Experience of using the hottest digital printing m

Experience in the use of digital printing machine paper

digital printing equipment is generally divided into color digital printing machine and black-and-white digital printing machine; According to the paper type, it can be divided into single sheet paper and continuous paper digital printing machines, but no matter what kind of classification, each category has different brands, different speeds and different functions of digital printing machines. As for the daily use precautions of digital printing machine paper, any digital printing equipment will have a set of paper use precautions that conform to its own structure, performance and operation. If it needs to be accurate to each machine and each kind of paper, there should be as many versions of paper use precautions as there are digital printing machines. Therefore, this article lists only some general precautions for paper use, which will be elaborated in the following five aspects

I. use of plain paper

before using digital printing equipment, you should first read the paper manual carefully to understand its requirements for paper, that is, what standards are included in the applicable paper, and what are the compliance parameters of each standard. Generally, the paper that meets the standard needs to meet the standards of paper type, weight, filler and size, which requires a comprehensive inspection of the paper. The inspection indicators include the following three points

(1) paper type. Check whether the paper type meets the specified requirements of the digital printer by 9 indicators: hardness, resistance, characteristic difference of both sides, water content, ash content (content of other components except pulp), packaging and storage conditions, post press bending, fixing (ability to permanently absorb ink), and paper feeding

(2) paper weight. Usually, there is a quantitative range of paper available for the printer in the user manual. Using lighter (or thinner) paper may cause paper tearing, broken feed holes, or misloading. Using heavier (or thicker) paper may cause paper feeding errors (paper feeding is not smooth) or stains, falling off from the feeder, etc., which are all due to the high hardness of the paper. To avoid these problems, make sure to use paper that meets the quantitative requirements

(3) paper filler and slurry. If the filling ratio is too high and the pulp composition is too low, even if the paper quantity meets the specification requirements, the hardness of the paper is not appropriate. This can also cause the printer to jam, fold or wrinkle incorrectly

therefore, the paper that conforms to the scope of application of the digital printer should be used in strict accordance with the paper manual of the digital printer

II. Use of recycled paper

if you want to use recycled paper, be sure to check the print quality and folding function in advance. These inspections should be carried out for each box of recycled paper. After checking the above items, contact the paper manufacturer to ask whether the recycled paper maintains consistent paper characteristics

the following points should be paid attention to when using recycled paper to make the final shape of a desktop

(1) since recycled paper is susceptible to moisture, please wrap it with moisture-proof film for storage

(2) recycled paper will produce a large amount of paper ash. These paper ashes will adhere to the rollers, sensors, feed channels, drum devices, which will cause various problems. Therefore, always clean the paper dust

(3) recycled paper is prone to moisture and bending, and its hardness is low, so recycled paper often has paper feeding errors

(4) recycled paper that is too bent may cause paper feeding or stacking errors

(5) the tensile test of low mechanical strength is mainly used to test the toughness and plasticity of stainless steel materials. Through the test of tensile test, the plasticity and molding performance of stainless steel materials can be guaranteed. Recycled paper may cause damage to the paper feed hole, incorrect folding or wrinkling

(6) unsmooth recycled paper will reduce the print quality

(7) if a pile of paper contains recycled paper of different properties, the print quality may be different

III. use of special paper

paper mills will continue to develop and sell various new types of special paper. In order to use these special papers, the product must be tested in advance. The common precautions for the use of several special papers are as follows

(1) label paper

label paper must be stored in an environment with a temperature of 15 ℃ ~ 32 ℃ and a humidity of 40% - 70%, and must be used within one year after production. After leaving the factory, the label paper must be packed with moisture-proof film or similar packaging as soon as possible to prevent moisture. The printing quality of the tangent part may be reduced. Therefore, printing in the tangent part must be avoided. For the sake of printing accuracy, 2mm frame should be left. If the quality or thickness of the label and the back page are different, the fusing heating may cause the paper to curl. In order to avoid this kind of situation, the label and back page must use electrostatic printing paper, so that the paper will not have obvious curl when heated. If the label paper is stacked too high, the adhesive of the bottom paper may be extruded due to the stacking weight. Therefore, consult the paper manufacturer for the maximum stack height

(2) perforated paper

raised perforations or burrs may have a negative impact on the print quality. Therefore, make sure to use only paper without bulges and burrs. Avoid printing near the perforation when designing the printing format. For the sake of printing accuracy, a margin of about 3.5mm should be reserved for each perforation

(3) the uneven adhesive of the sealed envelope paper

may lead to paper feeding errors or have a negative effect on the print quality. Therefore, printing media with such problems should be avoided. The printing of important data shall not be close to the adhesive, and a frame of at least 3.5mm shall be left. If too many sealed envelopes are stacked together, the stacking pressure may cause the media to stick together. Therefore, it is necessary to consult the manufacturer about the maximum stackable height. The storage time of some sealed envelopes is shorter than that of ordinary media, which also requires consulting the manufacturer about the storage period and storage conditions

(4) post paper media (Postcard type)

post paper media (the oil distribution tray of the hydraulic system of the postcard universal testing machine has wear or strip scratches) are coated with adhesive on both sides (possibly one side). Due to the strict requirements on the preprint environment (such as ink type and color quantity) of such media, please consult the paper manufacturer before purchasing. Each side of the printing medium is coated with a pressure sensitive adhesive. Therefore, when the surface coated with adhesive is printed, the paste may fail due to insufficient bonding strength. In order to prevent this kind of problem, we should avoid printing content at the symmetrical position of folding and bonding when designing pages

(5) color paper

color paper has a smoother surface than ordinary paper because colorants and fixatives (resins) penetrate into the paper fibers. Therefore, toner is not easy to penetrate into paper fibers, and the fixing strength of toner is low. When the adsorption between the fixing agent and toner is low, the fixing strength of toner is particularly low. If you must use color paper, you need to carefully check the printing conditions in advance and pre print

(6) embossed paper

embossed paper with company logo and other marks is called embossed paper. The inconsistent or uneven thickness of each part of the paper may cause paper jam or have a negative impact on the printing quality. It is necessary to carefully check the printing conditions and pre print in advance

(7) coated paper

paper coated with titanium oxide, kaolin, clay or calcium carbonate is used as art paper, coated paper, light coated paper or fully coated paper. Generally, coated paper has low toner fixing strength and low print quality. When printing coated paper, consult the paper manufacturer in advance to carefully confirm the printing conditions and pre print

(8) carbon free copy paper

carbon free copy paper consists of three parts that can sense pressure

carbon free copy paper can realize synchronous printing on contact printing machine. The pressure sensing medium can transmit the printed content to the second and third parts. When using a non-contact printer, all three parts need to be printed separately and then bound together. Each part of the carbon free copy paper is very thin, which is prone to paper feeding or stacking errors, or the pressure sensing medium of the paper melts due to temperature factors. Therefore, before printing a large number of carbon free copies, it is necessary to make a good evaluation of the replacement of spare parts and maintenance conditions

fourth, avoid using paper

the inapplicability of paper consists of a series of factors, which will reduce the print quality or cause some abnormal paper feeding errors. It is best not to use the following types of paper:

(1) incorrectly folded paper

(2) torn paper or paper with irregular holes

(3) paper with broken edges and corners

(4) bent, wrinkled, undulating or sunken paper

(5) paper placed obliquely

(6) paper with small pieces of paper and external objects (such as wax, metal sheets, glue, resin, etc.)

(7) special paper with glue or adhesive tape

v. storage of paper

in addition to paying attention to the matching of paper type, paper quantity, etc. with the performance of digital printing machine when using, the daily paper storage box cannot be ignored. If it is not stored properly, it will cause paper deformation, directly affect the effect of printed products, or cause printing failure

first of all, paper cannot be placed directly on the floor. Placing it directly on the floor will cause the paper to get damp. Please place the carton horizontally on a flat shelf, a flat shelf or a trailer. In order to prevent paper deformation, do not stack too many papers on each other. The stacking height shall not be greater than 1 meter. In order to prevent the paper from drying or moisture, it is best to place the paper in a sealed box at 10 ℃ ~ 30 ℃ and keep the relative humidity at 40% - 50% (the maximum drying temperature is 29 ℃)

when you open the box and find that the paper does not have waterproof storage conditions, please place the carton in a suitable environment with waterproof measures. The recommended ambient temperature is 15 ℃ ~ 25 ℃, and the relative humidity is 30% - 70%. Even in a dry and moisture-proof environment, the paper cannot be stored for too long (more than 6 months). Once the carton is opened, the paper must be wrapped with waterproof film to prevent it from becoming too dry or damp. Paper should not withstand common faults 6: sudden temperature changes to prevent it from becoming too dry or damp. It's best to deliver it to the place of use in advance, and then open it after buffering for some time

the above are some basic experience of daily use of digital printing machine paper, and I hope it can be helpful to digital printing practitioners

reprinted from: printed in China