Q. What is extrusion blow molding?
A. Simply put: it's the process by which plastic is "blown" into a mold cavity. Think of it like closing a mold on a hot balloon, then blowing the balloon up inside of the mold cavity. Once the hot balloon comes in contact with the cool surface of the cavity, it takes shape and solidifies.
Q. I thought blow molding was only used to manufacture bottles. Can other shapes be molded besides bottles?
A. Absolutely. Our own imaginations are usually the greatest limiting factors. Many industrial shapes are readily blow molded. Garden supplies, toys, electronic enclosures, automotive gas tanks, industrial containers, and specialty packaging, just to name a few.
Q. Is the tooling expensive?
A. Sometimes, yes. However, they are generally much less expensive than an injection mold of equivalent size.
Q. What are the molds made out of?
A. Molds can be made out of a number of good materials. Most blow molds are manufactured from aluminum. Some requirements will call for hardened alloy steels or berrillium copper.
Q. What is the life expectancy of an aluminum mold?
A. Millions of parts can be run on an aluminum mold. Maintenance is generally easy as well.
Q. I thought blow molding was a slow process. How many parts can you run in a day?
A. Multiple cavities, correct machine selection, and good tool designs are the key ingredients to high volume production. Of course, every part is unique, but you can expect to run thousands of parts per day on most small configurations