Today , we talk about a problem you will come accross when you using dual wall heat shrink tubing . 

There is a layer of hot melt glue inside , it is why we named it dual wall heat shrink tubing . The hot melt glue will melt when we heat the dual wall heat shrink tubing . The function of hot melt glue is waterproof and seal .

When the diameters of heat shrink tubing and cable are similar , you should  make sure the duanl wall heat shrink tubing be compeletely shrink . For example , the diameter of dual wall heat shrink tubing is 3.2mm and the diameter of cable is 3.0mm . 

One of our customer came accross this problem , they asked us that is there not enough glue in the dual wall heat shrink tubing . In fact , the reason the diameter of the cable and heat shrink tubing are similar ,  when it seem the heat shrink tubing already cover the cable tightly , the glue inside the tubing had not completely melted .  So we should heat it more .

Now , you can see the glue overglue , the dual wall heat shrink tubing stick toughly on the cable . 

Maybe , you will also come across some problem , when you use heat shrink tubing , sometimes , it is not because of the quality , but a wrong way using it . You can contact us once you coming across any problem about heat shrink tubing .