Automated manufacture of cave cut step index

MANUFACTURING A cave cut index has, up until now, involved intensive manual work. Durrer has now automated this process with its two new machines, Rebib and Klebib, thereby improving the product quality and efficiency of the manufacturing process, the company believes.

The cave cut, also often colloquially referred to as bible cut, is a form of thumb cut. Its compact cut shape offers much greater protection to the index area of products. This cut is, therefore, ideal for dictionaries, encyclopaedias, medical reference books and Bibles which have a long service life and whose indexes are subjected to frequent use. Cave cut indexes are usually combined with glued, lettered tabs (semi-circular stickers). One limitation of the cave cut is the thickness of the book, since books must be of a minimum thickness due to the cut shape.

Intensive manual work

Manufacturing cave cut indexes and affixing the stickers has, up to now, involved intensive manual work and has been commensurately time-consuming. Normally four to five people are required to find the position, cut the index and affix the tabs. The entire manufacturing process, therefore, is heavily dependent on the skill of the staff.

Durrer’s solution, comprising two separate machines, replaces the conventional, manual production process. The semi-automatic Rebib machine was developed to cut the cave cut index, whereas the Klebib affixes the pre-printed tabs. The advantages of the present solution are obvious: precise mounting in the Rebib machine ensures a high degree of repeat accuracy when cutting. This considerably increases the accuracy of the cut indexes, because exact cut-in depths and the precision positioning of the indexes to the millimetre are crucial to the shape of the cut. Once the accuracy of the cut has been achieved in this way, the printed labels can be affixed automatically using the Klebib machine. The resulting quality does not depend on the skill of the operating staff.

As with all Durrer machines, development focussed on a high degree of flexibility, short changeover times and safety. The automatic cutting process is user programmable. The machine processes virtually all paper qualities up to a maximum book thickness of 80mm.

Durrer presented the Rebib–Klebib concept as a whole for the first time at Ipex 2010 in Birmingham.

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