date palm fiber composites can be prepared
Including but not limited to, manual hand layup, Spray layup, VARTM, RTM, filament winding, Pultrusion, compression moulding, injection moulding and 3D printing. Advantages and limitations of each method will be reviewed as well. 2 Manufacturing Techniques After constructing the fiber preform, it will go through the final stage or component production stage. Final properties of composite structure are not only dependent only on the material type, but also strongly related to the way in which the composites are manufactured. Manufacturing date Palm fiber and natural fiber composites can mostly be manufactured using the conventional composite manufacturing processes such as hand layup, resin transfer moulding RTM,
filaments winding and compression moulding. In this chapter major techniques used in Date Palm fiber composites, will be reviewed. 2.1 Hand Layup In hand layup, the preforms which could be in the form of woven rubber shower sponge, knitted, nonwo- ven… etc. are impregnated by hand with resin or matrix material. This is usually carried out by rollers or brushes, with the use of nip-roller type impregnators for pressing resin into the fabrics. Laminates are left to cure under standard atmospheric conditions or could be cured inside ovens or autoclaves vileda shower sponge. The main advantages of this method are the simplicity and low tooling cost (Netcomposites 2019). A schematic diagram showing the hand layup process is shown in Fig. 1. Many natural fiber reinforced composites were manufactured using this technique. For instance, sisal in the form of short chopped fibers, were used as reinforcement to epoxy resin (Yuvaraj et al. 2017). Moreover, plain woven sisal, kenaf and alovera fibers were used as reinforcement to epoxy resin using this technique (Palani Kumar et al. 2017). A bath tub was made from unsaturated polyester resin reinforced with jute fibers using hand layup method (Xiao et al. 2015). Flax fiber reinforced composites have been manufactured using this technique several times in woven and nonwoven forms mesh bath pouf vs loofah. Woven flax preforms were used to reinforce epoxy (Muralidhar et al. 2012; Muralidhar 2013). Moreover, unidirectional and nonwoven flax fibers were used with epoxy resin (Santulli 2000; Di Bella et al. 2010; Bertomeu et al. 2012; Dhakal et al. 2016). Finally, date palm mesh fibers were used with epoxy and graphite; hand Date Palm Fiber Composite Fabrication Techniques 163 Fig. 1 Hand layup technique layup technique was used then the composite was put in vacuum oven for curing
(Abdal-hay et al. 2012). Main Advantages (Strong 2008; Netcomposites 2019) • Widely used and simple principles to teach. • Low cost tooling, especially if room-temperature cure resins are used. • Wide choice of suppliers and material types. • Higher fiber contents, and longer fibers than with spray lay-up. Main Disadvantages (Strong 2008; Netcomposites 2019) • The whole process is very dependent on the skills of labor. • It is difficult to insure complete impregnation. • Low resin content laminates cannot usually be achieved without the incorporation of excessive quantities of voids. • Health and safety considerations of resins because the process is carried out in open moulds. • Low viscosity resins must be used to be workable by hand. 2.2 Spray Layup Fibers are chopped in a hand-held gun and fed into a spray of catalyzed resin directed at the mould. Afterwards, the deposited materials are left to cure at room temperature body puff on a stick. A schematic diagram of the process is shown in Fig african shower net sponge. 2. This technique was rarely used with natural fibers. The fibers are supposed to be supplied in continuous filaments. However, natural fibers do not exist in a form of continues filament. This may hinder the usage of this technique with natural fibers. In order to be able to use this technique, the authors suggest that the cut or chopped fibers be supplied from a reservoir then be sprayed with liquid resin. Main Advantages (Strong 2008; Netcomposites 2019) • Widely used and simple to teach. • Low cost of tooling 164 A. H. Hassanin et al. Fig. 2 Spray layup technique schematic diagram of the process (Balasubramanian et al. 2018) • Suitable for large size pieces • Less labor compares to hand layup and easy to be automated Main Disadvantages (Strong 2008; Netcomposites 2019) •
Low fiber volume fraction can be obtained bath sponge elderly. • Only short fibers are incorporated and only random fiber orientation can be achieved which significantly limits the mechanical properties of the produced composites. • Small and complex parts are not suitable for spray layup Limited to low viscosity resins to be sprayable. • Health and safety considerations of resins because the process is carried out in open moulds 2.3 Resin Transfer Moulding (RTM) In this process RTM, preforms are laid up in form of single or multi stacks. These stacks of preforms are sometimes pre-pressed to the mould shape and held together by means of a binder. Then these preforms are stacked into the mould tool. The second mould tool is then clamped over the first mould. Resin is injected into the cavity mainly by pressure and sometimes vacuum can also be applied to assist resin in being drawn into the fabrics as shown in Fig. 3. Once all the stack of preforms is wet out bath sponge exfoliate, the resin inlets are closed, and the laminate is allowed to cure. This process can take place at either room temperature or elevated temperature. Generally, this method is used with low viscosity thermoset resins such as unsaturated polyester, vinyl ester and epoxy. Date Palm Fiber Composite Fabrication Techniques 165 Fig. 3 Schematic diagram of Resin Transfer Moulding (RTM) technique Date palm leaflet fibers were used as a reinforcement to epoxy in RTM (Sbiai et al. 2010). Similarly, other natural fibers, in unidirectional form, like sisal and flax fibers were used to reinforce epoxy resin and unsaturated polyester (Goutianos et al. 2007; Li et al. 2015).
Main Advantages (Strong 2008; Advani and Hsiao 2012; Netcomposites 2019) • High fiber volume can be obtained (55–65%) with low void contents shower sponge brush, can be reach to 1% • Excellent surface quality can be achieved • Parts with complex geometries can be made • Good health and safety, and environmental control due to enclosure of resin. • Less labor cost Main disadvantages (Strong 2008; Advani and Hsiao 2012; Netcomposites 2019) • Matched tooling is expensive and heavy in order to withstand pressures. • Generally limited to smaller components. • Pressure can cause fibers to move in the mould, this is called fiber wash. 2.4 Resin Infusion or Vacuum Assisted Resin Transfer Moulding Resin infusion or Vacuum Assisted Resin Transfer Moulding (VARTM) is a compli- cated technique for manufacturing composite structures, and usually it creates void