The objective of this project was the investigation of a compaction process using high-power ultrasonic energy. The application of the ultrasonic process was focused on the compaction of composite materials, in particular brake pads for the car industry. The new technology aims for a fast high-quality compaction process.
A high-power ultrasonic press was constructed and tested. New composite materials and new types of glue were developed and optimised for the ultrasonic technology. The work was focused on the analysis of the technology and on the optimisation of the process parameters. Computer simulations were included in the project.
The advantages of the ultrasonic process are manifold. In particular the ultrasonic technology allows for a lighter press construction and shortening the production time. In particular the pressing and the curing cycle can be shortened. One other major advantage was the increased fading coefficient.
The main deliverables of the project, which were successfully achieved are:
Press construction with an automatic feeder system:
-A hydraulic system for the generation of the pressing forces and a SPC control unit for the process control was used.
Ultrasonic system:
-The ultrasonic system is the key element of the press. It consists of the ultrasonic power generator, a converter, booster for the adjustment of the mechanical oscillations and the tool.
Tools:
-The tools for the ultrasonic system were specially developed in the frame of the project.
Instrumentation:
-Several different parameters were measured (temperature, force, pressure, mechanical waves) and used for the process control. All measurements were recorded in a central monitoring unit. The measurement of the mechanical waves was done with a newly developed device.
Development of different new types of composite materials:
-Different types of friction material powders have been developed for an optimisation in connection with the ultrasonic press process.
Development of different types of glue:
-A big variety of new glue compositions was developed, like different so-called hydro-glues, powder-glues and solvent-free glues.
Production of brake pads:
-Series of brake pads were produced and tested. The process, the materials and the glues were evaluated and optimised for industrial application.
