Low-consistency refining of CTMP targeting high strength and bulk: effect of filling pattern and trial scale

2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Jan-Erik Berg ◽  
Börje Hellstadius ◽  
Mikael Lundfors ◽  
Per Engstrand
Keyword(s):  
High Strength ◽  
Natural Fibre ◽  
Laboratory Scale ◽  
Process Conditions ◽  
Tensile Index ◽  
Filling Pattern ◽  
Basic Objective ◽  
High Bulk ◽  
Fibre Morphology ◽  
Bulk Effect

AbstractChemithermomechanical pulp (CTMP) is often used in central layers of multiply paperboards due to its high bulk and strength. Such a CTMP should consist of well-separated undamaged fibres with sufficient bonding capacity. The basic objective of this work is to optimize process conditions in low-consistency (LC) refining, i. e. to select or ultimately develop new optimal LC refiner filling patterns, in order to produce fibrillar fines and improve the separation of fibres from each other while preserving the natural fibre morphology as much as possible. Furthermore, the aim is to evaluate if this type of work can be done at laboratory-scale or if it is necessary to run trials in pilot- or mill-scale in order to get relevant answers. First stage CTMP made from Norway spruce (Picea abies) was LC refined in mill-, pilot- and laboratory-scale trials and with different filling patterns. The results show that an LR1 laboratory refiner can favourably be used instead of larger refiners in order to characterize CTMP with regard to tensile index and z-strength versus bulk. A fine filling pattern resulted in CTMP with higher tensile index, z-strength and energy efficiency at maintained bulk compared to a standard filling pattern.

scholarly journals Effect of Post Curing, Fibre Content and Resin-Hardener Mixing Ratio on the Properties of Kenaf-Aramid Hybrid Composites

2014 ◽  
Vol 548-549 ◽  
pp. 7-11
Author(s):  
R. Yahaya ◽  
S.M. Sapuan ◽  
M. Jawaid ◽  
Z. Leman ◽  
E.S. Zainudin
Keyword(s):  
Mechanical Properties ◽  
Hybrid Composites ◽  
Flexural Modulus ◽  
High Strength ◽  
Natural Fibre ◽  
Fibre Content ◽  
Curing Temperature ◽  
Process Conditions ◽  
Mixing Ratio ◽  
Full Factorial

Polymer composites reinforced with high strength synthetic fibres have been used for many engineering applications. Environmental and economic issues, encourage the exploration on the introduction natural-synthetic fibre hybrid composites. Mechanical properties are critical to composite performance and may due to the manufacturing process conditions. This study investigates the effect of post curing temperature, natural fibre content and resin-hardener mixing ratio on mechanical properties of kenaf-Kevlar hybrid composites. A full factorial design (23) was carried out to determine the effect these factors on the responses: flexural strength, flexural modulus and impact strength. A statistical study has been performed in order to determine the how the factors affect the responses. The study showed that post-curing temperature, kenaf content and resin-hardener mixing ratio gives significant effects on the mechanical properties of kenaf-Kevlar hybrid composites.

scholarly journals Handmade paper from waste banana fibre

2018 ◽  
Vol 53 (2) ◽  
pp. 83-88 ◽  
Author(s):  
KMY Arafat ◽  
J Nayeem ◽  
AH Quadery ◽  
MA Quaiyyum ◽  
M Sarwar Jahan
Keyword(s):  
Lignin Content ◽  
High Strength ◽  
Extraction Process ◽  
Natural Fibre ◽  
Morphological Properties ◽  
Pulp Yield ◽  
Adjacent Area ◽  
Banana Fiber ◽  
Handmade Paper ◽  
Banana Fibre

Banana fibre is a natural fibre with high strength, which can be blended easily with cotton fibre or synthetic fibre to produce composite material. In the fiber extraction process, a substantial amount of lignocellulosic wastes are generated, disposal of which creates problem in the adjacent area. In this paper, extracted banana fiber (EBF) and waste banana fiber (WBF) were characterized in terms of chemical and morphological properties to produce handmade paper. WBF was characterized with lower α–cellulose, lignin content and longer fiber length. Pulping of EBF and WBF was carried out with varying active alkali and cooking time at boiling temperature. Pulp yield of WBF was 35.9% after 120 min of cooking with 8% alkali charge. In the unbeaten state the degrees of drainage resistance i.e. SR values were 65 and 71 for EBF and WBF, respectively. The tensile, burst and tear indices of WBF were 23.7 N.m/g, 2.2 kPa.m2/g and 5.0 mN.m2/g, respectively; these were much lower as compared to EBF. These values however, meet the requirement for handmade paper.Bangladesh J. Sci. Ind. Res.53(2), 83-88, 2018

scholarly journals Effect of Spray Dryer Scale Size on the Properties of Dried Beetroot Juice

Molecules ◽  
2021 ◽  
Vol 26 (21) ◽  
pp. 6700
Author(s):  
Jolanta Gawałek
Keyword(s):  
Spray Drying ◽  
Industrial Process ◽  
Laboratory Scale ◽  
Industrial Scale ◽  
Process Conditions ◽  
Spray Dryer ◽  
Beetroot Juice ◽  
Centrifugal Atomization ◽  
Drying Conditions ◽  
Drying Efficiency

Experiments detailing the spray drying of fruit and vegetable juices are necessary at the experimental scale in order to determine the optimum drying conditions and to select the most appropriate carriers and solution formulations for drying on the industrial scale. In this study, the spray-drying process of beetroot juice concentrate on a maltodextrin carrier was analyzed at different dryer scales: mini-laboratory (ML), semi-technical (ST), small industrial (SI), and large industrial (LI). Selected physicochemical properties of the beetroot powders that were obtained (size and microstructure of the powder particles, loose and tapped bulk density, powder flowability, moisture, water activity, violet betalain, and polyphenol content) and their drying efficiencies were determined. Spray drying with the same process parameters but at a larger scale makes it possible to obtain beetroot powders with a larger particle size, better flowability, a color that is more shifted towards red and blue, and a higher retention of violet betalain pigments and polyphenols. As the size of the spray dryer increases, the efficiency of the process expressed in powder yield also increases. To obtain a drying efficiency >90% on an industrial scale, process conditions should be selected to obtain an efficiency of a min. of 50% at the laboratory scale or 80% at the semi-technical scale. Designing the industrial process for spray dryers with a centrifugal atomization system is definitely more effective at the semi-technical scale with the same atomization system than it is at laboratory scale with a two-fluid nozzle.

scholarly journals Conduction-Based Thermally Assisted Micromilling Process for Cutting Difficult-to-Machine Materials

2020 ◽  
Vol 4 (2) ◽  
pp. 34 ◽  
Author(s):  
Timo Platt ◽  
Alexander Meijer ◽  
Dirk Biermann
Keyword(s):  
Tool Wear ◽  
High Speed ◽  
End Milling ◽  
High Speed Steel ◽  
High Strength ◽  
Process Conditions ◽  
Manufacturing Processes ◽  
Central Process ◽  
Workpiece Temperature ◽  
Micro End Milling

The increasing demand for complex and wear-resistant forming tools made of difficult-to-machine materials requires efficient manufacturing processes. In terms of high-strength materials; highly suitable processes such as micromilling are limited in their potential due to the increased tool loads and the resulting tool wear. This promotes hybrid manufacturing processes that offer approaches to increase the performance. In this paper; conduction-based thermally assisted micromilling using a prototype device to homogeneously heat the entire workpiece is investigated. By varying the workpiece temperature by 20 °C < TW < 500 °C; a highly durable high-speed steel (HSS) AISI M3:2 (63 HRC) and a hot-work steel (HWS) AISI H11 (53 HRC) were machined using PVD-TiAlN coated micro-end milling tools (d = 1 mm). The influence of the workpiece temperature on central process conditions; such as tool wear and achievable surface quality; are determined. As expected; the temporary thermal softening of the materials leads to a reduction in the cutting forces and; thus; in the resulting tool wear for specific configurations of the thermal assistance. While only minor effects are detected regarding the surface topography; a significant reduction in the burr height is achieved.

A method for preparing extensible paper on the laboratory scale

2014 ◽  
Vol 29 (2) ◽  
pp. 317-321 ◽  
Author(s):  
Jussi Lahti ◽  
Franz Schmied ◽  
Wolfgang Bauer
Keyword(s):  
Large Deformations ◽  
Industrial Process ◽  
Laboratory Method ◽  
Laboratory Scale ◽  
Stiffness Index ◽  
Machine Direction ◽  
Tensile Index ◽  
End Use ◽  
Solids Content ◽  
Versus Strain

Abstract Extensibility is an important property for papers undergoing large deformations in converting or end use application (e.g. industrial bags). Industrially, high extensibility is created by compacting the moist paper web in machine direction (MD) using an extensible unit such as the Clupak or Expanda methods. In this study, a method was developed to produce extensible paper on the laboratory scale. The Clupak unit was simulated using a purpose-built MD compaction apparatus. A paper sheet is placed between two stretched rubbers which are recoiled under perpendicular pressure to create sufficient friction between paper and rubber. The laboratory method for producing extensible paper sufficiently corresponds to the industrial process, i.e. strain increased while tensile stiffness index and tensile index decreased. Increased solids content during rubber recoiling enhanced the sigmoidal shape of the specific stress versus strain curves whereas tensile index remained unchanged. The reproducibility of the method is at a good level and thus the developed method offers a feasible way to study the production of extensible paper on the laboratory scale.

scholarly journals Parametric Investigation of Effect of Abnormal Process Conditions on Self-Piercing Riveting

2020 ◽  
Vol 10 (7) ◽  
pp. 2520 ◽  
Author(s):  
Taek-Eon Jeong ◽  
Dong-Hyuck Kam ◽  
Cheolhee Kim
Keyword(s):  
Process Parameters ◽  
Dissimilar Materials ◽  
High Strength ◽  
Process Conditions ◽  
Al Alloy ◽  
Main Process ◽  
Cross Sectional ◽  
Practical Applications ◽  
Parametric Investigation ◽  
Offset Distance

Self-piercing riveting (SPR) is one of the mechanical joining processes, and its application to Al/Fe dissimilar materials combination, which is hard to weld, is expanding in the automotive industry. The main process parameters in SPR are types of rivet and die, setting force, and rivet setting speed. Previously, the relationship between the main process parameters and output parameters such as cross-sectional characteristics and joint strength has been studied to optimize the SPR process. In practical applications, there are unexpected and abnormal process conditions such as poor fit-up, angular misalignment, edge offset distance, and inaccurate setting and pre-clamping forces, and their effects on the joining quality have not been discussed. In this study, parametric investigation was performed using an experimental design on SPR joints for 1 mm-thick high strength steel (590 DP) and 2 mm-thick Al alloy (Al5052-H32). The main effect of each level of the abnormal process parameters on the output parameters was statistically investigated, and the analysis of variance was performed for each abnormal process parameter. In the range of abnormal process conditions applied, the set force was the most significant factor affecting the output parameters, and the effect of pre-clamping force on the output parameters was the least significant.

Experimental Research on the Stiffness of Hyperboloid Shallow Shell

2014 ◽  
Vol 940 ◽  
pp. 179-183
Author(s):  
Li Hong Zhao ◽  
Cheng Xi Lei ◽  
Zhong Wen Xing ◽  
Bin Wu
Keyword(s):  
High Strength ◽  
Process Conditions ◽  
Main Process ◽  
Technical Approach ◽  
Shallow Shells ◽  
Process Guidance ◽  
Experiment Method ◽  
Automobile Panel ◽  
Blank Holding Force ◽  
Panel Stiffness

Stiffness is a very important property of automobile panel, especially for high-strength thinning sheet due to personnel security and energy conservation on auto industry. It is difficult to study because of the complexity streamline feature of auto body. An experiment method for determining stiffness was presented. The experiment study models of which based on the hyperboloid shallow shells that could represent automobile panel’s surface features was established. The criterion and research technique of automobile panel stiffness were introduced. The experiment research works of effects of two main process conditions on stiffness which blank holding force (BHF) and boundary condition during the stiffness test were obtained. All conclusions provided a particularly effective process guidance and technical approach in the automobile panel production.

Press-Shaving Characteristics of Ultrahigh-Strength Steel Sheets

2013 ◽  
Vol 554-557 ◽  
pp. 1879-1886 ◽  
Author(s):  
Masao Murakawa ◽  
Kenta Nakamura ◽  
Tomio Shionome ◽  
Fumitoshi Komuro ◽  
Giichirou Muro ◽  
...  
Keyword(s):  
Surface Quality ◽  
New Technologies ◽  
High Strength ◽  
Process Conditions ◽  
Steel Sheets ◽  
Ultrahigh Strength ◽  
Ultrahigh Strength Steel ◽  
Experimental Researches ◽  
Very High

The paper proposes new technologies able to improve the surface quality in the case of press-shaving applied to very high strength materials. Experimental researches were developed and the best combination of process conditions was identified.

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