Study On The Antibacterial Process And The Effect Of The Medium Density Fiberboard

This article take MDF (medium density fiberboard) with different antimicrobial treatment as the research object. Do the mildew antibacterial treatment and inoculated bacteria on the surface of MDF to analyze and compare the physical and mechanical properties of the board, and the antibacterial effect; Then use the silver antibacterial agent and quaternary ammonium salt antibacterial agent to deal with wood fiber, and apply adhesive to press wood fiber into sheet. The antibacterial rate test was according to Japanese industrial standard Z2801 JIS and used scanning electron microscope to observe and analyze the antibacterial effect. The main conclusions are as follows:(1)After applying antibacterial treatment of immersion method, the physical and mechanical properties of finished MDF board had a large decline, moisture content increased, density decreased, and water absorption thickness expansion rate became larger. In order to prevent the board performance from declining, it could be advisable to shorten the soaking time properly under the premise of that the board performance would not affected greatly.(2)Silver antimicrobial treatment method slow down fungus erosion on the sheet effectively that proved it has good antibacterial effect. in addition. Chitosan has definite antibacterial effect.(3)It can be seen from the macro and micro aspect observing the finished MDF specimens’status being eroded by E. coli of each antibacterial treatment, the antibacterial effect of silver ion treatment plate with chitosan is the best and plate without chitosan is secondary. Titanium dioxide treated plate have definite antibacterial effect, but there is a certain disparity compared with silver ion treatment plate.(4)For the antibacterial effect of silver based antibacterial agent, with the increase of the concentration of silver antibacterial agent, the antibacterial rate is also rising. When the concentration reached 1.5g/L, the antibacterial rate of Staphylococcus aureus and Escherichia coli is more than 99%, which had reached to the requirement of antibacterial effect in Japanese industrial standard Z2801 JIS; And for the antibacterial effect of quaternary ammonium salt antibacterial agent, with the increase of the content of the agent, the antibacterial rate is also rising. When the content reached 15%, the antibacterial rate of Staphylococcus aureus and Escherichia coli is more than 99%, which also had reached to the requirement of antibacterial effect in Japanese industrial standard Z2801 JIS.(5)Scanning electron microscope observation results of wood fiber which treated by silver antimicrobial agent and quaternary ammonium salt antibacterial agent showed that there is a certain consistency between the wood fiber and accompanied with some granular objects. The former is the microcosmic reflection of adhesive while the latter is antimicrobial agent. It is exactly that the existence of these antibacterial particles made MDF possess good antibacterial properties.(6)Using the solid content of 15% quaternary ammonium salt antibacterial agent to do the Brushing treatment on the surface of various boards. The solid wood specimens in the antibacterial properties is much better than manmade board; In addition, due to the influence of the gluing quantity of the manmade board, the way of gluing, physical structure, material and hot pressing process, there are some differences in the antibacterial effect. The antibacterial properties among various material obtained by this experiment from high to low are:MDF, particleboard and plywood, birch and poplar.