Deep Drawing Sheet Metal or Aluminum Cans - Research Paper Example

?Manufacturing Materials and Processes CONTENTS Number Topic Pages Introduction 2 Cold Working 2 3 Blanking 3 4 Drawing 3-4 5 Deep Drawing 4 6 Aluminum Can Production Process 5-6 7 Summary 7 8 Bibliography 8 Introduction The report is focused on one of the subjects of manufacturing materials and processes i.e. production of aluminum cans or beverages cans with the help of deep drawing, blanking, and other manufacturing and inspection processes. Beverages cans are mostly manufactured by aluminum. Since aluminum is abundantly present on earth’s crust in the form of ores like bauxite, kaolin etc therefore extraction of aluminum through these ores is relatively easier than other metals. The presence of aluminum and the simple processes for extraction of aluminum from ores make aluminum an economical, viable and all time available raw materials for the production of beverages cans. The report does not focus the extraction processes involved for the production of aluminum but on the other side it is more precisely and briefly related to the processes of manufacturing of aluminum cans using aluminum as a raw material. As the subject of study is manufacturing materials and processes therefore the report is related to manufacturing instead of excavating or extracting materials from the ores. The initial parts of the report discuss the processes and the concepts that will be used in the production phase of aluminum cans. Cold working, blanking, drawing and deep drawing has been explained thoroughly then finally the report proceeds on the production of aluminum cans. 1. Cold Working Metals are strengthened with the help of cold working, it is done in a way that metals are subjected to plastic deformation due to which higher density of dislocation networks are obtained that actually strengthens the metals. Strain hardening, work hardening and cold working are same concepts. The deformation produced in a cold working process is always kept below the re-crystallization temperature; otherwise the process will be named as hot working rather cold working. In hot working processes metals are not strain hardened therefore strain hardening can only be achieved in the cold working process. Annealing is whereas a hot working process, in which a metal is heated above re-crystallization temperature and even though material, is subject to change its properties. Hot working process increases ductility but cold working process decreases ductility. Ductility is the property of metals by which they can be plastically distorted or manipulated under the effect of tensile forces; on the other hand malleability is the property of metals under which these are deformed with the help of compressive stresses. In engineering, elasticity is the level of metallic non permanent deformation where metal regains its original form when the applied stress is undone. Residual stresses are an enigmatic problem in metals, due to this stresses remained induced even if the applied stress is removed, consequently these residual stresses are very slowly liberated, since it’s some times undesirable therefore annealing is done to positively accelerate the process of stress relief in order to eliminate residual stresses. 2. Blanking Blanking is one of the important manufacturing processes which is based on the principle of shearing, in which a die and a punch plays a pivotal role in shearing a scrap out of the desired work piece. In blanking, the part sheared from the blank is used for further manufacturing process while the other blank work piece is scrap, on the other hand in piercing the remaining blank is useful while the sheared part is scrap. The whole phenomenon is same between blanking and piercing but the difference in seeking objective makes the two terminologies distinct. Perforating is one of the type of piercing process, in which a die is intended to make small holes on the work piece several times, leaving a pattern of small holes on the desired part for various purposes. For this operation of blanking or piercing, specialized dies and punches are there. Dies and punch can be mechanically driven. 3. Drawing Drawing is a specialized metal-operating practice that utilizes tensile stresses to draw out, elongate or extend the sheet metal in the form of wire or in the form tube or bar. The drawing process carries out deformation over a curved axis. The work piece is drawn with the help of a die that decreases the diameter of the work piece on the contrary increasing the length of the work piece. The drawing process is usually progressed through cold working conditions therefore it is classified as a cold working operation. However, cold working conditions are no more compulsion; it can be carried out in hot working conditions as well depending upon a certain condition. Drawing process is not a simple process rather proper lubrication and pressures are important factors during a drawing process. The sheet metal can be a subject of defect after the process because it can be found with wrinkles on its surface, this can happen because of the fact that sheet is not properly mounted with due pressure during the process of drawing or there was no proper lubrication. For this reason of improper lubrication the part can break or cannot move freely, therefore, a proper balance of pressure and lubrication must be there otherwise consequences might get out of control. 4. Deep Drawing In a drawing process, when the depth of the drawn work piece becomes more than the diameter present originally prior to drawing then the process is termed as deep drawing. Hence, it is not done in a single strike rather a drawn part is re-drawn through several dies for this purpose of re-drawing or deep drawing. A problem that is associated with deep drawing is about the wrinkles produced at the first order. These wrinkles results due to tangential compressive stresses but it can be avoided if a proper aligned blank holder is used to guide the motion of material flow from the blank and into the die. The percentage reduction in the diameter of the aluminum blank sheet by 50 percent requires a power of about 126 kN. Lubricants are used in a deep drawing process so as to reduce friction and heat between punch and die of a deep drawing process. Lubricant also helps the part to appear out of the process with an over all fine surface. 5. Aluminum Can Production Process Usage of aluminum in can making can be tracked back to 1957. Since aluminum is more economical than any other metal therefore the usage of aluminum in can making became popular and then finally aluminum captured the market of beverage cans manufacturing solely and replaced other metals in this cosmos. Aluminum coil, lubricating liquids, and small percentages of other alloying metals with aluminum are used as primary raw materials in the production process of aluminum cans. The aluminum can production process can be classified into three major portions of the assembling process. The assembling of these cans are done in a way that the bottom of the aluminum can is first integrated with the body of the can, then a content is filled in to the cup style body, afterwards the cup body is integrated with the top roof of the can. This is the general process of can making. The production process of aluminum cans starts with the shearing of aluminum blank sheets from the aluminum coils. This is done by uncoiler that unrolls the coil of aluminum and a suitable lubricant is applied to properly make the sheet flow into the upcoming processes. Then the aluminum sheets are sent for the purpose of blanking into circular discs. Now these circular discs are being used for drawing purpose in order to make the circular disc in the form of a cup, any scrap of aluminum during the shearing process is recycled again for the above processes. The process of re-drawing starts when these cups are sent to a stream line of conveyor that goes to a punch, this punch is called a body maker, there is not a single punch rather there are multiple body makers, and each of them contains punch. The cup in such line is being forced by these punched to acquire the shape of can by passing through gradually smaller ironing rings. This process actually ironed the cup into a can, here in this process as well; proper lubrication is maintained due to continuous action of body makers. After the can is being released from the body makers, it is subjected to the process of top trimming such that all cans accomplished a unified height. Again, the top can scrap is recycled to the beginning processes. Now, the can body is subjected to washing mechanism so that all lubricants can be removed, so in order to make the can ready for exterior decoration. After cleaning, the can is dried through driers and then send to decorators for exterior printing purposes. The exterior decoration is then protected by a covering and also an interior organic coating is applied so as to prevent any reaction of the drink with the walls of the can. Quality control and inspections tests are then applied to the can to ensure that there is not a single tiny opening left. The top can end is then attached with a lid, the lid is provided on these aluminum cans so as to make it easier for the customers to remove the cover of the cans and enjoy the drink inside. 6. Summary The report on manufacturing materials and processes exclusively encounters with the production processes of aluminum can. For this reason, the report focuses on main processes and manufacturing concepts that are used in the manufacturing of aluminum cans in the beginning and discusses each major process as a whole a part from the discussion of the exact sequential processes of aluminum cans. Therefore, with the help of these initial processes guide a basic understanding about the processes that will be used further for the production of aluminum cans can easily be grasped and under one’s comprehension. The second phase of the report is specifically related to the sequential processes of the production of aluminum cans; since the prior knowledge about the processes has already been obtained in the beginning topics, therefore, understanding of the processes of aluminum can manufacturing becomes easy and relatively more comprehensible. As a whole this project is a great learning prospect regarding the manufacturing concepts, and different processes that are stream lined in the production process. Manufacturing of Aluminum cans is taken as an example; through this a basic understanding of can manufacturing is obtained. As the study is based on aluminum cans the processes related to it’s manufacturing like blanking, piercing, drawing, and deep drawing can be easily learned. It will definitely assist in the career of metal working, since all the processes involved are a great learning exposure of metal working. Bibliography Bruce, D. a. Modern Materials and Manufacturing Processes. Degarmo, E. P., Black, J. T., & Kohser, R. A. (2003). Materials and Processes in Manufacturing . Wiley. Manufacturing Engineering and Technology. (2006). Pearson Prentice Hall. Van Vlack, L. (1985). Elements of Materials Science and Engineering. Addison-Wesley. Read More