Outdoor exposure tests of bamboo-fiber reinforced composite: evaluation of the physical and mechanical properties after two years

2014 ◽  
Vol 73 (2) ◽  
pp. 275-278 ◽  
Author(s):  
Rongxian Zhu ◽  
Yahui Zhang ◽  
Wenji Yu
Author(s):  
Antony Paul ◽  
Jeffery M. Gallagher ◽  
Raymond J. Cipra ◽  
Thomas Siegmund

Fiber reinforced composite materials are now frequently being used over conventional materials for their ability to achieve tailored properties and performance characteristics. With the recent advancements in manufacturing techniques, short-fiber composites are coming into prominence in this sector, with their cost advantage and their capability for large throughput. Randomness of fiber orientation is inherent to short fiber composite manufacturing processes. In order to effectively manipulate the mechanical properties of a short-fiber reinforced composite, it is imperative to adequately control the orientation of the fibers during the deposition stage. A process is currently developed to acquire geometrical data of the target object and to utilize it to create a short-fiber reinforced component with controlled fiber orientation. The topological data acquisition of the object is made possible using non-contact 3D imaging techniques. The geometric data is then transferred to a commercial CAD package for the added capability to manipulate the geometry as may be required for specific applications. Subsequently, geometric data constitutes the basis of path planning for the tooling processes. In our process, a novel rapidly re-configurable tooling and molding technology is employed by which a 6-axis robotic arm is used to sculpt a pin-device vacuum surface. After the tooling is completed, the robotic arm will use a deposition nozzle to orient a steady stream of initially random short-fiber from a feeder into a unidirectional output, onto the tool surface. By controlling the position and orientation of the deposition nozzle, it is possible to control the orientation and density of fiber in each section of the near-net shaped composite pre-form. The fiber pre-form is then impregnated with a suitable matrix medium and cured to create the required component. The outlined process is thus capable of manufacturing a near-net shaped short-fiber reinforced component with highly specific mechanical properties. One of the many applications envisaged using this process is the manufacture of custom form-fitting braces, masks and guards for use in healthcare products. A patient intervention can have his or her features acquired using stereo-imaging and have corrective measures incorporated into the device prior to manufacturing. By controlling the orientation and density of the fiber at different portions of the device, it is possible to provide adequate support at specific areas or to restrict movement in specific directions while providing compliance to movement in the others.


2019 ◽  
Vol 23 ◽  
pp. 40-56
Author(s):  
Shivkumari Panda ◽  
Dibakar Behera ◽  
Prasant Rath

In this chapter, bamboo fiber with parallel and anti parallel orientation has been introduced in the Unsaturated polyester (UPE)/ Epoxidized Soybean Oil Acrylate (ESOA) blend. The reinforced fiber mats were treated with NaOH and NaOH-silane to improve the stiffness and strength of the composites. Parallelly oriented fiber reinforced composite showed improved glass transition temperature. The mechanical, thermal, storage modulus and tribological properties are highly improved for parallel fiber oriented composite. Also alkali-silane treated fiber reinforced composite show optimum properties than alkali treated and raw fiber based composites. Anti parallelly oriented composites show reduced performance due to pull out of fibers. The FTIR analysis of all the composites was observed for the first time with valid reaction mechanism. So this new partially biodegradable composite can open a new door for potential application in various fields. This composite may be used as an alternating material to wood for various indoor and outdoor applications.


1998 ◽  
Vol 7 (4) ◽  
pp. 096369359800700 ◽  
Author(s):  
VK Ganesh ◽  
S Ramakrishna ◽  
HJ Leck

A method of fabricating fiber-reinforced composite based functionally gradient material is described in this paper. The material has continuously varying mechanical properties along the length. The continuous variation of the mechanical properties is achieved by continuously varying the fiber orientation using the braiding process. The test results indicate an elastic modulus increase by about 42% from the largest braid angle to the smallest braid angle for the material system and the orientation angle considered in the present study.


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