Air Shaft Slipping, Air Leakage, or Poor Grip? Common Problems Explained

 

In printing, packaging, laminating, and converting lines, the air shaft plays a critical role in web handling. When an air shaft starts slipping, leaking air, or failing to grip the core properly, it can cause unstable tension, material waste, and unexpected downtime.

These issues are common—but they are not unavoidable. In this article, we break down the most frequent air shaft problems, explain why they happen, and share practical solutions to help you improve reliability and production efficiency.

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1. Air Shaft Slipping During Operation

Common Symptoms

• The roll rotates independently from the shaft

• Loss of web tension during acceleration or deceleration

• Inconsistent winding or unwinding

• Noise or vibration at higher speeds

Main Causes

• Insufficient air pressure: The shaft is not inflated to the required working pressure

• Worn or damaged lugs: Lugs lose their gripping ability after long-term use

• Incorrect core size: Mismatch between shaft diameter and paper or film core

• Low-friction core material: Some plastic or coated cores are harder to grip

Practical Solutions

• Check and maintain the recommended air pressure

• Replace worn lugs in time

• Confirm core inner diameter tolerances before use

• Consider customized lug designs for smooth or special core materials

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2. Air Leakage: Slow Pressure Loss or Complete Failure

Common Symptoms

• Shaft needs frequent reinflation

• Pressure drops during long production runs

• Air hissing sound near valves or shaft body

Main Causes

• Aging or damaged air bladder

• Poor sealing at the air valve

• Internal scratches or contamination

• Low-quality bladder material

Practical Solutions

• Inspect and replace bladders periodically

• Use high-quality air valves and sealing components

• Keep the shaft interior clean and dry

• Choose air shafts with proven bladder materials designed for long service life

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3. Poor Grip on the Core

Common Symptoms

• Core slips even with sufficient air pressure

• Uneven expansion of lugs

• Localized gripping instead of full contact

Main Causes

• Uneven lug expansion

• Core deformation or poor-quality cores

• Improper lug layout for the application

Practical Solutions

• Ensure uniform lug expansion across the shaft

• Use stable, standardized cores

• Match lug quantity and layout to roll width and load

• For heavy rolls, consider reinforced or heavy-duty air shafts

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4. Problems Caused by Incorrect Air Shaft Selection

Not all air shafts are designed for the same working conditions. Using an unsuitable shaft often leads to repeated problems.

Typical Mistakes

• Using light-duty air shafts for high-speed or heavy-load applications

• Ignoring balance requirements for fast-running lines

• Choosing standard designs instead of application-specific solutions

How to Avoid This

• Define roll weight, speed, and material clearly

• Select shafts designed for printing, laminating, or coating applications

• Work with manufacturers who offer customization and technical support

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5. Preventive Maintenance Tips for Longer Air Shaft Life

Many air shaft problems can be prevented with simple daily and periodic maintenance.

• Do not exceed the recommended air pressure

• Release air when the shaft is not in use

• Clean lugs and shaft surface regularly

• Inspect bladders and valves during scheduled maintenance

• Replace worn components before failure occurs

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Conclusion

Air shaft slipping, air leakage, and poor grip are not just minor inconveniences—they directly affect production stability, print quality, and operating costs. Understanding the root causes of these issues helps you select the right air shaft, maintain it properly, and avoid unnecessary downtime.

A reliable air shaft is not just a component—it is a key factor in efficient web handling and consistent production performance.