The short answer: choose by the actual outer diameter of the cup rim, not by the cup’s volume or brand model. Beverage cups commonly come in two rim sizes — 90mm and 95mm. The two are not interchangeable on the same sealing die: picking the wrong one causes misaligned seals, leaks, or wasted film. If your outlet uses a single cup type, match the machine to that diameter. If you run hot and cold, large and small cups together, choose a machine whose sealing range covers both ∮90 and ∮95mm so one unit handles everything.
Why a 5mm difference matters
The heated sealing die is engineered around the cup’s outer rim diameter. When the die does not match the rim, two failures are common:
- Die too large: the heated face cannot press the full rim, leaving an unsealed gap where cold drinks leak once shaken.
- Die too small: the rim will not seat, or gets deformed under pressure, wrinkling the film and skewing print alignment.
Although 90mm and 95mm differ by only 5mm, to a heated die they are two distinct sizes that must each be matched.
How to measure your cup diameter
Do not rely on the printed capacity — 500cc or 700cc describes volume, not rim size. Instead:
- Use a caliper or ruler to measure the straight-line distance across the outermost edge of the rim.
- Around 90mm → 90-diameter class; around 95mm → 95-diameter class.
- Note the cup material (PP / PET / paper) at the same time — it affects the film and sealing-temperature pairing.
90 vs 95 — where each fits
| Item | 90mm rim | 95mm rim |
|---|---|---|
| Typical cups | Most small/medium beverage cups | Large-volume cups, some brand-specified cups |
| Machine check | Confirm the sealing head fits ∮90 | Confirm the sealing head fits ∮95 |
| Mixing condition | A single machine must support both sizes to switch freely; otherwise a die change is needed | |
Applicable models
For a single machine covering both 90 and 95, consider the Kai Will K-2590SA sealing machine: sealing range ∮90 or ∮95mm, output roughly 5–12 cups per minute, suited to both hot and cold sealing, with touch-and-button dual operation and a Traditional Chinese / Simplified Chinese / English interface. For bowl-shaped containers, the K-300 bowl sealer is an alternative. For exact diameter matching and tooling, send us your cup photos for confirmation.
FAQ
Q: Can one machine seal both 90 and 95 cups?
Yes — provided the model’s sealing range already covers both sizes (as the K-2590SA does with ∮90/95mm). A single-diameter machine requires a tooling swap to switch.
Q: Same capacity, different diameter — why?
Capacity is set by cup height and wall curvature, which has no fixed link to rim diameter. Two 700cc cups can measure 90mm and 95mm respectively, so always measure the rim.
Q: What if I’m unsure of my cup’s diameter?
Measure the rim, photograph the cup, and let the Kai Will technical team help identify it.
Next step
Once you’ve measured the outer rim, noted the material and your daily cup volume, contact Kai Will and we’ll recommend a matching model for your cups and output.
Compiled by the Kai Will technical team. Content is updated on an ongoing basis; the official version is pending Kai Will confirmation.