Continuous printing paper
Continuous printing paper (in short, continuous paper or tabulating paper , because it comes from the tabulating machine ) is paper that is used for printing with impact printers ( line printers ), but also with continuous laser printers , whereby no single sheets, but apparently endless paper webs are printed.
Continuous paper has the advantage over single sheet printing that the paper transport mechanism of the printer can be constructed more simply and therefore more robust. Pulling tractors, in particular, offer reliable and precise paper transport and allow unattended printing, which is particularly useful for larger print volumes. If necessary, the additional work steps for separating into individual sheets and for removing the guide hole edges can be disadvantageous . This may result in rougher edges at the horizontal and vertical dividing points than with individually printed sheets.
Continuous printing requires the use of printers that have a special paper transport mechanism, e.g. B. "tractors" or "spiked rollers" (also called "spiked rollers").
Areas of application
Continuous printing is used in particular to produce large amounts of print, for example in the data centers of companies or authorities. Also, the program prints were happy to make on continuous paper, as they are more clearly without disturbing page breaks. While prints on continuous paper were almost typical in the early days of the computer age (and with the advent of dot matrix printers, they were also particularly inexpensive in the home), printers are now almost only in use where production steps or operations of security-relevant equipment have to be documented promptly who process this paper (e.g. in train signaling systems of the railways).
Continuous paper as a user interface
The first computer terminals that were able to visualize output data on a screen did not come onto the market until 1969 and were very expensive at the beginning. Until the mid-1970s, it was common to use a printer with continuous paper for general output in addition to a keyboard as an input device. The answering of commands in the operating system and the output of functions in the application software took place line by line on a printer with continuous paper.
Differentiation according to the type of paper transport
With guide hole edge
The most frequently used continuous paper has guide holes (Remaliner perforation) on the left and right of the paper edge, into which the “spiked wheels” or belts (spike spacing ½ inch = 12.7 mm, see below) of the so-called tractor engage around the paper to transport. The side strips with the guide holes are optionally designed as separable edges with perforation or without perforation. The individual sheets are separated from one another by a perforation and alternately folded in a "zigzag" process (" Leporello ", once forwards, once backwards). The usual standard delivery units are cardboard boxes with a content of 2000 sheets and a paper weight of 80 g / m², with copies mostly of 500 or 1000 sheets at only 60 to 70 g / m².
Paper in rolls
Alternatively (for modern laser printers) the (continuous) feed is only generated with pressure rollers , since the paper no longer needs to be jammed during the (contactless) printing process. For this purpose, the pre-printed forms (possibly in color) and standard material (white) are usually delivered in roll form, as is customary in rotary printing , and printed (usually black). Since there is no longer any need to adhere to print lines, texts, lines, graphics, logos, etc. can be printed in one printing process.
Basic dimensions for continuous paper
Paper height
The paper format of fanfold paper is based on the paper guide mechanism of the printer, based on inches. Since the "DIN A4" format (297 mm) differs from this, in Germany mostly twelve inch high (= 304.8 mm) continuous paper is used. In the USA, fanfold paper is often only eleven inches high, which corresponds exactly to the "letter" paper format used there. As standard, the paper in line printers is printed "single-line" with six (in "narrow" mode eight) lines per inch; a page would have 72 lines, but you usually leave three headers and three footers free and (with 12 ″ paper) you can use 66 net lines, with “real” A4 format only 64 lines. Particularly in the case of preprinted forms, a full “fanfold fold” (e.g. twelve inches high) often contains several individual forms in the vertical direction.
Paper width
Typical line printers in EDP (not laser printers) have a fixed character width of ten characters per inch and can usually only print max. Print 132 characters per line, large machines can also create paper widths of up to 420 mm (equal to DIN A2 width corresponding to 16 ″) and thus max. 160 character positions per line. For narrow papers / forms, e.g. B. for 1-lane address labels (self-adhesive on backing paper), the paper guide of the printer can be adjusted accordingly narrower.
Form variants
Standard paper
A printer paper, also jokingly called “green and white” (because of the frequently used horizontal auxiliary lines that are preprinted in green and white), is used as the standard paper, usually for creating lists .
Pre-printed paper
Pre-printed paper is used for special print formats such as letters, invoices, account statements, customer cards, etc. Here, the form in the printer must be set up particularly precisely and the printer must be converted accordingly often for each type of form.
Multiple forms side by side
In special cases several forms are arranged side by side . This type is used, for example, for cards with different paper thicknesses, pre-cut adhesive labels , transfer receipts, etc. - which must be particularly taken into account when creating the print line (in the program).
Form sets
Special versions of continuous paper consist of sets of forms with several layers (up to seven) of self-copying paper, which are only connected at the leading edges, which results in individual copies after the side strips are separated. Due to the partial coating of the backsides of the individual layers of the self-copying paper, predetermined areas on the different copies cannot be written on, so that the addressees of the copies can receive different information.
Also, carbon paper is used as a liner for breakdowns. With laser printers, "carbon copies" are not possible, "multiple originals" are created here.
Guided tour of the printer
When using chain printers , the empty stack of paper is usually at the front under the printer, the paper web is pulled up, passes through the printing position and is again folded in zigzag behind the printer (with correct paper guidance; otherwise paper jam), according to the original folding direction, as Pile filed.
The transport of the paper in the printer was controlled by the chain printers that used to be used almost exclusively (for larger print volumes in data centers ) via an endlessly glued, approx. 4 cm wide "feed belt". Particularly useful for printing forms, certain line positions in the form (for example the head of the form or certain intermediate positions or a footer) were punched as holes in so-called "channels". In the case of print feed characters for certain channels in the individual print line (set in the computer program ), the printer's feed mechanism executes a “jump” to the respective channel (e.g. to channel 3 = in line xx). This achieved a higher print performance than when printing several blank lines (depending on the form filling and also programmatically).
Post-processing after printing
Depending on the type of form the printed paper is mechanically - horizontally or vertically and / - cut , so that the print products than individual documents if necessary, bundled into stacks, can be delivered. Often, mostly for list prints, the printed stack of paper is also forwarded to the recipients unseparated , possibly only with the edge of the guide hole being separated (with a paper cutting machine ).
With modern paper post-processing machines, different types of forms / receipts can be combined and also enveloped and franked ready for dispatch .
For easier manual post-processing, so-called cover sheets are often printed on each of which information on the type of print / form, recipient names and addresses, etc., parts of which are often printed in characters 20-30 lines high.
Individual evidence
- ↑ http://www.hnf.de/museum/nixdorf-wegbereiter-der-dezentralen-datenverarbeitung/die-produkte-der-nixdorf-computer-ag.html
- ↑ Explanation of Remaliner perforation ( Memento of the original from April 7, 2011 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice.
