Technical Issues and Treatments in Rubber Books (5)

V. Evasion of common quality problems

1. The round back and the back of the book are not rounded and convex: 1 The cause is that the height of the pallet is not enough. It should be adjusted to the standard gap between the back and the pallet; the second is the increase in the cover weight, and the increase in the cover weight. Unindented lines or crease lines are extra wide. 2 For super-heavy cover paper used in glue-binding production, it must be indented. The crease should be equal to the thickness of the book block or less than the thickness of the book block, 0 to 5 mm. can.

2, book degumming, loose leaf: 1 book block milling back depth is not enough, the signature page is not completely milled into a single page, cause the book to degummed, loose pages, should increase the depth of milling back and improve folding quality. 2 Slotting, the depth of the slot is not enough to cause the book off and loose pages, the depth of the slotted knife should be adjusted, and the sharpness of the slotting knife should be maintained. 3 The temperature of the hot melt adhesive is too low to make the adhesive liquid flow poor. The hot melt adhesive cannot penetrate into the slot of the book block, which causes the degumming of the book and loose pages. The hot melt adhesive should be heated to 160°C～180°C. Use it right and left. The optimum melting point of the hot melt adhesive depends on the temperature of the shop (hot melt adhesive requires a shop temperature of 20°C? 鄄 30°C). In winter, heating equipment is required in the glue shop of northern enterprises; The workshop also needs heating equipment to ensure the quality of plastic bags. 4 book spine hot melt sol glue on the book caused by degumming, loose pages, should control the thickness of adhesive, generally controlled between 0.6mm ~ 2mm, and adjust the distance between the rubber wheel and the book back. 5 Improper use of hot melt adhesives is also a cause of degumming and loosening of books. Therefore, the choice of hot melt adhesive should match the type and season of the plastic wrapping machine. 6 After the milling slot, paper hair, paper dust and paper scraps should be cleaned in time to avoid brushing. 7 Coated paper, offset paper mixed binding book block, slotted depth, glue, etc. should be based on the two papers stick firmly.

3, the back of the book is not square: 1 using a non-sharp milling cutter back to cause the book back is not square, should replace the sharp milling back knife. 2 The adhesive on the adhesive does not cause the back of the book to be square, and the gluing mechanism should be adjusted to make the adhesive glue even. 3 If the improper setting of the pallet setting mechanism causes the back of the book to be out of square, the pallet setting mechanism should be adjusted. 4 The fact that the book is not well-ordered due to the fact that the book is not square should be well-organized to ensure the formation of the book. 5 The key to deformation of the spine is the short setting time, the rapid fall of the book, and the heavy fall. Especially in thick books, it is more prone to this problem. (Some hot melt adhesives have a long open time and can also cause the same symptoms.) The solution is: in the production, the size and thickness of the book block should be used to control the speed of the plastic charter; and at the same time, the speed of the book should be adjusted by paying attention to the principle of thick book and fast payment.

4. The cover is not even and the cover line is obvious: the amount of plastic on one side is too large, which causes the cover to be uneven and the cover to be clearly visible. The amount of side glue should be controlled. When the temperature of the 2 side glue is too low, the uneven side coating causes the cover to be uneven and the cover line is obvious. The temperature of the side glue should be increased. With the book type of the book block, the glue temperature is generally controlled at 120~160°. C around.

5, book cutting size is not accurate, etc.: 1 first check the three-sided knife positioning file, front knife, side knife, push the book car (book pusher) size is equal to the size of the cut open, "Jack" pressure is Suitable, two-knife

The pressure of “thousands of pounds” should be adjusted to 3kg - 5kg. 2 Three-faced knives, “Thousands of pounds,” have caused excessive pressure on the books and caused large and small books and a back cover on the back. 3 Three-faced knives are under pressure to compact books, cover without wrinkles and without upper and lower knives. 4 If the platform cutter appears to have a non-standard book size, it should be adjusted to the left and right ends of the gauge to be in parallel or to repair the backlash of the lead. 5 The platform cutter cuts the book size when the upper and lower blades appear and the indentation, should adjust the "Jack" pressure, at the same time to "thousands" presser foot with "wooden board", the wood backing plate does not affect the back and forth motion for the back and forth The standard, thus avoiding the platform machine knife to cut the presser foot indentation left by the books.

6. Bubbles and empty glue appear on the back of the book. There are many reasons for this: 1 The hot melt adhesive is damp, and when the water content is high, air bubbles are most likely to occur. The hot melt adhesive should be stored in a dry warehouse to avoid moisture. 2 The back of the machine is not even after the milling and notching, which causes gaps in the uneven glue application. Check whether the milling cutter and the slotting knife are sharp. On the contrary, timely replacement and grinding are performed to control the evenness of the adhesive. (3) Empty glue can also occur when the pallet is not parallel to the back of the book, and the pallet mechanism is adjusted.

In the glue-binding process management, when no preheating glue pan is produced, the amount of glue added to the glue pot is strictly limited, so that the amount of ground glue is not increased, so that the time of the glue in the glue pot is shortened as much as possible to avoid the hot melt glue. Aging. In practice, it is proven that the glue temperature of the book block core in winter is generally increased by about 10° C. compared to other seasons, and the glue temperature is controlled between 180° C. and 185° C., so that the viscosity of the glue is lower than 4000 mPa·s. In order to make the glue on the page to maintain a good wet performance. In the normal use of the hot melt adhesive 170 °C ~ 220 °C within the critical temperature of aging, strict control of the higher temperature, not only to maintain good infiltration, but also to make glue drawing phenomenon greatly reduced or even disappeared. Reduces or avoids the processing time of each process failure caused by the winding of glue, which is beneficial to improve the production efficiency of the whole machine.

In short, as long as we continue to explore and summarize from practice, we must carefully understand and master the properties of materials, process parameters, and the strict process operations in production. We are able to obtain gel-bound products that meet the quality standards.

Source: China Equipment Network