PRODUCT REVIEWS
Galvanized
Dynamic positioning for bends
Jorns , a Swiss manufacturer of bendingand double-bending machines , developed its dynamic positioning ( DP ) function years ago and has now taken this to the next level . Dynamic positioning compensates for deformations at the ends of profiles during the bending and closing of parallel open hems .
The control technology allows users to measure , control and position clamping arms individually , and to keep them in position during bending . The clamping force exerted on the part remains even during the bending process . This reduces , or even completely eliminates , significant over-bending at the ends of profiles .
Long bending machines , unlike shorter swivel bending machines , have several clamping arms that are driven directly or via control shafts distributed over the entire bending length . When bending profiles , these exert a uniform pressing force on the sheet , over the complete bending length .
“ In practice , the problems usually start at higher sheet thicknesses and when the bending profile is two to three metres shorter than the machine ’ s maximum bending length
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– so that the outermost clamping arms do not grip the material . Until recently , there was only one solution to achieve an accurate bending angle to the very ends of the sheet , whether the clamping arms are driven individually or via a control shaft . Insert the sheet strip to keep the upper clamping tool parallel during bending ,” explained Jorns .
“ Previously , accurate parallel open hems could only be achieved through mechanical hem milling that allowed immutable opening dimensions or by inserting a sheet strip that had to be laboriously removed again after closing . Even precise positioning of the clamping tool across the entire bending length did not allow for a parallel open hem , as the material in the centre of the profile springs back more than at the profile ends ,” it continued .
Dynamic positioning ( DP ) allows the uniform closure of a hem over the entire length of the profile ; it is programmed into the control system and lets the clamping arms exert more pressure in the middle of the profile , up to the maximum clamping pressure if needed . Each clamping arm is fitted with a measurement system to ensure a precise closing dimension for each arm . Individually controlled hydraulic cylinders allow individual actuation of the clamping arms to size or to pressure . Because of the modular design of the machines , Jorns bending machines can also be retrofitted with this function - dynamic positioning can be integrated as an option when ordering new machines .
Email : r . staeger @ jorns . ch or click on the QR code below for further details . You can also see the ‘ dynamic positioning ( DP )’ function in action in an animated 3D visualisation on https :// youtu . be / Zz33pv-S5zg n
steel coating
“ The Alesta ® AP QualiSteel powder coating for hot dipped galvanized steel offers excellent degassing properties and a good flow to ensure superb surface appearance . Rapid and reliable curing at low temperatures enables energy savings and an increase in productivity . Strong UV and humidity resistance , according to QUALISTEELCOAT specifications , provide longer lifecycles of coated parts . Our new label-free and low consumption powder coatings , which are available in a wide range of RAL-based colours , make coating more sustainable ,” Axalta Coating Systems told ISMR .
When it comes to protecting galvanized steel structures and products , demands for durability , appearance and sustainability have increased significantly . In response to this trend , Axalta offers the Alesta ® AP QualiSteel powder coatings in architectural quality . The coating can be applied without a pre-degassing step . Compared to a traditional two-step process application , the new powder coating is designed to enable an increase in productivity without affecting the appearance of the coated surface .
“ The high yield and reduced curing temperature also contribute to improved value creation for contract coaters and in-house coating companies . Depending upon the substrate to be coated , Alesta ® AP QualiSteel can be cured at as low as 160 ° C , while productivity can be further increased at higher temperatures . In addition to the material and energy savings , the new powder coatings have hazardous label free formulations . The powder coatings , which are part of the international ‘ QUALISTEELCOAT ’ quality label , also offer very good UV stability and mechanical resistance , leading to a longer lifecycle of the components ,” said the coatings specialist .
Alesta ® AP QualiSteel is typically used for coating steel structures ; machine components ; garden and outdoor furniture ; fencing ; railings ; urban and outdoor lighting and more . The powder coatings are available in popular RAL-based colours from stock . n
. axalta . co . uk / qualisteel
68 | sheetmetalplus . com | ISMR July / August 2021