The IP.com Prior Art Database
Copyright © 2005 Kimberly-Clark Corporation
English (United States)
4 pages / 29.2 KB
Cradle Tracer Gas System for Testing Breathability
Lisa Bushman, Frank Kromenaker, and Jason Cohen Kimberly-Clark Corporation, Neenah, WI
A tracer gas system has been developed to measure the breathability of a diaper or other article in a cradle-shaped sample holder mimicking the orientation the product would have when used on the body during use. The system can be used to monitor changes in breathability induced by wetting. Other modifications to the system can be considered to allow a variety of physical effects to be explored.
Breathability is a desirable feature for many articles worn against the body, including clothing and disposable articles like diapers incontinence products. Good breathability requires good gas exchange between the environment and the region between the article and the skin of the wearer. For testing the breathability of materials and articles, tracer gas techniques have proven to be useful, exemplified by the methods reported by Larry G. Berglund and Frank J. Akin, in "Measurement of Air Exchange in Diapers by Tracer Gas Methods," Tappi Journal , vol. 80, no. 9, Sept. 1997, pp. 173-178, and in US Pat. No. 6,448,464, "Absorbent Article which Maintains Skin Temperature When Wet," issued Sept. 10, 2000, to Akin et al.
Berglund and Akin discuss a method in which tracer gas is injected into a test volume that is in communication with ambient air via gas exchange across a flat section of fabric. Gas is withdrawn from another portion of the same test volume at the same rate as the injected flow rate, and the concentration of the tracer gas is measured. Assuming perfect mixing in the test volume, the difference in the concentration of the tracer gas in the withdrawn sample is a measure of the rate of gas exchange between the test volume and the ambient atmosphere across the fabric being measured.
The tracer gas method of Akin et al. (US Pat. No. 6,448,464) is related, and can be used for both wet and dry articles to measure the air exchange rate for absorbent articles as they are worn by a wearer. Their Tracer Gas Test involves injecting a tracer gas at a constant rate inside the absorbent article next to the skin of the wearer while the article is being worn. Simultaneously, the concentration of the tracer gas in the air space between the article and the wearer is measured by withdrawing a sample at the same constant rate as the injection. The air exchange is then determined based on mass balances of the tracer gas and the air within the space in question.
The test of Akin et al. can be adapted for use on mannequins or other objects.
In some cases, one may wish to consider variations of the previously established test to explore the effect of different geometries or other factors. We describe one such
adaptation of the method of Akin et al. in which absorbent articles such as diapers are placed on a cradle that is contoured to simulate the shape of a user (e.g.,...