In blow molding, hollow plastic parts are being formed through a manufacturing process that is generally categorized into three main methods, namely injection blow molding, extrusion blow molding and injection stretch blow molding. Basically, the extrusion blow molding starts with melting down the plastic and forming it into a parison—a rounded mass of molten material formed by rolling it immediately after being removed from the furnace, with its final form being a tube-like plastic that has a hole in one end that serves as a passage way for compressed air. This material is then clamped into a mold and then blown by air, of which pressure will push the plastic out in order to match the mold. Once it has cooled and hardened, the mold would open up to eject the part. In the case of injection and injection stretch blow molding, these processes use a preform, which is a piece that already has a form beforehand.
Now, many plastic manufacturers use this method for the obvious benefits it brings. However, there are also some drawbacks to it that we should be aware of to know whether it is best to employ for the betterment of all. here are the advantages and disadvantages of blow molding:
List of Advantages of Blow Moulding
1. It is a revolutionary form of technology.
Blow molding is said to have revolutionized the industrial sector by allowing companies to use it widely to meet consumers’ needs for plastic ware. As you can see, this plastic production method brought about a lot of production perks, such as quick manufacturing and high volume outputs, which means that we are able to produce a lot of plastic containers.
2. It can produce a variety of products.
Most plastic containers on the market today that holds some forms of liquid has went through this process. In fact, the commonness of blow molding has allowed engineers to try and create a variety of applications and designs, which resulted to multiple interesting uses. Just to mention a few, the products created using this technology include fuel tanks, seat support for vehicles, flower pots and toy wheels.
3. It comes with low costs.
With a focus on extrusion blow molding, it uses a lower level of pressure, which means that machinery costs are low, making it easier and more cost-efficient to mold external threads or open-ended and large parts, which can be split by opening a closed molding. Moreover, the use of this technology will allow you to reduce labor costs.
4. It allows for multiple methods of production.
As already implied, blow molding uses various methods to create final products. For one, extrusion blow molding works similarly as traditional glass blowing, where materials are blown through a long tube to work on the end, which can create products, such as light bulbs. As for injection blow molding, it is employed to produce receptacles in huge quantities, where melted polymers are injected into the blow mold, instead of being blown through by air. Now, this technology is continuing to develop to improve such production methods, using tweaks in design and moving towards pure automation.
5. It promotes a higher level of productivity.
This technology has always been moving forward with the purpose of becoming universally used with plastic production. It has allowed for a significant increase in production capabilities, allowing manufacturers to produce greater quantities in just a short period of time. Using machines that allow for 3D moldings, it has allowed for a production cycle that is much faster.
6. It offers the benefits of automation.
Blow molding was taken to greater heights when the Placo X-Y machine from Japan was developed, giving rise to 3D blow molding. Basically, this is an automated production method that allows for minimal flash (excess polymer) around the material, seamless part incorporation and increased speed of production, thanks to the precise receptacle it creates.
List of Disadvantages of Blow Moulding
1. It is highly dependent on petroleum.
Like the gas industry, the blow molding sector highly relies on millions of gallons of petroleum to be able to produce plastic product. As oil is an essential factor in thermoplastics that is becoming automated and more streamlined, the technology has become an ongoing threat to the diminishing oil supply in the world.
2. It creates a huge impact on the environment.
As this technology depends greatly on petroleum and is an integral part in producing polymer, it carries a huge risk on the destruction of the environment. Aside from the fact that it contributes to the diminishing oil resources, it creates plastic that is not biodegrade. In a sense, it can increase plastic production, but it cannot remove the environmental risks its products bring.
3. It requires a lot of production methods.
While it is an advantage that this technology uses multiple production methods, it can be a disadvantage. As you can see, it would need more resources and the process could not be streamlined, thus removing correspondence in the process.
4. It comes with limited uses.
Considering that blow molding is limited to hollow forms, such as bottles and plastic containers, and air pressure is essential to the process, it would come with limited uses. For example, it will experience difficulties with wall thickness, which is difficult to control.
5. It requires process and material precision that creates waste.
Although this technology already uses automation to produce huge quantities of products, it is still limited to hollow forms. Considering that thickness should be precise, it can result in wasted material from processing containers with specific dimensions. Though thermoplastic is stretched to save on material, it can also lead to substandard products.
Indeed, the process of blow molding has taken the world of plastics to another level and the way people transport goods, with quick production and high volumes of output that allowed us produce receptacles at a lower cost for consumers around the world. However, it also comes with some disadvantages that we need to consider and build an opinion on whether it is best to make as a commonality, or not.
Natalie Regoli is a child of God, devoted wife, and mother of two boys. She has a Masters Degree in Law from The University of Texas. Natalie has been published in several national journals and has been practicing law for 18 years.