Non-destructive testing methods for examination of formaldehyde emission from wooden doors
The widely applicable non-destructive testing(NDT)methods for detecting formaldehyde emission from wooden doors were studied.The testing process and calculation model construction principles of three non-destructive testing methods for harmful substance release were compared and analyzed,and two calculation models for non-de-structive testing methods for detecting harmful substance release in wooden doors-NDT(direct measurement method)and NDT(conversion method)were developed.Medium density fiberboards were used to simulate the bearing capaci-ty range of wooden doors to prepare samples for formaldehyde emission testing in a climate box with a size of 5 m3,and the direct measurement and conversion methods were used to detect formaldehyde emissions.The current main-stream method for detecting the formaldehyde emission from wooden doors,i.e.,1 m3 climate box method,was a-dopted for detecting actual formaldehyde emissions,and the mass transfer theory analysis was conducted on examining the formaldehyde release.The results showed that the data tested by conversion method would deviate from the actual formaldehyde emission of the product.The larger the actual formaldehyde emission of the product was,the greater the deviation of the conversion method detection results was.The direct measurement method is equivalent to the 1 m3 cli-mate box method in the detection conditions,and the non-destructive testing of formaldehyde emission from wooden doors using the direct measurement method was true and accurate.Compared with the release rate of formaldehyde e-mission,it was more reasonable to use the concentration of formaldehyde emission in the cabin as an evaluation indi-cator for the release amount of formaldehyde.The non-destructive testing method(direct measurement method)is able to be used for the examination of formaldehyde emission from wooden doors,that is,the wooden door should be placed in a climate box as a whole,the ratio of the testing bearing capacity to standard bearing capacity(1 m2/m3)should be set as the air exchange rate,and the concentration of formaldehyde in the measured cabin is the amount of formaldehyde released from the wooden door.In this study,the non-destructive testing method was used to test the en-tire wooden door,the formaldehyde emissions of 20 wooden doors were tested with the non-destructive testing meth-od,and some of the testing data have significant differences with the testing data of the 1 m3 climate box method,which showed that the formaldehyde released from the edges of wooden doors cannot be ignored.Using the NDT(di-rect measurement method)to detect the formaldehyde emission of wooden doors could not only improve the authenti-city of the testing data,but also avoid the waste of a large number of wooden door products caused by destructive tes-ting and save wood resources.
wooden doornon-destructive testing methodrelease of harmful substanceformaldehyde emissioncal-culation model
国家科技期刊平台
NSTL
万方数据
维普
