Nylon Carpet Research Articles

Fungal and bacterial growth in floor dust at elevated relative humidity levels.

Under sustained, elevated building moisture conditions, bacterial and fungal growth occurs. The goal of this study was to characterize microbial growth in floor dust at variable equilibrium relative humidity (ERH) levels. Floor dust from one home was embedded in coupons cut from a worn medium-pile nylon carpet and incubated at 50%, 80%, 85%, 90%, 95%, and 100% ERH levels. Quantitative PCR and DNA sequencing of ribosomal DNA for bacteria and fungi were used to quantify growth and community shifts. Over a 1-wk period, fungal growth occurred above 80% ERH. Growth rates at 85% and 100% ERH were 1.1×104 and 1.5×105 spore equivalents d-1 mg dust-1 , respectively. Bacterial growth occurred only at 100% ERH after 1wk (9.0×104 genomes d-1 mg dust-1 ). Growth resulted in significant changes in fungal (P<.00001) and bacterial community structure (P<.00001) at varying ERH levels. Comparisons between fungal taxa incubated at different ERH levels revealed more than 100 fungal and bacterial species that were attributable to elevated ERH. Resuspension modeling indicated that more than 50% of airborne microbes could originate from the resuspension of fungi grown at ERH levels of 85% and above.

Compression molded composites from discarded nylon 6/nylon 6,6 carpets for sustainable industries

Discarded carpets with high amount of petroleum-based fibers are usually disposed in landfills, leading to waste of high value petro-polymers and environmental pollution. A novel method to reuse nylon carpet targeting environmental protection and material saving was developed. Recent studies showed that melt blended nylon carpet composites by screw extruder had low mechanical properties and disqualified carpet composites in transportation and construction industries. In this research, compression molded composites from discarded nylon 6/nylon 6,6 carpets had good sound absorption, mechanical properties and water stability. As compared with jute/PP composites, the compression molded composites from nylon 6/nylon 6,6 carpets had up to 40%, 59%, 124% and 32%, higher sound absorption, flexural strength, elastic modulus and impact resistance, respectively. Unshredded nylon 6,6 carpet yarns and styrene-butadiene-rubber/calcium-carbonate binders in carpets reinforced nylon 6 and polypropylene, and thus made the composites strong. Styrene-butadiene-rubber particles and multiple interfaces in the multi-component composites endowed compression molded nylon 6/nylon 6,6 carpet composites with good sound absorption. Developing compression molded carpet composites with good mechanical properties and sound absorption provides a new method of reusing carpets.

Preliminary evaluation of a next-generation portable gas chromatograph mass spectrometer (GC-MS) for the on-site analysis of ignitable liquid residues

The detection of ignitable liquid residues (ILRs) at a fire scene can be valuable evidence to indicate if the fire may have been deliberately set. In this study, a commercially-available portable GC-MS, the TRIDION-9, was evaluated for the purpose of on-site fire debris analysis. The instrument, which incorporates a low thermal mass capillary GC and a miniaturised toroidal ion trap mass spectrometer, is designed to use solid-phase microextraction (SPME) as the default sampling method. Four ignitable liquids (petrol, mineral turpentine, kerosene and diesel) and seven substrates (nylon, polypropylene and wool carpet, rubber and foam underlay, untreated pine and polyurethane) were considered. After method optimisation, substrates were burned and spiked with 0.1 μL of ignitable liquid (mineral turpentine, kerosene, diesel fuel, and both neat and weathered unleaded petrol). Sampling was performed via passive headspace SPME adsorption over 3 min immediately followed by analysis using the TRIDION-9 (analysis time < 2 min). Field trials were performed on fire debris samples collected from an accelerated structural fire. The data from the portable GC-MS analyses permitted the detection and correct classification of ILRs in the majority of samples analysed. Overall, the TRIDION-9 was found to be well-suited to the field-based analysis of fire debris samples as a preliminary screen to provide rapid presumptive results for fire investigators.

안전한 노인요양시설 환경을 위한 실내 바닥마감재에 관한 연구

The number of elderly who wants to access to Nursing Homes (NH) will increase due to the rapid aging society and domestic changes. Those who move into NH expect 24/7 care service in safe environment. Providing space free from danger, especially from fall, for the frail elderly is essential. The purpose of this study is to categorize performance needs of flooring materials in the aspect of safety, and analyze materials so that adequate ones for each space in NH can be suggested. Performance needs are as follows; slip resistance (dry/wet), fire resistance, resilience, water resistance, soil retardant, anti-bacterial, gloss, sound absorbtion. maintenance, durability, ease replacement, color and pattern variety, visual and tactual texture, tactile warmth, IAQ, sustainable material (before use), impact to nature (after use). They are categorized under function, economy, sensibility and sustainability. It was found that there are better materials than common ones that has been used repeatedly in NHs, such as vinyl sheets and VCT. In overall, Cork flooring and nylon carpet met all four categories, followed by wool carpet, rubber and linoleum. For bedroom, wood flooring, Cork, rubber, wool carpet, nylon carpets were suggested. In bathroom with shower, rubber, vinyl sheet and porcelain tiles were safe materials. As living/dining room and corridor floors, wool carpet, nylon carpet, cork flooring would be excellent as they are resilient and durable. The result of this paper can be used by both NH managers and material companies, resulting better quality of life of the elderly by providing safe environment.

Storm water harvesting and reuse in Australia: enhanced sand filtration for the treatment of storm water

This study details the removal of common storm water pollutants along with heavy metals by enhanced sand filtration. Three filtration flow rates were trialled: 5, 10 and 20 m/h. The performance of each filter was rated on the ability to remove turbidity, suspended solids, dissolved solids, phosphorus, nitrogen, lead, copper and Zinc. Conventional sand filter was used as a performance benchmark, and compared with four sand filters that are enhanced with a nylon carpet fibre, polypropylene carpet fibre, Syrian carpet fibre-enhanced and alum sludge-enhanced sand filter. Carpet fibre-enhanced sand filtration was highly effective at filtering simulated storm water and in most cases performing well above the conventional sand filters. The carpet fibre-enhanced sand filters had no drop in flow rates over the 4 h filtration period with following removal rates: up to 90% total suspended solids, 70% zinc, 60% turbidity, 25% phosphorus, 15% nitrogen and 10% total dissolved solids. However, results showed that alum sludge-enhanced sand filter performed the highest, with removal rates up to 100% for total suspended solids, 80% zinc, 90% turbidity, up to 80% phosphorus, up to 40% nitrogen and 3% total dissolved solids. But the flow rates dropped approximately two-thirds of the original flow rates within the first hour.

Analysis of arson fire debris by low temperature dynamic headspace adsorption porous layer open tubular columns

In this paper we present results of the application of PLOT-cryoadsorption (PLOT-cryo) to the analysis of ignitable liquids in fire debris. We tested ignitable liquids, broadly divided into fuels and solvents (although the majority of the results presented here were obtained with gasoline and diesel fuel) on three substrates: Douglas fir, oak plywood and Nylon carpet. We determined that PLOT-cryo allows the analyst to distinguish all of the ignitable liquids tested by use of a very rapid sampling protocol, and performs better (more recovered components, higher efficiency, lower elution solvent volumes) than a conventional purge and trap method. We also tested the effect of latency (the time period between applying the ignitable liquid and ignition), and we tested a variety of sampling times and a variety of PLOT capillary lengths. Reliable results can be obtained with sampling time periods as short as 3min, and on PLOT capillaries as short as 20cm. The variability of separate samples was also assessed, a study made possible by the high throughput nature of the PLOT-cryo method. We also determined that the method performs better than the conventional carbon strip method that is commonly used in fire debris analysis.

Effect of evaporation and matrix interferences on the association of simulated ignitable liquid residues to the corresponding liquid standard

Identification of an ignitable liquid in fire debris evidence can be complicated due to evaporation of the liquid, matrix interferences, and thermal degradation of both the liquid and the matrix. In this research, liquids extracted from simulated fire debris were compared to the original liquid using multivariate statistical procedures. Neat and evaporated gasoline and kerosene standards were spiked onto nylon carpet, which was subsequently burned. The ignitable liquid residues were extracted using a passive headspace procedure and analyzed by gas chromatography–mass spectrometry. Pearson product moment correlation coefficients, hierarchical cluster analysis, and principal components analysis were used to compare the liquids extracted from the carpet to the corresponding neat liquid. For each procedure, association of the extracts according to liquid type was possible, albeit not necessarily to the specific evaporation level. Of the three procedures investigated, principal components analysis offered the most promise since contributions from matrix interferences were essentially eliminated.

Preparation and Characterisation of Ink Formulations for Jet Printing on Nylon Carpet

Various ink formulations for inkjet printing on nylon66 carpet are prepared by using CI Acid Red 57, Natrosol and sodium alginate thickeners, ethylene glycol, diethylene glycol, and isopropanol with auxiliaries. The inks are characterised for their rheological, wetting, and storage stability properties. They were jetted by using a Printos P16 drop-on-demand jet print-head onto the nylon66 carpet materials, and the printed images were characterised by using an Image Xpert system. The inks that contained the synthetic thickeners at the optimum ratio provide good printing and imaging properties, such as optical density, drop size, and depth of penetration into the substrate at pH 4-5. The optimised ink formulation is found to have good storage stability. The study has focused on ink formulations based on CI Acid Red 57. Ink formulations based on other colorants could also be studied in order to assess the applicability of the ink formulation system found for other colorants. The ink formulations developed could find both uses in industrial scale printing and low cost ink formulations for printing of nylon66 carpets.

Acoustic characteristics of floor treatments for elementary school classrooms

Phase 1 of this study [J. Acoust. Soc. Am. 129(4), 2523 (2011)], determined the effects of hard versus soft flooring on overall speech and activity noise levels in elementary classrooms. A significant decrease in overall levels was found in carpeted rooms. This phase sought to investigate a range of floor materials and their pertinent properties. Nine different floor materials were mounted to 3 in. concrete slabs and evaluated using a battery of acoustic, impact, and chair scrape tests. Tested materials included vinyl composition tile, resilient rubber athletic flooring (virgin, blended/synthetic, and recycled), polyurethane, vinyl cushion tufted textile carpet, and rubber-backed commercial nylon carpet. Impedance tube measurements of sound absorption were made using International Organization for Standardization (ISO) 10534-2, while sound power measurements according to ISO 3741 were made while either (a) tapping on each mounted sample with a standard tapping machine or (b) while reciprocating an elementary classroom chair back and forth to produce repeatable scraping sounds. In general, the two carpet samples resulted in the lowest sound levels and the highest absorption. The relative performance of each material will be presented along with a discussion of additional usability factors, such as maintenance, cost, and durability. [Work supported by Paul S. Veneklasen Research Foundation.]

Preparation and characterisation of ink formulations for jet printing on nylon carpet

PurposeThe purpose of this paper is to prepare and characterise various ink formulations for inkjet printing on nylon 66 carpet.Design/methodology/approachVarious ink formulations were prepared using CI Acid Red 57, synthetic thickeners (BYK425 and BYK420), ethylene glycol, diethylene glycol, isopropanol with auxiliaries. The inks were characterised for their rheological, wetting and storage stability properties. The inks were jetted using a Printos P16 drop‐on‐demand jet print‐head onto nylon 66 carpet materials. The printed images were characterised using an ImageXpert system.FindingsIt is found that the inks containing the synthetic thickeners at the optimum ratio give good printing and image properties, such as optical density, drop size, and depth of penetration into the substrate at pH 4‐5. The optimised ink formulation is found to have good storage stability.Research limitations/implicationsThe study focuses on ink formulations based on CI Acid Red 57. Ink formulations based on other colorants could also be studied in order to assess the applicability of the ink formulation system found for other colorants.Practical implicationsThe ink formulations developed could find use in industrial scale printing.Originality/valueLow cost ink formulations for printing of nylon carpets are novel.

Preparation and Characterisation of Ink Formulations Based on Sod. alginate and Natrosol as Thickeners for Jet Printing on Nylon Carpet

Preparation and Characterisation of Ink Formulations Based on Sod. alginate and Natrosol as Thickeners for Jet Printing on Nylon Carpet

Preparation and characterisation of ink formulations for jet printing on nylon carpet

Preparation and characterisation of ink formulations for jet printing on nylon carpet

Potential exposure of children and adults to cypermethrin following use of indoor insecticide foggers

The magnitude and distribution of cypermethrin from total release, over-the-counter foggers was studied in a test room and in residences to facilitate evaluation of regulatory exposure algorithms and new human exposure assessments based upon urine biomonitoring. Surface residue (SR) was evenly distributed in a small test room (3.6 μ g cypermethrin/cm2) where thorough mixing of the aerosol occurred. In a residence SR was significantly affected by room size and distance from the fogger. Air levels in the residence were as high as 30 μ g cypermethrin/cm3 after 4.5 h. The availability of surface residues was measured with an automated surface cotton cloth wipe and ethyl acetate extraction. Only 5% of the SR was available from nylon carpet. Tile, wood and linoleum resulted in 30, 10, and 10% of SR being available, respectively. These data are used to estimate cypermethrin exposure of children and adults for comparison with existing regulatory reference dosages and exposure assessments based upon biomonitoring.

Measurement of transferable chemical residue from nylon carpet using the California roller and a new mega-California roller

Human chemical exposures resulting from transfer of surface deposition on indoor nylon carpets may be estimated by measuring transferable residues (μ g chemical/cm2 carpet). A weighted roller developed at California Department of Food and Agriculture (CDFA) has been extensively used to sample transferable residue for estimates of human exposure in risk characterization. A modified roller has been developed to evaluate the influence of pressure on transferable chemical residue since weight and force (or pressure, kg/m2) may vary person-to-person and activity-to-activity. A 30.5 cm diameter roller was used to apply 60 to 2100 kg/m2 to bracket pressures exerted by humans on a flat nylon-carpeted surface. Measurements of transferable cyfluthrin residues were made after 1, 7, and 21 days. Total Soxhlet extractable cyfluthrin residues were relatively constant during the test period. Residue transferability decreased during the study period. Modest increases in the transferability of surface residues were observed over the broad range of pressures applied by the modified roller.

Emissions from Carpet Combustion in a Pilot-Scale Rotary Kiln: Comparison with Coal and Particle-Board Combustion

The use of post-consumer carpet as a potential fuel substitute in cement kilns and other high-temperature processes is being considered to address the problem of huge volumes of carpet waste and the opportunity of waste-to-energy recovery. Carpet represents a high volume waste stream, provides high energy value, and contains other recoverable materials for the production of cement. This research studied the emission characteristics of burning 0.46-kg charges of chopped nylon carpet squares, pulverized coal, and particle-board pellets in a pilot-scale natural gas-fired rotary kiln. Carpet was tested with different amounts of water added. Emissions of oxygen, carbon dioxide, nitric oxide (NO), sulfur dioxide (SO2), carbon monoxide (CO), and total hydrocarbons and temperatures were continuously monitored. It was found that carpet burned faster and more completely than coal and particle board, with a rapid volatile release that resulted in large and variable transient emission peaks. NO emissions from carpet combustion ranged from 0.06 to 0.15 g/MJ and were inversely related to CO emissions. Carpet combustion yielded higher NO emissions than coal and particle-board combustion, consistent with its higher nitrogen content. SO2 emissions were highest for coal combustion, consistent with its higher sulfur content than carpet or particle board. Adding water to carpet slowed its burn time and reduced variability in the emission transients, reducing the CO peak but increasing NO emissions. Results of this study indicate that carpet waste can be used as an effective alternative fuel, with the caveats that it might be necessary to wet carpet or chop it finely to avoid excessive transient puff emissions due to its high volatility compared with other solid fuels, and that controlled mixing of combustion air might be used to control NO emissions from nylon carpet.

FINDING NEW LIFE FOR OLD CARPETS

JUST A FEW YEARS AGO , it looked as if the nascent carpet recycling industry was ready to be rolled up and put in the trash. In 2001, Evergreen Nylon Recycling, a high-profile carpet recycling joint venture, announced that it was unprofitable and closed its doors. Two years later, Polyamid 2000, a large German nylon carpet recycler, declared bankruptcy and shut down. Other firms were knocked back by these closures with the result that overall recycling rates, already lagging, fell well behind industry goals. Since last year, though, the industry has been staging a surprising rebirth. The Carpet America Recovery Effort, or CARE, reports that recycling in 2005 was up 100% over the year before, and it is projecting another doubling this year. Numerous manufacturing companies that consume postconsumer carpet are opening up, and Evergreen Nylon Recycling, once dismissed as a white elephant, is on the verge of reopening under a new owner. Participants in the ...

Evaluation and Comparison of the Electrostatic Dust Print Lifter and the Electrostatic Detection Apparatus2 on the Development of Footwear Impressions on Paper*

The Electrostatic Dust Print Lifter (EDPL) and the Electrostatic Detection Apparatus(2) (ESDA(2)) were compared to determine if both processes could be used to develop footwear impressions of the same or similar quality and in what order they should be used to develop the highest quality footwear impression. The sensitivity of each technique was also evaluated. The quality of the footwear impressions developed was determined by comparing 25 individual characteristics present on the known shoe to the footwear impressions developed using each technique. The footwear impressions were made by stepping on paper placed over several different surfaces, which included: linoleum, industrial Berber carpet, nylon carpet placed over a (3/8)-in. pad, ceramic tile, cardboard, 1-in. foam, 4-in. foam, cement, asphalt, grass, and mulch. Each of the papers placed on these surfaces was developed using the EDPL before the ESDA(2) and vice versa. The sensitivity test for the ESDA(2) was conducted by processing 10 sheets of stacked paper that were stepped on with the known shoe, beginning with the top sheet. The sensitivity test for the EDPL was conducted by processing 10 sheets of paper stepped on with the known shoe in succession. This study determined the footwear impressions developed using the EDPL were of better comparative value than impressions developed with the ESDA(2). On average, 72.4% of the individual characteristics from the known impression were identified on images developed when the EDPL was used first compared with an average of 38.9% when the ESDA(2) was used first. Therefore, if only one technique is used, the EDPL should be chosen. The sensitivity test determined the ESDA(2) develops high-quality footwear impressions on only the top sheet of paper. No footwear impressions were developed on any sheets under the top sheet of paper. The sensitivity test also determined the EDPL results increase in quality as the amount of dust residue decreases on the surface.

Sorption of VOCs on material surfaces as the deciding factor when choosing a ventilation strategy

The interaction between different ventilation strategies, and the adsorption and desorption of volatile organic compounds on material surfaces in small test chambers, is investigated. In test chamber experiments, nylon carpet was exposed to a mixture of toluene and α-pinene at two different dosing rates. The ventilation strategies were chosen to mimic the conditions in real buildings, i.e. with an air exchange rate of 2 h −1 during the working day (8–17) and a rate of 0.67 h −1 during the remainder of the 24 h. The results show that the sorption behavior has to be included when estimating the concentration variations in a room based on source characteristics and ventilation rates. The software application “EnviSim” was used to model the concentrations in a model room based on the experimental conditions. As the ventilation strategy influences the resulting concentrations, it is recommended that the ventilation system be “turned on” a couple of hours before the start of the working day and “turned down” again soon after the occupants have left the building.

Artificial Sweat Enhances Dermal Transfer of Chlorpyrifos from Treated Nylon Carpet Fibers

The dermal transfer and absorption of 14C-ring-chlorpyrifos from nylon carpet fibers was measured in skin penetration-evaporation cells with excised pig skin. Prior to application, synthetic sweat was applied to skin in half of the cells. Radioactivity was measured in receptor fluid, dermis, epidermis, tape stripping samples, and vapor trap samples during a 24-h period. The sum of radiolabel recovered from the dermis and receptor fluid represented the absorbed dose. There was no significant difference (p > 0.05) in percutaneous absorption between cells that received the synthetic sweat application and “dry” cells (1.3 ± 0.3% of applied dose). There was significantly more (p < 0.05) radiolabel recovered from tape stripping (5.4 ± 2.1 vs. 2.8 ± 0.6%) and in the epidermis (4.5 ± 0.8 vs. 3.1 ± 0.3%) from cells that received the synthetic sweat application, which indicated synthetic sweat facilitated transfer of chlorpyrifos from a treated substrate to the skin surface. The measured value for percutaneous absorption of chlorpyrifos agreed with the value predicted from an empirical model previously developed for nitro compound–containing soil.

Novel Fluorinated Inorganic-Organic Finishing Materials for Nylon Carpeting

Fluorinated inorganic-organic finishing materials prepared by a sol-gel process using poly(methacrylic acid) (PMAA), tetraethoxysilane (TEos), and perfluoroalkyltriethoxy-silane are applied to nylon carpeting, and their performance is evaluated by means of the industry standards for water repellency, compressibility, surface friction, soil release, and flame resistance of the carpet. Surface modification is further characterized by x-ray photoelectron spectroscopy. The carpeting treated with the fluorinated sol-gel finishing agent exhibits higher water repellency and improved soil release and surface friction despite its low fluorine content. The fluorine component is thought to migrate to the coating-air interface of the carpet and agglomerate at the surface during the finishing process. PMAA, used as an organic component in carpeting, functions as an effective stain blocker, preventing dyeing from acid dyes. Results indicate that fluorinated sol-gel finishing agents are useful for multiple improvements in the properties of nylon carpeting.