Paper Cup Machine Rim Forming Troubleshooting

Document 2： Paper Cup Machine Rim Forming Troubleshooting | Cup Mouth Wrinkling & Cup Sticking Fix Guide

May 27, 2026

Brand: Shunda | Manufacturer: Haining Chengda Machinery Co., Ltd.

Document Keywords: paper cup rim forming fault, cup mouth wrinkling solution, paper cup machine cup sticking, rim rolling blowing time adjustment

Meta Description: Complete troubleshooting guide for Shunda paper cup machine rim rolling system, solving cup mouth wrinkling, inward folding, cup sticking and other common rim forming defects with standard commissioning steps.

Rim rolling forming is a key process that affects paper cup mouth flatness and appearance quality. Unreasonable rim rolling volume, offset center position, improper support block height and incorrect blowing timing will cause a large number of defective cups. This document provides standardized adjustment procedures for Shunda series paper cup forming machines to effectively solve various rim rolling failures and ensure neat and smooth cup mouth forming.

2. Rim Forming Faults and Commissioning Standards

2.1 Primary Rim Rolling Volume Adjustment

During primary rim rolling, maximize the rim rolling volume on the premise of no wrinkling and edge folding at the cup mouth to ensure full forming of the cup rim. Sufficient rim rolling volume can enhance the structural strength of the cup mouth, prevent deformation during stacking and use, and improve the overall qualification rate of paper cups.

2.2 Adjustment for Single-Side Paper Inward Folding at Cup Rim

If single-side paper inward folding occurs at the upper cup mouth during primary rim rolling, it is judged as rim rolling center offset. Appropriately fine-tune the rim rolling center position according to the wrinkling and offset direction. Follow the principle of fine tuning toward the offset side to calibrate until uniform cup rim forming is achieved. Small-range fine adjustment is required to avoid secondary deviation caused by excessive displacement.

2.3 Troubleshooting of Cup Sticking During Rim Rolling

Cup sticking and poor cup demoulding during rim rolling are mainly caused by excessively high cup bottom support blocks, which leads to insufficient fitting between the paper cup and the rim rolling tank. Adjust the cup bottom support blocks downward by 1mm per operation, and calibrate step by step until the paper cup fits tightly with the rim rolling tank without loose clearance. Tight fitting ensures synchronous forming and demoulding, eliminating cup sticking and cup dropping failure.

2.4 Rim Rolling Blowing Time Calibration

Blowing ON timing: Activate the blowing system 20° phase before the upward movement of the rim rolling mechanism. Blowing OFF timing: Stop blowing when the rim rolling nylon parts are completely separated from the top of the cup mouth. Accurately match the forming sequence to avoid cup rim deformation and material accumulation. Reasonable blowing timing can effectively cool the cup mouth and prevent thermal deformation and adhesion defects.