What should I do if the heat shrink tubing does not shrink or shrinks unevenly?

We all know that the heat shrink terminal kits can provide insulation, protection and stress relief functions for wires and connection points in various electrical and mechanical applications. However, in some cases, the heat shrink tubing may fail to shrink properly or shrink unevenly, which can lead to potential product quality issues. So I will explain to you the possible causes and solutions.

Possible Causes of Insufficient Shrinkage

1. Insufficient heat: The first point is that the most common reason for the failure of our heat shrink terminal kits to contract is insufficient heating. Since the heat shrink terminal kits need to be heated within a specific temperature range to contract effectively, typically between 90°C and 125°C (194°F to 257°F), the exact temperature depends on the material type. So if your heating source is not hot enough, the terminal kits cannot contract fully.
2. Inconsistent heating: Another issue that may cause our heat shrink terminal kits to contract unevenly is inconsistent heating. Due to the inconsistent heating, certain parts of the terminal kits may contract more than other parts. However, this inconsistent heating situation may occur when the heating source is too far away, the pipe is not rotated during heating, or the heating gun moves unevenly on the pipe.
3. Product Quality Issues: Please remember that the most important point is that the quality of the heat shrink terminal kit itself also has a significant impact on its performance. Because poor-quality pipes may not shrink evenly, or even not shrink at all. Moreover, factors such as material composition, thickness, and manufacturing process all affect the ability of the pipes to shrink normally.

Solutions to Address Shrinkage Issues

1. Ensure sufficient heat: To address the issue of insufficient heat, a heating source capable of reaching the required temperature must be used. A hot air gun is usually the best choice as it allows for precise temperature control. Please make sure that your technicians review the specifications of the heat shrink terminal kit to determine the appropriate temperature range and ensure that the heating source can reach that temperature.
2. Uniform heating: To achieve uniform contraction, your technicians must heat the surrounding area of the terminal kit uniformly. Use the hot air gun to move in a circular motion, maintaining a constant distance from the kit. This helps ensure that all areas of the pipe receive sufficient heat.

3. Pre-use Testing: If you have any doubts about the performance of our heat shrink terminal kits, you can conduct a test before applying it to critical applications. Cut a small section of the pipe, heat it up and observe its reaction. This will enable you to understand how well it shrinks and whether it meets your requirements.