End Papering - Tony Clark

END PAPERING :

End Papers are not just the last page of welbound times; as you know. They are leaves of paper glued on to the outside signatures of a book block. The outside end sheets are glued on to the book case, during casing-in.
If any full-production “end – papering” is to be done, either before or in line, on perfect binding machines, the choice of an adhesive or adhesive system to bond the end papers must be chosen carefully. End paper could be printed and they could be bonded to wraparounds or heavily inked areas. A few of them are as given below:
1. The hotmelt film should be pliable enough, to be flatted by the subsequent nipping
2. If the hotmelt is firm and forms a ridge, then the first and last pages will be damaged during the rounding and backing operation
3. Hotmelt should be of very high quality so that it will not be affected by heated joints during the building-in operation*. (* Building –in machine is used for the rapid drying of cased books, by a means of several applications of heat and pressure)
4. Emulsions, if used, should have sufficient tack to be able to have end papers stepped up and to resist twisting.
5. Emulsions also should be easy to clean and yet be relatively fast bonding.

Combined end sheets

In the production of these components, the stretch-bind material should be produced so that at least 25-30 per cent stretch can be gained across the width of the spine. The adhesive bonding the endpapers to the centre lining must be pressed completely flat.
When endpapers with step-up ribbons are used in the first and last units on a gathering machine, the ribbons should be innermost so that they come into contact with the first and the last signatures. This prevents a build-up or a ridge during the lining operation (figure 1).



Rounding and backing unsewn book blocks

The production of book blocks on a standard perfect binding machine is now commonplace. However, a few points should be noted.

Any adhesive used should have sufficient stretch and a reluctance to shrink back. Hotmelts, for instance, should have an elongation of an adhesive film of at least 100 % and the regression should certainly not be more that 30 %.
Note also that the stretch crepe or cloth must have stretchability of more 30%. These figures are given as a guideline, since every country has its own preference regarding the amount of round that a book should carry. In Britain a book has to have a deep round with heavy shoulders, whereas at other places books are generally shoulderless with an attractive round.
Round retention can be judged by taking a book block before rounding and drawing a line across the head. After rounding, another line is drawn between the extremities of the original, which should now be curved. Inspecting the marks on the head of this test book will show how good or poor the round retention is. (Figure 2)