Acta Materialia Turcica Volume 3, June 2019, Pages 1-7 1 Corresponding Author E-mail: yboztoprak@marmara.edu.tr Investigation of Mechanical Properties of Polyester, Acrylic, Polyamide Fiber Reinforced Epoxy Composites Y. BOZTOPRAK Marmara University, Department of Metallurgy and Materials Engineering, Istanbul, Turkey Abstract: Composite materials are materials obtained by combining materials with two or more different properties that are used by people for thousands of years to solve problems without being aware of them. Polymer based composite materials have recently been developed to improve the properties of these materials, as they have many superior properties as well as insufficient strength. Depending on technological developments, different types of composites have been produced using different types of matrix and reinforcement. The purpose of this study is to produce and examine mechanical properties of polyester, acrylic and polyamide fiber reinforced epoxy composites. The composites were produced by the method of hand lay-up. Tensile, impact, flexural and interlaminar shear strength (ILSS) tests were performed on the prepared specimens. Increases in the fibre content had various effects on the above mentioned mechanical properties of the obtained composites. Keywords: Polyester Fiber; Acrylic Fiber; Polyamide Fiber; Araldite Resin; Composite Materials. DOI: 1. INTRODUCTION The polymers play very important role in our daily life. They can be combined with different materials to achieve special properties according to end use applications. Polymer based composites are being used more and more intensively in space, aviation, medicine, automotive, textile, construction, building and other developing technologies. Reinforcing fibers, which are generally used in polymer composites, provide strength and other desirable properties to the composite material [1,2]. In parallel with these developments, work on fibers with better mechanical properties and higher heat- resistant, non-cracking, high impact strength and hard polymer matrices continue in the world [3-7]. Today, most of the synthetic polymer fibers in use span applications such as clothing, carpets, ropes and reinforcement materials. Some of these fibers include polyamides such as nylon, polyesters (as PET, PBT), PP, PE, vinyl polymers (as PVA, PVC), PU and acrylic fibers (e.g. PAN) [8,9]. Polyamide refers to family of polymers called linear polyamides made from petroleum. The generic name polyamide fibre has the same meaning as nylon fibre [10]. Polyamides generally are tough, strong, durable fibers useful in a wide range of textile applications. The distinguishing characteristics are high elasticity, tear and abrasion free, low humidity absorption capability, fast drying, no loss of solidity in a wet condition, crease free, and rot and seawater proof. Application areas range from underwear to outdoor sports clothing [11], from automotive to aerospace [12]. PET is the world's most widely used fiber in a variety of forms. PET is widely used in both fiber and filament forms as a strong, dimensionally stable fiber. Large quantities of PET fibers are also used for both woven and