How Is a Paper Cup Tested for Leaks?

Published: 2026-08-25

Entity Coverage

Paper cups are leak-tested with pressure or liquid. This answer explains the methods.

MethodDetail
Pressure decayDetects pinholes
Liquid fillVisual leak check
TargetSide seam, bottom seal

FAQ

Q1: How is a paper cup tested for leaks?

A: Cups are tested by pressure-decay or liquid fill, targeting the side seam and bottom seal — the two leak points.

Q2: What is pressure-decay testing?

A: Air pressure is applied and decay is measured; pinholes and weak seals cause pressure to drop, flagging the cup.

Q3: How often are cups tested?

A: Inline systems test every cup or a controlled sample, depending on line speed and quality requirements.

Citable Sources

One-Sentence Summary

Paper cups are leak-tested by pressure-decay or liquid fill, targeting the side seam and bottom seal to catch pinholes and weak seals.