Sauce Cup Sealing: Foil Film vs Heat Seal vs Plastic Lid

The five cups this applies to

Note the packing difference: SC10 packs 2,000 per carton, everything else 1,000. That single line changes your carton count, your pallet count and your freight per piece — a buyer comparing quotes without checking this is comparing two different shipments.

Three closing methods compared

Why foil still dominates sauces

Three reasons, all practical:

1. Seal integrity on a wobbly cup. Sauce cups are small and flexible. A snap lid relies on rim tolerance of about ±0.2 mm; a heat seal bonds to the rim and tolerates more. On a 59 ml cup with a 3.5 g wall, that tolerance matters.

2. The oil problem. Oil-based dressings creep under a snap lid at 40°C. Heat-sealed foil does not. If your product is a vinaigrette shipped in summer, this decides it.

3. Cost. A foil lid on a 2 oz cup is a fraction of the cost of an injection-moulded lid, and it removes 2–4 g of plastic per unit — which is now a regulatory advantage in the EU, not just a cost one.

When the plastic lid is right

• Dine-in or buffet, where the customer opens and closes
• Refill or subscription programmes
• Markets where the customer cannot handle a sealed cup (no scissors, elderly, kids)
• Reuse programmes — a sealed cup is single-trip by design

What to specify on the PO

Four lines decide whether your order works:

1. Cup model — SC10/15/20/30/40, not "2 oz"
2. Lid type — foil, film or plastic, and the material
3. Seal diameter — measured at the rim, not the cup body
4. Film thickness — 30–40 micron foil for sauces; below 30 the seal weakens at the crease

Add the fill temperature. Sealing a hot sauce changes the seal: steam pushes the film before the bond sets. If you fill above 60°C, say so — the seal parameter changes and a standard film may fail the leak test.

The carton arithmetic nobody does

SC10 packs 2,000 per carton at 6.4 kg gross. SC40 packs 1,000 at 6.9 kg. Same carton weight, half the pieces — so the freight cost per cup on SC40 is roughly double that of SC10, before you price the cup itself.

If you are comparing two quotes for "4 oz sauce cups", check the pcs/ctn first. A supplier quoting 2,000 per carton is either using a bigger carton or a lighter lid — and you will find out at the loading dock.

FAQ

Can I seal PP cups with foil? Yes, with a PP-compatible lacquer on the foil. Plain aluminium foil does not bond to PP. Specify "PP-lacquered foil" and ask for a peel-strength figure.

Does a heat-sealed cup survive freezing? The seal does; the cup may crack if it is a homopolymer grade. Ask for copolymer PP if the product goes below −18°C.

Which is cheaper, foil or film? Foil, usually, at the same thickness. Film wins when you need product visibility or microwave transparency.

Can the same machine do cups and trays? Usually yes, with a tooling change. Confirm the platen size before buying a sealer.

Related reading

• 2oz PP Sauce Cup: PF-SC20 Specifications
• Food Container Sizes Guide: ml to oz for Takeaway Lunch Boxes, Bowls and Sauce Cups
• ml to oz: PP Food Container Capacity Chart

Models covered on this site: 600 ml PF-Z600 · 470 ml PF-520 · 950 ml PF-GG950 · see all models in this category.