Automatic pin wheel straightening system


Orthofact RMB-15 – Classic pin wheel straightening machine

To restore assymetrical distorted warp and weft threads to their original state, the Orthofact RMB generates a defined lateral tension using freewheeling, inclined pin wheels.

Removing irregular distortions

Asymmetrical distortions (wavy, S-shaped, etc.) in textiles have always represented a huge challenge in the textile industry. A special straightening approach is needed particularly when the straightening process does not take place in combination with a stenter (e.g. before decatizers, digital printing systems, etc.).

To restore the warp and weft threads to their original state, the Orthofact RMB generates a defined lateral tension using freewheeling, inclined pin wheels. This cross-tension stretches the warp threads. The resultant force controls the freewheeling pin wheels, since the weft threads will always seek out the shortest path from selvedge to selvedge.

Distortion, no matter whether wavy or S-shaped, will be corrected.

Specific Mahlo know-how

The lateral tension is generated with two inclined pin wheels. Two pneumatic cylinders, supplied via a pneumatic line, are used for a consistent straightening effect. To compensate friction losses and tolerances, a spring generates a counterforce which forces the uniform symmetric alignment of the pin wheels. Elaborate lever constructions requiring intensive maintenance can thus be dispensed with.

Special features

  • Unclipping roller with infinitely variable adjustment: Minimises residual bow and edge distortions.
  • Intelligent drive station with special tension control for smallest product tension activates or deactivates automatically (e.g. in case of blockages).
  • A bypass function is available at the push of a button for products that cannot be straightened with the pin wheel.
  • Intelligent wheel following: Product loss is nearly prevented entirely. The control immediately compensates product offset, poor seams, fringes and dents on the edges.
  • Width jump function: New wider products do not need to be pulled in separately when changing products. Sew the new product to the old one, pull in, done! No more downtime!
  • Break function: Reduces the lateral tension to a preselected level when the line is stopped, e.g. during breaks or when working on other machines in the line. Preserves the product!
  • Teflon rollers: On wet fabric teflon-coated feed rollers are used.

Product highlights

  • High lateral tension possible
  • Adjustable unclipping device
  • Bypass function
  • Intelligent drive

Customer benefits

  • The pin wheel straightens even without detection
  • Reliable, quick distortion correction
  • Effective also with asymmetric distortions
  • Less spoilage

Area of application

  • When confronted with asymmetrical distortions (wavy, S-shaped…)
  • For non-elastic fabric that cannot be detected


Orthofact RMB-15