Technical guide
Plastic packaging materials
The resin you specify determines shelf life, chemical compatibility with your formula and cost per unit. This comparison covers PET, HDPE, PP and multilayer laminate — the four families behind most personal care, food, pharmaceutical and chemical applications.
| Material | Resin code | Clarity | Barrier | Chemical resistance | Service temperature | Recyclability | Typical uses |
|---|---|---|---|---|---|---|---|
| PET (Polyethylene terephthalate) | #1 PET | Very high (crystal clear) | Excellent oxygen barrier; moderate moisture barrier | Good against weak acids; sensitive to strong solvents and hot alkalis | −40 °F to 140 °F (cold fill) | High: closed loop with food-grade PCR | Beverages, oils, cosmetics, supplements, personal care |
| HDPE (High-density polyethylene) | #2 HDPE | Opaque (natural translucent) | Excellent moisture barrier; moderate oxygen barrier | Very good against acids, alkalis and detergents | −58 °F to 194 °F | High: PCR available as pellet and flake | Detergents, bleach, lubricants, chemicals, industrial containers |
| PP (Polypropylene) | #5 PP | Translucent to opaque | Good moisture barrier; low oxygen barrier | Very good against most chemicals and solvents | −4 °F to 230 °F (hot-fill and microwave safe) | High: our sister plant P4P produces pelletized PP PCR | Closures, hot-fill containers, food, pharmaceutical, spices |
| Laminate (BOPP / PET / PE) | #7 other (multilayer) | Varies: clear, metallized or printed | Very high to oxygen, moisture and aroma (with metallized or EVOH layer) | High; the inner PE layer is heat sealable | −4 °F to 194 °F (heat seal 250–355 °F) | Limited post-consumer; mechanically recyclable in industrial streams | Coffee, spices, snacks, dry foods, pet food, powdered chemicals |
How to read the resin code
The triangle with a number (1 through 7) is the international resin identification code. For packaging the relevant codes are #1 PET, #2 HDPE and #5 PP. Flexible laminates fall under #7 other because they combine several layers.
Evaluating a change from glass? See the side-by-side plastic vs glass comparison, or read about packaging with recycled content and PCR resin.