Featured Research

from universities, journals, and other organizations

Ways to improve common furniture fire test

Date:
February 10, 2014
Source:
National Institute of Standards and Technology (NIST)
Summary:
The test widely used to evaluate whether a burning cigarette will ignite upholstered furniture may underestimate the tendency of component materials to smolder when these materials are used in sofas and chairs supported by springs or cloth, according to researchers.

Residues of an identical foam-fabric assembly in the current (left) and in the modified (right) smoldering ignition setup (45 min test duration). The new setup promoted an increase in smoldering rate as compared to the current setup and induced transition to flaming.
Credit: Zammarano/NIST

The bench-scale test widely used to evaluate whether a burning cigarette will ignite upholstered furniture may underestimate the tendency of component materials to smolder when these materials are used in sofas and chairs supported by springs or cloth, National Institute of Standards and Technology (NIST) and American University researchers report in a new study.

The study comes as regulations and methods for evaluating the likelihood that soft-furniture materials will ignite are undergoing scrutiny. In November 2013, California removed an open-flame test from its furniture flammability testing law**-the de facto national standard since no national regulation currently exists-and now relies solely on the so-called cigarette-smoldering-ignition test.

The new research identifies changes to this test that might make it more realistic-representative of a "near-worst-case scenario." The modifications, the researchers write, would make the test more consistent and, therefore, more useful for identifying "upholstery materials most likely to prevent smoldering ignition."

In the same article, the research team reports guidelines for making a reproducible reference foam for furniture flammability testing-a challenging, longstanding priority of standards developers, regulators and fire researchers. Such a standardized foam would help in comparing flammability data from different laboratories.

In the current setup for the test, two fabric-covered foam pieces are positioned like seat and back cushions on a small solid wood support structure. A lit standard reference cigarette (one certified by NIST to burn consistently***) is placed in the crevice formed by the two pieces. To pass, a fabric covering or barrier material under test must prevent the burning cigarette from igniting the underlying foam so that it does not smolder on its own, even after the cigarette self-extinguishes.

The researchers found that directly placing the test samples on top of the wooden support impedes air flow and, as a consequence, inhibits smoldering. They point out that the arrangement is not representative of furniture with cushions that rest on air-permeable substrates such as springs or cloth, which allows air to circulate and promotes smoldering.

The team introduced gaps between the foam samples and the underlying wood, permitting air flow. The adjustment increased-by up to threefold-the rate at which smoldering spread in the foam. It also generated significantly higher smoldering temperatures in the foam-as much as 400 degrees Celsius higher.

"Because it inhibits air flow, the current test apparatus may diminish the propensity for smoldering ignition," explains NIST's Rick Davis. "Creating gaps to increase air flow, and the other modifications we are suggesting-especially adoption of a reference foam-will enable more consistent smoldering behavior and help to minimize other causes of inconsistent flammability test results."

Either overlooked or considered unavoidable, differences in foam samples can be a significant source of ambiguity in flammability test results. Whether a lit cigarette burning on, say, a fabric covering initiates self-sustained smoldering in the underlying foam depends on whether the heat produced exceeds the heat lost. Both heat generated and heat loss are affected by the foam's internal physical structure, as well as other factors.

So, identical swatches of furniture fabric might pass one lab's cigarette-smoldering-ignition test and fail another's because the foam samples were not uniform.

The researchers' guidelines for making a standard reference foam focus on achieving uniformly sized pores, or open cells, that are arrayed throughout the material's internal, Swiss-cheese-like interior. Their experiments indicate that, for a given formulation, samples with same-sized open cells will smolder similarly.

The team found that the process for making polyurethane foams with a network-like, open-cell structure can be controlled sufficiently to minimize differences in cell size so that smoldering behavior is consistent across test samples. In fact, they say, the average cell size can be "easily tuned" so that the sample mimics the smoldering intensity observed in foams used in actual upholstered furniture.

In the United States, fires in which upholstered furniture is the first item ignited account for about 6,700 home fires annually and result in 480 civilian deaths, or almost 20 percent of home fire deaths between 2006 and 2010, according to the National Fire Protection Association.


Story Source:

The above story is based on materials provided by National Institute of Standards and Technology (NIST). Note: Materials may be edited for content and length.


Journal Reference:

  1. Mauro Zammarano, Szabolcs Matko, William M. Pitts, Douglas M. Fox, Rick D. Davis. Towards a reference polyurethane foam and bench scale test for assessing smoldering in upholstered furniture. Polymer Degradation and Stability, 2013; DOI: 10.1016/j.polymdegradstab.2013.12.010

Cite This Page:

National Institute of Standards and Technology (NIST). "Ways to improve common furniture fire test." ScienceDaily. ScienceDaily, 10 February 2014. <www.sciencedaily.com/releases/2014/02/140210114546.htm>.
National Institute of Standards and Technology (NIST). (2014, February 10). Ways to improve common furniture fire test. ScienceDaily. Retrieved September 1, 2014 from www.sciencedaily.com/releases/2014/02/140210114546.htm
National Institute of Standards and Technology (NIST). "Ways to improve common furniture fire test." ScienceDaily. www.sciencedaily.com/releases/2014/02/140210114546.htm (accessed September 1, 2014).

Share This




More Matter & Energy News

Monday, September 1, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Australian Airlines Relax Phone Ban Too

Australian Airlines Relax Phone Ban Too

Reuters - Business Video Online (Aug. 26, 2014) Qantas and Virgin say passengers can use their smartphones and tablets throughout flights after a regulator relaxed a ban on electronic devices during take-off and landing. As Hayley Platt reports the move comes as the two domestic rivals are expected to post annual net losses later this week. Video provided by Reuters
Powered by NewsLook.com
Hurricane Marie Brings Big Waves to California Coast

Hurricane Marie Brings Big Waves to California Coast

Reuters - US Online Video (Aug. 26, 2014) Huge waves generated by Hurricane Marie hit the Southern California coast. Rough Cut (no reporter narration). Video provided by Reuters
Powered by NewsLook.com
Chinese Researchers Might Be Creating Supersonic Submarine

Chinese Researchers Might Be Creating Supersonic Submarine

Newsy (Aug. 26, 2014) Chinese researchers have expanded on Cold War-era tech and are closer to building a submarine that could reach the speed of sound. Video provided by Newsy
Powered by NewsLook.com
Breakingviews: India Coal Strained by Supreme Court Ruling

Breakingviews: India Coal Strained by Supreme Court Ruling

Reuters - Business Video Online (Aug. 26, 2014) An acute coal shortage is likely to be aggravated as India's supreme court declared government coal allocations illegal, says Breakingviews' Peter Thal Larsen. Video provided by Reuters
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins