In paper mills, where massive paper-making machines speed out paper at lightning speed, inspection is not just a nice-to-have—it’s a necessity. These machines work with plant fiber pulp, which forms bonds in water as it glides through a series of mighty rollers. However, the nonstop operation and blazing hot temperatures in these rollers can take a toll on the equipment. Rubber and steel bonding areas and roller surfaces are especially prone to damage and cracks due to the constant temperature shifts and sheer exhaustion. That’s where regular inspections come in. They’re like the eagle eyes of the mill, scanning for any signs of trouble and nipping it in the bud.

The Challenge

Our client encountered two significant hurdles. Firstly, identifying the absence of fusion in rubber to steel bonding areas proved challenging using traditional manual ultrasonic inspection methods. The varying velocities of rubber and steel complicated the detection process. Secondly, pinpointing cracks in the steel area posed difficulties due to the complex geometry and thickness of the rollers. Manual ultrasonic inspection encountered further limitations as the velocity of rubber was four times lower than that of steel, resulting in outcomes dependent on the operator. Additionally, the manual approach led to prolonged inspection times, causing inefficiencies in the overall inspection process.

The Solution

Utilizing the OMNISCAN X3 ultrasonic testing system, Blue Star proposed the Phased Array Ultrasonic Testing (PAUT) method to address the challenges. To identify near-surface indications in rubber and address the lack of bonding in the rubber-to-steel area, Blue Star conducted zero-degree linear and -30 to +30 sectorial scans using specialized probes. Furthermore, a thorough phased array ultrasonic examination was carried out to precisely pinpoint and characterize cracks in the steel area. This approach facilitated accurate detection, detailed mapping, and precise depth measurement of defects, ultimately improving inspection efficiency, and enhancing overall reliability.


  • Accurate Detection: The solution enabled precise identification of bonding issues and cracks, ensuring a comprehensive assessment.
  • Detailed Mapping: Advanced techniques provided precise mapping of bonding areas and depth measurements, enhancing overall understanding.
  • Reduced Inspection Time: Implementation of innovative techniques significantly decreased inspection time, improving operational efficiency.
  • Improved Reliability: The method and approach delivered reliable, reproducible results, reducing the risk of oversight and enhancing overall inspection reliability.

Related Products

Send an Enquiry