- SPECIAL REPORTS
DEPRAG has recently introduced a Flow Form Screwdriving system (FFS) onto the market (aka flow-drill FDS). By incorporating their well established and trusted product lines of screwdrivers, measurement and feeder technology and screwdriving stations, the DEPRAG FFS is the premier Flow Form Screwdriving system in the world.
Flow Form Screwdriving is a groundbreaking screwdriving method that creates a high-strength fastening and forms a process-reliable joint for different types of sheet metal. Flow Form fastening only requires access to one side of the fastening point, which simplifies what were once difficult or impossible assemblies. With Flow Form Screwdriving, no punching or pre-drilling is required. Additional fastening components are not necessary because the thread is formed directly inside the through-funnel.
In the Flow Form Screwdriving process, special screws - available from select suppliers - are set in a six step process.
1) HEATING -The Flow Form screw is positioned onto the metal sheet, which has not been pre-drilled. The screw is applied with a high down-force and rotates at extreme rpm which develops an intense level of frictional heat and the material begins to melt.
2) PENETRATING - The tip of the screw penetrates the material compound.
3) FUNNEL FORMING – The screw tip penetrates further through the material, forming a funnel. At this point, the down-force as well as the rpm is reduced.
4) THREAD FORMING – The screw continues to penetrate the material and the screw threads begin to contact the newly formed funnel, creating threads in the material.
5) SCREWDRIVING – The newly formed threads allow the screw to be driven through the material.
6) FINAL TIGHTENING - The screw is tightened to the pre-configured torque and angle parameters.
The DEPRAG FFS is ideal for the automotive industry, which is currently tasked with creating lighter vehicles for lower energy consumption and CO2 emissions. To reduce weight, modern car body structures are constructed from a combination of materials such as steel, aluminum and magnesium alloys. This means traditional assembly methods, like resistance welding, are being replaced by alternative joining techniques. Rivets are ideal if the fastening point is accessible from both sides, but if the design prevents access to both sides, DEPRAG FFS is the solution.
Without the need for nuts or rivets or punching or predrilling, extremely short cycle times can be achieved in the assembly.
Auto body construction using the DEPRAG FFS have achieved cycle times less than two seconds per screw fastening.
In addition to the Auto Industry, the DEPRAG FFS is also ideally suited for “White Goods” such as dishwashers and refrigerators.
Any place, where sheet metal or a combination of different types of alloys (steel/aluminum) need to be fastened together, the DEPRAG FFS is the right choice.