Self-extinguishing polyolefin heat shrink sleeve with internal adhesive “TTPA41 Series”
- Material: Polyolefin
- Shrinkage: 4:1 with internal adhesive
- Scope: where a high degree of protection is required
- Minimum shrinkage temperature: > +110 °C
- Min/max operating temperature (external wall only): -55°C to +110°C
- Low Flexibility Temperature: No Split (-55°C)
- Self-extinguishing (external wall only): according to ASTMD2671B
- Colors: Black – other colors on request
- Tensile strength: 11 N/mm2 according to ASTMD638
- Elongation at break: 300% according to ASTMD638
- Elongation after heat aging test: 250% (168 hours at 175°C)
- Thermal shock: no damage (4 hours at 250°C)
- Dielectric strength: ≥ 15 KV/mm
- Longitudinal variation: ≤+1% ≤-10% maximum
- Water absorption: ≤ 0.5% according to ASTMD570
- Specific gravity: 1.45 G/cm3
- Mold Resistance: Good
- Fluid resistance: good
- Copper corrosion: None
- Volume resistivity: 1014 ohm.cm
Heat shrink indication
- When shrinking the heat-shrinking sleeve, use equipment made for this specific operation such as, for example, guns or hot air tunnels.
- Shrink the sleeve starting at one end, the most critical part, and then proceed slowly to the opposite end. This method avoids the formation of air bubbles between the inner wall of the heat shrink sleeve and the object it covers.
- In the event that the object to be covered is made of metal or a good heat conductor, it is advisable to preheat the object to avoid “cold areas”, so as to allow a perfect and soft adaptation of the heat-shrinking sleeve.
- In order to avoid overheating of the heat shrink sleeve, ensure there is regular heat distribution. Excessive overheating of the material during the shrinking process can cause bubbles, discoloration and in some cases even breakage of the heat-shrinking sleeve.
thermal shrinking sheaths
Frequently Asked Questions
The use of heat-shrinkable sheaths with internal thermal-fuse adhesive is mainly recommended in the following applications :
- When the part to be protected is located in a very humid environment due to the presence of water, snow or other particularly severe atmospheric agents. The internal thermal-fuse adhesive, which melts during the heating and shrinkage phase, completely envelops the object to be protected, making it watertight.
- When there is a need to improve the sealing between the electric cable and its connector, or between several electric cables and the multi-polar flying connector. This use of heat-shrinkable sheaths with an internal thermal-fuse adhesive is quite useful in minimizing any interruptions in the electrical connections between devices, which in some cases, and especially in certain sectors, can be particularly damaging.
The main and most requested types are three:
- NORMAL wall thickness, with a shrinkage ratio of 3÷1, Our series TTPA31 – TA3155, or 4÷1, Our series TTPA41 – TA4155, available with internal diameters ranging between 3 mm and 52 mm.
- AVERAGE wall thickness, with a shrinkage ratio of 3÷1, Our TTPAMS series, available with internal diameters ranging between 8 mm and 410 mm.
- HIGH wall thickness, with a shrinkage ratio of 3÷1, our TTPAAS series, available with internal diameters ranging between 9 mm and 310 mm.
The most commonly used adhesive in heat-shrinkable sheaths with an internal thermal-fuse adhesive is made of "EVA", (ethylene – vinyl – acetate). This type of adhesive is used because on contact with heat it fluidises very quickly, allowing the object to be covered to be wrapped by the adhesive very quickly. Once the heat-shrinkage is finished, the EVA adhesive solidifies just as quickly.
