Detection Requirements of Papermaking Machinery

In order to address issues such as paper wrinkling and uneven thickness that occur during the operation of high-speed papermaking machinery, as well as the higher precision requirements for equipment due to the manufacturing of new products, papermaking companies have decided to conduct systematic precision calibration of their large paper machines.

Challenges in Papermaking Machinery Detection

In the measurement and detection operations implemented for large papermaking machinery, traditional optical instruments and mechanical measuring tools are limited by measurement range, accuracy, and dynamic capabilities, making it difficult to efficiently complete comprehensive verification and adjustment of the overall geometric accuracy. The main challenges faced during the measurement and detection operations include:

① Super large size structure - The length of the drying cylinder group exceeds 30 meters, making it difficult for traditional tools to measure coaxiality and parallelism as a whole;

② Demand for dynamic accuracy measurement - It is necessary to evaluate the geometric tolerance measurement of rollers under simulated operating conditions (such as micro-vibration and thermal expansion);

③ Ultra-high precision 3D measurement requirements - Coaxiality, roller surface runout, and flatness of the bearing seat installation surface are all key parts of the equipment, requiring high detection accuracy;

④ Reduce downtime and complete detection and adjustment in the most efficient way - The cost of production line downtime is high every day, requiring efficient completion of measurement and calibration work.

Figure 1: API Series Laser Trackers (from left to right, models are: iLT / Radian Plus / Radian Pro / Radian Core / iLTx)

API Solutions

In response to the measurement needs and challenges of paper machinery, API provided the Radian Plus model laser tracker for the measurements in this case, facilitating the relevant measurement requirements. The Radian Plus laser tracker is portable, precise, has a large measurement range, and high efficiency, offering micron-level 3D measurement accuracy. Its ultra-high sampling rate of 1000Hz ensures excellent performance in both static and dynamic measurement needs. The Radian Plus laser tracker has a measurement range of over 160 meters, capable of addressing the demand for large-scale measurements of several meters in paper machinery. Additionally, the Radian Plus laser tracker features a battery-powered system and a wireless data transmission module, enabling completely wireless precision measurement operations, unaffected by complex measurement site environments and confined spaces, with simple operation and ease of use.

Figure 2: Measurement Site of Paper Machinery (1)

Measurement and Inspection Content

In this case, the Radian Plus laser tracker was used to measure and evaluate the following: ① Coaxiality and parallelism of the press rolls, guide rolls, and drying cylinders; ② Flatness and levelness of the bearing seat installation base; ③ Circular runout of the drying cylinder end face and linearity of the roll surface centerline; ④ Symmetry and verticality of the frame.

Figure 3: Measurement Site of Paper Machinery (2)

Measurement and Operation Process

1. Laser Tracker Setup: Set up the laser tracker at suitable positions around the paper machinery to ensure visibility of all measured component locations;

2. Establish Coordinate System: Establish a global measurement coordinate system in the measurement software;

3. Static Measurement: Use a 1.5-inch high-precision SMR target sphere, along with various pins and seats, to quickly collect the coordinates of the center holes of each bearing seat, measure the key circumferential points of the drying cylinder end face and roll surface, and scan important installation planes of the frame;

4. Dynamic measurement simulation operation verification: In a low-speed state, track the radial runout and axial movement of key rollers; collect the coordinate changes of key points in the drying cylinder during the temperature rise process to assess the impact of thermal deformation during operation;

5. Data analysis and adjustment guidance: By measuring the collected data and using measurement software, the coaxiality errors, parallelism deviations, flatness errors, roundness runout, etc. of each roller are obtained according to requirements; intuitive deviation reports and detailed data lists are generated; subsequently, the measurement report is used as data support to guide on-site adjustments, accurately correcting deviations by adding or reducing bearing seat shims, fine-tuning the frame position, etc.

Figure 4: Measurement site of papermaking machinery (3)

Summary

The Radian Plus laser tracker, with its micron-level measurement accuracy, ultra-large measurement range, and excellent measurement performance under dynamic/static conditions, fully meets the measurement needs for key positions such as shafts, rollers, drying cylinders, and frames of large papermaking machinery. After calibration using the Radian Plus laser tracker, the coaxiality of the key roller group, the flatness of the installation base surface, and the runout errors measured dynamically during operation all met design standards, completing measurement tasks that would traditionally take several days in a very short time, significantly improving work efficiency and saving time costs for the enterprise.

Figure 5: Radian Plus laser tracker (left) and iLT laser tracker (right)

Figure 6: Application site of iLT laser tracker

Breakthrough excellence, more choices

In addition to the Radian model laser tracker used in this case, the API brand has also launched the new iLT laser tracker, which reduces the overall size of the laser tracker by an additional 50% (compared to the Radian series) based on the fully wireless measurement capability of the Radian Plus/Core models, with a total weight of only 4.9 kg, maximizing portability and fully meeting the application environments of outdoor, field, confined spaces, and multi-machine integration.

Figure 7: Non-contact measurement operation site of 9D laser radar automotive frame hole positions

Leading the future, more expansions

In addition, the API brand's 9D laser radar (9D LADAR) products can achieve non-contact measurement without cooperative targets based on high measurement accuracy at the micrometer level. With the support of OFCI core measurement technology, the spatial coordinate data of the laser touch position can be fed back to the measurement software in real-time, with a data acquisition rate of up to 20KHz, instantly achieving point cloud data collection that is precise, fast, and efficient.

Figure 8: API Company Headquarters Building

About API

The API brand was founded by Dr. Kam Lau in 1987 in Rockville, Maryland, USA. He is the inventor of the laser tracker and holds multiple patents for globally leading measurement technologies, making him a leader in the field of precision measurement technology. Since its establishment, API has been committed to the research and production of precision measuring instruments and high-performance sensors in the mechanical manufacturing field. Its products are widely used in advanced manufacturing sectors around the world and are at the forefront of high-precision standards in coordinate measurement and machine tool performance testing.