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Urethane Strippers for trumpf standard punch
• No noise when punching
• Cushions the impact.
• Reduce sheet metal rattle.
• Safe: will not crack
• Markless even on polished aluminum.
• Improved sheet flattening, no puckering.
• Positive stripping keeps sheet metal from moving.
Key features for trumpf urethane stripper
The TRUMPF Push-On PU Stripper is an elastomeric counter-force element that surrounds the punch and is friction-fitted directly onto the punch body, specifically engineered for the company's tool systems (like those in their TruPunch machines).
This stripper is a unitary polymer sleeve—typically composed of a high-density polyurethane (PU) elastomer—that is designed for snap-fit engagement directly over the lower shank of the punch.
Its function is that of a localized, resilient cushion or material constraint device. Upon the machine ram's descent, the stripper compresses against the sheet metal, applying a concentric holding force around the immediate perimeter of the forming or punching zone.
The key features are its self-retaining, press-fit geometry and its viscoelastic dampening capacity. It exerts the necessary retraction tension (stripping force) to overcome the material's tendency to cling or *spring back (known as the stripping load) to the punch tip upon the ram's ascent.
This push-on design obviates the need for heavier, multi-part steel stripper assemblies in many applications, facilitating lighter tool cartridges and allowing for faster tool changes due to its simplicity and integral nature. Its precision lies in its calibrated durometer (hardness), which determines the appropriate stripping tension for various sheet metal thicknesses and material types.
Why Use This Urethane Stripper?
In a standard Trumpf setup, a steel stripper plate is the "default." You would swap it for a push-on urethane version for these specific scenarios:
*Mark-Free Fabricating: Steel plates can leave "halo" marks or pressure rings on sensitive materials like mirror-finish stainless, pre-painted aluminum, or PVC-coated sheets. Urethane is non-marring and acts as a soft cushion.
*Acoustic Management: Standard punching is loud because of the "metal-on-metal" impact. Urethane absorbs the shock of the hit, significantly reducing the "chatter" and the sharp decibel spike of the punch cycle.
*Nibbling Operations: When nibbling (overlapping hits to create a large cutout), the sheet can vibrate or "rattle" under a steel stripper. The urethane stays in constant contact, dampening harmonics and producing a cleaner edge
Operational Considerations
*Wear Life: Urethane is a consumable. Over time, it will lose its "rebound" or become oil-soaked and soft. In standard systems, if the stripper becomes loose, it can slip down and cause a machine "collision" error.
*Heat Sensitivity: If you are punching very thick material at high speeds, the heat generated by the punch can degrade the urethane faster than a steel plate.
