Non-contact inline and offline measurement and inspection systems for rubber strip and tyres

(See Micro-Epsilon at MachineBuilding.Live, 15 October 2025, on stand 87)

Many rubber processing and tyre manufacturing companies seek to use inline inspection and measurement equipment to provide continuous monitoring of the process to ensure quality at every stage.

Micro-Epsilon is a measurement specialist in this field and offers a range of non-contact, inline and offline measurement and inspection systems for process monitoring and quality control. These include specific measurement systems for rubber processing applications, including systems for measuring strip thickness, length, width and profile of rubber strip and sheet.

Specific systems have also been developed for the measurement of tyres for passenger, truck and commercial vehicles, including systems for measuring the thickness profile of tyres, tyre treads, sidewalls and inner tube linings, as well as systems for measuring other critical dimensions of tyres and for colour coding or marking of tyre treads.

These robust, complete turnkey measurement systems offer distinct technical advantages in terms of measurement accuracy, thermal stability and reliability, backed up by installation, servicing, maintenance and technical support.

These technical advantages include fully automatic calibration. The systems periodically re-measure against a known reference and have integrated measurement sensors in the framework and mechanical parts, which measure the thermal expansion of the system. The software then compensates accordingly.

Part of Micro-Epsilon's thicknessCONTROL family, the RTP 8302 is a C-frame system that measures the thickness profile of rubber strip and sheet. C-frame systems are modular in their design, offering flexibility and high performance. They can be installed in tyre production lines, extruders, roller heads, calendar lines and inspection rooms, providing reliable, high precision measurement results that creates a basis for controlling the production process and product quality.

C-frame systems measure differentially. An application-specific (confocal, capacitive or laser triangulation) displacement sensor is integrated in the upper and lower arms of the C-frame. The thickness of the target material is derived from the distance between the two sensors and the resulting signals. By combining highly efficient signal processing algorithms and visualisation software, the system is able to achieve accuracies in the sub-micrometre range.

The C-frame can be used as a traversing thickness measurement system on linear axes in order to ensure full width measurements of the target profile. The control and analysis software is developed in-house by Micro-Epsilon specifically to match the needs of the rubber processing and tyre manufacturing industries, providing all the required functions in order to continuously record and evaluate production quality. This includes graphical user interfaces and the ability to store multiple product libraries. Also, the software supports and displays Statistical Process Control (SPC) parameters and other 'Process Capability' analysis and reporting methods such as Six Sigma CPK and CPM. Various fieldbus interfaces are available, which enable integration to the customer's production control systems.

Fully automatic calibration ensures that measurements are not affected by temperature, enabling the system to be installed as a fixed, inline measurement system in harsh production environments, without the need for calibration or manual adjustments. All sensor technologies used are non-contact, wear-free and do not use isotopes or X-rays. The C-frame system provides long-term measurement reliability at an affordable price. C-frame systems can be used to measure strip widths up to 1m and strip thickness from xtagstartz1mm up to 18mm. Accuracies are from +/- 5um.