What is the difference between single wall and dual wall heat shrink tube?

For many manufacturers who use heat shrink tube, they only have a little general understanding of heat shrink tube. Under the understanding that the editor often wanders around the client, I found that many people use heat-shrinkable tubing in the production process. But they don't even know that there are thin wall heat shrink tube and dual wall heat shrink tube, let alone the differences in the use of thin wall heat shrink tube and dual wall heat shrink tube. However,we will not talk about the use here,just focus on popularizing the basic knowledge of heat shrink tube production, and the manufacturing differences between single wall heat shrink tube and dual wall heat shrink tube.

For the production process of heat shrink tube, there are three major steps:

The first step: raw material melt extrusion;

The second step: beaming after extrusion;

The third step:heatingandexpansion, cooling and forming.

After expansion, it is the finished product, then further cut or wound into small finished products for specific use requirements. Whether it is a standard wall or a adhesive lined heat shrink tubing, it will go through these three steps.

We know that the difference between two kinds insulation tube is that for the dualwall heat shrink tube, in addition to the outer layer of plastic material, there is also a layer of hot melt adhesive on the inner layer.This paperexpounds respectively the differences between these two items and from the above three main steps.

First of all, from the perspective of extrusion of the heat shrink tube,the dual heat shrink tube requires dual extruders for simultaneous co-extrusion. Here, because of the difference between the two layers of materials, the selection of the processing temperature range is very important, and it is necessary to take into account the two materials at the same time.

Secondly,the beaming process, which is mainly to cause the sheath material to undergo a cross-linking reaction, itself will have a certain impact on the hot melt adhesive. So parameter control is also very important. If thebeaming dose is toolarge,  the molecules of hot melt adhesive may partially decompose, resulting in subsequent abnormal expansion. And even the viscosity of the hot melt adhesive will become thin during use if the dose is too small,then the sheath will not meet the requirements.

Thirdly, from the view of the expansion process, the glue lined heat shrink has a narrower selection rangeof the temperature than the single wall heat shrink tube, and it prefers to lower temperature, otherwise the flow of hot melt glue will easily cause poor concentricity. In addition, after the expansion, the double wall heat shrink is generally not recommended to be flattened directly when it is rolled up, which is easy to cause self-adhesion.

Xiamen MJ Industrial Tech Co.,Ltd supplying top quality insulation shrink tube more than 10 years, with many partners all over the world,welcome to visit our website:www.mj-ist.com for more information.