Preparation And Application Of Hemp Seedling Film

It is known that the area of rice planting in our country can reach 450 million mu every year,but there are many problems in traditional seedling,such as: weak root system of seedlings,inconvenience in picking and transporting seedlings,easy to disperse seedlings,high rate of seedling leakage.Because of the large number of scattered seedlings in seedling trays,artificial transplanting can only be used temporarily,which has become an important problem restricting rice cultivation.In recent years,in order to solve this problem,a kind of hemp nonwovens called seedling membrane has been more and more widely used.As a degradable film,hemp seedling film has good hygroscopicity,permeability,heat preservation,degradability and pollution-free characteristics.The seedling technology with bast membrane of hemp seedling raised significantly improved the growth of seedlings: the roots were well discarded and the seedlings did not hurt the roots;the quality and efficiency of mechanical seedling transplantation could be improved;the green environment protection was worth popularizing and applying.China is rich in hemp fiber resources,of which planting area and output are the first in the world,so there will be more hemp waste in industrial production.The cost of seedling film can be reduced and the profitability of hemp spinning mill can be improved by using the leftovers from hemp spinning mill.In summary,biodegradable kenaf/noil fibers were used as raw materials,polyvinyl alcohol and cellulose adhesives were used as adhesives respectively,and then dried to prepare nursery seedling film.Scanning electron microscopy(SEM)was used to characterize the fineness of fibers and the surface morphology of seedling film.The effects of raw material ratio,types of adhesives and concentration of adhesives on the breaking strength,permeability,moisture absorption and uniformity of seedling film were studied and analyzed.The results of single factor experiment showed that with the increasing content of Kenaf in kenaf/noil ratio,the breaking strength of seedling membrane increased first and then decreased.When the ratio of kenaf/noil was 3:7,the breaking strength was the highest.Absorption increases first and then decreases.When the ratio of raw materials is 3:7,the absorption is the highest.The air permeability decreases with the increase of Kenaf content.When the ratio is 3:7,the netting is the most uniform and the CV value of the surface density is the lowest;in the choice of adhesives,the breaking strength is the highest when PVA2488 is selected,and the moisture absorption is the highest when cellulose adhesives are selected,and the air permeability is high and the uniformity is the best;with the increase of the concentration of adhesives,the breaking strength of the seedling film increases and the moisture absorption increases,but the air permeability and uniformity decrease.Secondly,orthogonal experiments were carried out with the ratio of 1:9,2:8,3:7,the types of adhesives as cellulose adhesives,PVA1788,PVA2488 and the concentration of adhesives as 1%,1.5% and 2%.The optimum indexes are fracture strength,hygroscopicity and permeability.It was found that the influence of various factors on the breaking strength of seedling film was in the order of adhesive type > adhesive concentration > raw material ratio from strength to weakness;the order of strength to weakness was adhesive type > adhesive concentration > raw material ratio;and the order of strength to weakness was adhesive concentration > raw material ratio > adhesive type.Considering that the hygroscopicity of seedling membrane has a greater impact on the performance of seedling membrane,the optimum technological scheme of seedling membrane is:the ratio of Kenaf to noil fiber is 3:7,the type of adhesives is cellulose adhesives,and the concentration of adhesives is 1.5%.Finally,planting experiments and degradation properties of the prepared seedling film were carried out.According to the experimental results,seedling film can promote the growth and development of plants,the leaves are green and the yield is high.The roots of seedlings with seedling film are vigorous and developed,while those without seedling film are sparse and thin.At the same time,the degradability of the seedling membrane was confirmed.The degradation rate reached 27.2% after 30 days of soil burial,and 36.3% after 40 days,which indicated that the bast seedling membrane could degrade rapidly in a short time and had good degradability.