Thermoforming is a go-to method for shaping food-grade plastics into everything from deli trays to industrial storage bins. But choosing the right plastic? That’s where things get technical. Different materials behave very differently when exposed to heat, chemicals, impact—or just a dishwasher.
If you’re designing packaging, equipment, or containers for food, four plastics dominate the conversation: HDPE, PP, HIPS, and PETG. Each has its strengths—and some important weaknesses.
HDPE: The Industrial Workhorse
High-Density Polyethylene is a favorite for cutting boards, food bins, and milk containers. It’s tough, resists harsh cleaners, and shrugs off impact. But it hates heat. Don’t put it near a steam cleaner or an autoclave.
Use HDPE when you need chemical resistance and durability, not thermal resilience.
PP: The Heat-Resistant Performer
Polypropylene is built for the heat. It handles microwaves, autoclaves, and steam cleaning without complaint. It also flexes without cracking—perfect for hinged lids and reusable containers.
It’s harder to form than others, but if your design needs to survive heat and repeated use, PP’s the clear winner.
HIPS: The Disposable Go-To
High-Impact Polystyrene is cheap, easy to form, and perfect for short-term use. You’ve seen it in bakery trays, takeout containers, and printed lids.
It’s not heat- or chemical-resistant, but for single-use applications where cost is king, HIPS delivers.
PETG: The Pretty Tough One
Polyethylene Terephthalate Glycol offers crystal clarity and decent strength. Great for clamshells, clear packaging, and medical trays, it looks sharp and holds up—if you treat it gently.
Avoid strong cleaners or high heat, but for display-friendly packaging, PETG is hard to beat.
Cleaning Compatibility Matters
- PP is the only one that’s reliably autoclave-safe.
- HDPE is okay with chemicals but struggles with heat.
- PETG wants mild detergents and soft handling.
- HIPS should avoid anything harsher than warm soapy water.
Get the Right Material for the Job
Choosing the best plastic depends on how your part will be used, cleaned, and disposed of. There’s no universal winner—just the right material for the right job.
Need help making the right call?
Visit rapidmade.com or email [email protected] for food-safe thermoforming solutions that hit the mark every time.
