Typical machine fold

There are many types of folding machines, and each has its own series. Therefore, machine folding books are also complicated. However, all machine folding books are developed from hand-folded signatures. Discussing typical machine folding signatures and mastering their regularity is also a prelude to mastering modern folding machines and their digital folding pages.

In order to avoid tedious and lengthy discussions of machine-folding signatures, it is proposed to reflect the regularity and characteristics of machine-folded signatures, and to use typical machine-folding signatures, as an example.

The basic concept of machine folding

Although there are many types of folding machines, in terms of their folding structure, one of them consists of a fence structure and a knife structure, and a mixture of the two. Second, in terms of the size of the folded blanks that can be folded, there are full-sheet and split-folders, and there are even eight boot-ups, of which there are various series. Thirdly, for machine-folding signatures, each printing manufacturer can work out the folding trend diagrams of each folding machine according to the existing folding machines, and formulate a process specification for the operators to perform according to the specifications.

Machine-folding “Folding blank” positioning reference and its orientation

What is a "blind"? Unfolded signatures are called blanks or blanks. Positioning reference refers to the critical point of dimension measurement in process production, or the standard position for processing.

In the process of folding the signature, the signature must have a positioning reference position, and the folded blank must have two positioning references. With the reference bit “blanket” it is possible to fold – the finished line signature of the line-to-line and code-to-code, otherwise it will be defective or scrap. Therefore, the dynamic size of the edge (refer to the concept of the so-called dynamic size on page 10) can not be used as a reference position.

The reference position of the blank is preferably selected at the front or lateral edge of the printing press, and the other option is at the edge of the blank opening of the printed sheet. The former consists of one signature, and the latter consists of multiple signatures. Both of them use the change of the starting position of the cloth plate (namely imposition), and the change of the front and back positions, so as to meet the requirement of the folding machine for the reference position.

The “billet” Q is conveyed by a row of conveyor belts to the forward gear A, and then pulled by the pull gauge device to pull the lateral pull gauge B. This completes the positioning of the “blank” and then the cutter D The descent causes the “blanket” to enter into two friction wheels (M1 and M2) that are rotating, as shown on the right-hand top left panel. Under the effect of the frictional force, a “folding” of the blanks is completed. ".

The reason why a signature can be folded multiple times is that the folding machine has multiple sets of folding devices. If the folding blank is required to have n folds, the folding device should have n folding devices, and the folding device should be adjusted or used. Some folding devices to adapt to different folding times signatures.

Folding principle of grid folding machine

The "fold blank" Q is transmitted to the fence 1 by a row of inclined rollers (oriented to the side fence B) when the front edge of the "fold blank" reaches the fence A1, thereby prompting accurate positioning of the "fold blank". ,The effect of the rotating force of the two friction rollers (M2 and M3) is affected by the interlocking of the fence (the space of which can only pass through a layer of paper). If the first folding is completed, then the "folding blank" enters the fence. When the double-paper edge of the 2 reaches the front stop A2, it will once again cause the "blanket" to be positioned, still being affected by the fence's clamp (the space can only pass through the two layers of paper), in the two friction rollers (M3 and M4). Under the effect of the rotational force, the direction of the red arrow "→" indicates that the "fold blank" completes the second folded outlet.

The folding device of the grid folding machine may have different combinations with the folding manner and number of folds of the signature, and may be similar to the stacked wood, and may use one or two folding devices to achieve the book. Posts have different requirements for folding, but there are still limitations in reorganizing or using them.

The trend graph is one aspect of the design machine folding the signature, which clarifies the schedule of the folding path of the folding machine, so it is also called the roadmap. The folding machine manufacturing instructions should be attached with a diagram.

The trend graph is drawn using mechanical sketches. It is to draw up some abbreviated symbols to indicate the route travel of the folded pages. The abbreviated symbols are shown on the right page.

Since the trend map is a process of expression folding, that is, a description of a folding route, it can also express the specific folding route of a certain folding machine in a textual manner. The form can be:
C : 3/5 = 1→3→4→c

This form can be referred to as an ordinal, or as an ordinal, which can be interpreted like this:

C: refers to the folding device, 3/5 is that the folding machine has 5 folding devices in total, 3 sets are enabled, and 2 sets are used. The specific itinerary for the folding route is: the fence 1 and the fence 3 and the fence 4, in order to complete the 3 fold, then the book into (fall) into the citation c.

From the folds to the graph, you can use a simulated blank to check if the fold is incorrect and determine whether the fold is correct. This is called interactive checking. The text description of "going to fold" can be issued as a technical instruction on the production bill.