Saddle stitcher
The saddle stitcher (English Saddle stitcher ) is a machine, which in the final processing ( bookbinding is used) of the photographic industry. With this machine, the individual folded sheets supplied by rotary and offset printing or from a folding machine are processed further and booklets , brochures and magazines are produced as the end product . The final processing of the printed matter carried out in this context initially includes, in broad terms, the collection of the folded sheets using today's computer-controlled feed stations. The second step is stapling with one or more staples through the spine of the book and finally cutting the finished product.
Working principle
Depending on the type of construction, the folded sheets, which are manually or continuously collected in a lying or standing compartment, are drawn in individually by means of suction air generated by compressors . Then they are pulled off by the mechanical grippers of the rotating feed cylinder and placed on top of each other on a saddle again by means of suction air acting on both sides. The takeover is carried out by an endless transport chain consisting of chain segments, which removes the product from the saddle and guides it to the other work stations by means of precisely fixed drivers, which have to be synchronized with the other rotary feeders. During this work step, additional units such as gluing stations (e.g. glued-on postcards, also smaller advertising goods) and, if there is a need for thicker cover paper, a separate folder feeder can be used within the transport chain.
In the next step, the collected folded sheets are subjected to a thickness control, and defective copies are separated from the rest of the production. In the following stitching station, a wire of continuous rolls over additions to the so-called is stitching heads (English Stitcher Heads ) transported. The stitching wire is cut to a length appropriate to the product thickness using these stitching heads, bent and shot through the center of the book spine (collar). Deflection plates (benders, so-called clinchers ) acting from below close the still open wire clips.
In the trimmer , the collected and stapled brochure is then trimmed to the final format on the three open sides. In the case of small formats, many types have the option of installing a cutting knife and doubling production by using it twice. The finished booklets are then laid out using a cross stacker , vertical sheet delivery or conveyor belts and stacked on pallets by employees. Palletizers are also used to minimize personnel costs . The currently most powerful saddle stitcher achieves up to 40,000 stitches per hour.
Additional units
- Continuous feed ("Streamfeeder")
- Goods / postcard stickers (electronically controlled hot glue systems)
- Insert station (s)
- Cover folder feeder
- Labeling / addressing unit ( inkjet systems)
- Cross bundling
- Foil sealing