Tube Drawing

Non-Destructive Testing in Tube Drawing

The first automated measurement system to optimize your drawing process

Pulling tubes through a die may seem pretty straightforward. In reality, many process variables affect the quality of your product and a simple lack of drawing agent may lead to large tube vibrations, also known as “chatter”. This unwanted effect may leave visible marks and geometric deficiencies on your product.

QASS developed the Opimizer4D for an efficient and fast structure-borne sound analysis. It monitors and optimizes manufacturing processes at the same time. With this device, chatter can be sensed before it becomes a problem.

Quality Issues Caused by Chatter

During the drawing process, vibrations may occur which lead to chatter marks on or inside the tube. This effect is caused by a lack of friction: The system’s tribology is a product of drawing speed, the degree of material deformation, and the amount of drawing agent on and inside the tube. When this delicate equilibrium is out of control, the internal mandrel quickly oscillates around its optimal position. The result is an irregularly shaped surface with chatter marks. Once this mass-spring system is set in motion, a system-relevant variable (drawing speed) must be changed to settle the chatter.

Status Quo

The current industry practice is to have machine operators manually reduce the drawing speed when chatter is audible. Along with all the other occupations, they must be aware of chatter, be quick to reduce the drawing speed, and cut out the defective part of the tube. This is not an easy task in a manufacturing environment, so from time to time, errors will occur. Therefore, to avoid high scrap rates, many manufacturers operate their machines at drawing speeds well below the optimum.

Automatic Adaption and Optimization During Your Production

The QASS measurement technology uses piezoelectric sensors that detect the faintest tube vibrations. By studying the vibration pattern of chatter, our experts found signs of premature chatter in the data before it becomes audible to any machine operator. The Optimizer4D analyzes the sensor data in real-time and keeps a steady line of communication with the machine controls. When necessary, our device asks the machine to slow down for a short time. Reducing the speed attenuates machine vibrations and averts damage. When the risk of chatter is gone, we can speed up again.

The Optimizer4D succeeds even in the most difficult production settings thanks to its powerful software with intelligent noise filters. It adjusts its detection parameters with each recorded process to keep track of slow-changing machine vibrations. All measurements are displayed in real-time and all results are documented in a database for easy and safe traceability. We can customize our Human-Machine-Interface (HMI) to meet the needs of our customers.

The QASS Update for Your Machine

Retrofitting your existing drawing bench is possible. It doesn’t take long and little effort is required.

Easy Implementation

Our coin-sized sensors are mounted close to the tool such that the sensors do not have to be moved during changes to your setup. The main computing unit is housed in the control cabinet and connected to the machine control system. In case your controls are a bit older, we can offer hardware that facilitates the analog communication between your drawing bench and the QASS Optimizer4D.

Little Maintenance Requirements

QASS staff assists with the entire retrofitting process of your machine. Our algorithm was developed with simplicity in mind: There are only a few process parameters to take care of. The rest runs fully automatically.