Book Bonding Fixed Edge Hot Melt Adhesive

                  How to use Hot Melt Glue correctly to bond books?

At present, the resin EVA Hot Melt Adhesive used in the binding industry is generally divided into two kinds of high-speed adhesive and low-speed adhesive. The curing speed of high speed glue is slightly faster than that of low speed glue. According to the different adhesive materials, it is divided into offset paper, coated paper glue and so on. And back and side bonding points. These classifications are developed to meet the strengths and needs of our customers. The aim is to achieve a good bonding effect. When we use EVA Binding Agent, we must first master the preparation process such as preheating and temperature control before use.

1. Heat EVA glue before use
In order to maximize the performance of EVA Hot Melt adhesives, solid hot melt adhesives must be preheated and melted before use. The main methods of preheating hot melt glue are: one is the oil bath preheating, that is, the glue pan preheating. The preheating time of hot glue is generally 2 hours. When the hot melt adhesive reaches the required melting and heating temperature and the hot melt adhesive has good fluidity, the hot melt adhesive preheating process ends, and then the hot melt adhesive is heated. The melted glue is then released through a thermostatic pipe into a glue container with a temperature of 160-200 degrees for books and book binding.

2, EVA hot melt adhesive adhesion and consistency
In the production process, the adhesion of EVA hot melt adhesive changes with the heating temperature of the hot melt adhesive, the difference and quality of the material to be bonded, the width and depth of the knife back, and the height of the adhesive. Depending on factors such as device speed, different connection effects can be achieved. Here's a short explanation:

(1) Hot melt adhesive heating temperature
The softening point of EVA hot melt adhesive is usually about 80 degrees, that is, when EVA hot melt adhesive is heated to 80 degrees, it becomes a liquid. The glue begins to soften and dissolve. This temperature is the melting temperature of the hot melt adhesive. The heating temperature of EVA hot melt adhesive should reach 130-180 degrees, and it should be melted to the ideal state of sticking books. At this temperature, the viscosity, fluidity, and stickiness of hot melt adhesives are ideal for sticking books together.

(2) The relationship between the quality of book paper and the pasting temperature
The quality of the paper used to make the book is different, so the temperature of gluing should also be different. This is not only because the fiber of the paper is different, but also because the thermal conductivity of the hot melt gel is different due to the type and texture of the paper, which changes the cooling speed of the hot melt glue. Taking the thermal conductivity of coated paper and letterpress paper (uncoated paper) as an example, the cooling rate of the former hot melt adhesive is slightly faster than that of the latter. Because the minerals in coated paper are about 10 times more than non-coated paper such as letterpress paper, newsprint, offset paper, and the minerals have good thermal conductivity, the cooling speed of EVA glue can be improved. If the glue temperature is 170 degrees, the tensile test value of hot melt adhesive on uncoated paper can meet the expected conditions, while the tensile test value of coated paper cannot. Therefore, to improve the bonding strength of coated paper, it is necessary to increase the heating temperature of the hot melt adhesive.

(3) The relationship between the opening time of EVA hot melt adhesive and the operating speed of the production Equipment
In the process of completing the wireless bonding, three time points must be strictly controlled when using EVA hot melt adhesive, namely opening time, curing time, and cooling hardening time. Opening time refers to the time EVA hot melt glue is applied to the back of the book. Curing time is the time it takes to glue the cover to the back of the book. Cooling hardening time Drying is the time it takes for the book and cover to cool together and cut after processing. Only after these three times can we finalize and complete the binding of the entire book.

Hot Melt Adhesive For Book

The number of applications of these EVA hot melt adhesives is closely related to the operating speed of the equipment. For example, the opening time of hot melt adhesive is generally 7 to 15 seconds, which is the time for milling and return of the binding machine. The process of attaching the glue to the cover and back of the book should be completed within 15 seconds, so that EVA hot melt adhesive has the best bonding properties.