Interior Materials Research Articles

철도차량 바닥재 연기밀도 측정의 영향인자분석

본 연구에서는 철도차량 내장재 화재성능평가기준 중 연기밀도 측정에서 주요 인자들의 영향을 합성고무바닥재를 이용하여 분석 및 검토하였다. 밀폐된 공간에서 운영되는 철도차량의 특성 상, 객실 내부에서 화재 발생 시에 연기로 인해 막대한 인명피해가 발생할 수 있다. 따라서 국내 외의 철도운영국가에서는 내장재의 연기 발생량을 엄격하게 규제하고 있으며, 이를 위해 내장재의 화재성능평가에 있어 연기밀도의 정확한 측정이 요구된다. 연기밀도의 측정에 있어 주요 영향인자로 시료 고유의 균질도, 장비를 이용한 조건 및 측정의 편차 그리고 장비를 운용 관리하는 환경의 영향을 꼽을 수 있다. 각 인자별 연기밀도에 영향도를 확인하기 위하여 불확도 추정에 따른 기여율 분석을 수행하였다. 그 결과, 광센서(PM tube)를 이용한 투과율 측정편차의 기여율이 약 86 %로 연기밀도 측정의 대표 영향인자임을 확인할 수 있었다. 그리고 높은 균질도를 가지는 시료를 대상으로 한 연기밀도 측정에서는 그 외 영향인자(시료연소용 복사열 조건(<TEX>${\pm}0.5 kW/m^2$</TEX>) 및 장비의 운용 관리환경)의 기여율이 약 11 %로 낮음을 확인할 수 있었다. In this study, we investigated the effect of factors that influence the measurement of smoke density using synthetic rubber flooring. The characteristics of rolling stock in an enclosed environment can cause enormous loss of life by smoke inhalation during fires inside passenger cars. The amount of smoke generation from interior materials for rolling stock is strictly restricted domestically and in other countries. Precise measurement of smoke density is therefore required to assess the fire performance of interior materials. Major factors that influence the measurement of smoke density include the uniformity of the specimen, the variations in conditions and instruments, and the operational and maintenance environment of the instruments. The contribution of factors was analyzed by estimating the uncertainty to investigate the contribution ratios of the major factors. The results show a contribution ratio of about 86% for the variation from the measurement of light transmission using a photomultiplier tube. Thus, this factor was the most representative for the measurement of smoke density. The contribution ratio of the other factors was low at about 11%, including irradiant flux conditions (<TEX>${\pm}0.5 kW/m^2$</TEX>) and the influence of the operational and maintenance environment of the instrument. These results were obtained using specimens with high uniformity.

Control of interior surface materials for speech privacy in high-speed train cabins.

The effect of interior materials with various absorption coefficients on speech privacy was investigated in a 1:10 scale model of one high-speed train cabin geometry. The speech transmission index (STI) and privacy distance (rP ) were measured in the train cabin to quantify speech privacy. Measurement cases were selected for the ceiling, sidewall, and front and back walls and were classified as high-, medium- and low-absorption coefficient cases. Interior materials with high absorption coefficients yielded a low rP , and the ceiling had the largest impact on both the STI and rP among the interior elements. Combinations of the three cases were measured, and the maximum reduction in rP by the absorptive surfaces was 2.4m, which exceeds the space between two rows of chairs in the high-speed train. Additionally, the contribution of the interior elements to speech privacy was analyzed using recorded impulse responses and a multiple regression model for rP using the equivalent absorption area. The analysis confirmed that the ceiling was the most important interior element for improving speech privacy. These results can be used to find the relative decrease in rP in the acoustic design of interior materials to improve speech privacy in train cabins.

Screening for perfluoroalkyl acids in consumer products, building materials and wastes

Perfluoroalkyl and polyfluoroalkyl substances (PFASs) are a large group of important chemical compounds with unique and useful physico-chemical properties, widely produced and used in many applications. However, due to the toxicity, bioaccumulation and long-range transport potential of certain PFASs, they are of significant concern to scientists and policy makers. To assess human exposure to PFASs, it is necessary to understand the concentrations of these emerging contaminants in our environment, and particularly environments where urban population spend most of their time, i.e. buildings and vehicles.A total of 126 samples of building materials, consumer products, car interior materials and wastes were therefore analyzed for their content of key PFASs - 15 perfluoroalkyl acids (PFAAs). At least one of the target PFAAs was detected in 88% of all samples. The highest concentration of Σ15PFAAs was found in textile materials (77.61 μg kg−1), as expected, since specific PFAAs are known to be used for textile treatment during processing. Surprisingly, PFAAs were also detected in all analyzed composite wood building materials, which were dominated by perfluoroalkyl carboxylic acids with 5–8 carbons in the chain (Σ4PFCAs up to 32.9 μg kg−1). These materials are currently widely used for building refurbishment, and this is the first study to find evidence of the presence of specific PFASs in composite wood materials. Thus, in addition to consumer products treated with PFASs, materials used in the construction of houses, schools and office buildings may also play an important role in human exposure to PFASs.

Impact of multisource VOC emission on in-vehicle air quality: test chamber simulation

Air quality inside vehicle may be strongly influenced by the presence of volatile organic compounds (VOC). The sources of these compounds may be different. In case of new vehicles VOC mainly originate from off-gassing of interior materials, while in used cars exterior pollution, like exhaust gases, starts to dominate. The aim of this work was to check the influence of multiple VOC sources on concentration of volatile organic compounds emitted from car interior parts. For this purpose material emission tests were performed in 1 m3 emission testing chamber (WKE 1000, Weiss, Germany) at 65 °C, 5% RH and with air exchange. Three different car parts were studied: sun visor, headlining, and handbrake lever cover. It was stated that volatile organic compounds concentration inside test chamber during the test performed with three different parts inside was significantly lower than those being result of addition of the results obtained for parts tested separately. Presented results indicate interactions between different materials and their emissions as well as prove that some of materials acts like sorbents.

Newly invented biobased materials from low-carbon, diverted waste fibers: research methods, testing, and full-scale application in a case study structure

This project demonstrates newly invented, biobased construction materials developed by applying low-carbon, biomass waste sources through the Authors' engineered fiber processes and technology. If manufactured and applied large-scale the project inventions can divert large volumes of cellulose waste into high-performance, low embodied energy, environmental construction alternatives that lessen society’s dependence on greenhouse gas emitting products associated with global warming. Biobased materials produced in this work include: 1. High strength-to-weight-ratio as a dense, thin, multi-purpose construction hardboard from 100% waste sources and without resins, binders, or adhesives. Bioboards are used in flat and multidimensional form to create the project inventions. 2. Modular, three-dimensional-core, structural insulated wall, floor, and roof panels developed using bioboards as main structural components. BioSIPs received patenting during the project. This publication describes research and computational methodologies, testing of project materials, and their full-scale application as the exterior and interior materials and construction system for a solar-powered case-study building. The authors are currently advancing project inventions for commercialization.

Experimental investigation of a PCM-HP heat sink on its thermal performance and anti-thermal-shock capacity for high-power LEDs

High-power LEDs demonstrate a number of benefits compared with conventional incandescent lamps and fluorescent lamps, including a longer lifetime, higher brightness and lower power consumption. However, owing to their severe high heat flux, it is difficult to develop effective thermal management of high-power LEDs, especially under cyclic working modes, which cause serious periodic thermal stress and limit further development. Focusing on the above problem, this paper designed a phase-change material (PCM) base heat pipe heat sink (PCM-HP heat sink) that consists of a PCM base, adapter plate, heat pipe and finned radiator. Different parameters, such as three types of interior materials to fill the heat sink, three LED power inputs and eight LED cyclic working modes, were separately studied to investigate the thermal performance and anti-thermal-shock capacity of the PCM-HP heat sink. The results show that the PCM-HP heat sink possesses remarkable thermal performance owing to the reduction of the LED heating rate and peak temperature. More importantly, an excellent anti-thermal-shock capacity of the PCM-HP heat sink is also demonstrated when applied in LED cyclic working modes, and this capacity demonstrates the best range.

Loosening analysis for fastening screw of automotive door trim parts

While a screw is a fastening element that can tighten the two parts at low cost, the loosening of the screw is generated due to external forces such as repetitive load, vibration, and thermal stress. This phenomenon decreases the initial clamping force, and this can be a serious problem to the safety of the product. However, while fastening parts are handled through experiment and experience, there is a lack of research on the screw loosening of plastic fastening parts. For example, vehicles have various fastening parts. Among the fastening elements, screws are typically used for tightening parts of the vehicle door trim. Vehicle interior materials are mainly composed of plastic parts. Especially, the temperature of the vehicle interior changes from a sub-zero temperature to 100 degrees (°C) due to solar radiation. Unlike metals, plastic materials are commonly susceptible to the environment. In this study, the fastening screw of automotive door trim parts is selected. First, a screw loosening mechanism is implemented through Computer Aided Engineering (CAE) analysis and the influences of degradation are then analyzed. Secondly, the selecting method of clamping force is suggested through the analysis result of reduction according to the tightening torque.

Evaluation of Volatile Organic Compounds and Carbonyl Compounds Present in the Cabins of Newly Produced, Medium- and Large-Size Coaches in China.

An air-conditioned coach is an important form of transportation in modern motorized society; as a result, there is an increasing concern of in-vehicle air pollution. In this study, we aimed to identify and quantify the levels of volatile organic compounds (VOCs) and carbonyl compounds (CCs) in air samples collected from the cabins of newly produced, medium- and large-size coaches. Among the identified VOCs and CCs, toluene, ethylbenzene, xylene, formaldehyde, acetaldehyde, acrolein/acetone, and isovaleraldehyde were relatively abundant in the cabins. Time was found to affect the emissions of the contaminants in the coaches. Except for benzaldehyde, valeraldehyde and benzene, the highest in-vehicle concentrations of VOCs and CCs were observed on the 15th day after coming off the assembly line, and the concentrations exhibited an approximately inverted U-shaped pattern as a function of time. Interestingly, this study also showed that the interior temperature of the coaches significantly affected the VOCs emissions from the interior materials, whereas the levels of CCs were mainly influenced by the relative humidity within the coaches. In China, guidelines and regulations for the in-vehicle air quality assessment of the coaches have not yet been issued. The results of this study provide further understanding of the in-vehicle air quality of air-conditioned coaches and can be used in the development of both specific and general rules regarding medium- and large-size coaches.

Acoustical performance of a completely renovated music recital hall from subjective and objective points-of-view

Swarthout Recital Hall located in Murphy Hall at the University of Kansas was initially constructed in the 1950s, with the original interior remaining largely intact until extensive renovations were completed in 2015. Two major complaints regarding the original hall were a lack of feedback from the hall to the performers onstage, and the acoustical coldness of the hall. With excellent cooperation between the School of Music Dean and the music faculty, the project architect, and the acoustic consultant and through the use of computer modeling, a new interior envelope was designed and interior materials selected which addressed these issues. In response, the renovated hall has received highly positive feedback from performers and patrons in both of these respects. This paper will address the measurable acoustic parameters of the renovated hall and how they correlate to both the digitally modeled versions of the hall and the hall acoustic perceptions by performers and audience.

학교 교실의 음환경 기준에 따른 실내마감 방안

교실 음환경은 학생들에게 매우 중요한 요소로 학습효과와 학업 성취에 매우 큰 영향을 미친다는 연구결과가 다수 발표되고 있다. 그러나 학교 교실의 신축이나 리모델링 시에 가이드라인 및 설계방안이 제시된 바 없어 적절한 음환경을 실현하는데 큰 어려움을 겪고 있다. 따라서 본 연구에서는 이론적 수식과 현장실험을 통하여 교실의 음환경 기준을 만족하기 위한 다양한 설계방안을 제시하고자 한다. 이를 위해 국내 중 고등학교의 교실에서 실내음향성능 기준을 만족하기 위해 필요한 최소 흡음면적을 계산하였다. 또한 교실의 천장 및 뒷벽의 다양한 마감상태에 따른 실내음향성능을 알아보고자 현장실험을 진행하여 실험 결과를 비교 분석하였다. 연구 결과, 국내 교실 천장에 현재 거의 모든 학교에서 시행하고 있는 것처럼 천정흡음재를 설치하지 않아도 잔향시간 기준인 0.8 s를 만족할 수 있는 것으로 나타났다. 특히, 천장 일부 면적에 반사재를 적용하되 면적의 비율이 흡음 2 : 반사 1이면서 가로로 구획하는 것이 음압레벨을 향상시키며 전체가 흡음인 경우와 비슷한 명료도[<TEX>$C_{50}$</TEX>, <TEX>$D_{50}$</TEX>, RASTI(Rapid Speech Transmission Index)]를 확보할 수 있다. There are many results in which acoustical conditions of a classroom play an important role for studying effects and academic achievement of students. However, there are very few guidelines or design proposals which could make appropriate acoustic environment when classrooms are built or renovated. The present study suggests various design proposals satisfying acoustic standards of classrooms based on theoretical calculation and acoustic field experiments. At first, minimum area of sound absorption was calculated which is required to satisfy the acoustic standard for domestic middle and high schools. Also, room acoustic measurements were carried out in order to investigate the acoustic performance of an existing classroom by changing interior finishing materials on ceiling and rear walls. As a result, it was revealed that reverberation time standard below 0.8 s can be acquired even if there is no sound absorption on ceiling which is a general practice executed in Korea. Specially, it was found that if partial area of ceiling would be treated as reflective with the ratio of sound absorption and reflection as 2:1, almost similar acoustic parameters of <TEX>$C_{50}$</TEX>, <TEX>$D_{50}$</TEX>, RASTI (Rapid Speech Transmission Index) and higher sound levels could be acquired in comparison with the case of entire sound absorption on ceiling.

폐 MDF 퇴비화 사용을 위한 생분해 환경 특성에 관한 연구 (I)

ABSTRACT http://dx.doi.org/10.7584/ktappi.2016.48.1.127Journal of Korea TAPPIVol. 48. No. 1, 2016, 127-133pISSN (Print): 0253-3200Printed in Korea • 충남대학교 농업생명과학대학 환경소재공학과(Dept. of Biobased Materials, College of Agriculture and Life Science, Chungnam National University, Daejeon, Korea)1 FITI 시험연구원 환경바이오평가팀(Enviroment & Bio assesment team, FITI Testing & Research Institute, Ochang, Cheonwon-gun, Chungbuk, 363-883, Korea)† 교신저자(Corresponding Author): E-mail: lachesis@cnu.ac.kr This study is performed that furniture and interior materials of MDF's (Medium Density Fiberboard) biodegradation properties, and the goal of this study is investigation of pos-sibility of waste-MDF's composting after landfilling. To investigate biodegradation, this study was performed according to KS M ISO 14855-1, and there were two different soil conditions including a compost condition and an activated vermiculite condition as arti-ficial soil. This experiment was tested for 40 days. The measurement of carbon-dioxide generation was processed every 24 hour in 1-2 week, and every 48 hour after 3 week. In the same days, MDF showed 24.4% of biodegradation in compost condition, and 6.2% in activated vermiculite. Also, the reference material of TLC (thin-layer chromatography) grade cellulose showed 26.4%, 11.4% in compost and activated vermiculite respectively. The dilution plate method was performed for biological analysis in the study. This ex-periment was used for investigation of inoculum's (Bacillus licheniformis) activity. As the result of bioassay, compost has more other germs include inoculum than activated ver-miculite in the first week. Especially in the 2nd week, the reference material under the compost condition showed the most germ's activity, and also the biodegradation was the highest. Consequentially, compost condition was able to reduce a performing period of biodegradation testing than activated vermiculite. However, activated vermiculite could be stabilizing errors between repetition.Keywords: Biodegradation, MDF, activated vermiculite, compost, ultimate biodegradation

Assessment of Selected Interior Flooring Materials On Indoor Air Quality

Indoor air quality depends on many factors, such as temperature, humidity, odours or presence of pollutants. A lot of materials used in the buildings, either as structural materials or as furnishings, are mostly the indoor air pollution sources. Interior surface materials are generally accepted as the main TVOCs emissions source. The chemical and sensory assessment of selected interior flooring materials on indoor air quality is presented within the paper. Air acceptability, odour intensity and TVOCs concentration for selected interior flooring materials (polyvinyl chloride flooring, tongue flooring and acrylic based flooring) were tested. The chemical and sensory measurements were performed in a glass test chamber. The parameters were monitored by different air change rate per hour. Chemical measurement is based on the absorbed TVOCs gas chromatography analysis. The panellists of sensory assessment consist of group of responsible persons from 20 to 38 years (35% smokers). Each approached subject assesses the odour intensity and the air acceptability. The improving of sensory assessment with increasing the air change rate was not confirmed. Conversely, the unfavourable results are improving with increasing air change rate, in the case of materials with significantly indented and porous surface.

Environment-friendly Interior Materials and Products

Environment-friendly Interior Materials and Products

Car indoor air pollution by volatile organic compounds and aldehydes in Japan

Fifty-five organic substances including volatile organic compounds (VOCs) and aldehydes present in indoor air were measured from 24 car cabins in Japan. A screening-level risk assessment was also performed. Acetaldehyde (3.81–36.0 μg/m3), formaldehyde (3.26–26.7 μg/m3), n-tetradecane (below the method quantification limit (<MQL) to 47.7 μg/m3), toluene (4.23–78.3 μg/m3), and n-undecane (<MQL to 6.24 μg/m3) concentrations exceeded method detection limits in all the investigated car cabins. Ratios between indoor and outdoor concentrations revealed that most organic compounds originated from the car interior materials. Total volatile organic compound (TVOC) concentrations in 14 car cabins (58% of all car cabins) exceeded the advisable values established by the Ministry of Health, Labour and Welfare of Japan (400 μg/m3). The highest TVOC concentration (1136 μg/m3) was found in a new car (only one month since its purchase date). Nevertheless, TVOC concentrations exceeded the advisable value even for cars purchased over 10 years ago. Hazard quotients (HQs) for formaldehyde obtained using measured median and highest concentrations in both exposure scenarios for occupational use (residential time in a car cabin was assumed to be 8 h) were higher than that expected, a threshold indicative of potential adverse effects. Under the same exposure scenarios, HQ values for all other organic compounds remained below this threshold.

Equation of State of the Interior Materials for the Earth-Type Planets by Laser Shock

Equation of State of the Interior Materials for the Earth-Type Planets by Laser Shock

Retrofit with Interior Insulation on Solid Masonry Walls in Cool Temperate Climates – An Evaluation of the influence of Interior Insulation Materials on Moisture Condition in the Building Envelope

For historic buildings, where an alteration of the exterior façade is not wanted, interior insulation can be the solution to improve the indoor climate and reduce heat loss, but might also introduce moisture problems like condensation in the wall. Capillary active/hydrophilic insulation materials have been introduced to cope with the moisture problem. An extensive amount of calculations indicating where the challenges lie in the complex work with interior insulation in cool temperate climate has been carried out. In areas with high precipitation like Denmark, capillary active insulation may not be feasible without additional driving rain protecting of the façade.

Technological Process Applied for the Coating the Pipe Profiles in the Manufacturing Industry

This paper deals with the specific technological process applied for the powder coating the pipe profiles as a part of interior, exterior and design manufacturing materials. In the introduction and first chapter of the paper, the main characteristics, possibilities, benefits and deficiencies of this progressive coating technology utilization applied in the manufacturing industry are described. The main part of the paper specifies the whole technological process related to the pipe profiles coating, contains the design of the specialized equipment (hanging hook) for hanging the pipe profiles on the beam and presents the sample calculation of the coating consumption for the specific metal element. This equipment was constructed and practically verified by the authors in real manufacturing environment. In conclusion, the possible applications of this coating technology for structurally similar materials are emphasized. The aim of the powder coating technology utilization simultaneously with using the proposed hanging equipment is to apply the coating specifically to those parts where it is desirable. This leads to reduction of the overall capital and operating costs and increasing the efficiency of the manufacturing process. In addition, the coating technology is considered to be environmentally friendly due to recyclability of the redundant coating.

Development of Thermally Enhanced Wood-Based Materials with High VOCs Adsorption using Exfoliated Graphite Nanoplatelets for Use as Building Materials

Wood-based materials are used to manufacture various types of panels, including particleboard, fiberboard, and plywood, and they can also be used to manufacture furniture as well as interior and exterior building materials. However, wood-based materials exhibit a number of problems, including the emission of indoor air pollutants from adhesives used during production and their inherent fire risk. To date, a number of studies have investigated the emission of indoor air pollutants, and in recent years, there has been an increasing amount of interest in the flame-retardant performance of wood-based materials. In this study, the use of carbon materials was studied to improve the flame-retardant performance of wood-based materials. A comparison was made with various methods that are currently in use. The thermal conductivity was measured by the TCi method developed by C-Therm Technologies Ltd to evaluate the energy characteristics of wood-based materials that are used as interior materials.

주요 건축 내장재의 연소가스 유해성 평가

Toxic gases from five types of interior building materials were investigated according to Naval Engineering Standard (NES) 713. The materials were plywood, indoor wall coverings (wood wall plate members and pine wood), reinforced Styrofoam insulation, laminate flooring, and PVC. Specimens were measured using an NES 713 toxicity test apparatus to analyze the hazardous substances in combustion gas from the materials. We used the US Department of Defense standard (MIL-DTL, Military Standard) to calculate the toxicity index of the combustion gas. Emissions of CO from all specimens did not exceed the NES 713 limit of 100,000 ppm. The amount of CO gas emissions from reinforced Styrofoam insulation was 6,098 ppm. 25 ppm and 49 ppm of formaldehyde were released from the reinforced Styrofoam insulation and PVC flooring, respectively. These values were less than the limit of 400 ppm. The highest emissions were from NO emitted by plywood and were above the limit of 250 ppm. The toxicity index of the specimens were calculated as 5.19 for plywood, 4.13 for PVC flooring, 2.35 for reinforced Styrofoam insulation, 2.34 for laminate flooring, and 1.22 for indoor wall coverings (pine wood). Our research helps us to understand the properties of these five interior materials by analyzing the combustion gas and explaining the toxicity of constituents and the toxicity index. Also, it would be useful for giving fundamentals to guide the safe use of interior materials for applications.

Pollution distribution and health risk assessment of heavy metals in indoor dust in Anhui rural, China.

Zn, Pb, Cu, Cr, V, Ni, Co, and As concentrations of indoor dust in Anhui rural were determined by inductively coupled plasma-optical emission spectroscopy (ICP-OES). The degrees of metal pollution in indoor dust ranked as follows: Zn > Pb > Cr > Cu > V > Ni > Co > As, on average. The arithmetic means of Zn, Pb, Cu, Cr, V, Ni, Co, and As were 427.17, 348.73, 107.05, 113.68, 52.64, 38.93, 10.29, and 4.46 mg/kg, respectively. These were higher than background values of Anhui soil for Zn, Pb, Cu, Cr, and Ni, especially for Pb with the mean value of 13.21 times the background value. Heavy metal concentrations of indoor dust were different from different rural areas. House type (bungalows or storied house), sweeping frequency, and external environment around the house (such as the road grade) affected heavy metal concentrations in indoor dust. The results of factor analysis and correlation analysis indicated that Cu, Cr, Ni, Zn, and Co concentrations were mainly due to interior paint, metal objects, and building materials. Pb and As concentrations were due to vehicle emissions. V concentration was mainly of natural source. Average daily doses for the exposure pathway of the studied heavy metals decreased in children in the following order: hand-to-mouth ingestion > dermal contact > inhalation. The non-carcinogenic risks of heavy metals ranked as Pb > V > Cr > Cu > Zn > As > Co > Ni, and the carcinogenic risks of metals decreased in the order of Cr > Co > As > Ni. The non-carcinogenic hazard indexes and carcinogenic risks of metals in indoor dust were both lower than the safe values.