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Perfect Packaging Materials Part 5: HDPE

January 15, 2013|BY: Rob Helmke

HDPE Material
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If you’re looking for plastic that’s tough but versatile, High Density Polyethylene, or HDPE, is the material for you. Renowned for its strength but applicable for everyday consumer products, too, HDPE is used the world over for the unique molecular structure that gives it its durability—in fact, this plastic is produced by plastic molding companies more than any other type, and can be found everywhere from the grocery store to the battlefield.

HDPE’s Unique Strength

HDPE is an exceptionally dense plastic, which is part of what makes it so strong. It can withstand relatively high temperatures and isn’t affected by chemicals like gasoline, which may have the power to completely melt other types of plastic. This is the strength that industry professionals rely on, which is why you see HDPE used in the construction of things like hard hats, mortars and chemical piping. It even plays a role in the medical industry—HDPE is so strong and so safe, it is used in reconstructive surgery.

HDPE and Your Everyday Life

What really makes HDPE special isn’t just its strength, though. This plastic is versatile and cost-effective to the point that most people rely on it every single day. For example, plastic milk jugs and laundry detergent bottles are typically made out of HDPE, as it resists turning brittle or breaking like other types of plastic. Even the plastic bags that you use for getting those groceries home are made out of HDPE, as is the gas tank in your car, the cap on your soda bottle and the folding chair you sit on around the campfire.

Crafting HDPE with Finesse

Despite all its strength and ubiquity, not just anyone can successfully mold HDPE. This material has a notably high shrink rate, so if a plastic manufacturer isn’t used to working with the material, accounting for the shrinkage may prove difficult. At PI, we have to take the shrinkage into account when building both the knife and the mold, so that the material always ends up in the right size and shape—if you don’t have much experience doing it, that hard that you’re molding.