| Along with the development of the current economic and social,the problem of large surplus of waste crop stalks in many major agricultural production areas and waste resources in forestry areas has become increasingly prominent in China.Most of the discarded straw is discarded at will or burned in a concentrated way,which causes very serious environmental pollution and a large amount of waste of resources.Therefore,it is urgent to solve the problem of harmless and comprehensive utilization of agricultural and forestry wastes.Seedling bowls extruded with agricultural and forestry waste materials are used to replace the plastic seedling bowls that are widely circulated in the market,which not only provides a new idea for factory seedling breeding,but also opens up a new way for the utilization of waste materials.In this paper,corn and buckwheat straw are taken as the research objects to study the straw cold-pressing seedling pot forming process parameters,and the multi-response optimization of the seedling pot cold-pressing process parameters is carried out,which provides a reference basis for the application of biomass seedling pot.The main contents and research conclusions are as follows:(1)Firstly,the single factor test is carried out with corn straw and buckwheat straw to analyze the effects of forming pressure,the amount of binder added,the holding time of forming mold and the particle size of the material on the physical characteristics of the seedling pot.The results are as follows: Under the conditions of pressure of 8MPa,the amount of binder is 100% of the amount of material,mold holding time of 10 Min and particle size of 0.16-0.63 mm,corn straw raw material can be formed into high-quality seedling bowl,and its density,drop rate of single bowl and pressure bearing rate of single bowl are all good.Under the conditions of pressure of 8MPa,the amount of binder is 80%,mold holding time of 12 Min and granularity of 0.63-1.25 mm,the raw material of buckwheat straw can be formed into a high-quality seedling raising bowl.Its density,single bowl drop rate and single bowl pressure bearing rate are all very good.(2)Response surface analysis(RSM)is carried out to find out the influence rule of each single factor on the formability of the seedling pot.The results show that the pressure,the amount of binder and the holding time have significant effects on the above physical properties.When the pressure is 8MPa-11 MPa,the binder dosage is 90%-110%,and the pressure holding time is 10min-13 min,the corn stalk biomass seedling pot with the density of 0.7878 g·cm-3,the drop damage rate is 2.59%,and the pressure damage rate is 2.61% can be produced.When the pressure is 8MPA-12 MPa,the binder dosage is 60%-90%,and the pressure holding time is 11min-14 min,the buckwheat straw biomass seedling pot with the density of 1.0419 g·cm-3,the drop damage rate is 2.97%,and the pressure damage rate is 2.65% can be produced.(3)MOPSO multi-objective particle swarm optimization algorithm is used to optimize the design of the seedling pot forming process parameters,and the optimal forming process parameters of corn straw and buckwheat straw seedling pot are obtained.The results show that the test data by MOPSO algorithm iteration and buckwheat corn straw,corn straw best molding process parameter for the pressure for 11 mpa,binder addition amount is 95%,the holding time is 12.8 Min,the density of the seedling bowl is 1.013 g·cm-3,drop breakage rate and the pressure on the damaged rate are 2.028% and 1.636% respectively.When the grain size of buckwheat straw is 0.63-1.25 mm,the pressure is 11.7MPa,the amount of binder is 60.5%,and the pressure holding time is 12.7Min,The density of the seedling bowl is 1.168 g·cm-3,and the rate of drop damage and pressure damage are 2.524% and 2.584%,respectively.The above research provides a strong basis for the promotion of the seedling pot of agricultural and forestry waste and a new direction for the research of the harmless comprehensive utilization technology of agricultural and forestry waste. |
