Physical and Mechanical Characteristics of Feather Fiber based Filled Circular Tube

Application of feather fibers in engineering applications is on growing trend and feather fibers are used in composite panels and thermal insulations. The intent of this paper aimed to study physical and mechanical properties of feather fiber based filled tube which is also known as FETUBE. Physical and mechanical properties are crucial to evaluate the industrial application of FETUBE. Experimental tests were conducted on FETUBE to evaluate tensile and compressive strength. Apart from tensile and compressive strength tests, various other important test such as bending strength, shear strength, torsion strength, and impact strength were conducted on FETUBE. The toughness of tube and modulus of elasticity were evaluated as a function of percentage of moisture content. Test results were reviewed and conclusions were drawn based on the exponential data. Experimental tests were conducted considering the average diameter of the FETUBE.


INTRODUCTION
Natural fibers have inherent superiority over conventional synthetic fiber materials, such as weight to strength ratio, cost advantages, raw material availability, carbon foot print and degradability. Poultry feather fibers (FFs) are gaining popularity in industrial applications and in the field of composite applications. Fibers play vital role in matrix based composites and synthetic fibers are being used extensively in the composite panel manufacturing. Environmental issues and dependency on petroleum based products made the composite industry to look for better options to use natural fibers and ecofriendly polymers from renewable resources.
Natural fibers can be broadly classified as cellulose based and protein based fibers. Animal based fibers are protein based fibers. Over 3.8 million metric tons of poultry meat was produced across India in 2019 [1]. It was estimated that 6% of a bird's body weight is feathers [3], the amount of feathers coming out of Indian poultry facility is around is about 0.32 million metric tons. Usually poultry feathers are treated as waste, and disposed in open ground or burned. Disposal of the poultry waste is very expensive and produces bad odder and ill effects on surrounding environment [4]. The use of poultry feather fiber as reinforcement in composites is an innovative solution for poultry feather waste disposition and also provides additional revenue for the poultry industry. Bird feathers are considered as the most conglomerate integumentary appendages in vertebrates [5]. Feather fibers are made of keratin proteins ([90 wt %) [6] and the amino acid contents were studied by Graham [7], Schmidt [8], and Franer et al. [9].
Poultry feathers have two important parts namely feather fiber and quill and they are equal in weight percentage contribution. Poultry feathers inclusive of quill and feather fibers are made of protein known as hydrophobic keratin, which has strength comparable to nylon and cross-sectional diameter smaller than wood fiber [10]. Feather fiber has high aspect ratio than the quill and very good durability. Feathers extracted and collected from poultry facility cannot be made into new materials and needs cleaning process. The central part of feather known as core is also called as feather quill, is a stiff part and must be separated from the barbs. Barbs can be used as reinforcement material for composites and barbs in powder format can be used as fillers in matrix materials. Feather barbs are comparatively shorter in length and cannot be spun into thread and cannot be woven into cloth due to surface property of the feather fibers, but they can be added with man-made synthetic materials to form mat or slab where fibers are randomly oriented. The length of the barbs purely depends on the position along the rachis. The barbs on the base of the rachis are longer when compared to the fibers at the tip. Feather fiber property depends upon the percentage of keratin, which varies with ecological conditions of poultry facility [11][12][13][14][15]. The average length of poultry feathers are roughly around 135mm. The density of poultry feathers was found to be around 0.8 g/cm3 and know to be lighter material [16]. Feather fiber diameters were found to be in the range of 5μm and lengths of 3-13 mm. These values correspond to aspect ratios of 400-2200. Mature and well grown 5lb or 2.25kg broiler chicken's feathers weigh about 74 grams or 2.6 ounces, or 3.3 percent of its body weight. Since that chicken has some 9,000 feathers, each one weighs about 0.0082 grams [17]. Some of the important tests and results on poultry feathers are tabulated in Clean and processed loose bundled feathers with or without quill reinforcement, wrapped in thin layer cotton based lenin was moulded in split pipe mold to form a filled tube. Dilute SR998 rubber based resin was used during the bundling process of feather fibers. FETUBE is vacuum cured and temperature cured as per the form fit functional requirements. Diameter of the tube ranges from 4mm to 12mm and tubes of diameter less than 6mm are without quill reinforcement and tubes with diameter greater than 6mm, comes with quill reinforcement of diameter 3mm to 4mm. The wrapping of thin layer of cotton based lenin acts like braiding and holds loose feather fibers intact. The exterior surface of the tube is provided with thin coating of SR998 to prevent moisture entrapment and activated surface for future fabrication. Visually, FETUBE resembles as dried maize stalk with good bending property. Based on preliminary testing, the axial tensile strength of diameter ø12mm FETUBE was 53.96MPa. The average secant modulus of elasticity is 28.06GPa and the average boundary deformation is equal to 0.98%. The destruction of the rods took place by cracking of the subsequent fibers. The detachment of the braiding from the bar core was noticeable. The destruction was accompanied by a decrease of strength. The intent of this paper is to study the behavior of FETUBE in detail so that FETUBE can be used in generic and industrial applications III. PHYSICAL CHARACTERISTICS OF FEATHER FIBER BASED TUBE -FETUBE FETUBE samples are available in running length and maximum length of the FETUBE is 1.25m. FETUBES are available in standard cross sectional diameter starting from 6mm to 12mm.The test samples of FETUBEs were prepared as pert test requirements. The important physical parameter for specific tests are tabulated in Table.4. Test samples were cut from the standard length tubes and were stored in oven maintained at 27 o C with humidity 50%. 10 specimens were prepared for each specific type of test.     Figure.5. The geometry of the test specimen is tabulated in Table.6. The conditioned FETUBE sample was held on the fixture with the help of U-clamps at both ends of the test specimens. During the down ward movement of the crosshead, the chisel cut the specimen by shear and passed through the slots provided in the fixture below the specimen. The force required for shearing the stalk was recorded. The maximum shear strength was calculated using equation σs = Fmax / A. The shear test was conducted for different type of FETUBE which are with and without quill reinforment.

Shear Test
Maximum shear strength σ s = F max / A      Table.6. The compressive force on the FETUBE sample was applied by a flat heads as shown in Figure. 6. During the test, the cross-head was moved down at 25 cm/s speed deforming the sample until failure of the sample and the modulus of elasticity in compression was calculated using above equation.

Bending Test on FETUBE
Bending behavior is very important property of the tube and the maximum bending moment was calculated by equation σb = My / I and M = Fb x L(refer Table.5). The geometry of the test sample is tabulated in Table.6. The bending property of the FETUBE was determined by simply supported teat and the test specimen axis is placed perpendicular to the plunger axis. Both end of the FETUBE specimen was fixed rigidly to the fixture with the help of a screw clamp with two inner semi-circular rims. The vertical force was applied by the chisel heads at the middle of the mounted specimen at a distance of 90 mm from the fixed point as shown in Figure. 8. Test was conducted till the failure of the test specimen.

Impact Test on FETUBE
The impact teat on FETUBE was performed for determining the energy required to shear the sample in transverse as well as along the axis. The impact test can be done in two types but Charpy impact test was performed on FETUBE. The test specimen required for Charpy impact test should be of length 55 mm and was placed in horizontal against the loading RAM. Load is to be released from 135 0 by using "V" notch for shearing as shown in the figure. 9. Figure. 9 Impact Test on FETUBE Table.12 Impact Testing results of FETUBE

4.6Torsion Test on FETUBE
The Torsion test on FETUBE was executed to determining the torque required to shear the test specimen. Test specimen required for torsion teat should be of length 350 mm and it should be clamp horizontally in the jaws provided on the testing machine as shown in figure. 10.   Table.14.  Table. 14 Test result summary

International
Detailed review of the test results shows that the superior property of the feather fiber based filled circular tube against the agriculture based byproduct namely maize stalk. Maize stalks are used in industrial products like "Corn Board", a maize stalk based composite panels and other civil building materials. Thus it is evident from the test results that feather fiber based tube can be used as reinforcements in composite panels and also in generic commercial applications. It is also advantageous to use feather fiber based tubes in composites as reinforcement, due to the fact that feathers and father based tubes have fire retarding characteristics and resistance to bacterial or fungal growth.