Oil filtration performance of a hemp/cotton spunlaced nonwoven

Hemp fiber has many superior performances and applications, for instance, the yarns, woven fabrics, knitted fabrics and composite materials. However, there is no hemp nonwoven in the market and in application. Therefore, in order to continue to expand the application fields and increase the additional value of hemp fiber, we developed a hemp/cotton spunlaced nonwoven to research its oil filtration property and verify the filtration mechanisms. The results indicate that the filtration efficiency of a hemp/cotton spunlaced nonwoven increases with the increase in particle diameter and the decrease in filtration time. In addition, compared with the change in filtration efficiency with the increase in particle diameter, it can be found that the filtration time has a relatively smaller influence on filtration efficiency. The experimental results suggest that the filtration efficiencies of direct interception and gravitational deposition are substantially higher than inertia collision, while the filtration efficiency of inertia collision is so low that can be neglected. Through a theoretical analysis of filtration we make a verification of the mechanisms and suggest a new equation to reduce the errors in filtration efficiency between the theoretical results and experimental values. Then, the hemp/cotton spunlaced nonwoven was used to develop two different automobile engine oil filters on an experimental scale.