Like so many of the plastics we work with here at PI, High Impact Polystyrene, or HIPS, is something that a great deal of people encounter almost every single day. Clear, brittle and impact-resistant, this amorphous material has a low shrink rate and is safe enough to use in different food-related applications.
HIPS is flexible, hygienic and cost-effective, making it a perfect fit for food service and containment. The plastic cutlery in your office break room, for example, may be made of HIPS, as is the disposable salad bowl that your lunch came in (though these may also be made out of a different member of the styrene family, too). It withstands cold temperatures and humidity, it's lightweight and provides excellent insulation, so you may also see it used in the construction of refrigerators.
A Real Jewel
While HIPS is clear by default, it lends itself to colorization through the use of modifiers, enabling you to create clear, colored plastics that also boast high impact strength. One of the most easily recognizable and universal uses of HIPS is in the manufacturing of CD jewel cases. While the average jewel case is clear, others—particularly ones in which CD-R discs are packaged—come factory-tinted in different colors.
You may not realize it when you're sifting through your CD collection, but HIPS is also advantageous in the hands of an experienced plastic manufacturer. HIPS doesn't lose its physical thermoforming properties as much as other plastics do, so if you know how to handle the material, you can separate the regrind and reuse it for other applications. This cuts back on waste, ensuring that we get the most out of our materials instead of sending regrind off to the landfill.