Polypropylene sisal

Fiber Cores. For all wire ropes, all fiber cores shall be hard-twisted, best-quality, manila, sisal, polypropylene, or equivalent. For wire ropes of uniform diameter, tbe cores shall be of uniform diameter and hardness, effectively supporting the strands. Manila and sisal cores shall be thoroughly impregnated with a suitable lubricating compound free from acid. Jute cores shall not be used. 

Improvements in melt spinning techniques and film filament processes have made polypropylene accessible for fiber production. Low-cost fibers made from polypropylene are replacing those made from sisal and jute. 

U.S. Pat. No. 6,983,571 [73] discloses a composite roofing panel comprising polyethylene, polypropylene, or a combination thereof in an amount of 20-40% by weight, and natural plant fiber in an amount of 40-75%, selected from the group consisting of wood flour, sugarcane bagasse, hemp, coconut coir, jute, kenaf, sisal, flax, coir pith, rice hulls, and cotton. 

U.S. Pat. No. 6,255,368 [114] describes plastic cellulosic composite pellets comprising 20-60% by weight of polyethylene, polypropylene or polystyrene, 40-80% of cellulosic fiber (jute, kenaf, sisal, bamboo, rice hulls, corn husks, wood fiber, and wood flour) with an aspect ratio of between 2 and 20 and a trace of mineral coating (talc) dispersed on the surface of the pellet. 

Biobased Composites of Sisal Fiber Reinforced Polypropylene... 

Natural fibers can be classified as seed fibers (such as cotton), bast fibers (like flax, hemp, jute, kenaf, ramie), hard fibers (like sisal), fi-uit fibers (like coir), and wood fibers. The chemical composition and dimensions of some common agro-fibers are presented in Table 5.21. The origin of wood fibers can be sawmill chips, sawdust, wood flour or powder, cutter shavings, pulp or wood residues. As binders for these fibers, both thermosetting (like phenolic, epoxy, polyester) resins and thermosetting matrices [such as polyethylene (LDPE, HDPE), polypropylene (PP), poly(vinyl chloride) (PVC), polystyrene (PS)j can be used. Thermoplastic composites are, however, less expensive to process than thermosetting composites, in addition to their ability to be manufactured into complex shapes. 

Types of reinforcements include fibers of glass, carbon, graphite, boron, nylon, polyethylene, polypropylene, cotton, sisal, asbestos, metals, whiskers, etc. Other types and forms of reinforcements include whiskers, bamboo fibers, burlap fibers, carbon blacks, platelet forms (includes mica, glass, and aluminum), and hemp fibers (Chapter 2). 

Plastic lumber is recycled plastics processed such as commingled plastic, polyethylene plastic, and polypropylene plastic. To improve their performances different developments have been used such as specialty additives (lubricants, deoxidizers, etc.). An example is by adding as low as 10 wt% of short glass fiber to these recycled plastics can double their strength. Other fibers used include hemp, flax, and sisal. They are principally extruded other processes are used such as injection and compression molding, to produce products competitive to wood lumber on land and in the water. Compression molding allows for a deep-molded grain and a much more dense board. The density also helps the product resist moisture absorption and improves weatherability. 

Arzondo, L.M. Vazquez, A. Carella, J.M. Pastor, J.M. A low-cost, low- fiber -breakage, injection molding process for long sisal fiber-reinforced polypropylene. Polymer Engineering and Science 44 (9) 1766-1772 (Sep 2004). 

K. Jayaraman, Manufacturing sisal-polypropylene composites with minimum fibre degradation. Compos. Sci. Technol. 63, 367-374 (2003)... 

A.K. Gupta, M. Biswal, S. Mohanty, S.K. Nayak, Mecharncal, thtamal degradation, and flammability studies on surface modified sisal fiber reinfOTced recycled polypropylene composites. Adv. Mech. Eng. 2012, 13 (2012)... 

P.V. Joseph, G. Mathew, K. Joseph, G. Groeninckx, S. Thomas, Dynamic mechanical pioptaties of shmt sisal fibre reinforced polypropylene composites. Compos. A Appl. Sci. Manuf. 34(3), 275-290 (2003)... 

Coarse products suitable for the manufacture of baler twines, ropes and hawsers are made by flat film extrusion, water-bath quenching, air-oven stretching and optionally annealing thick film strips. The oriented strips are twisted and coarse fibrillation then occurs spontaneously. These polypropylene twines and ropes are stronger than ropes of sisal or manilla... 

Albano C. Reyes J. Ichazo M. Gonzalez J. Brito M. Moronta D. Analysis of the mechanical, thermal and morphological behavior of polypropylene compounds with sisal fibre and wood flour, irradiated with gamma rays. Polymer Degradation and Stability, vol.76, (2002), pp. 191-203. 

Yuan XW, Jayaraman K, Bhattacharyya D (2004) Mechanical properties of plasma-treated sisal fibre-reinforced polypropylene composites. J Adhes Sci Technol 18(9) 1027-1045... 

Couto E et al (2002) Oxygen plasma treatment of sisal fibers and polypropylene effects on mechanical properties of composites. Polym Eng Sci 42(4) 790-797... 

Fukuzumi H, Saito T, Iwata T et al (2008) Transparent and high gas barrier films of cellulose nanofibers prepared by TEMPO-mediated oxidation. Biomacromolecules 10 162-165 Garcia de Rodriguez NL, Thielemans W, Dulfesne A (2006) Sisal cellulose whiskers reinforced polyvinyl acetate nanocomposites. Cellulose 13 261-270 Gousse C, Chanzy H, Excoffier G et al (2002) Stable suspensions of partially silylated cellulose whiskers dispersed in organic solvents. Polymer 43 2645-2651 Gray DG (2008) Transcrystallization of polypropylene at cellulose nanocrystal surfaces. Cellulose 15 297-301... 

Joseph et al. [34] thermally analyzed the polypropylene composites reinforced with sisal fibers. He applied the following modifications 10% NaOH, polypropylene glycol urethane derivative (PPG/TDI), and potassium permanganate (KMn04). He additionally investigated composites in which polymeric matrices were MAPP-grafted polypropylene. 

Studies on a similar group of materials - polymeric composites reinforced with sisal fibers - were conducted by Manchado et al. [35]. They analyzed the presence of different fibers, such as sisal, on crystallization of polypropylene. The composites were prepared in special chamber for mixing where the matrix was plastified at 190°C. Obtained materials were subjected to thermal analysis by DSC. The analysis of thermograms allowed for a similar finding like in Joseph s studies [34], The presence of sisal fibers, as well as other fibers used in the study, accelerated crystallization of polypropylene. This was explained by the nucleating effect of sisal filler. Also, the half-time crystallization (ti/2) decrease was observed for polypropylene with the addition of sisal fibers in comparison with unfilled polypropylene. The analysis of nonisothermal crystallization showed that the degree of polypropylene crystallinity is higher for the composites filled with sisal fibers than for unfilled polymer. 

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