Hot melt adhesives are not only widely used in packaging industry, but also often used in some public equipment production lines. Like cables or optical cables, because they need to be used more in wind, sunlight and corrosive environments, good glue is needed to achieve waterproof, moisture-proof and corrosion resistance to ensure the performance and service life of cables and cables.

 

At present, the number of metal communication cables produced and used in China ranks first in the city. The conductive medium of city communication cable is copper conductor. Polyolefin material is extruded on the surface of copper conductor as insulating layer. The whole cable is encapsulated with polyolefin material. Polyolefin material is a kind of macromolecule material. The gap between polyolefin molecules is larger and the diameter of water molecules is smaller. Therefore, polyolefin material can not prevent the permeation of water molecules. The waterproof and moisture-proof performance of cable is very important. Moisture in the cable will reduce the insulation resistance of the cable core, and other electrical parameters will change. It also causes corrosion of copper wire. Metal strips (aluminium or steel strips, etc.) are often used as moisture-proof layers for cable sheaths. The metal strip is filled with dry air or ointment to keep the core dry.

 

In the sheath process of cable production, the straight metal strip is rolled into a cylindrical shape through a longitudinal wrapping die, thus forming a lap joint. In order to increase the flexibility and lateral compression resistance of cables, metal strips are usually embossed. After embossing, the overlap of metal strip is difficult to match well, which will produce the same gap at the lap, thus reducing the waterproof and moisture-proof effect of metal strip. At the same time, the contact area of metal strip at the lap decreases, and the peeling force of metal strip lap joint decreases, leading to cable failure. In order to solve these problems and ensure the service life of cables, people often use hot-melt adhesives to bond metal strip joints, which requires the use of hot-melt glue machine.

 

In the cable longitudinal packaging industry, plastic cylinders with large capacity of rubber barrels are often needed because of the long continuous production cycle. Typically, 20 kg pressure barrel can meet the requirement of glue supply. The glue coating method is basically strip steel beating. It only needs to fix the hot melt glue gun on the longitudinal packaging assembly line, and control the hot melt glue gun to disconnect the glue through the pipeline switch signal.