Perforated metal sheets have been widely used in construction buildings, industrial products, machines, kitchen wares etc. Such as used in buildings ceilings, noise reducing barriers used in bridges, railway, roads etc. Dust cove used in sound box, machines etc.
 Most perforated work-pieces should be flat used in the above mentioned areas, but the perforated metal sheet will get curved after stamping (refer to following image in Fig 1), so it has to process the sheets to be flat.
 
Why it gets curved of the sheets after stamped? How to make the perforated sheet to be flat? Usually the stamped holes are very small and dotted with each other in the sheets, the inner stress get dispersive in the stamped holes edge, so the perforated sheets get out of shape and curved. It can be processed by the precision leveling machine then it can achieve making the sheets flat (refer to fig 2).
 
The perforated metal sheet goes thought the leveler machine’s leveling rollers, It’s based on “Bauschinger effect”, metal sheet was repeatedly twisted to make metal fiber gradually consistent, eliminate internal stress, restore and improve the flatness of work-pieces (refer to Fig 3).
For thinner material, it adopts thinner leveling rollers and narrower distance of neighboring leveling rollers. On the contrary, for thicker material, it adopts larger leveling rollers and longer distance of neighboring leveling rollers. For example, for material of 0.5-1.5mm thickness perforated metal sheets, our metal plate leveling machines equip with 19pcs×φ32mm leveling rollers (upper 9pcs/lower 10pcs), for material of 1.5-2.5mm thickness perforated metal sheet, it equips with 19pcs×φ42mm leveling rollers (upper 9pcs/lower 10pcs). The more thicker of the material, the more larger and stronger of the leveling rollers.
Main features of the perforated leveling machines
  ● It adopts GCr15 for all leveling rollers and backup rollers, finished quenching and tempering, precious machining, hard chrome plating, grinding etc. Surface hardness comes HRC60±2°(chrome layer thickness ≥0.1mm)

● All gears adopt material of 20CrMnTi, finished forging, tempering, surface carburization, precious grinding etc. coming to grade IT6.

● Main bearings are Shielded and sealed NSK bearing made in JAPAN, it can well reserve itself stocked lubrication oil and prevent dust enters, so it doesn’t need to add lubrication oil on bearings.
● Manual adjust leveling roller gap: At the guidance of digital display, operator can crank the two hand wheels to adjust leveler’s straightening performance.