Novel Parameter Identification Method for Basis Weight Control Loop of Papermaking Process

The basis weight control loop of the papermaking process is a non-linear system with time-delay and time-varying.It is impractical to identify a model that can restore the model of real papermaking process.Determining a more accurate identification model is very important for designing the controller of the control system and maintaining the stable operation of the papermaking process.In this study,a strange nonchaotic particle swarm optimization(SNPSO)algorithm is proposed to identify the models of real papermaking processes,and this identification ability is significantly enhanced compared with particle swarm optimization(PSO).First,random particles are initialized by strange nonchaotic sequences to obtain high-quality solutions.Furthermore,the weight of linear attenuation is replaced by strange nonchaotic sequence and the time-varying acceleration coefficients and a mutation rule with strange nonchaotic characteristics are utilized in SNPSO.The above strategies effectively improve the global and local search ability of particles and the ability to escape from local optimization.To illustrate the effectiveness of SNPSO,step response data are used to identify the models of real industrial processes.Compared with classical PSO,PSO with timevarying acceleration coefficients(PSO-TVAC)and modified particle swarm optimization(MPSO),the simulation results demonstrate that SNPSO has stronger identification ability,faster convergence speed,and better robustness.

Development and Evolution of Papermaking in Ancient China based on the Uses and Forms of Paper

In the past,scholars have divided the history of Chinese papermaking into different stages based on the development of ancient papermaking technology,emphasizing the development and progress of papermaking in different historical periods but paying less attention to the changes in the form of paper.Here,the stages are defined based on changes in use and function rather than technological developments.When this approach is combined with the history of printing,books,calligraphy,and painting,the history of Chinese papermaking can be divided into the writing paper,writing and printing paper,printing paper,and calligraphy and painting paper periods.Different periods of paper have significant differences in texture,form,and performance owing to their different applications.This significant difference provides a reference for the identification of ancient papers and reveals the internal connection between the history of printing,books,calligraphy,painting,and papermaking.

Review of energy consumption research for papermaking industry based on life cycle analysis

Papermaking industry is a high-energy-consuming industry with long supply chain.The growth of paper product demand further intensifies the need of energy consumption.Energy saving through the full supply chain has become a focal point for long-term sustainable development of the papermaking industry.This paper reviews the advances in life cycle analysis for the papermaking industry in recent years.All the stages from the full supply chain are involved to give a panoramic overview of the papermaking industry.The object of this paper is to provide scientific basis to industry and decision-makers with profound understanding of the energy consumption and energy saving potential in a life cycle perspective.

Application of Cellulose Nanofibril as a Wet-end Additive in Papermaking:A Brief Review

Recently,cellulose nanofibril(CNF)has emerged as a promising,sustainable reinforcement with outstanding potential in material science.Owing to the properties of CNF,it has been explored in food,cosmetic,and pharmaceutical applications,as well as in industrial applications such as paints,drill muds,packaging,and papermaking.The application of CNF in papermaking is expected to be implemented in the near future to broaden the commercial market of cellulose.Numerous studies and patents have reported on the manufacturing,properties,and applications of nanocellulose.This present paper focuses on the recent progresses in the application of CNF as a wet-end additive in papermaking.

FUNCTIONS OF POLYAMINES IN ROSIN SIZING UNDER NEUTRAL PAPERMAKING CONDITIONS

Functions of the polyamines in neutral rosin sizing were investigated using X-ray photoelectron spectroscopy (XPS) and laser diffraction particle analysis. The polyamine with a higher charge density and a smaller unite size could retain more rosin and cover larger fiber surfaces. The XPS spectra demonstrated that polyallylamine (PAAm) and polyvinylamine (PVAm) could react with a rosin size to form a -OC-N-CO- structure, but polydimethylamino ethyl methacrylate (PDMAEMA) could not. The formation of this structure may be a key step for effective sizing.

Production of Bamboo Fiber Reinforced Fibrillated Poly(Lactic Acid)(PLA) Material Obtained by a Papermaking Process

A devised beating process was applied, which enabled the formation of slurry consisting of uniformly dispersed fibrillated polylactic acid（PLA） fibers with bamboo fiber, and the polymer material was obtained by a conventional papermaking process. Owing to the fast dewatering time, good repeatability and the facility to manufacture on a large scale, this process was used. It was revealed that the beaten PLA fiber was overall in machinery extrusion by the results of optical microscope and scanning electron microscope（SEM） observations. The improvement in the tensile index, burst index, tear index and other mechanical properties was considered as a key benefit as a result of adding bamboo fiber.

Wet Pressing Models to Reduce Energy Consumption in Papermaking

Improved wet pressing reduces the need for drying and consequently energy needed in papermaking. Accordingly, it is desirable to optimize wet pressing, but the process is very complex with many interacting variables. It is therefore desirable to employ a mathematical model that accounts for the major variables to estimate the effects of changes in equipment and operating variables. This paper descibes such a model called the Decreasing Permeability Model (DPM). Mill and pilot plant applications over a wide range of basis weights for paper and paper board are described.

Coaxing Polysaccharide Granules into Supramolecular Biocolloidal Additives for Papermaking

In light of developments in polysaccharide-based sustainable processes involving supramolecular interactions,we herein present our findings pertaining to coaxing polysaccharide granules into functional supramolecular biocolloids.Translucent biocolloidal dispersions containing various forms of starch are facilely designable,essentially built upon complexation between disassembled native cornstarch granules and amphiphilic ligands.Oily moieties of guest molecules are dynamically attractable into cavities of helical structures,with cationic groups pointing toward the bulk phase.This noncovalent attraction can generate core-shell biocolloidal particles.The significantly higher gelatinizability of freeze-dried biocolloids in contrast to native cornstarch granules is attributable to complex formation,and a homogenous dispersion is readily formable at room temperature.Our results also show biocolloids'ligand-related antibacterial activity.The use of biocolloids as wet-end additives for biofiber assemblies(cellulosic paper)can enhance mechanical strength,fines retention,and filler bondability.Supramolecular biocolloids with positively charged,translucent,easily gelatinizable,antibacterial,and polysaccharide-bondable functionalities would find tailorable use in the paper industry.

THE PULPING AND PAPERMAKING CHARACTERISTICS OF YOUNG L.GMELINI AND B.PLATYPHYLLA

5, 10, 15, and 20 year old Larix gmelini and Betula platyphylla were used as pulping raw material in the research. The examination of young L. gmelini and B. Platyphyllafibrous structures showed that the fiber length and ratio of length to width of 5 years old L. gmelini noticeably differed from that of mature L. gmelini. but that of 5 year old B. platyphyllawere nearby equal to that of mature B. platyphylla. The research results indicated that 15 years old B. platyphylla and 20 year old L. gmelini were best suited to pulping among the eight experimental raw materials; 10 years old B. platyphylla and 15 year old L. gmelini were optimal to the ratio of beating degree increment and corresponding beating time. The pulp characteristics of 15 year old B. platyphylla and 20 year old L. gmelini were similar to those of mature wood, and it was feasible to consider 15 years to B. platyphylla and 20 years to L. gmelini as their rotation period; 10 years and 15 years as their thinning cycles for the papermaking forest base.

A Neural Network Controller for Basis－weight Control of Papermaking Processes

ＡＮｅｕｒａｌＮｅｔｗｏｒｋＣｏｎｔｒｏｌｌｅｒｆｏｒＢａｓｉｓ－ｗｅｉｇｈｔＣｏｎｔｒｏｌｏｆＰａｐｅｒｍａｋｉｎｇＰｒｏｃｅｓｓｅｓＨＵＨｅｎｇｚｈａｎｇ；ＳＨＥＮＹｉ（胡恒章）；（沈毅）（Ｄｅｐｔ．ｏｆＣｏｎｔｒｏｌＥｎｇｉｎｅｅｒｉｎｇ，Ｈａ...

The Protection and Inheritance of the Traditional Papermaking Process: A Case Study of the Zhang Paper Workshop

The Zhang Paper Workshop preserving the complete traditional papermaking process has been praised by experts as “the living fossil of Chinese papermaking”. Due to the impact of industrial papermaking, however, the traditional papermaking has gradually lost its market advantage, and the Zhang Paper Workshop prevailing for a time is already on the decline. In order to retain this precious cultural heritage, for more than 10 years, the Gleaners has spared no effort to provide various efforts to papermakers and has found a way out for the manual papermaking, and results have been achieved. How to protect and inherit the traditional papermaking process under the premise of conserving the ecological environment and maintaining the integrity of the papermaking process, and establish the Zhang Paper Workshop as a place for spreading the concept of nature conservation and cultural heritage protection is an urgent problem to be solved. This requires the support of policies, the investment of funds and the upgrading of technology, as well as the promotion of understanding and the cultivation of feelings.

Ministry of Water Resources and Ministry of Industry and Information Technology Issued Seven Industrial Water Quotas Including Papermaking

On December 30^(th), 2020, in order to further promote water conservation, Ministry of Water Resources and Ministry of Industry and Information Technology issued a notice on seven industrial water quotas including papermaking, and the quota standard was came into effect on March 1^(st), 2021.

Microwave Absorption and Mechanical Properties of Short-cutted Carbon Fiber/glass Fiber Hybrid Veil Reinforced Epoxy Composites

This work aims at investigating the microwave absorption and mechanical properties of short-cutted carbon fiber/glass fiber hybrid veil reinforced epoxy composites.The short-cutted carbon fibers(CFs)/glass fibers(GFs)hybrid veil were prepared by papermaking technology,and composites liquid molding was employed to manufacture CFs/GFs hybrid epoxy composites.The microstructure,microwave absorbing properties and mechanical properties of the hybrid epoxy composites were studied by using SEM,vector network analyzer and universal material testing,respectively.The reflection coefficient of the composites were calculated by the measured complex permittivity and permeability in the X-band(8.2-12.4 GHz)range.The optimum microwave absorption properties can be obtained when the content of CFs in the hybrid veil is 6 wt%and the thickness of the composites is 2 mm,the minimum reflection coefficient of-31.8 dB and the effective absorption bandwidth is 2.1 GHz,which is ascribed to benefitting impedance matching characteristic and dielectric loss of the carbon fiber.Simultaneously the tensile strength and modulus can achieve 104.0 and 2.98GPa,demonstrating that the CFs/GFs hybrid epoxy composites can be a promising candidate of microwave absorbing materials with high mechanical properties.

Physical Condition of Five Historical Land Deeds and Implications for Land Deed Paper Conservation

This work presents five land deeds(S1-S5)collected by the Deng family,the land deed papers were produced by the Deng family,and the content was about the transaction of the Deng family paper production site.Density,whiteness,pH value,and fiber morphology of the deed papers were measured and analyzed,and the physical condition of the deeds was determined.The results showed S1 and S3 were severely damaged,S2 and S4 were moderately damaged,and S5 was mildly damaged.The abovementioned deeds are physical witnesses to the history of Deng papermaking,and have high value as cultural relics and historical documents.It is hopefully this study could be used to inform scientific restoration plans,and provide a reference for the collection and protection of land deeds.

Transmutation of Cai Lun’s Image

The earliest description of Cai Lun is that of an inventor of papermaking,which is included in historical books such as Dong Guan Han Ji and The Book of the Later Han;later,in his hometown,he was also inked by scholars because of some monuments about him,or the authors used his experience to express their own emotions.Recently,Cai Lun’s image has been clarified in textbooks,literary works,and urban civilization construction and is no longer considered merely a pioneer of papermaking.The development of his historical and literary image derives not only from the need for academic research but also the need to establish the Chinese nationalism and patriotism and promote traditional culture.

CIPTE Gets ready to Sail Again|2023 China International Paper Technology Exhibition(30^(th) CIPTE) and Conference Successfully Concluded

The 2023 China International Paper and Technology Exhibition (CIPTE),a 3-day event that took place in the peak of summer,came to a successful conclusion.Numerous remarkable moments were witnessed.2023 CIPTE attracted authoritative leaders and experts from the papermaking industry to participate 2023 CIPTE,as always,was received the strong support and extensive attention by the leaders and experts from the papermaking industry and enterprises,such as Wang Keling,Deputy Secretary of the Party Communist and Gernal Mannger of Poly Sinolight Corporation。

Micro-electrolysis technology for industrial wastewater treatment

Experiments were conducted to study the role of micro-electrolysis in removing chromaticity and COD and improving the biodegradability of wastewater from pharmaceutical, dye-printing and papermaking plants. Results showed that the use of micro-electrolysis technology could remove more than 90% of chromaticity and more than 50% of COD and greatly improved the biodegradability of pharmaceutical wastewater. Lower initial pH could be advantageous to the removal of chromaticity. A retention time of 30 minutes was recommended for the process design of micro-electrolysis. For the use of micro-electrolysis in treatment of dye-printing wastewater, the removal rates of both chromaticity and COD were increased from neutral condition to acid condition for disperse blue wastewater; more than 90% of chromaticity and more than 50% of COD could be removed in neutral condition for vital red wastewater.

Pulp and Paper from Sugarcane:Properties of Rind and Core Fractions

Two distinct lignocellulosic fractions(rind and core)can be obtained through a physical separation of sugarcane stalks.Although presenting differences in morphology,both fractions can be employed to produce pulps and papers.The pulps and paper sheets produced from the core and rind fractions were characterized by their chemical composition,physical properties and mechanical properties.The pulps obtained from the core presented a higher amount of fines,lower drainage ability and rendered denser and stiffer sheets.The pulps from the rind,which have a higher content of fibers and higher degree of polymerization,produced sheets with higher air permeability and water absorption.Both paper sheets presented mechanical and physical properties comparable to commercial papers and papers from different cellulosic sources.The different properties exhibited by the papers produced from each fraction allow their use for distinct purposes,and expands the opportunities in the context of sugarcane biorefinery.

The Building of Papermaking Enterprise's Recycling Economy Evaluation Index System Based on Value Flow Analysis

At present,the research on circular economy has made a lot of substantive results both at home and abroad.But for the papermaking enterprise,which is the representative of the light industry,few studies have analyzed the evaluation index system of circular economy.Since the current material flow analyses have limitations that the researchers cannot calculate materials with different units.The authors take advantage of the intrinsic correlation between the basic principle of value flow analysis and circular economy,and then analyze the dynamic changes of material flow and value flow through enterprises internal production process.Considering the resource output,the authors set up the layered structure of the evaluation index system,and then preliminarily determine the index form.Next,the authors use the frequency statistics analysis method to adjust indicators,forming a preliminary index system.After that,the principal component analysis and independent analysis are applied for screening.Finally,the authors build a circular economy evaluation index system for papermaking enterprise to provide scientific guidance for the process of circular economy.

A Principle of Producing Multi-ply Paper Using a Wire in an Inclined Wire Machine

In this study,we improved the dispersibility of the stocks in the headbox of an inclined wire machine to produce a distinct paper,and analyzed some factors affecting paper formation in the production of multiply paper.We used FLUENT6.3 to analyze the flow of the stocks in the headbox and select the structure of the diffusion part required for improving the dispersibility of fibers.Moreover,based on a simulation experiment,the optimal rational angle of the diffusion part(g)was found to be approximately 8°~10°,and it improved the paper formation in the case of usage of two plates.Using the equation for the formation of paper layers in the headbox of an inclined wire machine,we obtained a paper with the given basic weight by controlling the inclined angle of the wire(a),initial height of water(H),and concentration of the stocks.We considered the effect of a and H of the stocks in the headbox on the fiber distribution,and according to the results,a should be set as approximately 20°~30°and H should be maximally high.When producing multi-ply paper by a wire,the line pressure of the couch roll should be maintained at 1.8~2.0 kN/m to avoid the damage to the paper sheets.In addition,we found the optimal structure parameter of the dehydrated roll was as follows:hole ratio of approximately 30%of the dehydrated roll surface area,width of 1.5~2.0 mm,slot pitch of 5~6 mm,slot depth of 2~3 mm,and inclined angle of diffusion part(b)of 5°.