordance with legally stipulated standards and specifications. From the results, an assessment as to the quality of the entire batch can be made. The higher the requirements on a product, the more stringent the prescribed guidelines are. The AQL is therefore a statistical procedure for determining quality.
International AQL standard for the medical grade gloves is set at a minimum AQL 1.5. This is a probability figure, which simply means that for every batch of gloves manufactured, there is a probability that 1.5% could have pinhole defects. The international standard stipulates that the probability of pinhole defects should not exceed 1.5% for any batch of gloves manufactured. At Unigloves, we have been able to achieve a much higher standard with a minimum AQL value lower than 1.5 for examination gloves.
Latex
Natural rubber latex is a milky sap-like substance produced by the rubber tree called Hevea brasiliensis, found in Southeast Asia, India and South America. When the trunks of these rubber trees are tapped, they produce latex. This latex is then collected and used in manufacturing.
Accelerator
A chemical used as a catalyst to accelerate the process of turning liquid latex into gel form.
Vulcanisation
A manufacturing process whereby latex gloves are treated and hardened from gel form into solid form in a heating oven.
Modulus
A low modulus glove is easy to stretch and flex, whereby a high modulus glove is hard to move and stretch.
Tensile strength
Measurement of the amount of force or pull required to break a glove. Tensile strength is expressed in Mpa, and the higher the number, the stronger the glove material.
Elongation
Measurement of the length a glove can be stretched before it breaks. It is expressed as a percent of the original length of the glove right at the moment it breaks. The higher the percent, the more stretchable the glove material.
Absorbable Dusting Powder
A glove powder used to ease the donning of gloves. It is made of edible modified cornstarch and a small percentage of magnesium oxide as defined by USP, the United States Pharmacopoeia.
Calcium Carbonate
A mold-release agent added in production to help the release of gloves from the hand molds or formers. Calcium carbonate occurs naturally in chalk, limestone and sea shells.
Leaching
The washing and cleansing process with water in the manufacturing of gloves, by which excess chemicals and/or latex protein are dissolved and washed away from the gloves.
Modified Lowry
Modified Lowry method uses a chemical assay to measure total protein levels. The assay uses a chemical dye to interact with certain amino acids. The result in a color shift is measured to determine the change in optical absorbance, which means the detection of protein when comparing it to a standard curve using egg protein (purified ovalbumin) as reference point. This procedure is the most common test for determining protein levels in latex gloves. However, the test is particularly vulnerable to interference from chemical substances added by manufacturers.
Permeation
Movement of substance through a thin film, such as a glove, on a molecular level.
Primary Skin Irritation Test
A test to determine if certain material can cause skin irritation. The test material, such as a piece of glove material, is attached to the skin of test subjects, such as rabbits or guinea pigs. After maintaining the skin contact for 24 hours, the contact area is observed for up to 72 hours for any kind of skin reactions.
Sensitisation
The process of developing an allergy.
Viral Penetration Study
Adopt the standard test method ASTM F-1671 to evaluate the viral penetration resistance characteristics of protective clothing materials against blood-borne pathogen hazards. The blood-borne pathogens of major concern are the hepatitis B virus (HBV), hepatitis C (HCV) and human immunodeficiency virus (HIV).
