Heat Shrink Tubing Difference Guide

Heat shrink tubing is a key component to ensure the safety and reliability of wire harnesses and cables. Single-wall heat shrink tubing, double-wall heat shrink tubing and printed heat shrink tubing are the three most common types. The following briefly describes their core differences based on material, function, application field and selection logic.

Single wall heat shrink tubing

Single-wall heat shrink tubing is the simplest heat shrink tubing, named because it contains only one layer of insulating substrate. It is a common choice for basic cable protection.

Single-wall heat shrink tubing: Made of polyolefins (such as polyethylene PE, polyvinyl chloride PVC) or fluoroplastics (such as PTFE), it achieves heat shrinkage characteristics through a cross-linking process. The temperature resistance range of ordinary PE materials is -40℃~125℃, and it has good insulation, flame retardancy, flexibility and chemical resistance. The upper temperature resistance limit of high-temperature PTFE materials is 260℃, but it is expensive and has poor flexibility. The shrinkage ratio is usually 2:1, and some special models can reach 4:1, which can be tightly wrapped around the cable;

Typical application areas​

• Consumer electronics: connector protection for headphone cables and charger cables, insulation and fixation of internal wiring in mobile phones;​
• Low-voltage electrical appliances: arrangement and insulation of internal wiring harnesses of household appliances (such as power cord branches of refrigerators and washing machines);​
• Automotive wiring harnesses: wear-resistant protection of low-voltage lines in cars (such as instrument panel connection lines), which must meet the temperature resistance requirement of 105℃.

Double wall heat shrink tubing

The double-wall tube adds a layer of hot-melt adhesive on top of the single-wall tube. When shrinking, it has the triple functions of "insulation + sealing + bonding", and is the first choice for protection in complex environments.

After the adhesive layer of the double-wall heat shrink tubing melts, it can seal the gaps in the cable joints and achieve an IP67 waterproof rating, making it suitable for humid and outdoor environments. The adhesive layer can also be used to firmly bond cables and connectors to resist vibration and shock. The outer substrate and the adhesive layer together can resist oil and solvent erosion, protecting industrial equipment cables.

Typical application areas

• Outdoor equipment: Solar photovoltaic cable connectors, street light power line connections, need to withstand rain, snow, and ultraviolet rays for a long time.
• Automotive industry: Protection of wiring harnesses in the engine compartment and chassis wiring harnesses (oil-resistant, high-temperature-resistant, and sealed and waterproof);
• Industrial control: Cable connectors of machine tools and robots need to resist the erosion of coolants and metal debris.

Printed heat shrink tubing

Printed heat shrink tubing is a special heat shrink tubing that has both protection and identification functions. It enables cable traceability and management by printing text and symbols on the surface, and is a core component of standardized wiring.

The printed sleeve uses polyolefin or PVDF with good temperature resistance as the base material. The surface is specially treated to allow the printing ink to adhere firmly. It has a wide temperature resistance range and can be printed in two ways: laser engraving and thermal transfer. The text is clear after shrinking, which can realize product traceability and functional identification.

Typical application areas

• Medical equipment: Internal wiring harnesses of monitors and ventilators need to be marked to distinguish power lines from signal lines to meet ISO 13485 quality management system requirements.
• Aerospace: Cable systems of drones and satellites need to be marked to withstand extreme temperatures and vibrations to ensure rapid identification during maintenance.
• Industrial wiring harnesses: Complex wiring harnesses of automated production lines use printing to achieve "one cable, one code" to improve troubleshooting efficiency.

In wire production, single-wall heat shrink tubing is selected for basic insulation and low cost. Double-wall heat shrink tubing is selected for sealing in humid or vibrating environments. Printed heat shrink tubing is selected for identification, traceability and compliance with regulations. They work together to protect cable safety, and the selection must be based on material, scenario and process requirements.