Mechanisms of fracture and prediction of the strength of unidirectional carbon-fibre-reinforced plastics

The principal difference in the mechanisms of fracture of unbound carbon fibres and reinforcing filler in unidirectional carbon-fibre-reinforced plastics does not allow predicting the strength of composites using Weibull distribution parameters and the average strength of the fibres on a standard testing base. An alternative approach that allows estimating the limiting strength of carbon fibres and the degree of its realization in a composite was repeatedly tested. The dependence of the strength realization coefficient of a reinforcing fibre on its volume content, the scaling effect of the strength, and the modulus of elasticity is given. The information required for predicting the strength of composites could be obtained from testing composites with a single fibre (SFC tests). __________ Translated from Khimicheskie Volokna, No. 1, pp. 51–57, January–February, 2006.     

Polymer composite materials with fibrous and disperse basalt fillers

The advantage of basalt fibres in comparison to glass fibres was demonstrated. The process parameters for production of basalt fibre are reported. The manufacturing processes in processing polypropylene composites with low combustibility and poly(ethylene terephthalate) composites filled with basalt fibres in lines based on a cascade screw-disk extruder are examined. Technology for obtaining polymer coatings using composites with basalt flakes and their properties are described. Translated from Khimicheskie Volokna, No. 3, pp. 59–63, May–June, 2008.     

Effect of UHF modification on the properties of fibre fillers and cation-exchange fibre materials

The expediency of modifying polypropylene and basalt fibres to increase the SEC of cation-exchange fibre materials (CEFM) made from them due to increasing the activity of the UHF-treated fibres was demonstrated. __________ Translated from Khimicheskie Volokna, No. 1, pp. 54–56, January–February, 2008.     

Basalt plastics — new materials for road construction

The effectiveness of using basalt fibres and substandard basalt wool — large-tonnage waste from chemical plants and nuclear generating stations — as a reinforcing component in road construction was demonstrated. Incorporation of basalt fibre or wool in asphalt concrete in an amount of up to 0.4 wt. % increased the strength characteristics of the asphalt concrete by 10–30%. The presence of a physicochemical reaction in the basalt fibre—polymer-asphalt binder system, which increased the strength characteristics, heat resistance, and lifetime of the polymer—asphalt—concrete, was demonstrated. IR spectroscopy showed ordering of the structure of the PAB due to formation of organosilicate compounds that strengthened the structure of the polymer asphalt concrete. Translated from Khimicheskie Volokna, No. 6, pp. 11–14, November–December, 2009.     

Polymer fibre composites, basic types, principles of fabrication, and properties. Part 3. Basic types of polymer fibre composites, properties, and use

The basic types of polymer composite materials (PCMM) made from different kinds of reinforcing fibre fillers: short-cut fibres, paper, yarns, tow, sliver, fabrics, and nonwovens, and their properties and use are examined. Information on the fabrication and properties of the different kinds of composites are reported: extruded fibre plastics, getinaxes, textolites, unidirectional composites, honeycomb plastics, and others. New kinds of composites with ultrahigh mechanical and thermal characteristics are also examined. Some of the reported information was previously covered very sparely in the literature. Based on the examination, the features of polymer fibre composites are summarized in comparison to other materials, and they can be summarized as the following basic points: 1) combining different kinds of fibre fillers and matrices (binders) allows fabricating PCM with a wide range of properties by selecting the optimum indexes for articles with a broad spectrum of applications; 2) articles made of fibre PCM are not very materials-intensive and are technologically effective for processing in comparison to many traditional materials, metals and ceramics in particular; 3) with respect to the specific mass characteristics, fibre PCM can be many times superior to articles made of traditional materials—metals, etc., so that the mass (weight) characteristics of articles made of fibre composites can be significantly reduced, which is especially important for using them in vehicles, aircraft, rescue equipment, and sporting goods; 4) articles made of composites have high performance reliability, are almost immune to corrosion, and do not require special protection or periodic painting of the surface. Due to the features of the properties and use, fibre PCM have a great future in the most varied areas of application. See No. 4, 7–12 (2005) for Part 1; No. 5, 54–69 for Part 2. __________ Translated from Khimicheskie Volokna, No. 1, pp. 41–50, January–February, 2006.     

Polypropylene fibres and yarns in the current state of development

Polypropylene (PP) production capacities in 2010 will exceed 60 million tons and by 2020, 90 million tons at an average annual growth rate of 8% in 2005–2010 and 4% in 2010–2020. Consumption of PP in 2010 will be 53 million tons, more than half of which will be in Asia, where 2/3 of production capacities are concentrated. World production of PP textile materials is slightly over 7 million tons, which is approximately 10% of natural and chemical fibres. Film fibres, staple fibre, carpet twist, and different kinds of nonwovens are the basic consumers of PP in the textile sector. In Russia, manufacture of PP for fibre applications is 7%, versus 11–12% in world practice. In 2007, production of PP fibres and yarns reached 24,300 tons (8.7% higher than the preceding year), and 56.4% was for manufacture of film fibres, 20.7% was for staple fibre, and 12.5% was for spunbond. Moscow Office of Coltech, Canada. Translated from Khimicheskie Volokna, No. 5, pp. 3–8, September—October, 2008.     

World production and consumption of carbon fibres

The total world production volume of carbon fibres (CF) is 70–80,000 tons/year. In the last two to three years, there has been a trend toward significant growth in their production and use. Polyacrylonitrile fibre is the basic type of raw material for production of CF. New areas of application of CF have appeared. The quality level attained for carbon fibres is examined on the example of several leading manufacturers.     

Effect of textile auxiliary substances on the processability of Fenilon fibre

Treatment of a fibre with textile auxiliary substances (ATS) affects its basic technological properties and consequently its processability into quality articles. The optimum preparations for processing of Fenilon fibre were determined: AF-12K+OP-10 (4∶1), Butafos K+Phthalanol 10M (1∶1) and Butafos K+OP-4 (1∶2). Successful processing is not only a function of the type of preparation used, but also of uniform application and the concentration on the fibre. The data from laboratory studies are confirmed by the results of processing in industrial conditions. The proposed method of narrowing the region of the search for and selection of optimum finishing preparations for processing fibres by modeling the processing process in a fibre can be considered acceptable. Translated from Khimicheskie Volokna, No. 1, pp. 40–44, January–February, 1997.     

Rusar para-aramid fibres for composite materials for construction applications

The basic properties of fibres manufactured by the company (SVM, Armos, and Rusar), and the areas of their application are reported. The features of production of Rusar fibre used for manufacturing construction materials are presented. __________ Translated from Khimicheskie Volokna, No. 1, pp. 19–21, January–February, 2006.     

Features of formation of cylindrical packs of mineral fibres

The danger of the appearance of fibre segments of increased linear density over the ends of cylindrical packs in winding of mineral fibres was substantiated. Dependences were obtained that allow determining the helix angle of the loops at which the linear density of the fibre will not exceed the acceptable values when the direction of movement changes. __________ Translated from Khimicheskie Volokna, No. 6, pp. 44–45, November–December, 2007.     

Fabrication of carbon fibres from wet-spun commercial polyacrylonitrile fibres

The possibility of fabricating carbon fibre from commercial PAN fibres for textile applications was demonstrated. It is necessary to make some changes in the temperature—time conditions for total completion of the thermal stabilization process. Better strength of the carbon fibres, equal to 1401 MPa, was attained in conducting thermal stabilization cycle B. __________ Translated from Khimicheskie Volokna, No. 5, pp. 31–33, September–October, 2006.     

High-strength synthetic fibres for reinforcement of thermoplastic organoplastics for construction. A review

An analysis of the published data shows that the expansion of the areas of application of high-strength synthetic fibres for creating promising thermoplastic organoplastics is due to the use of both new technologies (fibre, maximum reinforcement) and new materials (LC polyesters and fibres based on them, blended fibres of the molecular composite type or composite fibres with a predominant content of a rigid-chain polymer). Almost all of these directions are probably promising for further development and use in production of CM. The maximum tensile strength of organoplastics fabricated by the described methods is approximately the same: 1.1–1.8 GPa, that is, it is close to the indexes for traditional CM, and the advantages are obvious: simplicity of manufacturing technology, high fatigue characteristics, etc. Limiting reinforcement using high-strength thermoplastic synthetic fibres containing flexible-chain thermoplastics produced on the industrial scale to make them inexpensive and give them thermoplasticity without decreasing the strength properties is probably the most attractive. This is a mechanism of creating a fibre having the properties of CM on the molecular level. Translated from Khimicheskie Volokna, No. 3, pp. 44–53, May–June, 1997.     

Metal-containing chemical fibres and their use in biotechnology

The possibility of using metal-containing fibres, including carbon fibres, as sorbents of proteins, viruses, and bacterial cells was demonstrated. It was found that silver-containing fibres can be effective adsorbents — carriers of Gluconobacter oxydans — a destroyer of thiodiglycol. Silver-containing fibres of different types exhibit bactericidal activity with respect to different bacterial cells; this activity is a function of the number and shape of the silver particles attached to the fibre. __________ Translated from Khimicheskie Volokna, No. 2, pp. 44–50, March–April, 2007.     

Principles and basic trends in the use of carbon fibre adsorbents

The fundamental trends in development of activated carbons are formulated: selection of carbon raw materials, methods of activation and regulating the pore structure, and a study of the properties and areas of application. The basic properties of carbon fibre adsorbents (CFA) that determine the expediency and areas of their application are reported. The trends and areas of application of CFA are determined. Translated from Khimicheskie Volokna, No. 3, pp. 86–88, May–June, 2008.     

World development of chemical fibres in 1996

The Near and Far East (except for Japan) will be the primary promising markets for chemical fibres to the end of the 1990s. In particular, Taiwan is now in second place in the world (after the US) in production of chemical fibres. The fibre production capacities of China, the Republic of Korea, and recently India are continuously expanding. In China, according to plan specifications, the capacities of the chemical fibre industry will significantly increase from 3.5 million tons in 1995 to 4.5 million tons in 2000, while production will increase from 2.9 to 4.0 million tons, respectively. It is believed that this will allow increasing the degree of supplying the textile industry with domestically produced chemical fibres to 85–90% by 2000. The total production volume of chemical fibres in “third world≓ countries is now almost four times higher than the production volume for all of Western Europe. The structural changes in the world chemical fibre industry can thus hardly be considered complete; global, radical changes in the market for these fibres are most probably coming, and Russia will carefully monitor them, exhibiting patience and interest in the development of her own potential. Translated from Khimicheskie Volokna, No. 3, pp. 3–7, May–June, 1998.     

Structure of composite materials based on aluminum and coreless silicon carbide fibres

The kinetics of the reaction on the matrix—fibre interface in composite materials based on aluminum and silicon carbide fibres was investigated at temperatures of 700, 800, and 900°C. It was found that the fibres treated at high temperature have important stability in aluminum melt due to the reduced concentration of free carbon in them and the formation of a barrier layer of β-SiC on the surface of the fibres. However, because of their poor mechanical properties, it is not expedient to use them for reinforcement of aluminum. The fibres treated at low temperature are totally suitable for strengthening aluminum but require the minimum contact time with the melt or protective coatings. Moscow State Institute of Steel and Alloys (Engineering University); All-Russian Scientific-Research Institute of Polymer Fibres, Mytishchi. Translated fromKhimicheskie Volokna, No. 6, pp. 42–46, November–December, 1999.     

Basic scientific and practical results and prospects for development of collagen-based biomaterials

The methods of separating soluble collagen from collagen-containing sources and using it to manufacture different materials: fibres, films, fibre sheet materials, medical gels, etc., are examined. The features of manufacture of the materials and their basic properties are described. The areas of medical application of collagen materials and the prospects for expanding them are briefly characterized. __________ Translated from Khimicheskie Volokna, No. 2, pp. 20–26, March–April, 2007.     

Effect of the drafting force on the strength of the bottom of the spinneret

In spinning basalt fibres, the drafting force is in the same range as in spinning of glass fibres. The effect of the drafting force can not be considered in the calculation for the strength and rigidity of the bottom of the spinneret. __________ Translated from Khimicheskie Volokna, No. 5, pp. 47–50, September–October, 2007.     

Development of technology for high-strength nonwoven materials

It was found that chemical fibres modified with organosilicon compounds have better physicomechanical properties than the initial fibres. The effect of the chemical structure and properties of the organosilicon compounds on the modification process and physicomechanical properties of the modified fibres was investigated. The optimum process parameters for manufacture of thermobonded nonwovens with elevated physicomechanical properties were determined. It was shown that treatment of the fibre web with a catalyst — hydrogen peroxide — allows eliminating the stage of heat treatment of the webs after application of the modifier which reduces the power consumed for production of nonwovens. __________ Translated from Khimicheskie Volokna, No. 2, pp. 21–23, March–April, 2006.     

Effect of heat-treated basalt fibre on the structure of chemisorption composite material made from it

Preliminary heat treatment of basalt fibre used for synthesis of phenol-formaldehyde cation-exchange fibre material increases the activity of the reinforcing system. Better chemisorption properties of cationexchange fibre material (CEFM) made from this fibre are the consequence of heat treatment. Translated from Khimicheskie Volokna, No. 6, pp. 9–11, November–December, 2009.