Rim Rolling and Curling on the Paper Cup Machine: A Strong, Smooth Drinking Edge

A paper cup's rim has to be stiff enough to hold its shape and smooth enough to drink from. Rim rolling and curling folds the top edge into a tight, rounded curl, giving the cup a strong, comfortable drinking edge that resists crushing and won't leak at the lip.

The Scenario: Three challenges in rim forming

Rim forming faces three challenges:

Pain Points

• The rim must be stiff enough to hold the cup's round shape;
• The drinking edge must be smooth and comfortable, not sharp or rough;
• A poor rim can crush or leak at the lip during use.

The Solution: Three rim solutions

Rim rolling offers three solutions:

1. Tight edge curl Curl the top edge into a tight, rounded rim for strength.

2. Smooth drinking edge Form the rim smooth and even for comfortable drinking.

3. Leak-resistant lip A well-formed rim resists crushing and leaking at the lip.

The Result: A strong, smooth rim

With these steps, the cup has a strong, smooth drinking edge. Rim rolling is the detail that makes a paper cup pleasant and reliable to drink from.