Design Of Small Environment Chamber And Study Of VOC Emission Characteristic From Wood-based Panel

Environmental chamber has a high imitation of the real environment, and reflect a characteristic of volatile organic compound (VOC) emitting to the surrounding environment. Therefore environmental chamber is the common method of measuring VOC emission from wood-based panel. In this paper, in order to reduce the cost of measuring VOC emission from wood-based panel,15L environmental chamber was designed and manufactured. In order to study the correlation between15L chamber and lm3chamber, VOC emission rate of wood-based panel using for15L chamber was compared with that using for1m3chamber. Gas Chromatography-Mass Spectrometer was used to measure components and concentration of VOC emission from six market-sale wood-based panels. VOC emission characteristics of wood-based panels were detected under different external environmental conditions using15L chamber, and to find ways to reduce the concentration of indoor pollutants. The results are listed as followed:(1) The15L chamber designed reasonably, and can simulate a real indoor environment. The temperature, relative humidity, air exchange rate and wind velocity of small chamber were be controlled steadily. Small chamber with good air-tightness and the background concentration met the requirements of relevant standard. Most of materials used in the environmental chamber were glassware, easy processing and simple assembling. The cost of small chamber was less than3000yuan. The cost was much lower than that of1m3large chamber. The purpose of reducing cost was achieved(2) On the basis of the comparison of a small and large chamber for measuring VOC emission from wood-based panel, the correlation of two chambers was studied. The decay trends of VOC emission rates were the same using two chambers. There were the deviations between data measured by two chambers. The average deviation was2.35%. Compared with the large chamber, TVOC concentration level using the small chamber was slightly higher. The correlation of testing data using two chambers under the same temperature, relative humidity, air exchange rate, and the loading rate was very good.(3) The components concentration of VOC emission from market-sale wood-based panel were identified for twenty-eight days by GC/MS. The results showed TVOC emission rates of six wood-based panels from high to low were:HDF, MDF, particleboard, plywood, MDF veneer and OSB. Arene components were the main component emitting from wood-based panel. A small amount of alknes, alkenes, aldehydes, ketones and esters were emitted from wood-based panels. Toluene, ethylbenzene, styrene, and m, p-xylene were the main individual VOC emission from three panels. The emission rate of toluene declined rapidly. However, there was no obvious characteristic that emission rate decreased rapidly during the emission process of the other three components. The emission rates of other three components were stable during the emission process(4) The impact of external environment factors (temperature, relative humidity, air exchange rate and loading factor) on the VOC emission and concentration from plywood and MDF were investigated by small chamber. The experiment result showed that increasing temperature, relative humidity and air exchange rate accelerated VOC emission from wood-based panel. The influence of environmental factors on VOC emission was only significant for initial emission. Few days later, the effect was not obvious. The concentration in small chamber increased with the load factor increasing. But the concentration in chamber and loading factor dose not have the relationship of direct proportional. The VOC emission rate under high loading factor was less than that under low loading factor multiplied by corresponding multiples.(5) The influences of temperature, RH, and ACH on arene compounds were more obvious than those on alkane compounds. The reason was that alkane concentration was much smaller than arene. The degree of influence of the external environmental factors on the low concentration of VOC was not significant. The influence of environmental factors on three compounds (toluene, ethylbenzene, and m, p-xylene) had no major differences.