Paper Performance and Binding Technology (I)

Bookbinding This publication contains paper, in addition to the usual letterpress, offset paper, etc., also includes a binding cover paper, ring backing paper, back paper and other books. It is not only necessary to understand the types of papers that are commonly used, but more importantly, to understand the properties of the paper used in order to make better use of paper for various types of processing and achieve the desired results. Otherwise, defective or defective products will appear. Causes waste.

1, newsprint and use. Newsprint, commonly known as white paper, is commonly used in the printing of newspapers, periodicals, magazines, and general books and periodicals. It is one of the papers that are frequently touched during binding processing.
(1) Newsprint raw material and newsprint performance. Newsprint paper is generally made from over 90% groundwood pulp and less than 10% bleached chemical pulp. The raw materials used in newsprint are mainly broadleaf wood. In order to save some of the wood, some stalk raw materials, such as bagasse and grass, are used. Generally, no sizing is applied during processing, and only appropriate amounts of talc and brighteners are added.

Newsprint is one of the types of paper used in the printing industry. Because of the raw materials and processing, this type of paper is stored for a long time or is easily yellowed and brittle after being exposed to the sun. Therefore, it is not appropriate to make books that require long-term preservation. It is commonly used in the printing of newspapers, comics, periodicals, and low-grade books.

(2) Newsprint specifications. Newsprint is divided into web and flatbed paper. The length of the web is about 6000m; the width is 787mm, 781mm, 1575mm, 1562mm four specifications, flat newsprint specifications are generally two: 1092mm × 787mm, 1092mm × 78lmm. The national standard (GBl910-89) divides newsprint into four grades based on the quality level of products, namely A, B, C, and D. Among them, A and B are applicable to high-speed rotary printing presses; A and other products have reached the international advanced level. ; B and other products for the domestic advanced level of products.

There are many types of newsprint quantification, and the quantitative development of newsprint in China is positive and low. In the past, the quantification was 52 g/m 2 for a long time. In the early 1980s, news prints of 49 g/m 2 were generally started in foreign countries and have fallen to 45 g/m 2 in recent years. Low-quantitative paper can save raw materials and freight, save energy, reduce newspaper delivery postage and so on. With the improvement of papermaking technology, China has also begun to produce low-quantitative newsprint. The quantification according to the national standard (GBl910-89) is 51±2 to 3g/m2, 49±2 to 3g/m2, and 45±2 to 3g/m2. Three kinds.

(3) Notes on the binding of newsprint.

1 newsprint page sheet folding, you can use any kind of folding machine, up to four fold (to scratch); hand-folded four fold, the third fold in the crease should be cut to eliminate the air, Avoid wrinkling after folding the book.

After the 2 pages are printed and after the signatures are processed, they should not be placed under the sun or beside the heating area or in a damp place to avoid discoloration, brittleness, or inequality.

3 Adhesive for newsprint paper should not be too thin (because of the large gap between newsprint and water), it should be adhered firmly.

4 Wire staples have a thickness of up to 15mm and a minimum of 0.5mm.

5 When cutting a book, the angle α of the knife can generally be 20 to 23°.

2, letterpress paper and use. Letterpress paper, also known as letterpress paper, is generally used for letterpress printing. The use of letterpress machines in the printing of books and periodicals in our country is very extensive. Almost all general publications use letterpress paper.

(1) The properties of letterpress paper and relief paper. The main raw material of letterpress paper is bleached chemical pulp of stem fiber. Papermaking can be done without sizing or slight sizing, and some mechanical pulp can also be used to improve the papermaking performance of letterpress paper and increase the ink absorption, compressibility, and opacity of the finished paper. The high pressure of letterpress printing has certain requirements on the compressibility of letterpress paper. Adding a proper amount of ground wood pulp in the pulp can increase the compressibility of the paper.

Letterpress paper is superior to newsprint in terms of paper uniformity, smoothness, water resistance, compressibility, and opacity.

(2) Letterpress paper specifications. Letterpress paper is also divided into web and flat paper. Web length is generally 6000m, width 787mm, 850mm, 880mm. Flat paper format has 1092mm × 787mm, 1168mm × 850mm, 1230mm × 880mm. Professional standards stipulate that the tolerance range for width and skewness is ±3mm. Relief paper is generally 50 to 60 g/m2.

(3) Precautionary notes for letterpress paper. Letterpress paper is a commonly used paper for binding books and magazines. The specifications and standards used in general processing are mostly based on letterpress paper.

You can use any kind of folding machine when you fold 1 page, and you can fold up to 40% (draw); when you fold the manual folding folder, cut the opening on the third folding crease to eliminate the air in the signature. , guarantee that the book is folded without any wrinkles.

2 The maximum thickness of iron wire staples is 15mm, the minimum thickness is 0.5mm, and the wire diameter is 0.5 to 0.84mm.

3 Wide range of adhesives for relief paper. Relief paper is easy to adhere and the viscosity of the adhesive is easy to adjust.

4 The cutter knife angle α is the same as that of newsprint.

3, offset paper and use. Offset paper, also known as offset printing paper, is a relatively high-grade printing paper, which is generally designed for offset printing or color printing. Offset paper is divided into single-sided offset paper and double-sided offset paper, which are super calendered and ordinary calendered.

(1) The raw material of offset paper and the performance of offset paper. Offset paper is generally made from bleached chemical softwood pulp and a suitable amount of bamboo pulp. When processing offset paper, the filling and sizing are heavy. Some high-grade offset papers are also surface sizing and calendering.

Because the principle of ink and ink balance is used in offset printing, the paper requires good water resistance, dimensional stability and strength. Offset paper is mostly used for color prints. In order for the ink to recover the color of the original, it must have a certain degree of whiteness and smoothness.

Offset paper is generally used to print pictures, color illustrations, trademarks, covers, ring linings, high-end books and volumes. In recent years, due to the improvement of people's culture and living standards, book materials have also developed to higher grades, and more and more books and magazines have been printed using offset paper. Because offset paper has the advantages of whiteness, crispness, smoothness and fineness, etc., books and texts are clearly written and the books and publications are not easy to be deformed. Compared with Letterpress and newsprint, the grades are particularly different, and they are highly appreciated by readers and users. The number of offset bookbinding books and books will increase substantially in the future to meet the needs of the market.

(2) Specification of offset paper. Offset paper specifications are the same as those on the two previous papers. Other specifications can be found in the national standard GBl47 "printing, writing and drawing the size of the base paper", size error, skewness must not exceed ± 3mm.

There are many kinds of calibrating offset paper, the commonly used quantitative is 60,70,80,90,120,150,180,200,250g/m2. The printed offset papers were all below 90g/m2, and the covers were between 70 and 200g/m2.

Offset paper has the characteristics of crispness, smoothness, etc. It is easy to bind and process.

(3) Precautions when offset paper is bound.

1 When you hit a page, you can use any method to achieve a good knock-down effect.

2 Any folding machine can achieve a good folding effect, especially suitable for high-speed folding.

3 Offset paper books This book should be designed with three folds or less (never design four folds). It is best to double-fold (80g/m2 or more) afterwards, because the thickness of the offset paper is large and the basis weight is too large. Inconsistent cuts, unequal book block quality problems.

4 When the iron wire is stapled with the same number or thickness of letterpress sheets, increase the diameter of the wire.

5 The viscosity of the binder is much larger (thick) than that used for letterpress paper because of the large amount of offset paper, the smooth surface, the low viscosity (thinness), and the lack of stickiness or stick-off.

6 The hardcover book core of offset paper is not easy to round and ridge, especially when the sticker is thick. Because the offset paper is slippery, it is easy for each signature to be exposed and the front mouth is in a trapezoidal shape after being rounded. When the ridge is used, due to the manual knocking, the creases in the creases cannot be smoothed and cause defective products.

7 The production of books with offset paper is generally of a higher grade. Therefore, the cover material should be better than the book core material, so that the inside and outside of the book can be matched.