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Glass Versus Plastic Containers - A Packaging Machinery Manufacturer's Viewpoint

In designing and creating packaging machinery for a wide range of industries and products, the team at Liquid Packaging Solutions works with bottles and other containers from small to tall, thin to fat and straight to tapered. These containers also come in a range of materials, though almost all of them can be tagged as either glass or plastic. While there are a number of differences between these two materials, there are a couple of traits that always recur when working with one over the other.

CONTAINER CONSISTENCY

The manufacture of the bottle itself can be an important part of choosing and manufacturing the correct packaging machinery for production. While both glass and plastic will obviously work with the packaging machinery built by LPS, the focus will shift slightly depending on which material is being used for the given project. When working with glass bottles, the packager and machinery manufacturer must be aware that the consistency may vary from bottle to bottle, both internally and externally. If glass bottles vary in interior volume, using an overflow filler could lead to variations in product volume from bottle to bottle. On the other hand, using a gravity type filler may lead to correct volumes but fill levels that vary from bottle to bottle. The inconsistent interior fill must simply be taken into account, with numerous other factors, when selecting the ideal filling machine for the project at hand.

In addition to the interior volume, the exterior of the bottle may also vary from container to container when dealing with glass. Such inconsistencies can make labeling more difficult on glass bottles, causing off-center labels or wrinkles. Like the filler issue, this is not something that can not be overcome, but is normally an issue that must be considered when working with glass containers. In this area, plastic containers have a slight advantage over glass in that there will be less inconsistency from container to container when dealing with the plastic and the issues described above will be less pronounced, if they are an issue at all.

CONTAINER HANDLING

A second difference between glass and plastic containers often arises in transferring the containers down a power conveyor or through a packaging line in some other manner. The extra weight of glass bottles helps to keep them upright and secure as they progress through the packaging process. The lighter weight of the plastic bottle may require extra steps or components to keep containers stable. The main concern for a packaging machinery manufacturer is getting the empty plastic bottles to the filling machine. Once the bottles reach the filler, the extra weight from the product will help resolve any stability problems. Again, this is simply a recurring issue that both the packager and the manufacturer must be aware of and take into account when choosing the proper equipment for any given project.

Other differences between these two materials do exist. Concerns such as breaking, leaking or leaching may make one material type more advantageous or more desirable from a packager's point of view. However, as a manufacturer of machinery, LPS simply wants to ensure that the best equipment is designed and built for the unique project at hand. Learning about the container material being used is one of many steps taken to reach this goal.