Q & A on post press processing of the hottest digi

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Q & A on post press processing of digital printing

1 Is post press processing also important for digital printers

yes. In today's printing market, on-demand digital printing is still a new field. However, in the field of commercial printing, digital printing has made great progress in recent years. The application of digital printing has broken the processing concept in people's traditional concept. The working time is not calculated in hours, but can be calculated in minutes. With the development of digital printing technology, the post press processing is also progressing with the trend after cutting off the power supply. With the increasing application of digital printing, digital printers are trying to learn how to use digital printing machines and master post press processing technology, in order to process products that can meet the diverse needs of customers with the least cost and the fastest speed

post press processing is a very important link in the printing process of printed matter. After post press processing such as folding, page matching, die cutting, indentation, polishing, film covering, cutting and binding, the printed products can obtain the required style and performance. Whether in the field of traditional printing or digital printing, post press processing plays a very important role in determining the final appearance of printed matter in the market. Successful post press processing must be professional post press processing. Only with reasonable planning and process arrangement, appropriate equipment and rich professional experience can we successfully complete the post press processing of printed products. Digital printers should keep in mind that before a single print job is printed, the scanning should be interrupted to determine which COM port is interrupted, and then consider and determine how to carry out the final post press processing on the printed matter. Otherwise, the best printed matter will become waste once there is a problem in the post press processing

2. Is it better to do the post press processing by yourself or outsource the post press processing

with the improvement of customer expectations and the continuous change of demand, digital printers should not only ensure the printing quality and delivery speed, but also have the flexibility and diversity of processing. In other words, your post press processing capability should ensure the fastest delivery time and the least waste, so the less time required for equipment adjustment, the better, and the simpler the steps. Flexibility is undoubtedly very important. Therefore, more and more digital printers are starting to complete post press processing by themselves instead of outsourcing post press processing to other service providers. In a word, the digital printer can finish the post press processing by himself, which can make him master the processing progress of the whole live parts and reduce the production cost at the same time. Of course, if it is some special post press processing (such as die cutting, polishing, etc.), it may be better to hand it over to a professional processor

3. Should I choose online post press equipment or offline processing equipment

at present, there are two types of post press processing equipment supporting digital printing: online and offline. The on-line post press processing equipment can automatically complete the printing, folding, cutting, binding, etc. of documents, which is suitable for operations with a certain batch and a relatively fixed type of live parts. The advantages of on-line processing equipment are high degree of automation and small overall floor area of the equipment; The disadvantage is that the price of the equipment is higher than that of the single machine for offline processing, and the adjustment time of the whole machine is relatively long

the so-called off-line processing means that the post printing processing equipment is independent of the digital printing machine, which is suitable for processing small and medium-sized batches of printing. The price is cheap. Different single machines can process different types of live parts at the same time, and the machine adjustment time is short. Even when the digital printing machine is not working, the off-line post printing processing equipment can also work. Relatively speaking, the use of off-line post press processing equipment can make more effective use of resources. For example, one binding machine can serve three digital printers printing different moving parts at the same time, because the speed of most post press processing equipment is higher than that of digital printers

4. What kind of paper cutter is more suitable for digital printers

the function of the paper cutter is to cut the paper or printed product into the required size and shape. At present, there are various paper cutters in the market, including manual type and computer-controlled full-automatic type. The cutting specification of single-sided knife paper cutter is generally 52cm ~ 150cm. Practice has proved that paper cutters with a cutting width of 78cm are more suitable for digital printers, and large paper cutters with a cutting width of more than 78cm are more expensive. You can choose the paper cutter controlled by the computer, so if you cut the live parts that have been processed, you only need to call up the original program from the computer, which can save the time of machine adjustment

5. What should I pay attention to when using the paper cutter

in order to keep the blade sharp and prolong the service life of the paper cutter, it is better not to cut more than 40mm thick paper at a time, and the pressure of the paper cutter on the paper should also be appropriate. Generally, the pressure of softer paper is higher, and that of harder materials is lower

it is very important to keep the blade sharp when using the paper cutter. Pay attention to the correct maintenance and use of the blade. Once the blade is blunt, the blade should be reground, otherwise the cutting accuracy will be affected

in addition, attention should be paid to maintaining the ambient temperature at 19 ℃ ~ 23 ℃ and the relative humidity at 50%. Under such conditions, the characteristics of the paper are relatively stable, which is conducive to the correct use and maintenance of the paper cutter, because the determination of many cutting parameters depends on the processed paper

6. Why is it necessary to press creases without human error within 1 year? How to crease

when the weight of the printed paper exceeds 120g/m2, pressing the crease before folding can make the folding easier, and the folded sheet is smoother and more beautiful. In fact, no matter what kind of paper, if you press the crease before folding, you can get a good effect

creasing can be completed on a special creasing machine. This machine has desktop computers, as well as a larger type of both creasing and punching. If there is an indentation die, you can also press the crease on the flat press. In addition, some folding machine itself has the function of pressing creases

7. Why do some printing sheets crack after indentation or folding? What should be paid attention to when pressing creases

the cracks on the printed sheet at the image after indentation or folding may be caused by the drying of the paper, and the higher the quantity of paper, the more likely this fault occurs. Therefore, to avoid cracks, the paper should be kept at a proper humidity and not too dry. In addition, folding the paper along the direction of the paper filament can also avoid fracture at the crease. In the case of processed books and periodicals, during digital printing, the thread direction of the paper should be parallel to the spine direction of the final finished book. Of course, laminating the printed paper can also avoid cracks at the folding of the printed matter

the depth of the indentation shall be moderate. If the indentation machine is used, the speed shall not be too fast

8. How many folding machines are there? What specifications of folding machine are suitable for digital printing enterprises

manual folding can be used for a small number of live parts, but when processing live parts with large printing volume, it is best to use automatic folding machine to ensure production efficiency and folding accuracy. There are three kinds of folding machines: fence folding machine, knife folding machine and fence knife hybrid folding machine. The paper feeding part of the folding machine is divided into two types: air suction paper feeding and friction paper feeding. It is best to choose the air suction paper feeding folding machine, because the friction paper feeding is easy to damage the printed digital printing

generally, a folding machine with a maximum folding width of 52cm can meet the folding requirements of most digital printers. Do not drive the machine too fast when folding to avoid paper deformation or wrinkles. In order to avoid the double sheet feeding fault caused by static electricity, the folding machine should be equipped with an anti-static rod. In addition, if the indoor humidity is too low, the paper will break when folding, so pay attention to maintaining appropriate humidity. For the printing sheets that need to be folded for several times, be sure to indent them first and then fold them to avoid wrinkles or cracks on the paper

9. What are the common binding methods

the products that can be printed by the digital printer include books and periodicals, pamphlets, tenders, wall calendars, etc., so the commonly used binding methods include horse riding binding, wireless binding, sewing, iron wire binding, spiral binding, circle binding, etc. It is worth noting that the digital printer must decide which binding method to use before starting to print live copies, and do not blindly wait for the printing to finish before considering which binding method to use. Because different binding methods (such as wireless binding and horse riding binding) have different requirements for page arrangement in the pre press stage

10. How to select the binding method of printed matter

it is really not easy to decide which binding method to use. It should be decided mainly according to the customer's requirements, the characteristics of the paper used, the direction of the paper strands and the end use of the printed matter. Taking the binding of books and pamphlets as an example, although horse riding binding is a fast, efficient and economic way, the binding thickness is limited (generally not more than 4mm); The domestic digital printing shop used wireless binding method before its low cost. The bound books are not only beautiful, but also firmly bound. Although the stitching method has good binding firmness, its binding cost is high

11. What details should be paid attention to when selecting the binding equipment

when purchasing binding equipment, pay attention to check whether the paper transfer mechanism (such as paper guide roller, roller, etc.) is in good quality. If the roller is not in good quality, it is easy to damage the printed paper, and the paper transfer roller and paper guide roller will also generate static electricity

12. Why do the pages of a book or pamphlet bound wirelessly sometimes fall out

there are many reasons for page dropping, including glue and machine. Digital printers use wireless binding machine generally includes milling back, gluing, cover several steps, some cheap binding machine simply does not milling back this process; Some binding machines have milling back function, but the milling back processing of the spine is not in place, which will affect the firmness of binding. In addition, the type and quality of the adhesive also have an impact on the fastness of the binding. Improper temperature control during the binding process will also lead to scattered pages and missing pages of the book. In the binding process, there is a very important parameter, namely the open time, which refers to the time required for the book cover to bond firmly with the book. When the books or pamphlets are bound on the machine, the adhesive still needs a certain time to continue curing, sometimes as long as several hours. Therefore, do not read the book immediately after it has just been bound on the binding machine. You should read and check it at least 15 minutes later

in a word, in the face of binding machines with different prices and different quality in the market, you must pay attention to meeting the binding needs of your prints

13. What kind of prints are suitable for punching and binding

the punching or drilling binding method is more suitable for binding documents composed of single sheets of paper page by page, which is very suitable for materials used by students or samples used by salespeople. In particular, when it is necessary to change some of the contents, it is only necessary to reprint one or several pages with changed contents, and then add them after punching to replace the old pages, without reprinting the whole document or sample

when using the punching binding method, do not punch too much or too thick paper at one time, otherwise the punching quality will be affected. When drilling

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