3 Misunderstandings in Selecting Hot Melt Adhesive Particles with Double Process of Lock Wire and Adhesive Assembly: Don’t let good adhesive match the wrong process

Lock wire glue=use glue casually? wrong!

Many printing factories believe that books have already been sewn in,hot melt adhesive pelletsJust an auxiliary, just use cheap glue casually. This idea is completely wrong. The requirements for glue in the double process of wire locking and glue installation are actually more special. Please avoid the following three misconceptions.

• Misconception 1: “Lockbook does not require high adhesive”The lock thread provides longitudinal tensile strength, but the spine adhesive layer bears bending stress and transverse shear force during flipping. If the elasticity of the adhesive layer is insufficient, the adhesive layer will crack and the lock wire will be exposed after repeated flipping, resulting in extremely poor appearance. Medium viscosity and high elasticity hot melt adhesive particles should be selected.
• Misconception 2: “Just apply a thin layer of side glue casually”The spine of the lock thread book is relatively hard, and the side glue requires a wider coating area (recommended 3-5mm width) to ensure a tight fit between the cover and the book core. Coating too thin can cause the cover to curl.
• Misconception 3: “The higher the glue temperature, the stronger the adhesion”The sewing thread used for sewing is mostly cotton or polyester. If the glue temperature exceeds 190 ° C, it will burn the sewing fiber and reduce the strength of the sewing thread. It is recommended that the adhesive temperature should not exceed 180 ° C, and Sunlife hot melt adhesive particles can achieve the best bonding effect at 170 ° C.

Frequently Asked Questions (FAQ)

Q: Is it because the lock thread is broken or the glue has opened when the pages of the book are missing?

A: Both are possible. Open the spine of the book and see: if the stitching is intact but the paper leaves the adhesive layer → adhesive problem; Suture fracture → Locking process or wire problem. In most cases, the adhesive layer fails first, causing stress to transfer to the lock wire.

Q: What type of Sunlife hot melt adhesive particles are used for thread locking glue?

A: Recommend SL-168 (medium viscoelastic type) or SL-268 (universal type), both have good elasticity and moderate adhesive temperature, suitable for double process of wire locking and adhesive installation.