Disposable Food Service Packaging: PP vs PS vs PET

The material is chosen by the food, not the price list

Every disposable food packaging enquiry starts the same way: "what is the cheapest". The answer depends entirely on what goes inside and how hot it is, and there are only three materials in real use — PP, PS and PET — plus their compostable cousins.

Put a hot curry in a PS box and it crazes and cracks before the customer reaches the office. Put a cold fruit salad in a PP box and you have paid for heat resistance nobody needs. Put either in PET and you get clarity, but only up to about 65 °C.

Temperature decides first

Two traps in that table. First, PS is not "cheap PP" — it is a different product with a 30–40 °C lower ceiling, and it fails by cracking, not by softening. Second, CPLA cutlery is only compostable if the finished article is certified to EN 13432 or ASTM D6400; the resin certificate is not enough, because thickness and additives change the outcome.

Lids: where the returns come from

A container body is easy. A lid that seals is not. Three parameters control it:

• Snap bead engagement 0.6–1.0 mm. Below 0.5 mm the lid lifts in a stacked carton; above 1.2 mm staff cannot close it quickly during a lunch rush.
• Lid-to-body clearance 0.15–0.30 mm on the perimeter. Tighter and the lid will not seat on a warm body; looser and it leaks.
• Vent hole for anything going into a microwave. A sealed PP box with no vent pressurises and the lid pops at 90 °C — a failure that never appears in a cold leak test.

Then test the way a customer uses it. Fill with water at 90 °C, invert for five minutes, weigh the paper underneath. A leak rate of zero over five minutes is the normal acceptance criterion for a hot-fill container; for cold applications, drop the filled container from 800 mm first and then invert it.

Tamper evidence is a separate mechanism, not a lid feature. A TE tab should break at 8–15 N with a visible tear line, and the break must be obvious after opening — a tab that can be re-seated provides no evidence at all. Specify the break force and ask for a photo of the opened state in the PPAP, because this is the one property a sample cannot show you.

Cutlery: 177 mm is the number that matters

A disposable cutlery set is specified by length, material and break strength, in that order.

177 mm is the common standard length for a full set (fork, knife, spoon, napkin) in a wrapped pack. Shorter sets read as "kids" or "budget" on a catering table.

Material is PS for cold and ambient use, PP where heat or toughness matters, CPLA for a compostable claim. PS is stiffer and gives a cleaner snap from the mould; PP bends before it breaks, which is what you want for ice cream and dense desserts.

Break strength — the test that predicts complaints: support the fork at the handle and load the tines. A PS fork that snaps under 15 N will not survive a steak; 25–35 N is a workable target for a general-purpose set. Add a bend test at 60 °C for anything sold as heat-resistant.

Wrapped sets add a hygiene and a cost decision: paper napkin plus film wrap is the default, and the wrap must be specified as food-contact grade with a migration declaration, not as generic packaging film.

Charger plates are decor, not tableware

A moulded charger plate — the large decorative plate under a dinner plate at weddings — is often quoted alongside disposable tableware, and it is a different product category. It does not contact food, so it is not tested as tableware, and claiming food contact for it invites a compliance question you do not need.

The specifications that matter are visual: diameter tolerance, edge roundness, colour consistency between batches, and stacking height. A 330 mm charger plate with a 0.5 mm colour drift between two production lots will be visible across a table of ten.

Standards and declarations

Two practical notes. A Declaration of Compliance is per article, not per material — if you change the lid supplier, the DoC must be reissued. And recycled content in a food tray is a compliance question before it is a marketing claim: rPET needs either a food-contact notification or a closed-loop source with documented decontamination.

Stacking, nesting and the carton

Disposable packaging is bought by the thousand and shipped by the pallet, so the packaging economics are decided by nesting.

• Nesting ratio — how many bodies fit in one another. A 20 mm rim height gives about 12–15 pieces per 100 mm stack; a 12 mm rim gives 20. Ask for the ratio, not the stack height.
• Carton compression — BCT of the master carton, tested at 48 hours, not 1 hour. Disposable cartons creep.
• Polybag count — sleeves of 50 or 100 reduce handling, but add a film cost and a declaration.

RFQ checklist

1. Food type, fill temperature, and whether it is microwaved.
2. Material with grade and resin code, per component including lid and film.
3. Capacity in ml, plus usable capacity with the lid on.
4. Lid type: snap, TE, hinged, or film-sealed.
5. Leak test method and acceptance (invert time, drop height).
6. Cutlery length, material, break strength, and whether wrapped.
7. Food-contact declaration type (DoC, 21 CFR statement, LFGB report).
8. Compostability certification, if claimed, at article level.
9. Nesting ratio, carton BCT, units per carton.
10. Print method on lid or body, with food-contact-safe ink confirmation.

A disposable container is a low-margin, high-volume part where a 0.2 mm change in lid clearance decides whether a customer reorders. Specify the clearance, not the appearance.

Related product categories

The materials and part types discussed above are grouped in our sourcing directory:

• PET resin and rPET
• polypropylene homopolymer and copolymer
• disposable tableware