There are several tests disposable gloves manufacturers will do to ensure the quality of their gloves. These tests are used to evaluate dimensions, tensile strength, elongation, puncture, residual, powder, leakage, simulated use, heat aging degradation, and viral barriers.
1. AQL
A key quality measurement that glove manufacturers publish on glove boxes, bags and product literature is AQL, or Acceptable Quality Level. It’s defined as the “quality level that is the worst tolerable” in ISO 2859-1. It represents the maximum number of defective units, beyond which a batch is rejected. Importers usually set different AQLs for critical, major, and minor defects.
Let’s say a glove manufacturer produces 10,000 gloves from the same material, settings and processes. Two hundred gloves would be pulled randomly from the line, throughout the batch, to be tested. To meet an AQL of 2.5%, no more than 10 gloves can fail the quality tests. If more than 10 gloves fail, the entire batch fails, and each glove must be tested individually for quality, or else the whole batch is discarded. An AQL of 1.5% would mean that no more than 7 gloves could fail.
How the AQL is Determined
There are two key elements help to determine:
- How many samples should be picked and inspected, among a batch of product or parts?
- Where is the limit between acceptability and refusal, when it comes to defective products?
First Step: If your ‘lot size’ is comprised between 3,201 pcs and 10,000 pcs, and that your inspection level is ‘II’. Consequently, the code letter is “L”.
Second Step: Now you code letter is “L”, so you will have to draw 200 pcs randomly from the total lot size. Besides, assuming that your AQL at 2.5% for major defects and 4.0% for minor defects. Therefore, here are the limits: the products are accepted if NO MORE than 10 products with major defects AND NO MORE than 14 products with minor defects are found. For example, if you find 15 products with major defects and 12 products with minor defects, the products are refused. If you find 3 with major defects and 7 with minor defects, they are accepted.
2. Test Method
2.1 Visual Inspection
A visual inspection of the gloves is the initial preliminary check. If there are any visible defects like tears, holes, or missing fingers within a batch, there is no need for further testing. Visibly defective gloves are removed and discarded.
2.2 Watertight Test
Watertight test determines the quality of the gloves in terms of pinholes. Gloves are filled with water and suspended to observe any leakage. The AQL specifies the maximum number of defective items that could be considered acceptable during the random sampling of an inspection.
2.3 Dimension Test
This checks for the glove’s dimensions to ensure that they conform to the pre-determined specifications. It includes checking the length, width, and thickness; this ensures the customer will be getting the size they expect.
2.4 Tensile Test
This determines the strength and elongation of the glove. A sample of the glove material is stretched until it breaks. The force required to break the material and how much the material can stretch before breaking are both recorded.
2.5 Aging Test
This evaluates how the gloves hold up over time. It involves storing gloves in specific conditions for a predetermined duration, and then testing their physical properties afterward. The testing conditions could include exposure to extreme temperatures, or levels of humidity and dryness.
2.6 Chemical Resistance Test
This test checks how well the glove can resist specific chemicals. It’s especially important for gloves that are marketed for use with certain chemicals. For example, some gloves are better suited for handling the drugs used in chemotherapy, such as our Grape Grip Powder Free Nitrile Exam Gloves. Check out our handy chart for more information on the chemical resistance of GloveNation’s gloves.
2.7 Protein Content Test
This is mainly for latex gloves. It measures the amount of protein content, as some users can be allergic to natural rubber latex proteins. Our gloves contain low levels of latex proteins, but we still recommend using nitrile or vinyl if the wearer is sensitive to latex.
2.8 Powder Content Test
If gloves are powdered, this test ensures that the powder level is within acceptable limits.
2.9 Viral Penetration Test
This evaluates if the glove can act as an effective barrier against viruses. General purpose gloves don’t need to go through this testing process.
2.10 Force at Break Test
Like the tensile test, this assesses the strength of the glove material when it is stretched to its breaking point.
2.11 Freedom from Holes Test
This is an electrical test where the glove is filled with water and then placed in a solution. Any pinholes or imperfections would complete an electrical circuit, indicating the glove’s failure. This is similar to the watertight test as described above.
2.12 Dexterity Test
This test ensures that the glove doesn’t impair the wearer’s ability to handle and manipulate objects.
To ensure that gloves meet international and national standards, manufacturers typically adhere to standards set by organizations such as ASTM International, the European Committee for Standardization (CEN), and the ISO (International Organization for Standardization). A manufacturer won’t use all the tests above for all their gloves; the type of tests and the criteria they need to fulfill can vary based on the intended use and the material of the glove.