Preparation and oil/air filtration properties of hemp paper

The hemp root bast paper is innovatively prepared to research the oil filtration properties and air filtration properties for practical application. It can be found that beating degree and weight both have great influence on air permeability, pore diameter distribution, oil/air penetration and oil/air filtration efficiency of hemp paper. The oil filtration efficiency of hemp papers for 0.33 µm particles is 99.7%–99.975% and air filtration efficiency for 0.26 µm NaCl aerosol particles is 99.942%–100%. Through comparison of oil filtration properties and air filtration properties with commonly used automobile engine oil/air cotton paper filtration materials, it can be found that hemp paper has the smaller thickness, weight, mean pore diameter, porosity and oil/air penetration, while the better oil/air filtration efficiency and higher pressure drop. Due to the higher filtration efficiency of hemp papers and green, biodegradable, sustainable resources of hemp plants in the case of environmental requirements, the pilot trial hemp paper automobile engine oil filter is successfully manufactured. The results indicate that hemp papers have better oil/air filtration properties than cotton paper in practical application. We hope that such an attempt will be helpful for practical application of hemp paper and meet the needs of domestic market for filtration materials. Furthermore, it can enlarge the application field and increase the added value of hemp.