What is the inner diameter of the pigtail hot melt tube

The inner diameter of a pigtail hot melt tube depends on the specific tubing size, typically ranging from 3 mm to 40 mm for 3M MDT-A heat shrink tubes before shrinkage.

Typical Specifications

For hot melt heat shrink tubes like 3M MDT-A: Expanded inner diameter (ID before shrinkage): 3. 0 mm to 40. 0 mm depending on the tube size selected.

Recovered inner diameter (ID after shrinkage): Approximately 2. 5–3. 3 mm wall thickness subtracted from the expanded size, giving a smaller ID once heated and shrunk.

Shrink ratio: Up to 4. 5: 1, meaning the tube can shrink to roughly one-fourth of its expanded diameter. Material: Halogen-free cross-linked polyolefin with a factory-applied hot melt adhesive layer ensures sealing and mechanical protection.

For hot melt hoses used in pigtail applications (e.g., UES hotmelt hoses), the inner diameter is determined by the PTFE core and varies by hose type. These hoses are designed to maintain smooth adhesive flow and are compatible with standard hot melt systems.

Exact I

D values are typically specified by the manufacturer based on the adhesive type and application head connection.

Practical Considerations

When selecting a pigtail hot melt tube, ensure the expanded ID is slightly larger than the component or wire bundle to allow proper shrinkage and adhesive flow. Consider the wall thickness and shrink ratio to calculate the final recovered ID for a tight seal. For custom applications, manufacturers like 3M or UES can provide specific inner diameter options to match your system requirements.

In summary, the inner diameter of a pigtail hot melt tube is not a single fixed value but depends on the tube size, shrink ratio, and material. For 3M MDT-A tubing, expanded IDs range from 3 mm to 40 mm, shrinking to smaller IDs after heat application, while hot melt hoses have PTFE cores sized for smooth adhesive flow and system compatibility.