Control methods to avoid loose pages

(1) The process design must be appropriate.

① A milling back amount of 2 to 3 mm must be reserved.

② In order to prevent books from being flipped, missing labels, and mixed, labels must be differentiated and controlled in advance (according to the category of the product, methods such as color separation of folding labels, color separation of book titles, and code distinction should be adopted.

③In order to drive a long car, when doing folding hands, the self-reprinting must be placed in the middle of the book.

④ When putting together the cover, try to put a 5mm white border between the two covers to prevent wild glue.

⑤ In order to facilitate the observation of the quality of the package and avoid scratches and abrasions on the seal, the Western-style flaps should be as flush as possible, and the Chinese-style flaps should be as flush as possible.

(2) Avoid passivation or incompleteness of the grooving knife, or only one of the two grooving knives works and the other does not work; avoid the mismatch between the main machine and the grooving speed, which will increase the groove spacing and the glue penetration and bonding points. Fewer and loose leaves; avoid the mismatch between the height of the milling back cutter and the height of the grooving tool, resulting in insufficient groove depth and easy to cause loose leaves. The preventive method is: before starting each shift, the captain is required to take a copy of the broaching machine to verify whether the broaching knife is working normally. If it is normal, it needs to be signed by the flight captain and quality inspector for confirmation; if there are any problems, they need to be adjusted and solved in time. The solution is to replace the broaching knife or the rotating broaching knife teeth, and adjust the height of the milling back knife or broaching knife, depending on the configuration.

(3) When books enter the book binders, the spacing between the book binders should be moderate to allow the books to enter normally, but should not be opened too wide to prevent the signatures from being deformed due to the soft material, resulting in the inability to drive a long car or Milling does not reach the back, forming loose pages.

(4) The back of the milling must be milled completely and thoroughly (the first and last posts of the platform folding page must be bundled, otherwise the flanging may not be milled and the leaves may form loose pages). Be careful not to mill the back sideways, otherwise Very easy to form loose pages. The main reasons for the formation of slant back are the following two points: ① The edge of the milling back knife is passivated; ② The transition block on the side of the small turntable that bears on the book plane is worn. The editor of the fully automatic wireless binding machine reminds you that if the slanted back causes high and low points in the subsequent gluing (that is, the low points are full of glue and the high points have insufficient glue), resulting in the loose pages above, the feasible solution is Replace the milling back cutter in time, fill the worn transition block with welding, and repair it in place (especially in spring and autumn, you must ensure that the milling back cutter is properly maintained).

(5) The hot melt adhesive temperature must be strictly monitored. The back adhesive temperature is 165~175°C and the side adhesive temperature is 155~165°C (specifically based on the requirements of the hot melt adhesive manufacturer). The temperature setting value of the preheated glue pot should be slightly higher than the usage value, and the preheated glue pot must be refilled in time. It is strictly forbidden to add raw glue directly to the glue pot.

  In order to ensure that the temperature of the hot melt adhesive is normal, in each shift during actual production, the captain and quality inspector must regularly use a thermal thermometer to measure whether the temperature of the hot melt adhesive is within the specified range, and make relevant records and sign for confirmation. date, specific time. During the busy period of work, the glue pot must be cleaned every two weeks to remove the sediment at the bottom of the pot to prevent the sediment from blocking the temperature rise, causing the temperature display to be inaccurate and eventually causing the book to fall apart. Some loose leaf conditions may not be discovered in time at the production site, so each batch of hot melt adhesive must be sealed to facilitate quality traceability in the event of loose leaf failure. During quarterly maintenance, the errors in the thermostat's set value, thermal probe display value and thermal measurement thermometer must be corrected to avoid loose pages caused by improper adjustment due to inaccurate temperature display.

Offset glue and coated glue must be used separately according to different paper types, such as offset glue for high-quality coated paper.

(6) The thickness of the adhesive layer should be controlled between 0.6 and 1.2 mm, and should be adjusted appropriately according to the thickness of the book. For thick books, when the adhesive layer is thin, pages in the middle are easy to fall apart. In principle, for books with a thickness greater than 20 mm, it is recommended to have perfect binding.

(7) Destructive strength testing must be in place. Pull the 3rd, 4th, middle, and 3rd and 4th pages from the bottom respectively. If you find that the strength is not enough, you must find out the reason and solve it immediately.

(8) Indentation of cover. The two positive indentations near the back of the book must be tightly attached to the ridge line of the back of the book. The indentations should neither be cracked nor too shallow. The key is to be full.

(9) The clamping support of the book must be in place, and the book must be completely inserted into the slot, and the minimum clamping value must be about 2 mm smaller than the thickness of the book. Strictly speaking, the support after clamping cannot be displaced, otherwise it will not be conducive to cutting. The specific support strength should be adjusted.

(10) Product protection against extreme weather must be in place. Allocate relevant personnel and implement relevant systems and processes.