What office paper is?In times when computers only began to occupy offices and offices, there was a concept “ paperless “ office. It was supposed that all office work will be computerized so that all documents will exist only in a digital form and need for paper will simply disappear. Forecasts turned out too courageous that with “ firm “ it is simpler to work with the document (hard copy). In - the first, information is more visually provided; in - the second, for her perception are not required special devices. So, apparently, “ firm “ the carrier will never disappear from office.
Now there is a set of means and ways of display of information on paper: copiers, printers, faxes. Naturally, the same brand of paper cannot be applied to all these devices. Such approach or will be very wasteful (if to use only expensive and good paper), or will lead to breakage or reduction of service life of equipment (if to buy cheap and insufficiently qualitative paper that, however, too is wasteful as repair “ will cost a pretty penny “) . Each technology of obtaining the image ideally requires the paper which is characterized by a certain set of parameters.
Quality of paper and it “ professional suitability “ are estimated in the following parameters:
density (g/sq.m) - 40 - 250 g/sq.m (it is higher than 250 g/sq.m - a cardboard);
thickness (micron) - depends on density; the paper is thicker, the it is more rigid;
rigidity - resistance to the bending effort. Too rigid or too friable paper can get stuck in the printer;
to humidity (%) - optimum humidity of paper of 4,5 - 4,7%, such value provides necessary electric resistance;
conductivity - at transfer of the image paper is loaded with electrified) and if it has no corresponding electrostatic characteristics, process of transfer of a toner on it happens incorrectly or not completely. High conductivity - the reason of low-quality transfer and deleting of the image. On the other hand, the increased value of electric resistance can lead to pasting of sheets under the influence of static electricity;
smoothness - the paper microrelief defining its resolution: the leaf is more smooth, the quality of the image is higher. However smoothness not only provides optimum interaction of paper and paint, but also improves optical properties of a surface. Paper without finishing - opaque. For giving of high density and smoothness it is calendered - pass through system of the condensing shaft;
a roughness - on rough paper the toner can be fixed by incorrectly, further “ picture “ it is erased or showered;
a whiteness (%) - ability of paper to reflect light absent-mindedly and evenly in all directions. The whiteness is higher, the image is more accurate and more contrast. Compliance of color accuracy of the image to the original is possible only when printing on rather white paper. For increase of a whiteness by production of expensive high-quality paper add optical bleaches, and also the blue and violet dyes eliminating the yellowish shade inherent in cellulose fibers to raw mix. The whiteness is specified as a percentage. Now along with value of a whiteness according to the ISO standard its value according to other standard - CIE is specified also sometimes. But in both cases the this parameter is higher, the is more white and paper is more qualitative;
opacity (%) - at the bilateral press it is important that paper was opaque;
a skruchivayemost - high-quality paper should not have a residual deflection after process of the press. The skruchivayemost is influenced by the high content of moisture, influence of high temperatures and pressure.
Paper for copy equipment
the Bend and humidity. Being in “ belly “ the copy machine very short time, a leaf, nevertheless, is exposed severe “ to tests “. Passing around drums, the giving rollers and other details of the mechanism of the conveyor, it is bent and if moisture content is too high, gets stuck. Under the influence of the high temperatures and pressure characteristic of processes of formation of the image, damp paper can be twisted. From - for it there are frequent jammings too. As information: if humidity of paper exceeds 5,3%, twisting of paper is inevitable.
Reliable work of the equipment is guaranteed by the paper which is specially intended, correctly packed and containing optimum amount of moisture. Paper with the lowered moisture content when unpacking begins to absorb quickly it from air. Edges of a leaf become wavy - reliability of work of the equipment promptly falls.
To compensate a tendency to twisting under the influence of heat and pressure, some types of paper make slightly curved. On their packing it is represented the shooter, specifying the correct orientation when loading.
Friction. the Majority kopirovalno - multiplying devices is used by frictional feeders of a leaf. That there were no failures, paper has to have a certain coefficient of friction. If devices are equipped with vacuum feeders, then for their correct work there is important such parameter of paper as porosity.
Formation of the image. At transfer of the image paper is loaded. If the charge on it does not keep, there are areas with the erased image or other defects. The toner is fixed by means of heating under pressure. On a leaf with a rough surface the image can be fixed incorrectly and then be smeared. Besides, the polluted paper can leave marks on a photoreceptor that will worsen quality of the subsequent prints.
Electrostatic charge. the High temperature used for fixing of a toner in combination with friction of paper at its movement on tapes of the conveyor leads to the fact that sheets accumulate an electrostatic charge. This phenomenon is aggravated if humidity of paper is too small. From - for electrostatic a charge there are problems at postprinting processing, for example, when laying prints or their sorting.
Dust. Paper dust - one of the main reasons of failure kopirovalno - multiplying equipment. Dust is formed not only when cutting paper and its packing. Insufficiently fulfilled technology, in particular, the excess quantity of a carbonate of calcium entered when gluing also creates a problem of pollution of devices.
It is especially important not to use paper of poor quality in devices with recirculation of a toner (in which the toner applied on a drum, but which did not get on paper goes not to working off, and it is reused). Pile of cheap paper can get to capacity with a pure toner that will have an adverse effect on quality of copies.
Paper for duplicators Operation of these devices is based by
on a digital method of transfer of the image and a stencil process. From paper ability to well absorb paint is required, but, speaking generally, similar multiplying cars are very unpretentious to paper and are able to print both on import, and on domestic grades with a density from 46 to 210 g/sq.m
Paper for laser printers Laser printers impose on
to paper the same requirements, as copiers as use the similar principle of the press.
Paper for inkjet printers color inkjet printers are Most extended by
today. In their printing head there are several separate groups snuffled, each of which “ shoots “ ink microdrops of a certain color. Diameter of a nozzle makes less than 25 microns. The it is less, the image, however minimization of a point - not the only way of improvement of quality of an inkjet printing is more accurate. Technology of an inkjet printing such is that it yields the best results when using special paper. This results from the fact that the structure of fibers of usual office paper is uneven. Getting on such surface, the drop spreads and absorbed far not in the best way. As a result of the photo on usual paper look dim and indistinct. All producers of inkjet printers let out special paper for the equipment. Unlike usual it has several layers. Listings on such paper approach on quality a photo.
Paper for matrix printers
For work with such devices does not exist any restrictions for paper, except, perhaps, only thing - it has to be rather dense, Paper for fax machines
The one who considers that any sheets suit for the faxes working at usual paper is not lower than 70 g/sq.m
is mistaken. As the printer these devices can be divided into two main groups: laser and jet. To type of the printer also grades of the applied paper have to be corresponding.
As we see, paper plays an important role and reflects not only the document, but also leaves a mark on the budget of the organization. Buy and use intelligently!