As the global population continues growing, the demand for textiles also increases, putting pres- sure on cotton manufacturers to produce more natural fiber from this already undersupplied resource. Synthetic fibers s...As the global population continues growing, the demand for textiles also increases, putting pres- sure on cotton manufacturers to produce more natural fiber from this already undersupplied resource. Synthetic fibers such as polyester (PET) can be manufactured quickly and cheaply, but these petroleum-based products are detrimental to the environment. With increased efforts to encourage transparency and create a more circular textile economy, other natural alternatives must be considered. This article discusses the existing condition and future possibilities for man- made cellulosic fibers (MMCFs), with an emphasis on using non-woody alternative feedstocks as a starting material. This work focuses on conversion technology suitable for producing textile- grade fibers from non-wood-based dissolving pulp, which may be different in nature from its woody counterpart and therefore behave differently in spinning processes. Derivatization and dissolution methods are detailed, along with spinning techniques and parameters for these pro- cesses. Existing research related to the spinning of non-woody-based dissolving pulp is covered, along with suggestions for the most promising feedstock and technology combinations. In addi- tion, an emerging method of conversion, in which textile fibers are spun from a hydrogel made of an undissolved nano/micro-fibrillated fiber suspension, is briefly discussed due to its unique po- tential. Methods and concepts compiled in this review relate to utilizing alternative feedstocks for future fibers while providing a better understanding of conventional and emerging fiber spinning processes for these fibers.展开更多
The paper and paperboard production in 2016 in the world was 110.07 million tones.1 Bangladesh consumes only about 3.5~4 kg paper and board products per capita,while the developed countries consume about 300 kg/capita...The paper and paperboard production in 2016 in the world was 110.07 million tones.1 Bangladesh consumes only about 3.5~4 kg paper and board products per capita,while the developed countries consume about 300 kg/capita.Bangladesh’s consumption is also much lower than the world’s average(@50 kg/capita)and the Asia’s average(@50 kg/capita).2 To reach the world’s or Asia’s level,Bangladesh’s consumption of paper and board products needs to increase 10 folds.As forest resources are very limited in Bangladesh,alternative fibrous raw materials are required to achieve this goal.Therefore many studies have been carried out on alternative raw materials available in Bangladesh.展开更多
Forest management planning faces uncertainties regarding future timber prices,tree growth,and survival.Future seed production is an additional source of uncertainty in Korean pine stands managed for the joint producti...Forest management planning faces uncertainties regarding future timber prices,tree growth,and survival.Future seed production is an additional source of uncertainty in Korean pine stands managed for the joint production of timber and edible seeds.Modern forest planning uses optimisation to determine the best possible cutting schedule.Optimisation can accommodate uncertainty by using decision rules for adaptive forest management instead of optimising cutting years and intensities.In this study,we optimised two adaptive decision rules for managing Korean pine plantations for the joint production of timber and pinecones when timber prices,tree growth,and seed production are stochastic.The first rule indicated the minimum price to sell timber,i.e.,the reservation price,as a function of the mean tree diameter and stand basal area.The second adaptive rule expressed the mean tree diameter at which cutting is optimal as a function of timber price and stand basal area.Both decision rules resulted in nearly the same mean net present value when the optimised rule was applied to 100 stochastic scenarios for future timber prices,tree growth,and seed production.The net present values were over 20% higher than those for the deterministically optimised cutting schedules under the same scenarios.Therefore,the expected economic gain from switching from deterministic to adaptive stochastic optimisation was at least 20%.The cutting years of the adaptive optima were frequently later than those indicated by the deterministic optima,and optimal adaptive harvesting often involved waiting for high timber prices.The minimum price or minimum mean diameter to sell timber was higher when the income from seeds was considered in the optimisation.The cuttings were later,and the rotations were longer in the joint production of timber and pinecones than in timber production alone.展开更多
基金the financial support by the USDA National Needs Fellowship Program(Grant 12513354,project NCZ09489,“Developing Expertise in Risk Analysis and Risk Management for the Bioeconomy”).
文摘As the global population continues growing, the demand for textiles also increases, putting pres- sure on cotton manufacturers to produce more natural fiber from this already undersupplied resource. Synthetic fibers such as polyester (PET) can be manufactured quickly and cheaply, but these petroleum-based products are detrimental to the environment. With increased efforts to encourage transparency and create a more circular textile economy, other natural alternatives must be considered. This article discusses the existing condition and future possibilities for man- made cellulosic fibers (MMCFs), with an emphasis on using non-woody alternative feedstocks as a starting material. This work focuses on conversion technology suitable for producing textile- grade fibers from non-wood-based dissolving pulp, which may be different in nature from its woody counterpart and therefore behave differently in spinning processes. Derivatization and dissolution methods are detailed, along with spinning techniques and parameters for these pro- cesses. Existing research related to the spinning of non-woody-based dissolving pulp is covered, along with suggestions for the most promising feedstock and technology combinations. In addi- tion, an emerging method of conversion, in which textile fibers are spun from a hydrogel made of an undissolved nano/micro-fibrillated fiber suspension, is briefly discussed due to its unique po- tential. Methods and concepts compiled in this review relate to utilizing alternative feedstocks for future fibers while providing a better understanding of conventional and emerging fiber spinning processes for these fibers.
文摘The paper and paperboard production in 2016 in the world was 110.07 million tones.1 Bangladesh consumes only about 3.5~4 kg paper and board products per capita,while the developed countries consume about 300 kg/capita.Bangladesh’s consumption is also much lower than the world’s average(@50 kg/capita)and the Asia’s average(@50 kg/capita).2 To reach the world’s or Asia’s level,Bangladesh’s consumption of paper and board products needs to increase 10 folds.As forest resources are very limited in Bangladesh,alternative fibrous raw materials are required to achieve this goal.Therefore many studies have been carried out on alternative raw materials available in Bangladesh.
基金funded by the Joint Funds for Regional Innovation and Development of the National Natural Science Foundation of China(No. U21A20244)the National Natural Science Foundation of China(No. 32071758)the National Key R&D Program of China (No.2022YFD2201000)
文摘Forest management planning faces uncertainties regarding future timber prices,tree growth,and survival.Future seed production is an additional source of uncertainty in Korean pine stands managed for the joint production of timber and edible seeds.Modern forest planning uses optimisation to determine the best possible cutting schedule.Optimisation can accommodate uncertainty by using decision rules for adaptive forest management instead of optimising cutting years and intensities.In this study,we optimised two adaptive decision rules for managing Korean pine plantations for the joint production of timber and pinecones when timber prices,tree growth,and seed production are stochastic.The first rule indicated the minimum price to sell timber,i.e.,the reservation price,as a function of the mean tree diameter and stand basal area.The second adaptive rule expressed the mean tree diameter at which cutting is optimal as a function of timber price and stand basal area.Both decision rules resulted in nearly the same mean net present value when the optimised rule was applied to 100 stochastic scenarios for future timber prices,tree growth,and seed production.The net present values were over 20% higher than those for the deterministically optimised cutting schedules under the same scenarios.Therefore,the expected economic gain from switching from deterministic to adaptive stochastic optimisation was at least 20%.The cutting years of the adaptive optima were frequently later than those indicated by the deterministic optima,and optimal adaptive harvesting often involved waiting for high timber prices.The minimum price or minimum mean diameter to sell timber was higher when the income from seeds was considered in the optimisation.The cuttings were later,and the rotations were longer in the joint production of timber and pinecones than in timber production alone.
