With standardized function blocks from the Finishing Toolbox from Siemens, L.R. Schmitt Nachfolger, Europe's leading manufacturer of flame-laminating machines, will generate high-performance automation solutions in the future. The starting point is a PLC-based, end-of-line winder application that automatically implements constant web tensions and thus consistently high winding quality over the entire diameter range.
Flame lamination is a productive, economical and versatile process for manufacturing textile composite materials from roll to roll. Europe's leading manufacturer of flame-laminating machines is L.R. Schmitt Nachfolger Sondermaschinenbaugesellschaft m.b.H in Aschaffenburg, Germany. Its machines produce both thick and thin, two- or three-layer composite materials for diverse applications without the need for significant modification measures.
The core component is always a foam material that is melted by a controlled flame treatment as it passes by, thereby becoming adhesive. This allows fast and easy laminating of the backing material with any visible and/or functional layers. Typical end applications are seat covers, door coverings and roof linings for the automotive industry, which is the largest end customer with more than a 90% share. Costs and quality are crucial for this end customer.
For contract laminators in particular, the flexibility to manufacture a wide range of materials on one and the same machine is essential, and this in turn poses special challenges for the machine builder. For example, a constant web tension must be ensured for all material thicknesses. This is increasingly important and difficult, when laminating thinner end products, whose share is continuously growing. These can quickly wrinkle if wound too loosely, or they can blister or become irreversibly damaged if overstretched.
With production speeds of 35 m/min and higher, the operator had to constantly monitor the winding in the past so that quick intervention could be taken to adjust the web tension via the motor torque – and with an extremely broad range of web tensions from 20 N to 500 N, or rather different web velocities. Another "disturbance variable" is the different starting diameters of the various A-frame carts.
When winding thinner and more flexible materials, we ran into limits and had to act, and develop a high-performance – and ideally fully automated – web tension control for all machine setups.Peter Klaucke, Sales & Service Agent at L.R. Schmitt
For many years the machine builder has relied on the integrated automation technology of Siemens because of its reliability, availability and reputation on the world market. Examples of this state-of-the-art technology are the SIMATIC S7-1500 Advanced Controller and a modular drive system consisting of SINAMICS S120 and high-performance SIMOTICS S servo motors. Recommended by the local Siemens sales engineer, the SINAMICS drive system on the winder was discussed as the key to the solution, because it delivers all the process parameters required for high-performance winding and unwinding practically free of charge. And with the Finishing Toolbox, Siemens supplies suitable tools for making use of these: standard libraries with functional and tested function blocks that are aimed at fast and reliable creation of customized automation solutions for textile processing. Currently, the Finishing Toolbox has the following modules: Winder and Unwinder, Tension Control, Electronic Gearbox, Load Sharing, Separate Chain, and Setpoint Cascade. Additional blocks can be found in the supplementary Converting Toolbox.
The cost-free toolbox is available for the SIMOTION, SIMATIC and SINAMICS automation platforms.
We saw the extremely versatile, pretested and, above all, cost-free possibilities of the Finishing Toolbox at a multi-day Converting Workshop at Siemens in Erlangen.Peter Klaucke, Sales & Service Agent at L.R. Schmitt
For the first practical application, L.R. Schmitt was supported by Siemens Würzburg and a drive specialist from the Siemens Application Center (APC) in Erlangen, Germany. The latter implemented a high-performance winder application in a short amount of time for a continuously operating flame-laminating machine at Hofer Textilveredelungs GmbH and integrated it into the existing user program. The contract laminator and machine builder have long cooperated on innovative ideas. The key functions of the winder innovation are a diameter calculator and a tension control with measurement of the actual web tension via a tension load cell. The current bale diameter is calculated from the ratio of the material web setpoint velocity and the actual speed of the winder. With this information, it is relatively easy to reduce the speed and increase the torque accordingly as the diameter increases and thus to automatically control the web tension to a setpoint. The Finishing Toolbox generally supports common winder functions such as torque precontrol, diameter calculation and winding tightness characteristic. It likewise supports controller concepts based on dancer systems and tension load cells as well as indirect tension control.
Meanwhile, the machine builder has implemented and commissioned another machine with two winders on its own. It was able to simply duplicate the application developed jointly with Siemens and adapt it to the specifics of the machine.
We will also use the standardized function blocks of the Finishing Toolbox to quickly and conveniently implement future automation solutions with optimized costs. It can hardly be easier to offer real added value to our customers.Peter Klaucke, Sales & Service Agent at L.R. Schmitt
With the ready-made and tested function blocks of the Finishing Toolbox, a high-performance winder application was generated and integrated in the existing PLC program of the machine within a short amount of time.
The operator now specifies the desired web tension and the starting diameter of the A-frame and simply starts production. The winder application ensures constant web tensions adapted to the respective material throughout the process, thereby ensuring an optimal winding pattern. The operator no longer has to intervene manually and can fully focus on the supply and disposal activities for the machine(s).
The automated winding process yields a consistently high product quality across the entire spectrum. Even thin materials do not become overstretched or wound too loosely, which prevents wrinkles, blisters and other flaws, while significantly reducing scrap.
The optimized winder application can be easily transferred and adapted to other winders or machines. Moreover, the Finishing Toolbox opens up many other concepts for innovative processing machines.