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What to do when problems occur stretch forming processing

3 Solutions to problems in stretch forming processing

Stretch profile bending, some defects may inevitably occur. Are there any remedies for these defects, or how to avoid them? Let’s take a look at how has taken measures to address different bending defects.

When shoulder collapse occurs

Stretch Forming of Stainless Steel: Wrinkles and Springback
stretch forming machine
  • If the stretch forming die slot is too deep stretch production, a suitable thickness of shim can be added at the bottom of the slot or the mold can be repaired. However, if the slot is too shallow, the root of the part at that location will protrude.
  • Control the stretching amount appropriately.
  • Aluminum molds are prone to wear at locations where the curvature radius changes abruptly. Steel blocks can be inserted locally at these positions, and the depth of the slot should be reduced by 0.5-1mm compared to the part’s belly plate.
3 Solutions to problems in stretch forming processing
3 Solutions to problems in stretch forming processing

When profile shrinkage occurs

When the stretching amount of the bent part is large, profile shrinkage may occur, which affects the fit, clearance, and strength in structural design. When using a rotary stretch forming machine with side-pressure, the phenomenon can be reduced by the rolling action of the side-pressure roller (or side-pressure block). When bending on a lever-arm stretch forming machine, the profile size of the material must be adjusted to overcome this.

Stretch Forming Process of Aluminum Alloy Automobile Roof Rack【Stretch Forming Machine】

When profile warping and distortion occur

Profile warping and distortion can occur stretch the bending process of expanded section profiles, horizontally curved profiles, I-beams, hollow profiles, and other complex profiles. To overcome this phenomenon, snake-shaped blocks or filling materials such as low-melting-point alloys and sodium thiosulfate can be used. Snake-shaped blocks can be made of zinc alloy, aluminum, PVC plastic, hardwood, etc. They are connected by hinges, fine steel wires, or rubber ropes and placed inside the profile stretch forming.