Equipment & Solutions for Newspaper and Commercial Printers

Wednesday, June 4, 2014

Which Stacker to use for your POST PRESS- Log or a Compensating Stacker.

A short comparison with focus on book, directory, magazine & catalog Printers...

Why this comparison?

On every Post Press project we have two challenging choices ahead of us:

1)  What are the right machines for the productions which will be run on the press

2)  How do I layout these machines in order to optimize

ƒ   the available space and the plant logistic

ƒ   the product flow through the system (including intelligent back-up

ƒ   the ergonomics for the operators (easy access, free floor space, safe environment)

This comparison wants to be a help for question 1) with a focus on small and medium presses with limited need of automation where the Post Press mostly consists of a conveying system and either a compensating stacker (optionally with a trimming line) or a semi-automatic log stacker.

Unfortunately we still see plants inefficiently running books, directories or magazine work through a compensating stacker or retail work through a log stacker from where they pile down loose bundles.

Here the two main question which help to make the right choice:

ƒWhat will the press print : books – directories – magazines & catalog – inserts – newspapers

What is the degree of automation (manual pocket feeding or stream feeders) in the bindery

Here under a fast and simple guide to what could be the best machine for your operation. It is not a “black or white” choice since space; budget, future plans etc. will also influence the choice:

Compensating Stacker - best the press products“

  • For retail applications, with our without trimming (finished products)
  • For Loose, compensated bundles, 100-250 mm
  • Newspaper printing (direct print, at the end of inserters,..)
  • Builds loose, counted & compensated bundles behind web presses
  • As alternative solution in magazine / catalogue printing to handle WIP


<120 .000cph="" span="">
heat set + coldest

Semi-automatic Log Stackers – best for „work-in-process“

  • For magazine / catalogue applications (unfinished work-in-process WIP)
  • For book & directory Compressed, counted and secured logs, 450 – 800mm
  • Printing (direct print, at the end of inserters,..)
  • Builds compressed & strapped logs behind web presses
  • Copies in the strapped & stable logs are secured between two end boards


<70 .000="" cph="" span="">
Heatset + coldest

Delivers loose, counted, compensated and unstrapped bundles
Delivers counted, compressed, uncompensated logs secured by two end boards and safely strapped.
100-250 mm bundles height ( in average)
450-800 mm log length on semi automatic log stacker.
No need of consumables for the loose bundles. Possibly need of consumables ( strapping belt/film) to stabilize & protect the pallets
End boards and strapping material needed for each log. Normally no additional cosnumables needed to stabilize & protect the pallets.
The stacks are only shortly compressed in the stacker. After placing the products on the pallet the spine will tend to build up again ( memory effect on the paper). The higher position of a bundle on the pallet the more air will be in the bundle>no uniform bundles
The logs are compressed resulting in completely flat sections with no risk of folded edges. No alternation will happen to the products once they are placed onto the pallet> all products are flat & uniform.
The loose bundles on the pallet are unprotected. They tend to move, especially in the lower layers. Loose bundles are exposed t dust, temperature and humidity. The level of compression also varies with the position of the bundles on the pallet ( with high compression on 1st layer, no compression on last layer).
All products in the log are equally compressed. The products in the log are protected, they can not move ( neither in the log nor on the pallet). The products are not exposed to dust, temperature or humidity.
Slip sheets & pallet film wrapping will protect the loose bundles. This adds costs for labor & consumables. The use of film can lead to folded edges of the sections which can increase the risk of jams in the bindery. Optionally carton corners can be used before film wrapping.
Slip sheets may be used but no film is necessary. No costs for additional consumables. No folded edges of the sections.
Work load of a compensating stacker is higher-higher frequency of bundles which are mostly placed manually on a pallet. Example 7 layers x 14 stacks = 98 movements per pallet.
Lower frequency of logs which can be placed manually ( short logs) or by means of a semi-automatic clamp or a log palletizer on a pallet. Example: 4 layers x 4(6/11) logs = 16 ( 24/44) movements per pallet.
One man operation on compensating stacker behind slower and smaller presses. Two men operation on compensating stacker behind high volume and faster presses.
One man operation on semi-automatic log stacker. One man operation on two fully automatic log stackers ( configuration allowing).
It is difficult to stack pallets with loose bundles w/o damaging the product. Securing the pallets entails additional costs.
Easy stacking of pallets.
Pallets will have to be shrink wrapped if transported to a bindery which is not in house.
Printed products are secure whether to be taken to a bindery in house or outside. Only end boards need to be returned.