Learn the secrets to successfully binding large size documents with Plastic Coil

So you came here looking for answers and although we offer some tools that will help, the real answer is in the holes you are currently punching.

Many have attempted a few of these:

  • Jogging books into oval shaped channels
  • Inserters with rollers that have gap space adjustments
  • 4:1 oval punching dies (oval dies can help)
  • Inserters that use mandrel drive systems that allow you to split the book in half.
  • Inserters with larger more powerful rollers

All these are valiant attempts to solve the problem of large document coil binding but you end up hand coiling the document. Through trial and error we have narrowed it down to it being so difficult because of the holes being punched.

The most common punching pattern for coil binding is 4:1 pitch. If you are binding a standard letter size document, you have 44 holes punched on an 11″ binding edge. This translates to 44 loops of coil that needs to get inserted into the document. Unfortunately, all these holes create friction, which restricts the coil and causes it to jam. This problem only gets worse as the book gets thicker because there is that much more friction.

What if you punched that same document using a 3:1 pitch oval hole instead? Now you have 33 holes punched on an 11″ binding edge. Because you have fewer holes, you have reduced the friction. Additionally, because the coil is spaced wider apart, 3:1 coil can be manufacture with thicker filament. This makes the coil more ridged and makes it easier to insert coil.

When working with 3:1 pitch plastic coil it is recommended to use a 6.5 mm x 5.5 mm oval punching die. The key to this is using an oval hole die, trying to utilize a 3:1 pitch Wire-O round die doesn’t work well with these large books. When a thick book is being bound, the book will curve to follow the curve of the coil. As this happens, the punch hole window is reduced. The expanded height of the 6.5 mm x 5.5 mm oval hole provides sufficient space to keep this window as free and clear as possible, so that the coil can wind its way through the punch holes unencumbered.

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