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Properties of Bio-Composites Made with Thermally Bonded Roving Towpregs
Published in R. Alagirusamy, Flexible Towpregs and Their Thermoplastic Composites, 2022
Mahadev Bar, R. Alagirusamy, Apurba Das
Like tensile properties, the flexural strength and modulus of the Glass-PW composites are higher than those of TBR-based woven fabric composites. It is mainly attributed to the high modulus and the brittle nature of glass fibre. Interestingly, the roving-UD composite reaches to approximately 90% flexural strength and 45% flexural modulus of glass-PW composites, whereas the roving-PW composite reaches approximately 80% flexural strength and 60% flexural modulus of glass-PW composites. Although the roving-UD composite has higher bending stress, it fails catastrophically once it reaches the pick load. On the other hand, the roving-PW composite can sustain a high degree of deformation at pick load level, which is an added advantage for load bearing applications. In the case of roving-PW composites, withstanding deformation at pick loading could be attributed to its interlaced woven fabric structure.
Reinforced composite materials
Published in Andrew Livesey, Motorcycle Engineering, 2021
These are formed by grouping untwisted strands together and winding them on a “cheese.” They are used for chopping applications to replace mats either in contact molding (spray-up) or translucent sheet manufacture of press molding (preform). Special grades of roving are available for each of these different chopping applications. Rovings are also used for weaving, for filament winding, and for pultrusion processes. Special forms are available to suit these processes.
Fabrication Processes
Published in Manas Chanda, Plastics Technology Handbook, 2017
Rovings are rope-like bundles of continuous untwisted strands for use in such processes as perform press molding, filament winding, spray-up, pultrusion, and centrifugal casting. They can also be converted into chopped strand mats or cut into short fibers for molding compounds.
Flexural behavior of high-performance and non-high-performance textile reinforced concrete composites
Published in European Journal of Environmental and Civil Engineering, 2023
Mojdeh Zargaran, Nader K. A. Attari, Saeid Alizadeh
High-performance roving usually has high modulus and significant tensile strength. But, these materials have high costs and this item could limit their popularity. Non-high-performance roving has low modulus and low tensile strength, but they are cheaper and easily available. Since non-high-performance roving has low modulus and lower tensile strength compared to high-performance roving, more fabric layers are required to gain a similar bending capacity as samples with high-performance roving. Increasing the fabric layers is not a practical solution because the bond between fabric and concrete may be reduced by increasing the number of transverse reinforcements and penetration of concrete between layers of fabrics may be impossible. For solving this problem, in this part of the research transverse reinforcements are omitted and only longitudinal PP roving is used for increasing the flexural capacity and achieving the strain hardening behaviour.
Effects of graft modification on apparent viscosity, adhesion, and film properties of sesbania gum for warp sizing
Published in The Journal of The Textile Institute, 2020
Manli Li, Enqi Jin, Shiyao Chen
A sized roving method was used to measure adhesion of the SG to polyester fibers. This method was initially developed by Faasen and Van Harten (1966) to evaluate the adhesion of sizes to cotton fibers. About 30 years later, Behera and Pakhira (1998) denoted that the adhesion of sizes to synthetic fibers (i.e. polyester fiber) could be also determined by measuring the tensile strength and elongation of sized rovings. Compared with warp yarn in weaving, roving has two features, i.e. low twist and low strength, which provide a base to evaluate the adhesion of a sizing agent to fibers exactly since tensile strength of unsized roving is so low that it exerts little influence on the evaluation result. Therefore, slight sizing of rovings gradually becomes a relatively accurate and simple way to evaluate the adhesion. After more than 40 years of practice, the roving method is adopted as an industry standard to estimate the adhesion of sizes to fibers in China (FZ/T 15001–2008, a criterion regulated by Textile Association of China). In the measurement, a slightly sized roving is drawn to tensile failure. It is the failure loads that were adopted to exhibit the adhesion.
Comparison of composite yarns fabricated with ring spinning technologies for extreme environment
Published in The Journal of The Textile Institute, 2023
Zhiyi Jin, Pei Peng, Shunzheng Zhang, Chaoyue Zeng, Xuanyuan Hu, Jie Li, Shuhan Yang, Genyang Cao, Shan Jiang
While In 2011, a novel spinning method named ELS was introduced by Xu et al. (2010) which can be interpreted as the combination of two sirofil spinning devices, as shown in Figure 1c. Two rovings are fed in parallel with certain distance, and the other two filaments are fed outside each roving through the front roller. The rovings are firstly pre-twisted with the filaments respectively, and then these two preformed-yarns further twist to forming the final yarn (Wang et al., 2012).