In 2016, the "3 • 15" quality inspection activity first proposed the "one improvement" requirement to solve the problem of opening glue. In response to the "pain points" of publication quality management: the problem of ungluing loose pages, the General Administration took advantage of its collaboration, organized special research, conducted cause analysis, and wrote solutions to achieve significant results. The heating mantle is widely used in hospitals, biomedicine, life science, agriculture and forestry, education, health and epidemic prevention, animal husbandry and veterinary, scientific research institutions, laboratories and other departments at all levels. We specialize in manufacturing lab instruments, such as biology Microscope, histology microtome, heating mantles, cover slides, Lab Consumable materials and so on. Heating Mantle,Lab Heating Mantle,Heating Mantle Price,Digital Heating Mantle Xinxiang Vic Science&Education Co.,Ltd. , https://www.hnhumananatomymodel.com
Still worrying about the problem of ungluing loose pages? The medicine is here, prescribe it now!
According to the results of random inspection, the problem of "opening loose pages" in substandard products has dropped significantly, which is about 48 percentage points lower than the previous year. The problem of "opening loose pages" has been effectively controlled and achieved good results. However, the phenomenon of side glue opening, adhesive backing breakage, exposed roots, page drops, empty backing, and adhesive backing holes are still prominent. To this end, the General Administration formulated and issued a solution, made a comprehensive analysis of the cause of the problem of opening glue and loose pages, and put forward relevant requirements in a targeted manner, focusing on solving the problem of opening glue and loose pages.
Four major issues resolved in 2017
One side glue opening problem
The glue-gluing on the side of the glued book refers to the phenomenon that the cover and the book block are not firmly bonded, and the performance is as follows: glue on the front or rear side, glue on the front and back sides or part of the glue (see Figure 1), In severe cases, the cover is separated from the book block, affecting readers' use (see Figure 2).
figure 1
figure 2
One reason: a small number of books have side glue opening phenomenon. One is that there are too many shutdowns during the operation of the equipment, and the cover has not been fixed in the opening time of the glue. The second is that the thickness of the batch book is inconsistent, and the thin side glue has poor contact.
Solution:
(1) Minimize the number of downtimes during normal equipment operation;
(2) When the shutdown exceeds the opening time of the glue, 6-8 copies (3-5 copies for a single machine) shall be removed;
(3) The rejected book can be reheated and flattened into a qualified product by hot pressing without removing the cover and throwing it away;
(4) After folding, the pressure should be bundled to reduce the air in the signature to ensure that the thickness of the batch book is basically the same.
Reason two: the phenomenon of side glue opening in batch books, one is improper adjustment of the distance between the rubber wheels on both sides, and the contact with the book block is poor; the second is the inappropriate selection of the side glue model; the third is that the temperature of the side glue is not set according to the technical parameters ; Fourth, the clamping distance is too large when holding the clamp.
Solution:
(1) According to the paper quality, choose the type and model of adhesive correctly;
(2) Correctly adjust the spacing of the side rubber wheels according to the actual thickness of the book block to ensure that the glue is uniform, stable and appropriate;
(3) The temperature of the glue used must be based on the technical parameters specified by the type and model used, with a tolerance of ± 5 ° C and a special case of ± 10 ° C. The use data cannot be changed at will;
(4) Correctly adjust the distance of the clamping block, based on the actual thickness of the booklet, it should not be too large or too small.
2. The problem of broken or glued roots of wireless adhesive staples
Some books have adhesive cracks when they are flipped, and the pages at the broken points are not firmly adhered and are easy to loose pages, which affects the readers' reading and use (see Figure 3). The gum root is exposed when opened (see Figure 4).
image 3
Figure 4
Reason 1: The book clips on the clip board are not parallel or skewed, the grooves on the milling back are uneven, and the glue cannot be filled.
Solution:
(1) Correctly adjust the verticality and clamping degree of the book clip to ensure that the back of the book is in parallel contact with the glue wheel;
(2) Correctly adjust the heights of the three groups of rubber wheels: rubber-coated wheel, rubber-filled wheel and even rubber wheel.
Reason two: The cutter device is not parallel.
Solution:
Check the parallelism of the rotation of the milling cutter disk and the stability of the tool in time, and repair or replace the problem in time.
Reason three: The type and type of adhesive used is inappropriate or the quality of the adhesive is poor.
Solution:
(1) According to the paper quality, choose the appropriate type and type of adhesive that meets the standards;
(2) Check the technical parameters of the adhesive according to the standard;
(3) Adhesive materials shall not be misused or mixed.
Reason four: Adhesive aging or deterioration or improper adjustment of adhesive temperature.
Solution:
(1) Clean the glue pot on time, the amount of glue stored should be reasonable, and the glue liquid should not be melted repeatedly for a long time;
(2) The adhesive temperature is subject to the technical parameters of the adhesive used, the tolerance is ± 5 ℃, and the special case is ± 10 ℃. It cannot be adjusted up or down at will;
(3) Different types of adhesives cannot be mixed.
Reason five: The paper quality is different and the glue is improper.
Solution:
(1) When different types of paper and paper quality are used in the same volume, the type and type of glue used should be based on the best paper quality;
(2) Different types of adhesives cannot be mixed.
Reason 6: The roots of the front and back of the booklet are exposed.
Solution:
(1) When the paper, thickness and weight of the cover and book block are different, the process design should be increased
Add lined paper to make the tension between the two transition;
(2) When the cover paper is thicker and harder, try to deepen the cover indentation (side rubber flip mark) as far as possible, so as not to crush the mark or the paper.
Three page off issues
When the book is glued and bound wirelessly, the page inside the book block appears to fall off when it is flipped, which affects the reader's reading (see Figure 5).
Figure 5
Reason one: The signature paper is thick and hard and has too many folds, the depth of the milling slot is not enough or the slot spacing is too large, and the glue has not fully penetrated into the slot.
Solution:
(1) Increase the depth of the milling back and the slot, so that the glue can penetrate the innermost sheet.
(2) According to the paper quality, thickness and fold of the signature, adjust the depth of the slot to 2mm (standard 1.5 ± 0.5mm) according to the standard requirements.
Reason two: When folding, the crease runs away, and the innermost sheet is not milled or glued.
Solution:
Adjust the pressure, parallelism and verticality of the folding paper feed roller, so that the sheets are correctly transported in place, and the folding seam is tight and seamless.
Reason three: The books were not collided and stored in a single machine. The indented books were not milled or glued.
Solution:
(1) For single-machine processing, the book should be backed first, and then be bound and processed by the binding machine;
(2) The linkage line should increase the amount of vibration of the vibrator to make the loose book book vibrate neatly;
Reason four: Paper scraps and paper wool have not been cleaned up, blocking the slots and the glue liquid cannot penetrate.
Solution:
(1) Correctly install and use the paper suction device;
(2) Clean up the equipment used on time to ensure the neatness and cleanliness of the milling back device and make the production proceed smoothly.
Reason five: The type of adhesive used is inappropriate, the quality of the adhesive does not meet the standard, or the use temperature is incorrect.
Solution:
(1) According to the requirements of EVA hot melt adhesives and the different paper quality, choose the correct type and model of adhesive.
(2) The use of adhesive temperature is subject to the technical parameters of the adhesive, the tolerance is ± 5 ℃, and the special case is ± 10 ℃;
(3) According to the requirements of the standard, the softening point of the adhesive should be> 82 ℃. Those that do not meet the standard are unqualified products and should not be used;
(4) Mixtures of different types of adhesives are strictly prohibited.
Reason six: There is residual adhesive on the bottom edge of the clip board, and the front and back pages are pulled off.
Solution:
(1) Correctly adjust the retention of the book clip on the book clip board, not too high or too low, generally the sticking opening is 10mm;
(2) Frequently clean the residual adhesive on the edge of the book holder or apply some silicone oil in advance to prevent the adhesive residue from sticking and pulling off the front and back pages of the book block.
Four empty back or glue hole problem
There are cavities of different sizes in the back adhesive area of ​​the book or at one or both ends of the back adhesive, which affects the bonding strength and appearance quality (see Figure 6 and Figure 7).
Image 6
Picture 7
Reason one: The air in the book block is not excluded, resulting in inconsistent width of book back and book block thickness, which leads to unequal clamping of the book clip board, resulting in the glue wheel not working properly.
Solution:
(1) Solve from the folding process. Correctly adjust and use the guillotine, the air in the signature should be eliminated as much as possible;
(2) The folded signatures must be bundled together so that the excluded air no longer returns; ensure that the thickness of the batch book after the distribution is basically the same;
(3) After folding, the stacking and pressing method can also be used to pile up the signatures in a stacking manner. One board is laminated every two, and the top layer is also pressed to achieve the effect of bundling;
(4) The spacing (clamping degree) of the book clamped by the machine is adjusted according to the actual thickness in the middle of the book block;
(5) Trapezoidal paper can also be pasted in the clip board to solve the parallelism of clamping.
Reason two: Improper adjustment of the height of the rubber wheel, and do not understand the role of the three wheels.
Solution:
(1) Correctly understand the purpose of each of the three groups of rubber wheels, rubber wheel and rubber wheel, and adjust the height of each wheel correctly;
(2) The tolerances of the front and rear rubber wheels of the double glue pot must not be too large.
Publishing units and printing enterprises should further enhance their understanding of product quality, strictly implement standards and norms, strengthen personnel technical training, establish and improve a long-term quality management mechanism, and effectively improve the quality control capability and level. Each management department and quality inspection agency shall vigorously promote the implementation of the resolution plan, communicate with relevant units in a timely manner when quality problems are found, compare the plans, help analyze, and rectify and improve.