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This study introduces an innovative approach for developing high strength-high softness recycled fibers through soft mechanical treatment. Recycled fibers from old corrugated containers were treated using a homogenizer, a refiner, and in tandem. The recycled fibers and tissue paper sheets after the treatments were evaluated for the effect on critical properties such as fiber morphologies, freeness, water retention, hard-to-remove water, bulk, softness, tensile strength, and water absorption. High softness and tensile strength were achieved with mechanical treatment by utilizing a homogenizer alone or in tandem with a refiner. Overall, the homogenized recycled fibers and tissue paper sheets provided higher bulk, water absorption, and tensile strength while maintaining the softness and drainage (freeness) behavior similar to unrefined paper sheets. It was found that homogenization helps in deflocculating the recycled fibers without negatively affecting the fiber quality, such as fines generation.

The utilization of paper on a commercial scale is increasing day by day throughout the world that produces million of tons of paper waste yearly and burdened for landfills. The present study focuses on the exploitation of waste papers (office paper, newspaper and tissue paper) as a cheapest alternative source of energy to extract fermentable sugar by applying chemical and enzymatic pretreatments. The quantification of released sugar was analyzed by spectrophotometer and high performance liquid chromatography refractive index (HPLC-RI) detector. Cellulose (12 FPU/g) and β-glucosidase (12 FPU/g) was found to be effective for the extraction of fermentable sugar from paper waste. The contents of cellulose (C6H10O5)n, hemicellulose (C5H10O5)n and lignin (C9H10O2,C10H12O3,C11H14O4) found in office paper were 40%, 32.5%, 22.5%, in newspaper 46.5%, 30.5% 22.5%, and in tissue paper 62%, 22%, 15.5%, respectively. The percentages of sugar contents assessed in this study were 62% in tissue paper and 46.5% in newspaper and 40% in office papers. Among the three substrates, tissue paper (23.4 mg/mL) released a significant amount of glucose (C6H6O12), whereas newspaper (20.8 mg/mL) and office paper (19.6 mg/mL) released less amount of sugar. This research of acid pre-treatment and enzymatic hydrolysis was an efficient method to improve glucose conversion from lignocellulosic waste. Furthermore, this approach can be proved the first step towards the sustainable production of bioethanol from wastepaper-extracted sugar.

Embossing is a converting process in which the surface of a tissue paper sheet is changed under high pressure, allowing different functions. In this work, the authors intend to study how the embossing pressure affects the main properties of tissue paper, using a laboratory embossing system. An optimum pressure was achieved at 2.8 bar to this embossing laboratory set-up. The effect of pressure when densifying the paper sheet gives it a gain in mechanical strength but no differences in terms of liquid absorbency. The two embossing patterns present different behaviors but both evidence losses in mechanical and softness properties. On the other hand, the finite element method (FEM) does not show clear evidence of how the pressure affects the paper strength. For the deco die, it is possible to observe that the amount of yielding is slightly higher for lower pressure (2.4 bar), but this plasticity state parameter is very similar for 2.8 bar and 3.2 bar. For the micro die, FEM simulations of the manufacturing pressure do not show a considerable impact on the amount of plasticity state of the material; only for 3.2 bar, it shows a change in the pattern of the plasticity state of the paper during the embossing processes. In the end, to achieve a final product with excellent quality, it is important to make a compromise between the various properties.

Abstract The surface of tissue paper is relatively complex compared to other paper grades and consists of several overlapping structures like protruding fibres, crepe and fabric-based patterns at different spatial frequencies. The knowledge of tissue surface characteristics is crucial when it comes to improvement with respect to surface softness and the perceptual handfeel of tissue products. In this work we used the optical based, non-contact measurement principle of focus variation for surface characterization of dry-creped, textured and through air dried (TAD) tissue. Based on the three tissue grades, a procedure which includes the characterization of the whole tissue surface throughout different scales within one setup, was developed. Surprisingly, focus variation was rarely used in tissue-related research, as it provides robust and reliable 3D surface information which can be used for further areal surface analysis. Special attention was given to the preparation and discussion of the raw data up to the final analysis including several spatial filtering steps. Enhanced surface parameters like the developed interfacial area ratio (Sdr) and the power spectral density (PSD) were used to describe the surface adequately. The surface roughness of the three tissue grades was compared, with the textured tissue showing the highest roughness in Sdr and PSD analysis. Although both methods are based on different principles, a high correlation in terms of evaluated roughness is evident. Regular structures like crepe and patterns are obtainable as peaks at the respective frequency with a certain intensity in the PSD evaluation. Apart from topography in terms of structures and roughness, the wide field of view of the focus variation measurement also allows assessment of effects related to flocculation and sheet formation. The developed procedure could also be appropriate for other fibre based materials and/or fabrics, which are similar to tissue with respect to optical properties such as for example nonwovens. Graphic abstract

Perforation is used in multilayer tissue products, such as toilet and kitchen papers, as part of the converting process. Perforation facilitates the detachment of consecutive sheets by the user. The compromise between the strength required to detach a perforated sheet and the strength required to break a sheet affects the perforation efficiency. In this work, the mechanical behaviors of 15 commercial papers from different European producers were studied. A morphological analysis of the materials was performed, followed by the determination of their perforation efficiency (through tensile tests). A qualitative analysis of the cuts quality, along with a quantitative analysis of the same cuts dimensions was performed through an optical system. Finally, the stress concentration in the holes and the influence of the cuts distance were analyzed using a finite element model implemented in Abaqus/Standard finite element software. The results showed that a cut distance of 2.0 mm should not be used in these types of papers, and the perforation efficiency increased with the cut distance, regardless of the number of plies in the toilet paper. The stress concentration factor was also determined to have a limit value of 0.11. Papers above this limit value tear at the perforation line, as desired.

Effects of cellulase enzymatic treatment followed by mechanical beating were evaluated relative to the properties of cellulase-derived tissue pulps and handsheets. When different cellulase concentrations (0.0012 FPU/g, 0.0018 FPU/g, and 0.0024 FPU/g) of oven dried pulp (a 65/35 w/w ratio of beech to eucalyptus) were used for tissue production, a slight deterioration of the morphological characteristics was observed. Thus, a possibility of controlling the changes in the degree of polymerization of cellulose, as well as the fiber properties (in particular the length and coarseness) appeared. With an increased treatment time and enzyme concentration, these effects increased. The enzyme activity did not affect the apparent density of the paper, but the porosity drastically increased. The zero-span strength of the enzymatically treated pulps decreased with an increase in treatment time and amount of cellulase. However, mechanical beating improved the bonding between the cellulase fibers, which helped prevent the eventual decrease in mechanical properties of the handsheets. With the use of cellulase, the proposed moderate changes to fiber structure were achieved, giving the possibility of predicting and controlling the properties of tissue paper.

Effects of enzymatic modification were evaluated in bleached Eucalyptus kraft and sulfite cellulosic pulps, separately, to improve key tissue paper properties and design new Eucalyptus fiber applications. Different cellulase dosages (0.01 mg and 0.1 mg of enzyme/g of pulp) and reaction times (30 min and 60 min) were used to modify the fibers and replace the traditional mechanical based refining or beating process. The results showed that for enzymatic modified kraft and sulfite pulps, the softness properties were improved by 1 and 2 units, respectively, for each unit of decreased strength properties. To achieve a balance between the tissue properties, the different fiber pulp furnishes that contained 80% of the enzymatically treated kraft pulp and 20% of the sulfite pulp with and without enzymatic treatment, were studied. Overall, the structures made with these mixtures presented softness properties in the commercial range (57.8 to 74.4), improved absorption properties (107 mm to 120 mm of capillary rise), and good strength properties (13.0 to 17.7 N.m/g). This study was conducted in order to adjust the fiber furnishes according to industrial tissue standards, using one Eucalyptus fiber type providing strength and another providing softness.

The human perception of softness is an important yet complex property of hygiene tissue paper products. Softness is a function of the combination of machine technology, chemical additives, and furnish composition. As a result, it is difficult to investigate the influence of single parameters. Because no completely satisfactory method for determining the softness of furnishes is available at the laboratory scale, the influence of different fibrous materials in combination with their treatment cannot be comprehensively investigated. To work toward this possibility, this publication describes the development of a method to obtain reliable results based on laboratory handsheets using a modified tissue softness analyzer (TSA). With the help of basic statistical methods, a procedure was developed that reproducibly distinguished the influence between softwood and hardwood. To demonstrate the potential of this method, it was tested on an industrial tissue machine and the influence of four different furnishes on the softness of the semi-finished product was determined.

The embossing operation is one of the processes of tissue paper converting. The embossing parameters influence the final properties of tissue products, such as mechanical, softness, and bulk. In this study, the influence of the rubber hardness used against the embossing steel rolls with a pattern created by intaglio engraving was studied. Three different configurations of rubber plates stacking, each plate with different hardness, were studied. After embossing, mechanical properties, softness, and bulk were evaluated to analyze the effect of rubbers hardness on these properties. Furthermore, a Finite Element Model of the embossing operation was used that considered the same rubber plates stacking configurations used in experiments, and it was able to replicate the experimental results. This work led us to conclude that the configuration where two rubber plates with different hardness, where the rubber plate with higher hardness is in contact with the tissue paper sheet, has shown to be the best solution to obtain higher softness. These findings support the use of embossing operations rubber rolls with a low hardness internal layer and a high hardness external layer in industry. Thus, finite element models were also shown to be reliable tools to virtually test other configurations, such as, for example, three or more rubber plates with different hardness. Since embossing is one of the tissue paper transformation operations with the greatest impact on the key properties of the final product, this study allows the producer to optimize them by varying the hardness of the rubber roll, as well as its configuration.

Background/Aims: The incidence of disease outbreaks in clinical settings arising from ultrasound examinations is well documented, and is a source of worry. The ultrasound transducers and the coupling gel are potential sources of these infections since they come in direct contact with the patient’s skin. In this study, we examine the efficacy of the widespread practice of the use of plain non-sterile tissue paper in some low-cost private ultrasound centres in our locality as a method of disinfecting ultrasound transducers after each use. Its potential impact on nosocomial infection management in clinical practice is also examined. Methods: Swab samples from convex ultrasound transducers before and after transabdominal scanning of three consecutive patients were obtained from 10 different ultrasound centres in urban and rural areas of Enugu state. Ultrasound coupling gel samples were equally obtained, and all samples cultured for bacteria growth which was quantified in colony-forming units per ml (CFU/ml) and reported in 1000/ml. Paired sampled t-test was used to check for significance in a reduction in a bacterial load before and after the transducer was cleaned. Results: Nine different bacterial strains were isolated. Staphylococcus aureus and Klebsiella spp had the highest percentage of occurrence in all centres. Significant bacteria growth was recorded in the morning before the examination, and plain tissue paper significantly reduced the bacteria load in the ultrasound transducer. Conclusion: Even though disinfecting ultrasound transducers with non-sterile plain tissue paper alone is statistically effective and has the potential to minimize nosocomial infection, it is however not clinically effective and hence not advised.

Paper wastes form the major biodegradable fraction of the municipal solid waste. One of the best ways to treat paper wastes is using them as a feedstock for biomethane production through anaerobic digestion (AD). However, the AD characteristics, kinetics, and energy potential of different types of paper wastes are not clear. In this study, four kinds of typical paper wastes including corrugated board (CB), office paper (OP), tissue paper (TP), and magazine paper (MP) were used as feedstocks to produce biomethane at different volatile solids (VS) organic loading (OL). TP had a high cellulose content and showed high biomethane potential, while the lowest was obtained by CB, possibly due to its high lignin content. Kinetic analysis showed that Cone and modified Gompertz model could fit the biomethane production process well. Energy potential analysis revealed that biomethane yield, electric generating efficiency, and electricity price were the principal factors accounting for the profitability of biomethane production project treating paper wastes. Overall, paper wastes could be a promising feedstock for biomethane production, because paper wastes not only had high biomethane yield and biodegradability that exceeded many kinds of organic wastes but also could be continuously supplied for AD plants without the influence of seasonal changes.

The study of water absorption by capillarity on paper with a simple technique is simple but important to do to inform the public about the characteristics of paper and for the development of research on the absorption of different types of paper. In this study, five types of paper were used, namely HVS paper, cardboard, tissue paper, concord paper and buffalo paper. In the capillary water absorption test on paper, the physical quantities analyzed are the water absorption, the absorption time and the water absorption rate. The capillarity of the paper is a comparison of the rate of water absorption by the paper which is analyzed using the straight line movement approach. The value of water absorption is estimated using the ratio between the height of water absorption and the time absorption. Based on the results of the capillary test on paper, it was found that the water absorption height for the five types of paper increases with increasing absorption time. The highest water absorption capacity is tissue paper, which is 7.4 ± 0.2 cm every 180 seconds. While the lowest water absorption capillarity is HVS paper which is 0.5 ± 0.1 cm at the 180th second. Cardstock and buffalo paper have almost the same water absorption value and are higher than HVS paper and match. The absorption speed which is almost the same between cardboard and buffalo paper is due to the fact that both belong to the same type of paper, namely printing paper.

Abstract Tissue paper softness relies on two major factors, the bulk softness, which can be indicated by the elasticity of the sheet, and surface softness. Measurement of surface softness is complicated and often requires a multi-step process. A key parameter defining surface softness is the topography of the surface, particularly the crepe structure and its periodicity. Herein, we present a novel approach to measure and quantify the tissue paper surface crepe structure and periodicity based on the detection of waviness along the sample using laser scanning confocal microscopy (LSM) and X-ray tomography (XRT). In addition, field emission scanning electron microscope (FESEM) was used to characterize the tissue paper surface. We demonstrate that surface topography is directly correlated to the erosion of the doctor blade, which is used to remove the dry tissue paper from the Yankee cylinder. Because of its accuracy and simplicity, the laser confocal microscopy method has the potential to be used directly on the production line to monitor the production process of the tissue paper. XRT revealed more structural details of the tissue paper structure in 3D, and it allowed for the reconstruction of the surface and the internal structure of the tissue paper. Graphic abstract

Tissue paper conversion consists of the transformation of base tissue papers into finished tissue products to meet specific demands. When base tissue paper arrives at the converting line, it already holds different requirements that were met during its manufacture in the paper machine (e.g., grammage, bulk, tensile index, etc.). However, what happens during converting can still influence the performance and quality of the finished products. The current work addresses this topic and aims to evaluate the influence of converting conditions on the final softness. For that, two 5-ply finished tissue products were analyzed using different methodologies for their proper characterization in terms of softness and surface analysis. The analyzed products are composed by the same base tissue papers, but some changes were applied on their settings in the converting line. In particular, the base tissue papers arrangement and the embossing pressure affected the finished products, resulting in one of them being softer and more pleasant to touch, with a global handfeel (HF) value of 75.3 units, and the other revealed to be rougher and less pleasant, with a global handfeel (HF) value of 68.0 units.

A comparison between uncreped and creped handsheets was performed to study the effect of fiber morphology and creping process on fiber web structure and tissue properties. Four wood and non-wood pulps refined at different levels were used to manufacture uncreped and creped handsheets using a creping simulator. A characterization of the fiber web structure using scanning electron microscopy (SEM) and evaluation of tissue properties (e.g. tensile strength, water absorbency, softness) was performed on the uncreped and creped handsheets. The results obtained with the creping simulator were compared with commercial products to evaluate the significance of the creping simulator results. The SEM images of the fiber web structure showed that the creping process promoted buckling and distortion of fibers, delamination of surface fiber layer, development of free fiber ends and creation of crepe folds, which enhanced water absorbency and softness at the expense of reduced tensile strength. Short and thin fibers seemed to be more effectively creped than long and coarse fibers. Long and coarse fibers seemed to offer higher resistance to the compressive forces acting at the creping blade. A reasonable correlation between the performance of uncreped and creped handsheets made with different fibers was observed. The results indicate that the performance of uncreped handsheets can be used as a semi-quantitative indication of the performance of creped handsheets. The performance of the creped handsheets were similar to commercial products, which indicates that the creping simulator can be used as an alternative to study the creping process at laboratory scale.

Absorption capacity is a key feature of toilet tissue papers. Several parameters can affect their final absorption capacities, such as pulp composition, stock preparation, number of sheets, additives, bulk, grammage, and converting process parameters, such as the embossing operation. In this work, the absorption capacities of four different 2-ply industrial toilet tissue papers, as well as the respective base papers from the mother-reel was compared using the immersion method according to ISO 12625-8 (2010). Previously, these samples were characterized in terms of morphology, grammage, thickness, and bulk. It was concluded that the embossing operation noticeably increased the thickness and bulk of toilet tissue paper. Furthermore, it was also verified that among the various toilet tissue paper samples there was not a noticeable variation in the time of water absorption because the samples revealed similar morphology and porosity. However, it was found that the bulk increased more than 150%, resulting in an increase of water absorption capacity over 60%.

The paper presents the method for assessment the performance of high-speed Yankee hoods in the production of tissue paper grades and the results of its use in working machine. The following parameters are found applying this method: paper web dryness, air pressure in the wet and dry ends of high-speed convective dryers and temperature of the air spilled out of the hoods. The methodology is based on the measurement of these characteristics during the operation of working equipment with further adjustment of the separate system units. Thermal imaging was carried out during the experiment. It has been found that blowing hot air on the front side of the hood and sucking in the cold air on the drive side leads to uneven moisture profile (measured on the paper machine roll) across the paper web width, a decrease in energy efficiency and the machine capacity. Performance indicator may be, for instance, the spilled air temperature, which on the studied machine is significantly different from the standard value and is 175 °C. The rationality of regular monitoring of air characteristics when changing processing modes is proved. The relevance of the cascade system is substantiated, where not only a direct cascade from the dry end to the wet end is possible, but also there is an opportunity to adjust the humidity of exhaust air by addition/reduction of part of it to/from the dry end. The direct effect of adjusting the humidity of exhaust air in the drying section on reduction of energy costs, as well as the effect of make-up air on the amount of infiltration and the air balance of the system are confirmed. A set of measures implemented within the framework of this methodology makes it possible to achieve energy saving in existing industries. The prospective saving potential of gas is 62 m3/h or 17 % of the current consumption and actual electricity consumption is 6.8 kWh or 4 % for the studied machine. For citation: Prokhorov D.A., Smolin A.S. Performance Assessment of the Drying Section of Machines for the Production of Tissue Paper Grades. Lesnoy Zhurnal[Russian Forestry Journal], 2020, no. 2, pp. 159–168. DOI: 10.37482/0536-1036-2020-2-159-168

The study aimed to investigate the presence of some heavy metals in the different used paper tissue paper in the local market, evaluate their types in terms of their safety and highlight the risks arising from the excessive use of anonymous tissue paper. At highlighting the potential damage from the impact of the use of different tissues paper on human health in terms of the probability of the presence of heavy metals in the tissue paper product. The presence of the following metals (Cadmium, Lead, Chromium) war investigated in 20 random samples from the market where seven different types of homemade and imported brands were collected. The concentration of cadmium in all types of samples ranged from (0.21 - 0.05) ppm, where the highest concentration of the cadmium in the sample (A8) and the lowest concentration was in the sample (T4). The concentration of lead in all types of samples ranged from (0.01 - 0.32) ppm where the highest concentration of the lead in the sample (A9) and the lowest concentration was in the sample (A3 / A1). For the samples K2, A11 did not give absorption. The concentration of chromium in all types of samples ranged from (0.07-1) ppm where the highest concentration of the element in the sample (A4) and the lowest concentration were in the sample (A9).

An innovative approach for preparing hemp fibers from hemp hurds for use in tissue and towel grades of paper is described. Hemp hurds are a low value by-product of industrial hemp processing that are generally used for animal bed litter. Tissue paper was fabricated from hemp hurd fibers by following three pulping processes: autohydrolysis (hydrothermal), sodium carbonate-based defibration, and high yield kraft pulping, and benchmarked against hardwood pulp. To meet industrial standards, hardwood and hemp pulp fibers were mixed at a dry mass ratio of 75:25, from which tissue paper sheets were prepared. Desirable tissue paper properties, such as water absorption, burst resistance, softness, and tensile strength (dry and wet), were measured and compared. Characterization of morphological and chemical properties of tissue handsheets was conducted with SEM and time-of-flight-secondary ion mass spectrometry (ToF-SIMS). The combined kraft pulped hardwood and autohydrolyzed hemp pulp fibers displayed improvements in tensile index, burst resistance, and softness of tissue handsheets compared to only kraft hardwood pulp handsheets without adversely impacting water absorption. Hardwood fibers showed a sparse distribution of surface lignin compared to hemp fibers using the same defibration. This technology can lead to a variety of eco-friendly tissue paper products that are not only highly energy efficient, but avoid harsh chemical processing.

Tissue papers are products used for hygienic and sanitary purposes such as toilet paper, paper towel, napkin and facial tissue. Some of these papers have the characteristic of wet strength, which is defined as the strength of the paper after receiving a certain amount of water. In the manufacture of papers that demand a high wet strength value, the use of an additive for this purpose is extremely important and must be strictly controlled, always seeking to optimize the dosage to reduce costs. This work aimed to study the wet strength resin loading in tissue paper production and how the control of ionic charge in fiber suspension can help to optimize the dosage of wet strength resin. The ionic charge of the pulp suspension was kept between -10 to -21 μEq/mL, the zeta potential obtained was between -16.6 to -22.3 mV. Tensile strength values of paper sheets formed with and without the addition of the ionic charge control additive were compared. When it was controlled the ionic charge of the pulp suspension, it was possible to achieve greater values of wet tensile strength with lower dosage of wet strength resin. Papéis tissue são produtos utilizados para fins higiênicos e sanitários, tais como papel higiênico, papel toalha, guardanapo e lenço facial. Alguns desses papéis possuem a característica de resistência a húmido, que é definida como a resistência do papel após receber uma determinada quantidade de água. Na fabricação de papéis que demandam alto valor de resistência a húmido, o uso de um aditivo para essa finalidade é extremamente importante e deve ser rigorosamente controlado, sempre tentando otimizar a dosagem para reduzir custos. Este trabalho teve como objetivo estudar a carga de resina de resistência a húmido na produção de papel tissue e como o controle da carga iônica em suspensão de fibras pode ajudar a otimizar a dosagem da resina de resistência a húmido. A carga iônica da suspensão de fibras foi mantida entre -10 a -21 μEq / mL, o potencial zeta detetado ficou entre -16,6 a -22,3 mV. Foram comparados os valores das folhas de papel formadas com e sem adição do aditivo de controle de carga iônica. Quando foi controlada a carga iônica da suspensão de fibras, foi possível obter maiores valores de resistência à tração a húmido com menor dosagem de resina. Mestrado em Química

With the development of energy-storage devices, separator is encountered by several challenges including adequate safety, higher current density and superior stability. Tissue paper, composed of packed cellulose fibers, possesses lower production cost, more easily accessibility, superior wettability and outstanding thermostability, thus being prospective as a substrate of high performance separator. To address structure collapse phenomenon occurred in conventional coating layer after long term electrolyte swelling, nano-SiO2 hybrid crosslinked network was constructed on tissue paper through chemical reactions between polymer poly (vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and hyperbranched polyethyleneimine (PEI) in this work. The influences of crosslinking degree on physical properties and electrochemical performance were studied thoroughly. It can be found that when the crosslinking ratio of PVDF-HFP and PEI fixed at 10:1, the crosslinked composite separator displays excellent electrolyte uptake and wettability, superior ionic conductivity, better interfacial compatibility as well as higher Li+ transference number (0.56), thus offering battery with prominent rate capabilities. Besides, this crosslinked composite separator exhibits satisfying dimensional stability even treated at 250 oC, better flame retardancy, enhanced mechanical behavior, wider electrochemical window and outstanding cycle stability. Accordingly, tissue paper-based crosslinked composite separator can meet higher requirements put forward by high power lithium ion battery.

Tissue paper production frequently combines two main types of raw materials: cellulose fibers from renewable sources and polymer-based additives. The development of premium products with improved properties and functionalities depends on the optimization of both. This work focused on the combination of innovative experimental and computational strategies to optimize furnish. The main goal was to improve the functional properties of the most suitable raw materials for tissue materials and develop new differentiating products with innovative features. The experimental plan included as inputs different fiber mixtures, micro/nano fibrillated cellulose, and biopolymer additives, and enzymatic and mechanical process operations. We present an innovative tissue paper simulator, the SimTissue, that we have developed, to establish the correlations between the tissue paper process inputs and the end-use paper properties. Case studies with industrial interest are presented in which the tissue simulator was used to design tissue paper materials with different fiber mixtures, fiber modification treatments, micro/nano fibrillated cellulose, and biopolymer formulations, and to estimate tissue softness, strength, and absorption properties. The SimTissue was able to predict and optimize a broader range of formulations containing micro/nanocellulose fibers, biopolymer additives, and treated-fiber mixtures, saving laboratory and industrial resources.

In der vorliegenden Fallstudie wird der Einfluss von Maschinenparametern einer LDC-Papiermaschine auf den Weichheitswert von Hygienepapier untersucht. Als Fall dient eine Papiermaschine in Niederösterreich. Das bisherige Vorgehen im Unternehmen beruht auf subjektiven Erfahrungen des Maschinenpersonals, die auf Optimierungsversuchen während des Vollbetriebs basieren. Mit einer multivariaten Regression, die 66,4% der Varianz vom Weichheitswert erklärt, konnte eine Stärke der Beziehung zwischen Flächengewicht, Trennmittel, Kreppgrad, Feuchte, Kreppschaberdruck und Schaberstandzeit mit der Papierweichheit nachgewiesen werden. Ausgehend von den Schätzungen der Regression lassen sich Empfehlungen für die Optimierung der Papierweichheit ableiten, die unter anderem in der Reduktion des Flächengewichts in g/m² und des Feuchtegehalts sowie der Erhöhung des Kreppschaberdrucks liegen. Ein in dieser Fallstudie durchgeführtes Beispiel zeigt die Funktionalität des Regressionsmodells, die erhaltenen Werte liegen jeweils deutlich über den Medianwerten der Labormessungen im Untersuchungszeitraum.*****In this case study, the influence of machine parameters of an LDC tissue machine on the softness value of tissue paper is investigated. A tissue machine in Lower Austria serves as the case. The previous approach in the company is based on subjective experiences of the machine personnel, which are based on optimization tests during full production. With a multivariate regression explaining 66.4% of the variance from the softness value, a strength of the relationship between basis weight, release agent, degree of creping, moisture, creping doctor pressure and doctor life with paper softness could be demonstrated. Based on the regression estimates, recommendations for optimizing paper softness can be derived, including reducing basis weight in g/m² and moisture content, and increasing creping doctor pressure. An example carried out in this case study demonstrates the functionality of the re