Chapter 7 Chapter 7 Conclusions and Future Scopes
1.16 Motivation and Scope
Past literatures indicate that, a variety of modern composite materials are available nowadays both in structural and nonstructural elements for day-to-day life application in industrial as well as household appliances. The major advantages of polymer composite materials such as:
low cost, ease of fabrication, high strength and modulus, acceptable fatigue and fracture resistance values compared to their density and excellent formability make them suitable for structural application substituting the need of metallic materials (Oprişan, 2010).
Over the past decades, polypropylene is used as a matrix material for design and development of composite and its applications. However, very few works have been carried out where Portland pozzolana cement (PPC) is used as a filler material into the polymer matrix. A Patent on: ‘Oriented composite thermoplastic material with reactive filler’ (Maine and Newson, 2006) is identified where cement material is used as fillers to fabricate the composite material; Another patent on, ‘Toughened Polyethylene Terepthalate (PET)’ where Portland cement is used into recyclable PET polymer and it is observed that 5-15wt%
Portland cement particles greatly enhance the toughness, elastic modulus and improved resilience properties of the composite (Simmons and Simmons, 2008). For light to medium duty industrial applications, the proposed cement reinforced PP composite material is used to fabricate the spur gear due to its specific advantages over other composites and metals. For this, the research has been accentuated to fabricate the composite spur gear and its performance analysis. As the trends, i.e., metallic gears are mostly used in automobiles and other industrial applications for their advantages such as durability, availability, smooth workability and reliability on performance. Although, disadvantages such as high cost, higher wear, more weight to power consumption limits usages of metallic gears applications. To remediating these problems, metallic gears can be replaced by proposed composite gears as the latter have certain advantages such as cheaper than metals and other polymers. The cost of polypropylene is Rs. 80-100/kg and density is 0.9 g/cc which is quite lesser than other polymers such as Nylon, PEEK, PET, Acetal etc. as well as any metals which leads to less weight to power consumption for gear application. It is also inactive to chemicals such as
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concentrated acids, proves durable and ease of processing and fabrication, since the melting temperature is 190ºC. Further, waste cement dusts as filler materials was incorporated into the rubber compounds results in improved tensile strength and modulus (Andrzej and Marek, 1984). Thus, a detailed scientific investigation is in demand on fabrication and characterizations of the composite materials in order to optimize the material properties to achieve optimal performance.
However, till date, very limited works have been carried out that address the design and development of low cost polymeric composite materials suitable for industrial needs incorporating cements as a filler material. In addition, few factors such as effectiveness, durability, chemical reactivity, processing difficulties and power consumption etc. get high interest for PPC filled thermoplastic composite materials. This motivates to explore the grey areas exist on design and development of low cost composite materials for fabrication of non- metallic parts substituting the need of metallic parts. Hence, it is relevant and justifiable to try very low cost polypropylene as matrix material and cement as filler material over other polymers such as Nylon, Acetal, PMME, etc. and carbon nanotube/nanofibre, silicate pallets, montmorillonite nanoclay as filler materials respectively.
This work primarily focuses on to fabricate a low cost, recyclable and durable cement based composite material proves to be an advanced, alternative and unique material for next generation that substitute the need of metallic materials in industrial applications. The improved mechanical and thermal properties of the composite material validate its suitability for fabrication of non-metallic spur gear for small-to-large duty device applications.
The motivations along with scope of the present work are briefly outlined as follows:
Fabrication of a low cost, non-hazardous and recyclable thermoplastic composite for industrial applications such as polymeric composite gears, rotor and propeller blades, automotive body parts and other structural applications etc. In addition, fabricated composite materials are subjected to thermo-mechanical analysis (TMA), thermo- gravimetric analysis (TGA) and differential scanning calorimetry (DSC) test to understand the thermal stability and fire retardant properties of the fabricated thermoplastic composite materials. Further, rheological properties of the material have been evaluated to find out the correlation between viscosities of the materials with respect to temperature.Chapter 1 Introduction and Literature Review
It is essential to investigate the resulting mechanical properties of the composite material as the small amount of filler particles concentration significantly affects the properties of the composite material and its performance. Mechanical characterizations such as tensile behavior, correlation of reinforcement factor with mechanical properties, effect of circular notch size in mechanical properties, bending deformation and short-term fatigue analysis are carried out. In addition, dynamic mechanical analysis (DMA) of the composites is also carried through.
An inexpensive, lightweight, recyclable thermoplastic composite spur gear was manufactured using proposed composite materials for light to medium duty device applications.
Geometrical structure of the developed product depends on the parameter like loading-unloading condition and temperature fluctuation that severely influence the material performance and shorten the product life. Direct performance analysis of the fabricated composite spur gear has been carried out to evaluate its load bearing capacity. A theoretical stress model is developed that correlate experimental results and describe stress distribution along the tooth contact surface using the modified Hertz’s contact theorem.
Modification of a dynamic test-rig setup is carried out to study the dynamic performance of the gear subjected to variable loads and speeds and equipped with an online Infra-Red assisted camera to monitor the temperature emission during running condition.
Investigation and assessment of friction and wear behavior of composite materials are necessary before finding suitable application of the product. Thus, wear characteristics of the composite material under adhesive and abrasive modes are evaluated using standard pin-on disc arrangement. These include evaluations of weight loss and wear volume after a certain period of running of gear pair and quantifying optimum wear characteristics.
Experimentation and investigation of damping and vibration characteristics on the effect of cracks of the fabricated composite cantilever beam for vibration prone structural applications. In addition, metal skinned sandwich panel with cement filled composite as core material was fabricated and underwent experimentation to estimateTH-1430_09610309
its performance for structural applications; an extended application of fabricated composite material.