No abstract

Two bolts of cotton duck fabric that meet military specifications and the purchasing guidelines described by the National Institute of Standards and Technology (NIST) for use as a substrate in "Test Methods for Quantifying the Propensity of Cigarettes to Ignite Soft Furnishings" were tested with smoldering cigarettes to determine the effect of inter-bolt variations on cigarette ignition propensity test outcome. The test was designed around an ASTM method that calls for the control of all known test variables, except for those inherent to the fabric's manufacture. The ignitability of each fabric was determined by testing two sets of 48 replications for each of two experimental cigarettes. The two bolts of cotton duck fabric showed a statistically significant difference in ignitions, independent of environmental and experimental fac tors. Two additional bolts of cotton duck #4 were analyzed. Cigarette ignition test results and the physical parameters of the additional bolts offer evidence that the NIST specifications are difficult to meet and further that test results are extremely sensitive to fabric properties.

The objective of this research was to determine the effect of soil ing, through wear, on the smoldering potential of upholstery fabrics. This research was done to test the supposition that smolder resistant fabrics on new furniture will become more susceptible to smoldering with soiling and age. This is shown not to be the case. Sixty used upholstery fabrics were collected from eight upholstery shops, and areas of each fabric were determined to be either "soiled" or "unsoiled." A soiled area is an exposed surface of the upholstery fabric, whereas an unsoiled area is not exposed. Each fabric's compo sition, e.g., cellulose or synthetic, was determined, and soiled and unsoiled samples from each fabric were analyzed for pertinent chemical and physical characteristics. For the majority of fabrics, the smoldering potential of the soiled areas did not increase with respect to the unsoiled areas. In fact, more fabrics exhibited a reduced (versus increased) tendency to smolder upon soiling. Of the 27 cellulosic fabrics, only 2 fabrics changed from non-smoldering in the unsoiled area to smoldering in the soiled area. But, 6 fabrics that smoldered in the unsoiled area did not smolder in the soiled area. Two ions that play a major catalytic role in smoldering ignitions, sodium and potassium, showed increased levels in soiled areas by approximately 800 ppm and 480 ppm, respectively. These increases did not account for the observed changes in smolder potential. The increase in sodium and potassium ion levels for the synthetic fabrics was equivalent to those of the cellulosic fabrics. Calcium and magnesium did not in crease between soiled and unsoiled fabric areas. Of the six anions analyzed for unsoiled and soiled areas of the 60 fabrics, levels of chloride and sulfate anions increased in the soiled samples compared to the unsoiled.

To determine the effect of inter-bolt variability of duck #6 fabrics on cigarette ignition propensity, four bolts of duck #6 fabrics purchased accord ing to guidelines described by the National Institute of Standards and Technol ogy (NIST) were used in testing the ignition propensity of two experimental cigarettes according to a test method proposed by NIST. Results for each of the cigarettes were highly dependent on the bolt used in preparing the mockup. Inter-bolt variability of cotton duck #6 fabric was found to produce a statisti cally significant difference in the ignition results for the same cigarette. The results support an earlier study performed with duck #4 fabric. Numbered duck fabrics are no longer manufactured in the USA. Use of imported duck fabrics might introduce additional variables to the cotton duck fabric proper ties that could well lead to an even greater variability in cigarette ignition pro pensity testing.

A factorial matrix consisting of 25 cigarette samples, where tobacco density, circumference, paper porosity and paper citrate were varied at three levels was tested on cotton duck, treated sailcloth and four commercial fabrics. Duck fabrics are heavy canvas-type fabrics that have very high levels of potassium ions. Treated sailcloth is a light areal density fabric treated with potassium sulfate and hydroxide salts to produce ignition results that mimic those obtained with light areal density commercial fabrics. The chosen commercial fabrics had light, heavy and mid-range areal densities. The results underscore the fact that changing tobacco column parameters does not produce cigarette designs that perform consistently well on all fabric types. Lower cigarette density and reduced circumference levels reduce ignitions on duck fabrics but increase ignitions on treated sailcloth and the light areal density commercial fabric. Reducing paper porosity reduced ignitions on duck fabric, had little effect on treated sailcloth and increased ignitions on the light areal density commercial fabric. Paper citrate had the smallest effect. Ignition results on duck fabrics correlated with each other but were in contrast to those obtained with treated sailcloth. The heavy and light areal density fabrics produced similar ignition results to the duck fabrics and treated sailcloth, respectively. The two mid-weight commercial fabrics produced ignition results dissimilar to the other fabrics.