Marianne Purdie/Moment/GettyImages

Advantages & Disadvantages of Blow Molding

Growth Trends for Related Jobs

The process of blow molding has revolutionized the world of plastics and how people transport their goods. Its advantages of quick production and high volume output have allowed companies to cheaply produce receptacles for many of the world's most essential foods from milk to orange juice. This method is not without its disadvantages, however, as polymers of this type depend on diminishing resources to be created and have an environmental impact that yet to be adequately dealt with.

Variety of Products

Nearly every plastic container in the supermarket that holds a liquid has undergone some variety of blow molding. The ubiquity of the process has lead engineers to attempt a host of designs and applications of the design technique resulting in some interesting applications. Seat backs for automobiles, toy wheels, fuel tanks and flowerpots are just some of the objects and devices created using blow molding. The use of this technique works to cut down on labor and the potential for breaking parts, as the molded component is essentially one piece.

Multiple Production Methods

Different methods of blowing molding are currently available. Extrusion blow molding works much the same way as traditional glass glowing where the compound is blown through a long tube and worked on the end like a glass bulb. Injection blow molding is used for producing receptacles in large quantities where the melted polymer is injected into the blow mold rather than blown through using air as with extrusion blow molding. The technology continues to grow adding to these production methods with tweaks in production design and moves toward complete automation.

Blow Molding Automation

The Placo X-Y machine was developed in Japan and has given rise to three-dimensional blow molding, an automated production method that allows for seamless part incorporation, minimal flash (excess polymer) around the object and increased production speed due to the precision of the receptacle created.

Environmental Impact

Plastics depend greatly on petroleum production, as it is an integral component of the polymer's production. As a result, its production carries several risks, the largest of which is the diminishing resource aspect that petroleum presents. In addition, plastic does not biodegrade, which means every bottle, cup, wheel and other plastics ever manufactured is still on Earth today. Blow molding increases the production viability of plastic, but cannot remove its environmental risks.

Limited Uses

Blow molding is limited to hollow forms, such as plastic containers and bottles, as air pressure is an integral component of the process. Wall thickness is also hard to control, as the larger the product being built gets, the thinner the polymer has to be stretched.

References

About the Author

Jonathan Lister has been a writer and content marketer since 2003. His latest book publication, "Bullet, a Demos City Novel" is forthcoming from J Taylor Publishing in June 2014. He holds a Bachelor of Arts in English from Shippensburg University and a Master of Fine Arts in writing and poetics from Naropa University.