rapidFOX
Sustainability
Company
Get in touch
A mount that enters the core of a reel on a cylindrical mandrel and holds the load positively or by expansion. Because the reel is carried at the core alone, the web stays untouched. Sizing covers bending in the mandrel and surface pressure in the core; for long reels a support at the free end is added to limit sag.
A mandrel gripper enters the core of a reel or spool horizontally with a cylindrical mandrel. The reel then rests on the mandrel – it is carried by shape as long as the axis stays horizontal. The winding itself is not touched, which makes the mandrel the usual attachment for film, paper, nonwovens, labels and wire.
A lip at the mandrel tip, a slight backward tilt or an expansion in the core secures the reel against sliding off forwards.
Mechanically the mandrel is a beam fixed at one end. The bending moment at the fixing is weight force times the distance to the reel’s centre of gravity – the wider the reel, the further out it lies. Deflection grows with the cube of the free length: a mandrel twice as long deflects eight times as much under the same load.
The same lever arm acts on the handling device. The centre of gravity of the reel lies well in front of the suspension, and the device has to take that moment or compensate for it through the position of the suspension. Mandrel, reel and device are therefore sized together.
A thin mandrel in a large core touches the core only along a narrow line at the top. With cardboard cores that line is pressed in. The remedy is a mandrel diameter close to the core diameter, or a support shell that spreads the load over a larger area.
The mandrel must also be long enough for the centre of gravity of the reel to rest securely on it. If it carries only the front section, the reel tips over the mandrel tip and loads the core at its edge.
Many tasks require the reel to be swivelled from a horizontal to a vertical axis – for example from the pallet into the unwind station. As soon as the axis leaves the horizontal, a plain mandrel no longer carries: the reel would slide off. The mandrel is then fitted with an expansion that clamps the core from inside, and the clamp is safeguarded against pressure loss.
The weak points of a mandrel gripper are almost always at the edges of the task.
What Entracon offers here is on the matching page.
See what we offer| Task | Design | Holds by |
|---|---|---|
| Transfer reel horizontally | plain mandrel with retaining lip | positive locking |
| Up-end or lay down reel | expanding mandrel with swivel axis | friction in the core, safeguarded |
| Very wide or heavy reel | mandrel with support at the free end | positive locking, supported both ends |
| Changing core diameters | mandrel with interchangeable sleeves or shells | positive locking |
Long enough for the centre of gravity of the widest reel to rest on it with a margin. In practice the mandrel extends over most of the reel width; there is no fixed rule – sizing for bending and against tipping governs.
The mandrel carries the reel by shape with a horizontal axis, without clamping. The expanding gripper clamps the core from inside and therefore also holds with a vertical axis. An expanding mandrel combines the two.
Only if the winding is dimensionally stable at the bore. With soft, coreless reels the mandrel crushes the inner layers; a large support shell or a different gripping principle is then needed.
One short conversation usually settles more than three quotations. Call or write — you will reach an engineer directly.
Start typing – for example “balancer”, “SAP” or “pipe stress”.
Reach Entracon
How can we help?
Thank you.
