Felix Stirnimann, Marketing Manager of Müller Martini Saddle Stitching Systems, in front of a PrintRoll feeding system.

Publishers’ binderies are regularly coming under fire for occupying too many people on the finishing machines in comparison with other sections of the printing house. “This may be true, but the accusation is not justified,” insists Felix Stirnimann. “The number of workers required to complete a brochure or magazine primarily depends on which buffer variant one chooses. It stands to reason that feeding a system by hand requires considerably more personnel than feeding with logs or via PrintRoll.”  

Factors for Increase in Productivity
Therefore Stirnimann advocates – at least in the mid to high performance sectors – consistent automation in finishing: “This applies predominately to feeding and palletizing.” The requirements for modern saddle stitcher systems are therefore heading in three directions:

1. High Net Output
In order to produce the required quantities cost-effectively, the machines – particularly in the mid to high-performance range – have to run at near maximum performance for long periods of time. In addition to speed, operational comfort and system reliability are important factors for success. Stirnimann says: “Here our sophisticated quality controls have made our saddle stitchers the safest and most reliable on the market.”

2. Fast Setup
As job and format changes are continually increasing, an intelligent control system is becoming increasingly important. Amrys (Automatic Make Ready System) can reduce the setup times for Muller Martini machines by up to 50%. This can be particular advantageous for continually changing job structures. “In addition, all new Muller Martini saddle stitcher models can be integrated into digital workflow according to the CIP4 standard,” emphasizes Stirnimann. “The trend towards digital workflow was already clear at Drupa 2004, and at the coming Drupa it will most definitely be the main focus for many exhibitors.”

 3. Automated Feeding and Palletising
“There is little use in having the fastest saddle stitcher, if signatures cannot be quickly fed and the finished products quickly delivered,” insists Stirnimann. Feeding with streamfeeders, logs and rolls means Muller Martini is automating the processes as it is doing with bundle building and delivery systems which palletize and deliver the products at the end of every print finishing operation.

How much automation would you like to see?
The saddle stitcher system feeders can be loaded either manually, or with logs or rolls. Which variant is the most worthwhile and economical must be decided case by case. It is clear that hand feeding offers the highest level of flexibility in production but is also the most personnel-intensive way. For a saddle stitching system with eight feeders operating with a medium production speed of 14 000 copies, it is assumed that five to six operators are required. (Compare diagram).

Automating Feeding with Streamfeeders
This is why Muller Martini already offers automation for the hand feeding of its mid-performance range saddle stitchers via short streamfeeders. They are compactly built and can be changed from hand feeding to automatic log feeding in a matter of minutes. The advantages of the streamfeeders are clear:

Stream feeder feeding with bundle extension on flat pile feeder.

In the first stage, the logs are reformed into thick shingles which are transported to the feeder. In the second stage, the signatures are separated with an accelerating belt and protectively placed in the hopper. This means that no extra care is required in order to bring the products into the hopper. In addition, the entire mechanism, which measures the log height in the hopper, is controlled via a sensor. This guarantees the same requirements for the separation process every time, which has a significant effect on the system’s net output.

Streamfeeders are therefore the ideal loading device for signatures and covers. Setup and changeover time is saved thanks to motorized adjustments. In just a matter of minutes, the attachable log feeding module turns the hand-fed streamfeeders into an automatic log feeding system for variable size logs.

Log Feeding is State of the Art
The finishing of signature logs in middle and large print runs has established itself in the production of saddle stitched print products due to its profitability. The continual material flow significantly increases the saddle stitchers’ net output and guarantees that machines are constantly running. “A main point about log feeding is the log quality,” underlines Felix Stirnimann. “The logs must have neatly jogged signatures without any protruding signature parts which could be damaged by straps.” For this reason, Muller Martini recommends the Vivo and AvantiPlus log stackers for perfect log building.

Nowadays, short logs (800 mm) are still widely used. Stirnimann suggests that this log length could be prohibitive in terms of performance. “One achieves considerably higher loading performance per person with logs of 1200 mm length. Furthermore, short logs require 50% more end board.” As the “Buffer Systems” diagram shows, Muller Martini presumes that when using logs, one person is required per four to five feeders – a considerable reduction in manpower in binderies.

The logs can be ergonomically fed with a crane system. The stream feeders can be easily relocated thanks to transport rolls and then freely used at any station.

 Buffer System Comparison Bundles – Logs – Rolls

Maximum Automation with Roll Feeding
“Automation with rolls may be a big investment but it offers the highest level of automation for saddle stitcher feeding,” explains Stirnimann. “Even for multiple production lines, feeding by PrintRoll only requires one person who brings all the rolls to the saddle stitcher and the empty rolls back into the store.”

Roll feeding guarantees continuous and highly efficient workflow. This can be further optimized with a fully-automatic logistics system – as has already been done on numerous occasions by Muller Martini.