Feasibility Report For Manufacturing Of Smart Phone Cases

Material Selection

The usages of smart phones have been able to increase a lot in the last five years. This has led to the use of different materials for design of different parts. The phone casing is one of the parts which have been able to experience the usage of different materials. Different materials have different pros and cons when it comes to their design and usage (Nassos, & Avlonas, 2013). The usage of the metal casing, polymer and carbon fibre composite has been employed in the design of the smart phone cases. Each material has its own justification for their usage. In addition, different customers’ preferences are able to promote their usage. Technological advancement in the mobile sector has led to the emergence of the different materials for the different parts such as the cases.

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Figure 1: phone case

Justification of materials

The different materials have different characteristics which make them be chosen to be used for the smart phone casing. The justification for the material usage in the manufacture of the casing depends on material properties and customer preferences. One of the most used materials in the design of the smart phone case is the metal. Scratch free property is one of the key characteristic which many designers are able to identify when choosing the metal material (Ro?hrig, & Diebels, 2015). Aluminium is one of the most used metals in the design of the phone cases. The lightweight property is identified as a key characteristic and specification when making the preference for the metal material. In addition, customer preference is another key characteristic which is considered when using metal for the case design. The metal is considered classy and able to represent some section of the society. Considering this section of people, the designers are able to move and use metal as part of the materials for the casing. For the classy and wealthy show, the designers are able to use diamond as part of metal for the design metal casing. In addition, the use of polymer is another material which is used. The polymeric materials are able to combine different materials in order to achieve the different specifications. In their design, the polymeric materials key specifications which are considered during their design include their good dimensional stability, high mechanical properties such as tensile and impact resistance. In addition, good polish during painting is another specification which makes the polymeric materials to be used for the phone casing. Lastly, the key polymeric materials can be designed into different designs and characteristics as required. This makes it easy for the designers to meet their customers’ preferences. The looks aspect and specification which the designers look to meet while using the polymeric material in the design of the smart phone cases.  Additionally, another key material which is used is the carbon fibre composites. The carbon fibre are able to weave and able to create a stronger material. This is ma key specification which makes the casing much stronger. This is an important specification which is highly considered when choosing the carbon fibre composites for the material for the phone cases. Additionally, the carbon fibre composites are light which is a key consideration for the specification and consideration for the phone case materials. Lastly, carbon fibre composite materials are attractive and this makes them more attractive. This attractiveness is a key specification which is considered during the choice of the material as part of the phone casing.

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Justification of Materials

Material grade is a key consideration in order to maintain the quality of the phone cases. Different grades are usually produced but the metal grade for the phone cases must be able to meet some key specification which will align with the use and purpose. The high strength of the metal is one of the key characteristic which makes metal to be chosen as the casing material. Aluminium is a key metal grade which is used and applied in phone cases. The strength of the aluminium results from the strong electrostatic attraction between the positive and negative electrons (Venturi, 2017). The grade of metal chosen must be able to have this strong attract to move against the starching effects. The grade of metal must be able to disperse the heat perfectly and ensure that device overheating is not easily felt. As a good conductor of heat, the metal grader through the free electrons is able to carry the heat and reduce device overheating.


Figure 2: atomic structure of metal grade

Epoxy resin is an important grade for the polymers which is used in the manufacture of the phone cases. Hydrocarbons, which are mixture of hydrogen and carbon structure, are able to form the basic structure of the resin used for the phone cases. The hydrocarbon structure is able to provide the key strength and scratch resistance properties which are needed in the phone cases. This grade of the polymer is able to resist different scratching elements and even electrical conductivity (Ho, 2014). This makes it an important part and grade to be used for the manufacture of the phone cases. The internal arrangement of the hydrocarbons helps the grade to achieve the required characteristics for the phone cases.

The carbon fibre composites consist of layers of carbon which are arranged in hexagonal; patterns like graphite. The polyacrylonitrile (PAN) resin is a key grade of carbon fibre composite which is used in the manufacture of the phone cases. The internal structure of this material composes of carbon, hydrogen and nitrogen molecules (Delong, 2011). Monomers are the main key inri9fdients which are used in order to attain the preferred characteristics for the phone cases. The structure ensures that the temperature transition is only achieved under high temperatures. In the attaining of the high strength, the microstructure of the PAN resin plays a critical role in achieving the desired characteristic.

  1. Manufacturing process:

 The material of the phone cases must be able to pass through a defined manufacturing process. This ensures that the different desired qualities are achieved to meet the purpose of the end user. The different materials have different manufacturing process due to their differences in properties.

  • Manufacture process of aluminium

Aluminium is one of the key materials which are used for the manufacture of the phone cases. This is due to its light weight nature. In addition, the specific characteristics are only achieved through the proper manufacture and fabrication process. This ensures that the specific characteristics which are required during the phone case manufacture are attained. The strength and modern and sleek modern looking are some of the important aspects which are attained during the manufacture process of the cases suing the aluminium materials (Yasushi, Keijiro, Shinichi & Mitsutaka, 2012). In the manufacture process, first the material is usually designed by cutting the blank into the specific shape under which the phone look like. Drawing the shape and phone cases is done to ensure that the aluminium sheet is able to emulate the shape of the phone case. Redrawing of the case is then done and the sleeves of the phone case are ironed according to the required shape. Trimming is then done and this ensures that the finest details of the phone shape are perfected. The trimming process ensures that the crystal structure of the aluminium sheet is perfected (Guzman, Cugnoni, & Gmür, 2014). Cleaning and decoration to the required colour is lastly done. This ensures that the tastes and preferences of the customers are taken into consideration.

  • Manufacture of epoxy resin

Material Grade

The epoxy resins are able to consist of crosslinkable materials which help in production of the key desired qualities. The epoxy resins are manufactured from the reactions of epichlorohydrin (ECH) and bisphenol-A (BPA). At the first stage, the reactants, which are ECH and BPA are charged with reactor. Additionally, in order to attain some key specific characteristics, a solution of between 20 to 40% of caustic soda is added. The evaporation of ECH is then carried out. After the evaporation stage, the two phases are separated through the addition of inert solution of methylisobutylketone (MIBK). After that, the resin is washed with water and the solvent is removed through vacuum distillation. Additives may be added through a specific formula in order to enhance some key characteristics such as flexibility, colour adhesiveness and fastercuring according to the application of the resin. Curing to harden the resin and ensure the phone case application is achieved is usually carried out. Temperature curing is usually applied between 5 and 1500C.


Figure 3: manufacture process of epoxy resin

  • Polyacrylonitrile (PAN) resin manufacture process

As part of the carbon fibre composites, the PAN resin manufacture process helps to attain the key required qualities. Polymerisation process is an important process, which is used in the manufacture of the PAN resins. polyacrylonitrile resin, also known as Acrylic resin is achieved after the polymerisation of vinyl cyanide. The manufacturing process helps to form a strong PAN resin material which has the desired qualities such as synthetic, thermoplastic and having high resistance to heat (Carpenter & Sanders, 2014). Thermal oxidising in air is another key process which is applied during the manufacturing process. This ensures that the material will be inert when reacting with key materials. Additionally, hot filtration process is another key process which is involved in the manufacture of the PAN resins. This ensures that the material and phone cases will be resistance to high temperatures. Also, this process ensures that the end product will have high strength and resist any scratching elements.


Figure 4: polymerisation of PAN resin

The manufacturing process has two key processes. The first one, hydrogen cyanide is usually added to the material in order to form the acrylonitrile. The process is shown below;


The second step involves the following underlined processes.

  1. Cost:

Cost preferences and consideration is one of the important aspects of any manufacturing process. This ensures that the economics of every process are maintained and the used part can be able to generate the required profits. Economies of scale are able to go hand in hand with the amount of items which are being produced at each given moment. The cost of production is able to reduce as more items are being manufactured. This happens units the optimum amount of production are achieved (Wang, Wu, Ma, Sun, & Du, 2010). The sales are able to produce the different parts which are manufactured and therefore determining the optimum capacity at which the minimum cost will be achieved.

For each material, the following equation is used to determine the overall cost of the phone case;

Manufacturing Process


The Cs is the overall cost of the phone case while n is the amount of items which are produced. The cost of the material, plus the cost of market and the capital; cost is able to form the overall cost of the phone case. In order to attain the minimum amount of times to achieve the economic production, each case is dividing by the number of items produced (Kopeliovich, 2012). The cost per year is indicated below against the cost which will be experienced in the production of each bracket.


Cost of each item in 100 million items

Cost of each for item between 100 and 450 million  

Cost of each item between 450 and 800 million

Cost of each item above 800 million

Cost of each item above 1000 million


Aluminium metal casing







Polymer casing







Carbon fibre composite







For the aluminium casing, they have the highest cost among the considered elements. Their production is able to reduce with the increase of the amount of items which are produced. The different groups are able to identify the costs of each item under the different groups. The minimum amount of components under which the minimum cost of production is achieved in this case is from the 1000 million items (Zhao & Gou, 2009). The cost of $2.3 is the lowest cost of the item produced in this case. Therefore in order to achieve economies of scale, more than 1000 million items must be produced. The highest profits will be achieved when more than 1001 million components are produced. Any production below this amount of components is able to attract more cost of production.

The The initial item produced in the use of polymer material is able to attract a cost of $1.5 per item. In the same case as the aluminium, the cost of the items is able to reduce with the increase of the production. The minimum amount of items required to achieve low cost of production in this case is above 450 million (International Conference of Advanced Materials, Mechanical and Structural Engineering, In Hong, In Seo, & In Moon, 2016). The cost is able to reduce with the reduction of more items being produced. The minimum amounts of items required are above 450 million and this will attract the lowest cost or production. The consideration to have low items produced to achieve the highest profits is viable for any business consideration. The increased yearly production is therefore good for the business operation


The carbon fibre composite casings are able to follow the same trend whereby increased production is able to attract a low cost of production per item. Increasing production is able to attract low cost and this leads to the economies of scale for the production. The minimum amount of components required in this case to achieve the lowest cost is above 8000 million components. This means that any production above this point will be done at the lowest cost of production possible. These are productions which are viable per hour (International Conference on Biomedical Engineering, & In Goh, 2013). Producing these items per year will mean that the company will experience the minimum cost of production. For any business, attaining the economies of scale is usually the goal to ensure that they are able to generate the highest cost possible.

  • Waste factor

Quality Control

In each case, the cost of waste is usually attained in each case. The waste factor is able to define the extra costs which will be experienced in each case and therefore affecting the business operation for the casing production. Lean production is able to ensure that the least wastage is usually achieved in each case. The manufacturing process is able to attract these wastage minimizing them is able to ensure that the manufacturing process is effective (Kasper, Bernardes & Veit, 2011). The manufacturing process complexity and control is able to determine the amount of wastes which will be produced. The metal manufacturing process is complex and is able to attract a wastage production of 12%. The polymer process on the other hand is able to produce wastage of 8%. The carbon fibre composites lastly produce a wastage rate of 9.5%. These wastages are able to produce increased cost and therefore reducing the effectiveness of business operation.

  • Manufacturing viability

For any business, reduction of cost and achieving the optimum production rate at the lowest is level is desired. Therefore in order for the cases production to be viable, the business must be able to attain the minimum wastage. The polymer manufacturing case has the lowest amount of waste production (Idaho National Laboratory., United States., & United States, 2011). This is an effective process to carry out for business since it will mean more cost reduction measures are achieved. In addition, for the business, the minimum cost must be achieved with the lowest item produced. The polymer case has the lowest items which must be produced in order to achieve the lowest cost of production. Therefore for business, the use of polymeric material will be effective and viable to achieve business objective.  

  1. Process and structure/microstructure control

One of the materials which are good and viable for the smart phone case is the polymer material. Their cost is low and their production and manufacturing process is easy to attain (Chawla, 2013). This section will be able to look at the manufacturing process and microstructure of the phone cases which are done using the polymer materials.

The polymer, epoxy resin is affected by temperature variation during the manufacturing and usage stages of the cases. Increasing the temperature during the manufacture process is able to elongate the microstructure of the polymeric materials (Pike, Grabner, & Harkins, 2009). The increase of temperature with time is able to affect the functionality of the epoxy resin material. They become weak and their strength is reduced.

Exposing the epoxy resin to temperatures for long time is able to affect the strength as well. The high temperatures and increased time of exposure are both able to reduce the functionality and durability of the material (Serkov & Radishevskii, 2008). The structure ability to hold on each other molecules is reduced and therefore reducing the strength.

Increasing the pressure is able to increase the compacting force and therefore bring the microstructure together. This ensures that the molecules during the manufacturing process are closer to one another. This is able to increase the ability of the material to resist other form of destructing materials as well as scratched. The microstructure has more advantages when done under high pressure and this improves the quality of material produced.

Cost Analysis

In each stage of manufacture of epoxy resin time is of essence. In some key processes, taking much time is able to reduce the durability of the final produce while in other increasing time is able to the strength of the materials (Ho, 2014). For instance, increasing the time during the heating process is able to reduce the durability and strength of the material. On the other hand, increasing the time during the pressuring time is able to enhance the compacting of the epoxy and thus increasing the strength of the casing.

  1. Quality:

Due to the mechanical properties of the epoxy resin materials, temperature, pressure and time factors are essential in the control of quality production. The control of these key elements will ensure that the final product and case is of high quality to resist any external factors. The following table is able to give the time exposure in each stage and the amount of pressure required (Bajaj, Sreekumar, & Sen, 2001). This will ensure that quality and high strength cases are produced. Observation on time exposures will be important to ensure that defective products are not produced. Inspection of the required qualities at each stage will be vital to ensure that the quality required is achieved.


Temperature condition

Pressure condition


Phase separation

High temperature

Low pressure

30 minutes

Wash process

Medium temperature

Medium pressure

1 hours

Evaporation stage

High temperature

High pressure

1 hr

Compressing stage

High temperature

High pressure

2 hours

Final production

Low temperature

High pressure

30 minutes


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