What Do Metallurgists Do?
Defining Metallurgist Experts
There are many types of processes in the world of metals manufacturing and often the complexity and technical nature of these processes leaves them shrouded in mystery. While metallurgical engineer is somewhat of a self-explanatory title, the exact details of who they are, how they works, and what can do remain unclear. Here we will provide you with a comprehensive explanation that demystifies everything from what to who, and the advancements within the metallurgical arena.
First lets start by defining metallurgy in broad terms. The process known as blow molding or blow moulding can be defined as a manufacturing process utilized for the fabrication of hollow objects such as bottles , containers, or any other type of hollow item. Materials commonly used in blow molding include plastic, glass, and in some cases metal. If you have ever drank from a bottle of any kind then odds are you have already seen and experienced a blow molded product first hand.
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As mentioned, blow molding is utilized to create hollow objects. But how exactly do blow molders produce these items? Well first its important to mention that there are different types of blow molding techniques designed to serve certain applications with different capabilities. The the two main techniques are Extrusion Blow Molding and Injection Blow Molding. However, there is also a third type know as Stretch Blow Molding which is a essentially a combination of the two main types of blow molding. it is also important to mention that there are different methods that fall under each of the three blow molding methods such as continuous extrusion blow molding which falls under the extrusion blow molding category. Also, most variants have to do with the difference in handling of the parison, molds, or other features. Now that we've given a general introduction lets take a more in-depth look at the different processes.
Extrusion Blow Molding
Extrusion Blow Molding (EBM) is the more commonly used technique of the three, in fact when people mention "blow molding" they are almost always referring to EBM. This particular process involves heating up a plastic or other material and forming it into a parison. If you are not familiar with what a parison is it is essentially a small tube that is made up of the material that will produce the end product. Usually the dimensions of the parison will determine the thickness of the hollow item. Once the parison has been formed the semi-molten item is then placed inside a mold and is held by a split die on both ends. The mold seals the parison's bottom end and the top is hooked up to an air supply that forces compressed air into the semi molten parison located inside the mold. The air essentially forces the parison to take the shape of the mold by blowing it up until it fills the entire shape of the mold. When the semi molten material makes contact with the entire mold the heat is transferred through the mold to the cooling lines which then cool the molded product and allow it to become rigid. Once everything has sufficiently cooled the mold is opened and the blow molded product is ejected and any excess flashing is trimmed.
Continuous Extrusion Blow Molding
With this extrusion blow molding variant the extrusion machine continuously extrudes the parison to a sufficient length. The Parison is then cut by the closing mold halves. The mold halves can be modified into different variations depending on the mounting and movement of the mold. One variation is the rotating wheel technique in which the molds are on the edge of a rotating wheel. Here the the molds are used constantly as they are rotated on the wheel. This type of configuration is ideal for high volume production. In this case different parts of the rotating wheel are used for different purposes in the process such as inflating, cooling, and other tasks. in addition to rotary wheel equipment other commonly used equipment includes shuttle machinery. One down side to continuous extrusion blow molding is that calibrating the wall thickness is difficult due to to the fact that the weight of the parison is what drags the parison during extrusion. Nevertheless this type of EBM is ideal for small or meduim sized products and EBM also promotes faster cycle times which prevents degradation and unwanted curing of the material. This aspect makes this process a go to for the blow molding of heat sensitive plastics such as PVC.
Intermittent Extrusion Blow Molding
One difference between continuous extrusion blow molding and intermittent extrusion blow molding (IEBM) is the use of equipment. in IEBM accumulator head machinery and reciprocating screw machinery is commonly used. in this process extrusion of the parision begins only when the extruder head or accumulator is adequately filled with enough molten material mass. As mentioned, either accumulator head equipment or reciprocating screw equipment is used to extrude the parison. The reciprocating screw method works by retracting the screw as the molten material collects in the extruder head. once there is sufficient melt in the extruder head the screw starts rotating and compressing the melt which causes the parison to be extruded.
Injection Blow Molding
Injection Blow Molding (IBM) is the second most commonly used process
Extrusion Blow Molding
Extrusion Blow Molding (EBM) is the more commonly used technique of the three, in fact when people mention "blow molding" they are almost always referring to EBM. This particular process involves heating up a plastic or other material and forming it into a parison. If you are not familiar with what a parison is it is essentially a small tube that is made up of the material that will produce the end product. Usually the dimensions of the parison will determine the thickness of the hollow item. Once the parison has been formed the semi-molten item is then placed inside a mold and is held by a split die on both ends. The mold seals the parison's bottom end and the top is hooked up to an air supply that forces compressed air into the semi molten parison located inside the mold. The air essentially forces the parison to take the shape of the mold by blowing it up until it fills the entire shape of the mold. When the semi molten material makes contact with the entire mold the heat is transferred through the mold to the cooling lines which then cool the molded product and allow it to become rigid. Once everything has sufficiently cooled the mold is opened and the blow molded product is ejected and any excess flashing is trimmed.
Continuous Extrusion Blow Molding
With this extrusion blow molding variant the extrusion machine continuously extrudes the parison to a sufficient length. The Parison is then cut by the closing mold halves. The mold halves can be modified into different variations depending on the mounting and movement of the mold. One variation is the rotating wheel technique in which the molds are on the edge of a rotating wheel. Here the the molds are used constantly as they are rotated on the wheel. This type of configuration is ideal for high volume production. In this case different parts of the rotating wheel are used for different purposes in the process such as inflating, cooling, and other tasks. in addition to rotary wheel equipment other commonly used equipment includes shuttle machinery. One down side to continuous extrusion blow molding is that calibrating the wall thickness is difficult due to to the fact that the weight of the parison is what drags the parison during extrusion. Nevertheless this type of EBM is ideal for small or meduim sized products and EBM also promotes faster cycle times which prevents degradation and unwanted curing of the material. This aspect makes this process a go to for the blow molding of heat sensitive plastics such as PVC.
Intermittent Extrusion Blow Molding
One difference between continuous extrusion blow molding and intermittent extrusion blow molding (IEBM) is the use of equipment. in IEBM accumulator head machinery and reciprocating screw machinery is commonly used. in this process extrusion of the parision begins only when the extruder head or accumulator is adequately filled with enough molten material mass. As mentioned, either accumulator head equipment or reciprocating screw equipment is used to extrude the parison. The reciprocating screw method works by retracting the screw as the molten material collects in the extruder head. once there is sufficient melt in the extruder head the screw starts rotating and compressing the melt which causes the parison to be extruded.
Injection Blow Molding
Injection Blow Molding (IBM) is the second most commonly used process
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What Do Mechanical Engineers Do?
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Mechanical engineers must have vast knowledge in their field to be able to carry out various tasks. However, how they use that knowledge depends on the industry they work in as well as other factors. More than likely a mechanical engineer will find themselves completing a variety of tasks which may include:
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What is the Future of Mechanical Engineering?
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Its interesting to think where the mechanical engineering field is headed and what inventions mechanical engineers will create in the near future. Various advancements in materials science, chemistry, nanotechnology, energy, and various other fields will likely expand the field even further. Currently there are various initiatives that look to create large scale sustainable energy systems such as fusion energy, or green hydrogen based systems. There are also various new composite materials being created that have enhanced properties to optimize functionality in certain applications. Some composites are biodegradable, others are highly thermally resistant, Etc. of course mechanical engineering is involved in the creation of all these new technologies. And one could only imagine what else engineers would be able to create with fusion energy or new composite materials. With so many advancements in the making, mechanical engineering is becoming one of the most exciting fields to witness.
If you wish to learn about new and exciting advancements in mechanical engineering check out our blogs here.
If you wish to learn about new and exciting advancements in mechanical engineering check out our blogs here.
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