What should I do if the labeling machine frequently jams or runs out of labels?

On automated production lines, labeling machines are the core equipment that ensures both the efficiency and quality of product packaging. However, the frequent occurrence of label jamming and label breakage not only causes production lines to come to a standstill but can also lead to defects in product appearance, directly impacting enterprise profitability. This article, drawing on industry practices and failure case studies, systematically analyzes the root causes of these issues from three perspectives—equipment, materials, and operations—and provides targeted solutions.

## I. Equipment Factors: Optimization of Mechanical Structure and Parameter Configuration

### 1. Label Stripping Plate Wear and Imbalance in Tension Control

As the core component responsible for label stripping, the sharpness of the stripping blade directly affects the integrity of the backing paper. If the edge of the stripping blade is too sharp, it can easily scratch the backing paper during the stripping process, causing the label to break when being pulled. A food packaging company once experienced a series of continuous label-breakage failures due to the stripping blade not being sharpened in a timely manner. Testing revealed that the backing paper had scratches 0.1 mm deep. **Solution**: Regularly inspect the condition of the stripping blade and use an oilstone or sandpaper to round off its edges. At the same time, adjust the stripping angle to between 120° and 150° to reduce concentration of mechanical stress.

The tension control system is another key factor in preventing label breakage. After a pharmaceutical company introduced a tension-adjusting device driven by servo motors, it began automatically adjusting the traction force in real time by monitoring changes in the diameter of the label roll, reducing the label breakage rate from 3.2% to 0.5%. **Operational Recommendation:** Set tension thresholds on the equipment’s control panel, and in hot summer conditions, slightly reduce the initial tension setting to prevent the adhesive from softening and causing the backing paper to stick together.

### 2. Die-cutting Process Defects and Abnormal Roller Pressure

The quality of die-cutting directly affects the tensile strength of the label liner. Flat-to-flat die-cutting equipment, due to pressure fluctuations, is prone to perforating the liner. A certain cosmetics company used a dyeing method for inspection and found that the color penetration depth at the die-cutting line reached 0.08 mm, exceeding the standard value by 0.03 mm. **Improvement Measures:** Switch to rotary-to-rotary die-cutting technology. This method, with its line-contact cutting approach, can control die-cutting accuracy within ±0.01 mm. Additionally, equip the machine with pressure monitoring sensors to enable dynamic compensation.

Improper adjustment of roller pressure can also cause problems. One electronic component manufacturer experienced edge tearing in labels as a result of excessively tight compression springs on the labeling shaft, which induced lateral stress on the labels when they passed through the labeling rollers. **Debugging Tips**: Use a torque wrench to adjust the compression spring pressure to the value recommended in the equipment manual, and use a high-speed camera to observe the deformation of the labels as they pass through the rollers, ensuring that the deformation does not exceed 15% of the label’s thickness.

## II. Material Factors: Managing the Compatibility Between Labels and Release Liners

### 1. Label Material Selection and Adhesive Seepage Control

The compatibility between the label facestock and the release liner directly affects the stability of labeling. One daily chemical company used an 80 g/m² glassine release liner paired with a high-viscosity adhesive, which resulted in severe adhesive seepage under the high-temperature conditions of summer, causing the labels to stick together inside the roll. **Solution**: Based on the ambient temperature, select an appropriate type of release liner. For environments above 30°C, it is recommended to use a silicone-treated release liner with a basis weight of 100 g/m² or higher. At the same time, the supplier should be required to keep the adhesive application rate within the range of 18–22 g/m².

Damage to the edges of labels is a common issue that often goes unnoticed. A logistics company discovered that during transportation, the edges of labels—specifically within a 0.5mm range—experience cracking in the backing paper due to packaging collisions. Under the tension applied by the labeling machine, these cracks quickly propagate and lead to complete tearing. **Preventive Measures**: After die-cutting the labels, implement edge-reinforcement processes, such as applying localized UV-curable adhesive, or require suppliers to use 45° mitered joints to reduce stress concentration.

### 2. Optimization of Label Roll Structure

The rewinding tension of label rolls directly affects their operational stability. A certain automotive parts manufacturer experienced speed fluctuations in the labeling machine when pulling labels due to the label rolls being loose on the inside and tight on the outside, which led to label breakage. **Quality Control Standard**: Suppliers are required to keep the rewinding tension within the range of 0.8–1.2 N/cm and conduct random inspections using a tension tester. Meanwhile, the diameter of the label rolls must match the dimensions of the equipment’s material hopper to prevent traction deviation caused by shaking.

## III. Operational Factors: Standardized Processes and Intelligent Monitoring

### 1. Speed Matching and Parameter Settings

The synchronization between the conveyor belt speed and the labeling speed is crucial. A food company experienced bubbling caused by the conveyor belt moving too fast, resulting in labels being squeezed by subsequent products before they could fully adhere. **Debugging Method**: Implement closed-loop speed control using an encoder to ensure that the difference between the conveyor belt’s linear speed and the label-delivery speed of the labeling head does not exceed 5%. At the same time, set a speed-gradient curve on the HMI interface to enable smooth acceleration during the equipment’s startup phase.

### 2. Intelligent Detection and Predictive Maintenance

Introducing a machine vision system enables real-time monitoring of label status. An AI inspection module deployed by a certain 3C product manufacturer can identify defects such as edge damage and glue leakage on labels using deep learning algorithms, achieving an accuracy rate of 99.3%. **Maintenance Recommendations**: Establish equipment health records to document key parameters such as the replacement cycle of stripping plates and the usage duration of die-cutting blades. Combined with vibration analysis technology, predict trends in bearing wear and implement preventive maintenance.