Main factors that affect the fastness of Subject notebooks With Dividers

Main factors that affect the fastness of Subject notebooks With Dividers

The factors that affect the fastness of the wireless adhesive are: the quality of the back surface processing, the temperature of the hot melt glue, the thickness of the back glue liquid, the degree of cover and back pressing, etc.

Subject Notebook With Dividers the quality of the return job

The quality of back milling and hackling is the main factor affecting the fastness of wireless binding. The quality of the back surface processing is characterized by the macro and micro geometry of the surface of the back paper, which can be expressed by the average arithmetic value of the macro non slip of the end of the paper. In the process of milling and shaming the back of the book, the fibers on the edge of the paper are loose, and a rough surface is formed. The glue liquid penetrates into the surface of the paper along the fiber and binds to each other. The back is unwoolened, the milling incision is smooth, the paper and the glue bonding surface is small, so that it can not ensure the infiltration and adhesion of the glue in the paper. The back of the book after the formation of too rough surface, similarly, the glue in the paper is not easy to infiltrate, because on the back of the book surface gathered paper hair and air, prevent glue and paper contact. Milling the back seam with a blunt knife to get a rough back surface, also affect the fastness of the binding.

The temperature of hot melt adhesive

The bonding properties of different kinds of hot melt adhesive are different. For the same kind of hot melt adhesive, with the increase of temperature, the lower its viscosity, the better the infiltration between the adhesive liquid on the back of the book and the pages, the better the wireless binding fastness. When the temperature is too high, the polymer, which is the main component of hot melt adhesive, may undergo pyrolysis polymerization, thus reducing the adhesion of hot melt adhesive. If the temperature is too low, the fluidity of the glue is poor, affecting the bond fastness of the glue. At present, the hot melt adhesive commonly used in the printing plant has good viscosity and infiltration at 170℃ ~ 185℃, so it is necessary to continue heating and maintain a constant temperature in use.

The thickness of the adhesive layer

With the increase of the thickness of the hot melt adhesive layer, the bond fastness increases. When the thickness of the adhesive layer increases to a certain value, the bond fastness will begin to decline. This shows that the use of too thick hot melt adhesive layer, not only waste glue, but also reduce the bond fastness, destroy the overall structure of the book.

The thickness of hot melt adhesive should be determined by the thickness of the publication, the type of printing and cover paper, the type and quality of hot melt adhesive. Generally speaking, in the latter two conditions are basically the same, the fastness of wireless binding, depending on the thickness of the book block. Regardless of the fiber direction of the paper and the back of the book block parallel or not, the thin book block adhesion fastness is the best, the middle thickness of the book block adhesion fastness, the thickness of the largest book block adhesion fastness is poor.

The results show that appropriate thickness of adhesive layer should be chosen for different thickness of book block. For example, for books printed on convex paper with a thickness of 10 ~ 12mm, the thickness of the hot-melt adhesive layer is 0.4mm. For 20mm and thicker publications, the hot melt adhesive thickness must be 0.8 to 1.0mm. Cover and book block compression degree. The cover should be glued to the back of the book and all parts on both sides, without wrinkling, and the back should be a neat rectangle.