Study On Preparation And Performance Of Jute Degradable Nonwoven Packaging Material

Plastic pollution has become a global environmental problem,and the main source of its pollutants is our daily use of the plastic packaging bags.As people's awareness of environmental protection continues to increase,the use of traditional plastic bags has been gradually reduced.Durable non-woven packaging bags have become a substitute for plastic shopping bags.However,both plastic bags and their current substitutes are difficult to degrade.To fundamentally solve this environmental protection problem,the key is to prepare green and environmentally friendly materials that can replace the current packaging bags,which is of great significance for improving the status of"white pollution".This thesis take jute,viscose,polylactic acid fibers and other degradable materials as raw materials,and prepare degradable non-woven packaging materials through mechanical carding into a net,needle punch pre-reinforcement and thermal bonding reinforcement.Firstly,the effects of different mixing ratio of raw materials and gram weight on mechanical properties of packaging materials were investigated.The rules are as follows:(1)When the gram weight is similar and the proportion of PLA fiber is constant,the mechanical properties of the sample gradually increase with the increase of the viscose fiber ratio.This is due to the roughness of the jute fiber itself,which makes the fiber difficult to entangle,and the fiber web has a poor netting effect.Appropriately increasing the proportion of viscose fiber can improve this problem.(2)Under the condition that the gram weight is similar and the proportion of jute fiber remains unchanged,as the proportion of PLA fiber decreases,the mechanical properties of the sample are greatly decreased,especially the decrease of transverse mechanical properties,which indicates that the contribution of PLA fiber to the formation of the net was greater than that of entanglement of viscose fibers.(3)The change of the sample weight will affect the number of entanglements between fibers per unit volume and the range of PLA fiber hot-melt bonding.The decrease of weight will cause loss of the mechanical properties of the sample.Compared with the change of raw material mixing ratio,the impact of weight is relatively small.(4)Needle-punched pre-reinforcement can increase the entanglement between fibers and reduce the looseness of the fiber web,which is more conducive to the subsequent hot-pressing process.The hot-melt fiber PLA melts and consolidates jute and viscose fibers under heat and pressure to form a more stable structure.Considering the influence of the raw material mixing ratio and weight on the mechanical properties of the sample,combined with the actual raw material consumption and cost,it is considered that the sample weight should be controlled at about 100g/m~2,and the raw material mixing ratio of jute 50/viscose 35/PLA 15 is more appropriate.Orthogonal test method,combined with range analysis and variance analysis was used to explore the optimal process scheme of hot-pressing process parameters.The results showed that for a non-woven packaging material with a gram weight of about 100 g/m~2and a raw material mixing ratio of jute 50/viscose 35/PLA 15,the comprehensive optimal hot pressing process parameters were:hot pressing 10s under the temperature of 170?and the pressure of 6MPa.The mechanical properties of the nonwoven packaging materials prepared under the above process parameters are as follows:the longitudinal and transverse breaking strengths are 156.50N and 76.03N,respectively;the longitudinal and transverse tearing strengths are 22.78N,9.60N,respectively;the bursting strength is 47.14N,which can meet the mechanical performance requirements of the packaging bags.On the basis of optimized process,the portable shopping bag was designed and prepared by ultrasonic thermal bonding.The test results show that it has good mechanical properties and can replace traditional packaging bags to meet the needs of daily use.Environmentally-friendly and inexpensive natural beeswax is used for surface coating treatment.After the treatment,the contact angle of the sample surface is increased from 40°to 129°,which improves the waterproofness of the packaging material to a certain extent.This can expand the scope of use of the packaging bag and prolong its service life.