Composite materials have been continuously replacing traditional materials, because of their superior properties, such as high tensile strength, low thermal expansion, and high strength-to-weight ratio. Natural fiber reinforced composites are more attractive, due to their high specific strength, lightweight. Natural fiber mixed with other reinforced polymer composites are finding increased applications in many engineering fields, especially in the construction, automobile and aviation industries.
Our department student project mainly concentrates on medical applications based on aspects of composites. We are planning of introducing our new natural fiber composites to the medical field, so that, we can replace such synthetic reinforced composites. We have decided to go for a prosthetic socket limb, which is a mechanical-medical application. A Ten year old Girl and 45 year old man, who are all amputees due to Accident, were opted for the project and dimensions were obtained from him for further design and analysis. We have decided to use Cisssus quadrangularis stem fiber and cotton fiber along with polyester resin composite in our project to manufacture prosthetic limb socket. We have also taken the same design and manufactured glass fiber prosthesis. Since glass fiber reinforced has been an existing one, certain properties were compared with natural flax fiber reinforcement, where desirable properties were obtained from natural fiber, which was favorable.
Later for the natural flax fiber a test specimen was prepared according to the ASTM standards for the following tests such as Tensile test, Flexural test, Impact test, Water absorption test, which was prepared in a die of dimension 300 x 125 mm measurement. The following results are obtained from tensile, flexural, impact, water absorption test. Later the design was done using the results from the test specimen in SolidWorks premium edition (2014), and analysis was done in ANSYS 15 using properties such as young’s modulus, poisson’s ratio and density. The properties obtained were Tensile strength of 132.2±3.5 MPa, Poisson’s ratio of 0.45, Density of 1.22gm/cm3 , Flexural strength of 143.9 MPa, Impact strength of 12.87 J/cm2, Failure stress of 193 MPa. We did both the fabrication of this project (Using glass fiber and natural fiber) by RTM process under the supervision of internal guide and a prosthetist authorized from CMC Vellore. After the curing of the product, certain surface finish operations are performed by grinding off its sharp edges. Later rough checking is done and limb is attached to the foot. The foot is made of rubber with internal wooden structure to avoid sudden shocks. Through our project, we compared the existing synthetic glass fiber and natural flax fiber by designing and manufacturing them. The weight, cost, toxicity and economic problems were solved in the project. When comparing with the glass fiber reinforced prosthesis, which was used previously, our product is of low weight, low cost and free from toxicity. The product was successfully handed over to the patients, who is economically very poor, at free of cost.