Digital Printing Postpress

1. For digital printers, is finishing after printing important?

Yes. In today's printing market, on-demand digital printing is still a new area, but 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 concepts. The time spent on intercourse is not calculated in hours, but it can be calculated in minutes. With the development of digital printing technology, post-press processing continues to advance with the trend. With the ever increasing number of digital printing applications, digital printers are striving to learn how to use digital printers and master post-press processing technologies in order to process products that meet the diverse needs of customers with the least cost and fastest speed.
Post-printing is a very important part of the printing process of printed matter. After printing, such as folding, collating, die-cutting, indentation, glazing, laminating, cutting, binding, etc., printing products can obtain the required requirements. The style and use of performance. Whether in the traditional printing field or the digital printing field, post-press processing has a very important role. It determines the final appearance of the printed matter on the market. The successful post-press processing must be a professional post-press processing. Only after reasonable planning and process arrangement, proper equipment, and rich professional experience can we successfully complete the post-press processing of printed products. Digital printers should keep in mind that they should consider and determine how to perform final post-press processing on a printed product before it is printed. Otherwise, once the printed product has problems, it will become a waste product.

2. Are you doing your own post-press processing or outsourcing your post-press processing?
As customer expectations increase and demand changes, digital printers must not only guarantee print quality and delivery speed, but also have the flexibility and variety of processing. That is to say, your post-press processing capacity must be able to guarantee the fastest delivery time and the least waste. Therefore, the less time the equipment needs to be adjusted, the better and the simpler the steps. Flexibility is undoubtedly also very important. Therefore, more and more digital printers are now finishing their own post-press processing instead of outsourcing the post-press processing to other service providers. In short, the digital printers themselves can complete the post-press processing, so that they can master the processing of the entire job and reduce the production cost. Of course, if it is some special post-press processing (such as die-cutting, polishing, etc.), it may be given to professional processors to do better.

3. Should you choose online or offline processing equipment?
At present, there are two kinds of online and offline processing equipment for digital printing. The on-line post-press processing equipment can automatically complete the printing, folding, cutting, binding, etc. of documents, and is suitable for jobs with certain batches and relatively fixed types of job types. The advantages of on-line processing equipment are the high degree of automation, and the overall footprint of the equipment is small; the disadvantage is that the price of the equipment is higher than that of 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 and the digital printing press are independent of each other, and are suitable for processing small and medium-volume print jobs. The price is cheap, and different stand-alone machines can process different types of jobs at the same time. The required turn-around time is short, even in digital printing. When the machine is not working, the offline post-press processing equipment can also work. Relatively speaking, the use of off-line postpress equipment can make more efficient use of resources. For example, a perfect binder can serve three digital presses that print different jobs at the same time because the speed of most postpress equipment is Higher than digital printing presses.

4. What kind of paper cutter is more suitable for digital printers?
The role of the paper cutter is to cut the paper or printed product to the desired size and shape. At present, there are various types of paper cutters on the market, including both manual and automatic computer-controlled types. The cutting specifications of single-sided knife and paper cutters are generally from 52 cm to 150 cm. Practice has proved that the cutting machine with a cutting width of 78 cm is more suitable for digital printers, and a large paper cutting machine with a width of 78 cm or more is relatively expensive. You can choose a computer-controlled paper cutter, so that if you cut the work that you once worked on, you just need to call up the original program from your computer and save time.

5. What should I watch out for when using a paper cutter?
In order to maintain the sharpness of the blade and extend the service life of the cutter, it is best not to exceed 40mm thick for the paper that is cut at a time. Moreover, the pressure of the paper cutter on the paper should also be appropriate. Generally, the softer paper requires more pressure. Hard materials require less stress.
It is critical to maintain the sharpness of the blade when using the paper cutter. Care should be taken to properly maintain and use the blade. Once the blade is blunt, the blade should be reground, otherwise the cutting accuracy will be affected.
In addition, pay attention to keep the ambient temperature at 19 °C ~ 23 °C, 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 paper being processed.

6. Why do you want to crease? How to press crease?
When the amount of paper you print is more than 120g/m2, press-folding before the folding can make the folding easier, and the folded-out print is more even and more beautiful. In fact, regardless of the kind of paper, if the creases are folded before the folding, it can get good results.
Crimp creases can be done on a special press creaser machine, which has a desktop machine, but also has a larger press crease, punching dual-use type. If there is an indentation mold, it can also be done on a flat press. In addition, some folding machines themselves have the function of creases.

7. Why are some printed sheets cracked after creasing or folding? What should you watch out for when pressing creases?
The appearance of cracks in printed images of printed sheets after indentation or folding may be due to the drying of the paper, and the more quantified the paper, the more likely this failure occurs. Therefore, to avoid cracks, the paper should be kept at a proper humidity and not too dry. In addition, folding the paper in the direction of the paper web can also avoid the occurrence of breakage at the crease. If you are processing books and digital printing, the orientation of the paper should be parallel to the spine of the final finished book. Of course, laminating the printed paper can also prevent cracks from appearing at the printed hinges.
Indentation should pay attention to the depth of the indentation should be moderate, if you use the indentation machine should pay attention to speed do not open too fast.

8. What are the folding machines? What size folding machine is suitable for digital printing companies?
A small number of jobs can be completely used for manual folding, but when processing a large number of jobs, it is best to use automatic folding machines to ensure production efficiency and folding accuracy. There are three main types of folding machines: a fence-type folding machine, a knife folding machine, and a grid knife folding folder. The paper feeding part of the folding machine is divided into two types: suction type feeding and friction type feeding. It is best to choose a paper folding machine with suction type feeding method, because the friction type feeding can easily damage the printed digital printing. Printing products.
Under normal circumstances, a folding machine with a maximum folding width of 52 cm can be full

Most of the digital printer's folding requirements. Do not open the machine too fast when folding, so as not to cause paper deformation or wrinkling. In order to avoid double-sheets and other paper-feeding failures caused by static electricity, anti-static bars should be installed on the folder. In addition, if the indoor humidity is too low, it will cause the paper to break when the paper breaks, so pay attention to maintain the appropriate humidity. For printed sheets that require continuous folding, fold indentations and then fold the sheet first to avoid wrinkles or cracks on the sheet.

9. What are the commonly used binding methods?
Digital printing machines can print books, brochures, bids, calendars, etc., so the commonly used binding methods are saddle stitching, wireless glue bookbinding, lock stitching, iron wire stitching, spiral stitching, and circle stitching. It is worth noting that digital printers must decide which binding method to use before starting to print jobs, rather than blindly waiting for them to consider how to bind them after printing. Because different binding methods (such as perfect binding and saddle stitching) have different requirements for the layout of pages in the prepress typesetting stage.

10. How to choose the binding method of printed products?
Deciding which binding method to use is not an easy task. The main method of binding should be based on the customer's requirements, the characteristics of the paper used, the direction of the paper, and the end use of the printed product. In the binding of books and booklets, for example, saddle stitching is a fast, efficient, and economical method, but the bound thickness is limited (usually no more than 4mm); domestic digital print shops currently use more wireless glue binding methods. Binding books are not only beautiful, but also bound firmly. Although the staple binding mode is very good, the binding is time-consuming and costly.

11. What should you watch out for when choosing a finishing device?
When purchasing the binding equipment, it is necessary to check whether the paper conveying mechanism (such as paper guide rollers, rollers, etc.) is of good quality. If the quality of the rollers is not good, the printed paper can be easily damaged. The transfer roller and the paper guide roller also make Paper generates static electricity.

12. Why does a book or book that has been glued off sometimes fall off?
There are many reasons for the page drop, the reason for the glue, and the reason for the machine. The binders used by digital printers generally include milling backs, gluing, and package covers. Some inexpensive gluebinders do not have the milling and backing process; some binders have milling and backing capabilities. However, the milling and back machining of the spine is not in place, and these will affect the firmness of the glue binding. In addition, the type and quality of the glue also have an impact on the fastness of glue binding. If the temperature is not properly controlled during the glue-binding process, it will also cause the book to be loosened or dropped. In the bookbinding process, there is a parameter that is important, that is, open time, which refers to the time required for the glue to bond the cover of the book to the book. When a book or booklet is glued on the machine, it will take some time for the glue to continue curing, sometimes up to several hours. Therefore, do not read it immediately after the book has been stapled on the perfect binder. At least 15 minutes later, please read it and check it.
In short, in the face of the market with different prices, different quality of the perfect binding machine, must pay attention to meet the binding requirements of your printing products.

13. What kind of printed product is bound for punch binding?
Punching or boring binding methods are more suitable for binding documents consisting of sheets of one page, which are applicable to student materials or sales staff samples. In particular, when it is necessary to change some of the contents, only one or more pages of the contents of the changes need to be reprinted, and then the old pages can be replaced after the holes have been completed, without reprinting the entire document or sample. .
When using the punch binding method, the punched paper should not be too thick or too thick, otherwise it will affect the quality of punching. When the drill hole drills, the heat will cause the digitally printed image toner to melt. Care should be taken not to drill excessively. When the polyester material is to be punched and bound, the punching process should be used as far as possible without drilling, because the heat generated by the drilling easily melts and sticks the polyester material.

14. What is the difference between a spiral and a circle?
Spiral stitching and stitching need to be punched first and then bind the prints into a booklet. The types of spirals or loops used are various, both metallic and plastic; both monochromatic and colored. Spiral is to use a continuous plastic wire or wire from the first hole of the print to the last hole; and the ring is to use a separate ring wire or plastic ring through the hole "clamp" to live Leaflet. Spiral stapling and stitching are characterized by low binding costs and good flatness. A manual A small desk-top punching spiral or bookbinding machine (books with a thickness of 20 to 28 mm can be bound) binds an A4 booklet. It takes 5 minutes. If the number of binding is large, it is better to use a computer-controlled punching and binding machine with a high degree of automation. $Page break $

15. Can digital printing products also be coated?
can. In order to make the prints more beautiful and durable, many prints are covered with various bright films, matt films, and matt films to achieve distinctive effects. Digitally-printed prints are usually hot-laminated. This method is easy to use and inexpensive.

16. What are the specialties of choosing a film when laminating?
The main film used for hot film is polyester film and polypropylene film. Generally, it is required to use polypropylene film when covering thin film.