The Exchange Test Method
LABORATORY TEST METHOD NO. H-2: STRIKEBACK- PERSONAL HYGIENE PRODUCTS
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PURPOSE:
To determine the amount of liquid that is not fully absorbed by a specimen. This also indicates the amount of moisture released by a specimen under externally applied pressure. The extent to which a specimen "feels" dry during use is dependent on its ability to hold moisture when stress is applied to the specimen. The lower the amount of strikeback, the higher the comfort and dryness for the consumer.
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PRINCIPLE:
A predetermined amount of solution is poured into the center of a specimen and allowed to soak the specimen under con- trolled conditions of time and load. Strikeback is measured by weighing blotter with the amount of liquid it absorbed and comparing it with the dry blotter weight.
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APPARATUS AND MATERIALS:
- 3.1 Blotting paper, 76 by 76 mm (3 by 3 in.)
- 3.2 Heavy plastic, 76 by 76 mm (3 by 3 in.)
- 3.3 1% saline solution at 38°C (100°F)
- 3.4 2282 g (5 lb) weight
- 3.5 Mettler AE200 scale, or equivalent
- 3.6 Timer
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PROCEDURE:
- 4.1 Weigh individual blotting paper square and adjust the scale to read zero.
- 4.2 Place the specimen, opened, on flat surface. Slowly pour solution on to the center of the specimen. Use the following amount of solution depending on the product being tested.
- 20 ml for incontinent products
- 10 ml for maxi pads
- 5 ml for mini pads
- 3 ml for diapers
- 2 ml for liners
- 4.3 Leave the specimen for 30 seconds.
- 4.4 Put blotting paper on wet area, then put a plastic piece on top of it. Apply 2282 g (5 lb) weight on this assembly for 30 seconds.
- 4.5 Remove weight and blotter, weigh blotter again and record the weight.
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EVALUATION:
Calculate the difference between dry and wet weights of the blotting paper. This gives the moisture not absorbed by the specimen. Also, this indicates the amount of moisture released by a specimen under externally applied pressure.
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REPORT
The strikeback is reported in terms of grams to the nearest thousandth.