Study On Particle Size And Shape Distribution Characteristics Of Bamboo Milling Dust

China is the biggest country of bamboo resources in the world because bamboo has characteristics of fast growth,short finishing cycle,high productive capacity and long-term use.Bamboo processing industry is developing vigorously in our country in recent years,especially integrating bamboo and wood-based panels of bamboo developing fast.There is a lot of cutting process in the production of this kind of products,and a lot of dust will be generated when the cutting process.Dust is a major hazard to the health of workers.Long-term exposure to dust pollution can cause atopic dermatitis,asthma,pulmonary fibrosis,chronic respiratory diseases,and even cancer in severe cases.Dust will also aggravate the wear of mechanical equipment,shorten the service life,and dust is easy to burn,under certain conditions,will cause dust explosion accidents,greatly harm the production safety and environment.At present,the vacuum device used in bamboo processing is simply applied to the device used in wood processing.There is no systematic study on the characteristics of bamboo dust,such as the characteristics of particle size distribution,grain shape distribution,fluidity,etc.,and the vacuum device used in bamboo processing is also lack of reasonable configuration and design.In this paper,the dust produced during milling of side pressed monolayers Phyllostachys pubescens was studied.The influence of milling parameters on the distribution characteristics of dust particle size and the relationship between the dust size and its morphological characteristics were discussed.The influence of milling parameters on atmospheric particulate matter(particle size <100 μm),explosive dust(particle size <500 μm),large particle dust(particle size >1000 μm)and the surface roughness of the specimen was analyzed.Finally,the correlation analysis was carried out between the mass proportion of large particle dust(particle size >1000 μm)and the surface roughness of the specimen.This paper provides a theoretical basis for optimizing the selection of filter media,the structure design and operation parameter setting of the conveying and handling device in the production workshop of bamboo processing industry.The main conclusions are as follows:(1)Study on the particle size distribution of bamboo milling dust.In the milling process of single-layer bamboo sheet with side pressure,the dust with particle size less than 100 μm has the smallest mass proportion,and the dust with particle size greater than 1000 μm has the largest mass proportion.Milling dust particles have a wide size distribution,but most of them are less than 100 μm,belonging to the total suspended particulate matter,with strong suspension and diffusion ability,which poses a serious threat to the working environment and human health.(2)Study on the grain shape distribution of bamboo milling dust.In the milling process of single-layer bamboo plate under side pressure,the data distribution span of the dust particles with diameter ratio and roundness within 100 μm is large,the appearance of the particles is irregular,and the morphological difference between the particles is large,and the data distribution of the dust particles’ firmness is relatively concentrated,and the particles have relatively smooth surface texture.With the increase of the average milling thickness,the difference of particle length-diameter ratio,roundness and firmness increases,and the influence of adjusting spindle speed on the difference of grain shape parameters is more significant than that of adjusting feed speed.Milling dust particles have a significant difference in shape with the change of particle size,large particles of dust on the whole shape is not regular,while small particles of dust is more regular,the overall side pressure of single-layer bamboo board milling dust flow is poor.(3)Influence of milling parameters on milling dust size and surface roughness of bamboo.The range analysis results show that the main shaft speed has the greatest effect on the mass ratio of atmospheric particulate matter(particle size <100 μm)in milling of single-layer bamboo sheet with side pressure.The influence of the feed rate on the mass ratio of explosive dust(particle size<500 μm)is the largest.The milling depth has the greatest effect on the mass ratio of large particles(particle size >1000 μm).The depth of milling has the greatest influence on the surface roughness of the specimen.The results of variance analysis show that the main shaft speed,feed speed and milling depth have no significant influence on the mass ratio of atmospheric particulate matter.The feed rate has a significant effect on the mass proportion of explosive dust.The main shaft speed,feed speed and milling depth have significant effects on the mass ratio of large particles.Feed speed and milling depth have significant influence on the surface roughness of the specimen.