Effect of Paper Texture Direction on Bookbinding Quality

Paper is the basis for all printing and stapling operations, and it is also the pad where each image appears. Before planning to print a job, the type, weight, thickness, coating, texture, texture direction, opacity, and color of the paper should all be carefully considered. The type of image to be printed will affect the type of paper selected. Similarly, job binding needs also take into account paper factors.

Paper is made of cellulose. These celluloses are most often from wood, but cotton, flax and other materials are sometimes used. People are still trying to study other paper materials that can replace cellulose, including bamboo, hemp, and straw straws. An appropriate amount of clay or other material can also be added to produce "coated" paper after the basic cellulosic material has been placed.

For bookbinding companies, there are two main paper-related factors: texture direction and coating. These two characteristics are very important for various processing methods. When processing a separate book, we used two knurled rollers to squeeze the paper, grabbed the paper with a robot or suction pump, crushed the paper with a hydraulic press, heated and dried, and then used six kinds of Different types of glue stick. Press creases, folds, staples, sizing, cutting, etc. are all affected by the performance of the paper. Texture orientations and coatings often have a different impact on book binding companies. Through the meticulous processing of book binding companies, monotonous printed paper becomes a beautiful, long-lasting book.

Paper texture

The direction of paper texture is very important to both printing companies and bookbinding companies. It is very important to consider it when planning operations at the beginning. This will not only affect the appearance and durability of the book, but it will also affect the size of the paper—thereby affecting the size, yield, and cost of the press.

In the processing of paper for business processing, the cellulose in the pulp is more or less aligned in one direction. This is what is commonly referred to as the paper texture direction. There are many ways you can tell the direction of the texture of a piece of paper. Only the paper is bent to see obvious signs: the paper is harder in the direction of the vertical and the texture than the direction parallel to the texture. Another reliable way to determine the direction of the paper grain is to gently place a small sheet of paper material on the surface of the water. This will make one side of the paper wet and the other side dry. At this time, the wet paper texture expands, curling the paper into a tube—the direction of the length of the tube is the direction of the paper's texture. This simple experiment illustrates one of the reasons why the paper texture direction is very important for bookbinding companies.

Texture direction and glue

There are many situations in which a water-based glue is used to bind a hard cover book. Fine glue drops are usually used when pasting the liner onto the front page or the last page. Also in the upper case, the entire exterior of each lining is glued, and the contents of the book are often glued to the cover. Naturally, these glues wet the paper and cause the cellulose to expand perpendicular to the paper texture. However, no one wants a tubular book, so we cannot allow curling of the liner when the text is pasted. After adding glue to the liner, immediately place the hard cover over the inside of the book, and squeeze the glue together. Since the texture direction still has a tendency of expansion at this time, only the backing sheet will wrinkle due to being fixed in the cardboard of the binding apparatus, so the process of moisture vaporization and glue drying must be fixed under a certain pressure.

If the texture direction of the backing page is correct - for example, parallel to the bound edge of the book - the expansion of the texture may cause the bound cardboard to slightly bend (the texture direction of the cardboard is also the same), but with the glue drying, the book is under a certain pressure, The expanding texture begins to shrink, and this swelling tendency is gradually eased; the book is gradually relieved from the pressure state, and the lining page will not appear wrinkles. If the texture of the lining page is perpendicular to the binding edge of the book, the direction of the wrinkles is parallel to the grain direction because the cardboard does not swell in this direction. The same is true when pasting the liner, even if a small amount of fine glue is used, the vertical texture of the liner will still produce waves.

The texture direction of the hardcover book body department does not usually cause trouble, but the color coating material that needs to be pasted on the book should still keep the texture direction parallel to the binding direction.

However, the direction of the texture of the body of a binding book is often troublesome. If the grain direction is not parallel to the binding edge, the use of hot glue can cause the paper to wave in some cases. Keeping the paper fibers parallel to the binding edge also maximizes the tackiness of the thermosetting glue used in the binding.

Texture direction, creases and folds

The paper texture direction is also an important issue when selecting saddle-stitched cover materials, cordless binding materials, or thread-wrapped soft covers or folders. In fact, thicker heavy materials used for covers and folders tend to be scratched before they can be folded cleanly and reliably. In addition, the direction of folding or scoring should be consistent with the texture direction. The cover perpendicular to the texture direction is likely to require special relief scratches and the finished product will be very good.

Coating materials and non-coating materials

Adding clay and other grinded coatings to the paper not only changes the appearance of the paper, but also changes the properties of the paper during binding in the printing press. For bookbinding, coating not only affects scratches and folds, but also affects the suitability of the glue. Printing inks on coated materials tend to have higher coverage, and additional protective coatings such as varnish and UV materials are printed, which will affect the bookbinding process.

Clay-coated materials are more likely to wrinkle when glued with glue during binding. Therefore, the coated material is rarely used as a backing sheet. If proper protective measures are not taken, wrinkling may occur even if the body part is coated with coating material inside the envelope.

When a hard cover book is installed with a printed cover, the film laminate, like the hinge of the door, enhances the strength of the paper. If you do not use plastic film reinforcement, but only use paper, even if processed by UV or other coating process, it will tear at the hinge quickly. The material that can be laminated with a film should be 80 or 100 lb.. The coated book has only one layer of glue-laminated laminated film on the outside. Many processing plants currently use relatively heavy non-coated materials, which can be applied to both lithographic offset printing and foil bronzing.

The coated text material is very difficult to bind, and the hot melt cannot reliably bond with these coated papers. For best results, these books should be stapled and then affixed.

Both single-coated (C1S) and double-coated (C2S) cover materials can be used for perfect binding. However, make sure that no ink, varnish, or other paint adheres to the area where the glue is to be applied.

cardboard

Some of the information in this article discussing paper can also be applied to cardboard. Cardboard used for binding is also composed of pulp fibers and processed in the same way as paper. Although cardboard used for hardcover book bindings often undergoes scratches or folds, the cardboard also has a certain grain direction and must be considered during processing. In fact, the texture of the bound cardboard must be parallel to the binding edge of the book in any case. This can ensure that any bending of the board during the bookbinding process is to open the cover without damaging the binding process of the book.