Feasibility/Recommendation Report

Recommendation report sample:

Introduction:

Purpose:

The purpose of this report is to recommend the best material for making Ohio license plates.

Problem:

For years, the Ohio State Highway Patrol has complained to the Ohio Department of Public Safety about being unable to easily read some license plates. They allege that corrosion of older license plates can inhibit their ability to easily make out the numbers. In January of 2013, a bill was proposed requiring every driver in the state of Ohio to replace their license plates every seven years whether they were corroded or not, but the idea was unpopular and did not become law (Blackwell).

The idea of using RFID chips or transponders rather than license plates has been considered. However, police want civilians to be able to read license plates as well. It would be difficult to report someone swerving and driving recklessly on the highway to a 911 dispatcher if the citizen cannot read the vehicle’s license. Also, civil rights groups such as the ACLU are strongly opposed to the use of RFID chips in or in place of license plates. Their opposition would make RFID chips even more politically challenging than replacing traditional license plates every seven years.

Still seeking a solution to the rust problem, the state legislature introduced a bill to repeal the law requiring license plates to be made of steel. Sub House Bill 51 eventually did go on to become law (Beck) and allows “the use of steel, aluminum, plastic or other suitable materials to fabricate license plates” (Blackwell). Joe Andrews, the communications director for the Ohio Department of Public Safety has said that they are unsure of what new material they will switch to, but the hunt is on. (Blackwell)

Scope:

This report will look at continuing to use galvanized steel, stainless steel (alloy 436), plastic (PVC), and aluminum (alloy 6061-O). The criteria used to evaluate the options will be hardness, resistance to corrosion against salt, and ease of manufacturing. Cost could not be considered because accurate pricing data could not be found. Alloy 436 was chosen to represent stainless steels because it is a common sheet form of stainless steel. PVC was chosen to represent plastics because it is inexpensive and has proven its durability and ability to hold color by being used in some street signs. Alloy 6061-O was chosen to represent aluminums because it is a common general-purpose alloy that can be produced by recycling scrap metal (Callister).

Discussion:

Hardness:

Explanation:

Hardness is the ability of a material to resist indentation and scratching when a force is applied to it by a sharp object. In the case of license plates, the hardness of the material is important to resist denting and scratching from gravel, sand, and other road debris that is kicked up when a vehicle travels.

The hardness of the material will be compared by looking at the tensile strengths of the material. There are several different hardness scales for different materials, making comparisons difficult, but hardness correlates linearly with tensile strength, making a comparison more simple (Pavlina). Tensile strength is measured by seeing how much force is necessary for a machine to rip a piece of metal in two. The metric units for tensile strength are MegaPascals (MPa). A MegaPascal is a unit of pressure like pounds per square inch.

Data:

The tensile strength of galvanized steel was found to be 365 MPa (United States Steel). The tensile strength of stainless steel 436 was found to be 530 MPa (Alexander). The average tensile strength of PVC was found to be 0.98 MPa (Alexander). The tensile strength of Aluminum 6061-O was found to be 124 MPa (Matweb). Table 1 summarizes these values.

Table 1: Tensile strengths of the materials under consideration

Interpretation:

The stainless steel is the strongest material. The other two metals are still plenty strong enough to take the beating of being a license plate, but the PVC would most likely not be a good choice based solely on this criteria. If PVC plates were to be used, a commercially produced, aftermarket, clear plastic cover over the license plate could help to counter this problem. In this case the stainless steel is preferred.

Resistance to Corrosion against Salt:

Explanation:

Resistance to corrosion against salt is a determination of how deep into a material a salt solution penetrates after a year at room temperature. Resistance to corrosion against a salt solution is important because salt is used on roads across the state. The road salt mixes with snow and slush to form a salt solution.

Data:

Galvanized steel was found to corrode less than 20 mm per year (Schweitzer). Stainless steel was also found to corrode less than 20 mm per year (Schweitzer). PVC was found to not corrode at all (Schweitzer). Aluminum showed negligible corrosion (Schweitzer).

Interpretation:

Aluminum instantly forms a thin layer of aluminum oxide on its surface when exposed to the air (Callister). This thin layer instantly repairs itself when it is scratched and it makes the aluminum metal very resistant to surface corrosion. The best example of aluminum oxide coated metal compared to the plain metal itself is aluminum foil. One side of aluminum foil is shiny because it is coated in wax, preventing the aluminum from forming the oxide layer because it is not exposed to the air. The dull side of the aluminum foil is aluminum covered in the protective layer.

Stainless steel corrodes less quickly than galvanized steel or regular carbon steel, but it still does corrode. From these data it can be seen that PVC or aluminum would be optimal for corrosion prevention.

Ease of Manufacturing:

Explanation:

Ease of manufacturing looks at the method of making the material into license plates. This is important because the state already has equipment for manufacturing metal license plates. The data for this criterion is qualitative in nature.

Data:

Galvanized steel license plates are made by a process known as stamping (Callister). A sheet of metal is cut into the shape of the license plate using what is essentially a large industrial cookie cutter. The material is then pounded once with a machine that it bends the raised letters and numbers into the plate. Stainless steel license plates and aluminum plates are made using the same method and could even utilize the equipment that the state already possesses.

Plastic is typically shaped using injection molding (Callister). Injection molding is used to make bottle caps, the hard shell of smartphones, the dash in cars and many other common items. It is ideal for producing large amounts of identical objects. PVC license plates could not have raised numbers or letters without changing the plastic mold for every license plate. Instead, the license plates would be flat and the design, numbers, and letters would be added using acrylic paint. This method is commonly used to make street signs. Figure 1 shows an example of a PVC street sign.