In the first part of this series, I described five general types of void fill —
- Loose fill materials
- Industrial papers
- Flexible foams and bubble material
- Expandable foam
- Inflatable air pillows
Now let’s look at the qualities you may need from your void fill material, and see how the various options stack up.
Surface protection. For glass, metal, and scratch-sensitive plastics, polypropylene (PP) foams are the least abrasive option, followed by polyethylene (PE) foams and bubble. Industrial papers, depending on the grade, may also work.
Dust free. Loose fill, whether polystyrene or one of the various biodegradable varieties, are prone to flaking. Industrial papers sometimes contain dust as a result of the trimming process. For shipping things such as pharmaceutical or personal health care products, look in other directions for void fill.
Cushioning. Expandable foams, which hold a product tightly in place, provide the best cushioning function, though they may be overkill. Foams and bubble are the next best choice, followed by air pillows, industrial papers, and loose fill. When considering your cushioning needs, take into account the entire package, not just the void fill. For instance, if you are using loose fill, a switch to air pillows may allow you to use a smaller corrugated box. If that’s the case, you will reduce the total amount of packaging used, and your total packaging cost as well.
Lightweight. The heavier the void fill, the more expensive the shipping costs and the more energy required for transport. For a given volume, industrial papers and paper-based loose fill materials are the heaviest among the five void fill types. Expandable foam weight varies depending on density, but in almost all cases it will exceed the weight of flexible foams and bubble. For many years, polystyrene loose fill was the lightest weight option, but today, air pillows are lighter still.
Cost. Expandable foams and flexible foams tend to be the most expensive per cubic foot. Bubble materials range from very expensive to moderate, depending mainly on overall bubble thickness and what type of coating, if any, is applied to the material to keep air sealed in. Industrial papers are one step up in cost from air pillows and polystyrene loose fill. The best ways to compare cost of void fill materials are cost per cubic foot and cost per application. As I mentioned earlier, different void fill can involve changes to other components of the package, making cost per application the ultimate test.
(Photo – Bubble Wrap, by Hey Paul on Flickr)