Impregnation of fibrous fillers with polymeric binders 6. Effect of parameters of ultrasound treatment on strength properties of wound fibrous composites

1990 ◽  
Vol 25 (4) ◽  
pp. 548-555 ◽  
Author(s):  
A. E. Kolosov ◽  
A. A. Karimov ◽  
I. A. Repelis ◽  
V. G. Khozin ◽  
V. V. Klyavlin
Keyword(s):  
Strength Properties ◽  
Ultrasound Treatment ◽  
Fibrous Composites ◽  
Polymeric Binders ◽  
Fibrous Fillers

Investigation of the Influence of Linear Dimensions and Concentration of Carbon and Glass Fibers on the Properties of Polyetherimide

2019 ◽  
Vol 816 ◽  
pp. 48-54
Author(s):  
Azamat L. Slonov ◽  
Ismel V. Musov ◽  
Azamat Zhansitov ◽  
D.M. Khakulova ◽  
Elena V. Rzhevskaya ◽  
...  
Keyword(s):  
Heat Resistance ◽  
Glass Fibers ◽  
Melt Flow Index ◽  
Strength Properties ◽  
Flow Index ◽  
Melt Flow ◽  
Linear Dimensions ◽  
Slight Advantage ◽  
Fibrous Fillers

The effect of glass (GF) and carbon (CF) fibers of various linear sizes (0.2 and 3 mm) and concentrations on the properties of polyetherimide (PEI) has been studied. It is shown that the introduction of fibrous fillers leads to a decrease in the melt flow index, and to a greater extent in the case of fibers with a length of 3 mm. Also, it was found that both GF and CF lead to a decrease in toughness and an increase in the elastic-strength properties with a slight advantage of composites containing fibers of a length of 3 mm. In this case, GF composites have significantly higher properties. The study of heat resistance shows a slight decrease for composites with CF and the absence of influence of the filler for composites with HC, regardless of the size of the fibers.

scholarly journals Experience nature as a basis for building strong composite structures

Vestnik MGSU ◽  
2021 ◽  
pp. 1191-1216
Author(s):  
Alexander N. Polilov ◽  
Nikolay A. Tatus’
Keyword(s):  
Composite Structures ◽  
Open Space ◽  
Fiber Composite ◽  
Crack Arrest ◽  
Strength Properties ◽  
Fibrous Composites ◽  
Reinforcement Structure ◽  
Correct Determination ◽  
Design Calculations ◽  
Effective Use

Introduction. The article is devoted an analytical overview of the methods of applying the Nature solutions for designing structures made of plastics reinforced with fibers, in particular, using rational curved fiber trajectories. The first section provides an overview of different structural models and some approaches to the micromechanics of composites. Materials and methods. Sections 2-7 discuss: analysis of rational elastic-strength properties of wood and composites for crack arrest by weak interface; methods for constructing curved paths of fibers of “flowing holes”; analyzes the applied and promising technologies for manufacturing attachment points, in which holes are formed using curvilinear fiber paths; “nature-inspired” principles of optimal design of pipe composite structures similar in structure to ladder of bamboo stalk; examples of the effective use of fibrous composites in elastic elements such as leaf springs; developing additive technologies for 3D printing of fiber composite parts with fiber laying along calculated trajectories. Results. Each section of the article presents conclusions related to the peculiarities of composites structures calculation and design: calculations show that in order to increase the crack resistance of fibrous composites, it is necessary to significantly increase the shear characteristics of the binder and strive for rational properties created by Nature in wood; as a result of the calculation, it turns out that the maximum stress per fiber at the optimal reinforcement structure becomes about 3–4 times less than with a uniform rectilinear laying; rational reinforcement leads to a significant reduction in local stresses per fiber, elimination of splits and damages of fibers and an increase in the carrying capacity of the assembly; it has been shown that the bamboo rings are arranged to prevent the barrel from splitting from bending compressive stresses and tangential stresses when the barrel is twisted by wind load; analyzed the relationship of equal-strength profiling with Leonardo’s rule for tree crown branching. The works on creation of bio-similar shape and structure of curvilinear reinforcement of specimens for correct determination of unidirectional composites strength at tension along fibres were discussed; analyzed the role of composite technologies in modern mechanical engineering, in particular, in the creation of composite structures in open space. Conclusions. The article is devoted to the analysis of the tasks of fibrous composites macromechanics, therefore, in the opinion of the authors, the three most promising and related areas in macromechanics of composites that require further research are biomechanics of strength, computer modeling of optimal structures and technological mechanics of composites.

SEM Study of Tension Wood Fiber Morphology and its Effect on Paper Properties

1977 ◽  
Vol 35 ◽  
pp. 308-309
Author(s):  
K. W. Robinson
Keyword(s):  
Tension Wood ◽  
Wood Fiber ◽  
Strength Properties ◽  
Fiber Morphology ◽  
Paper Properties ◽  
Pure Cellulose ◽  
Short Rotation ◽  
Hardwood Trees ◽  
Sem Study

Tension wood (TW) is an abnormal tissue of hardwood trees; although it has been isolated from most parts of the tree, it is frequently found on the upper side of branches and leaning stems. TW has been classically associated with geotropic alignment, but more recently it has been associated with fast growth. Paper made from TW is generally lower in strength properties. Consequently, the paper industries' growing dependence on fast growing, short- rotation trees will result in higher amounts of TW in the final product and a corresponding reduction in strength.Relatively few studies have dealt with the role of TW in the structure of paper. It was suggested that the lower strength properties of TW were due to a combination of factors, namely, its unique morphology, compression failures in the cell wall, and lower hemicellulose content. Central to the unique morphology of the TW fiber is the thick gelatinous layer (G-layer) composed almost entirely of pure cellulose.

Co-cooking nonwoods with hardwoods

TAPPI Journal ◽  
2014 ◽  
Vol 13 (6) ◽  
pp. 19-24
Author(s):  
TROY RUNGE ◽  
CHUNHUI ZHANG
Keyword(s):  
High Performance Liquid Chromatography ◽  
High Performance ◽  
Paper Industry ◽  
Pulp And Paper Industry ◽  
Strength Properties ◽  
Agricultural Residues ◽  
Kraft Pulping ◽  
Pulp And Paper ◽  
Strength Increase ◽  
Xylan Content

Agricultural residues and energy crops are promising resources that can be utilized in the pulp and paper industry. This study examines the potential of co-cooking nonwood materials with hardwoods as means to incorporate nonwood material into a paper furnish. Specifically, miscanthus, switchgrass, and corn stover were substituted for poplar hardwood chips in the amounts of 10 wt %, 20 wt %, and 30 wt %, and the blends were subjected to kraft pulping experiments. The pulps were then bleached with an OD(EP)D sequence and then refined and formed into handsheets to characterize their physical properties. Surprisingly, all three co-cooked pulps showed improved strength properties (up to 35%). Sugar measurement of the pulps by high-performance liquid chromatography suggested that the strength increase correlated with enriched xylan content.

Chemical, anatomical, and technology aspects of Eucalyptus benthamii and Eucalyptus dunii for use in an integrated pulp and paper mill

TAPPI Journal ◽  
2015 ◽  
Vol 14 (2) ◽  
pp. 73-81 ◽  
Author(s):  
GISELY SAMISTRARO ◽  
PETER W. HART ◽  
JORGE LUIZ COLODETTE ◽  
RICARDO PAIM
Keyword(s):  
Energy Levels ◽  
Black Liquor ◽  
Basic Density ◽  
Paper Mill ◽  
Frost Tolerance ◽  
Strength Properties ◽  
Kappa Number ◽  
Pulp Yield ◽  
Chemical Compositions ◽  
Physical Strength

Eucalyptus dunii has been commercially used in southern Brazil because of its relatively good frost tolerance and adequate productivity in the winter months. More recently, interest has grown in cultivating Eucalyptus benthamii Maiden & Cambage, which presents even superior frost tolerance compared to E. dunii and is highly productive as well. The quality of E. benthamii for pulp production is not yet proven. Thus, the chemical, anatomical, and technological aspects of pulp made from E. benthamii were compared with those of E. dunii for unbleached paper production. Samples of E. benthamii chips were obtained and analyzed for their basic density, chemical composition, higher heating value, trace elemental analysis, and chip size distribution. The chips were kraft cooked using conditions that produced a 74 ± 6 kappa number. The pulps were characterized for kappa number, yield, viscosity, and morphologic characteristics (e.g., length, wall thickness, and coarseness). Black liquor was analyzed for total solids, organics, inorganics, sodium sulfide, sodium hydroxide, and sodium carbonate. Brownstocks were beaten at five different energy levels in a Valley beater, and the physical strength properties of 120 g/m² handsheets were measured to develop a beater curve. The results of this study showed differences in delignification between the two woods and lower pulp yield for E. benthamii , which are related to their chemical compositions and basic densities. The E. benthamii studied in this work exhibited higher amounts of lignin and extractives, lower carbohydrate content, and lower basic density. However, cooking a blend of the two woods afforded good results in pulping and in physical pulp properties.

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