An object of the present invention is to provide a heat shrink tube excellent in peelability and transparency, and a method for producing the heat shrink tube. The present invention provides a peelable heat shrink tube comprising a composition containing a melt-processable fluororesin and PTFE, the PTFE lacking a heat history of its melting point or higher after polymerization and having a specific gravity, as measured according to ASTM D4894, of 2.20 or less. The content of the PTFE is 0.05 to 3.0 wt % based on the total weight of the melt-processable fluororesin and the PTFE. The present invention also provides a method for producing the tube which comprises melt-extruding the composition at a temperature lower than the melting point of the PTFE.

An object of the present invention is to provide a heat shrink tube excellent in peelability and transparency, and a method for producing the heat shrink tube. The present invention provides a peelable heat shrink tube comprising a composition containing a melt-processable fluororesin and PTFE, the PTFE lacking a heat history of its melting point or higher after polymerization and having a specific gravity, as measured according to ASTM D4894, of 2.20 or less. The content of the PTFE is 0.05 to 3.0 wt % based on the total weight of the melt-processable fluororesin and the PTFE. The present invention also provides a method for producing the tube which comprises melt-extruding the composition at a temperature lower than the melting point of the PTFE.

A method for producing a thermoplastic fluororesin tube, the thermoplastic fluroresin tube having tearability in a longitudinal direction, wherein a thermal expansion coefficient in the longitudinal direction upon heating in a gaseous phase at a temperature of 100 C. for 5 minutes is 0% or more, the method including the steps of: subjecting a thermoplastic fluororesin to melt extrusion molding to obtain a raw tube of the thermoplastic fluororesin tube; and expanding an inner diameter of the raw tube while heating the raw tube to a temperature of from 110-135 C.

Provided are methods and systems for manufacturing and using heat-shrink elastomeric. An example method of manufacturing a heat-shrink elastomeric element comprises providing a thermoplastic elastomeric element having a first shape; modifying the thermoplastic elastomeric element to produce a thermoset elastomeric element having the first shape; heating the thermoset elastomeric element to a temperature of at least the glass transition temperature of the thermoset elastomeric element; adjusting the first shape of the thermoset elastomeric element to produce a second shape with at least one dimension greater than that of the first shape; and cooling the thermoset elastomeric element to a temperature below that of the glass transition temperature of the thermoset elastomeric element to produce the heat-shrink elastomeric element.

Provided are methods and systems for manufacturing and using heat-shrink elastomeric. An example method of manufacturing a heat-shrink elastomeric element comprises providing a thermoplastic elastomeric element having a first shape; modifying the thermoplastic elastomeric element to produce a thermoset elastomeric element having the first shape; heating the thermoset elastomeric element to a temperature of at least the glass transition temperature of the thermoset elastomeric element; adjusting the first shape of the thermoset elastomeric element to produce a second shape with at least one dimension greater than that of the first shape; and cooling the thermoset elastomeric element to a temperature below that of the glass transition temperature of the thermoset elastomeric element to produce the heat-shrink elastomeric element.

A heat-shrinkable tube according to an aspect of the present disclosure includes a base layer that is tubular and that covers outer peripheries of a plurality of electric wires, and a plurality of ridges that are formed on an inner peripheral surface of the base layer and that extend in an axial direction of the base layer.

The disclosure provides a tube which is rarely broken and is stable during the process of the production of a heat-shrinkable tube having tearability in a length direction. The tube includes a melt-processable fluororesin and when the strain of the tube is defined as , the stress at the strain is defined as (MPa) and the strain is put on the horizontal axis and the stress is put on the longitudinal axis on a coordinate graph, each of a straight line ab and a straight line cd which are defined by four coordinate points a (0.4,8.8), b(0.4,2.4), c(1.0,9.9) and d(1.0,3.2) on the graph intersects with a mechanical property curve of the tube which is obtained by carrying out a tensile test under the conditions of an ambient temperature of 60 C., an initial chuck-to-chuck distance of 220.05 mm and a tensile speed of 5 mm/sec.

The disclosure provides a tube which is rarely broken and is stable during the process of the production of a heat-shrinkable tube having tearability in a length direction. The tube includes a melt-processable fluororesin and when the strain of the tube is defined as , the stress at the strain is defined as (MPa) and the strain is put on the horizontal axis and the stress is put on the longitudinal axis on a coordinate graph, each of a straight line ab and a straight line cd which are defined by four coordinate points a (0.4,8.8), b(0.4,2.4), c(1.0,9.9) and d(1.0,3.2) on the graph intersects with a mechanical property curve of the tube which is obtained by carrying out a tensile test under the conditions of an ambient temperature of 60 C., an initial chuck-to-chuck distance of 220.05 mm and a tensile speed of 5 mm/sec.

The disclosure provides a tube which is rarely broken and is stable during the process of the production of a heat-shrinkable tube having tearability in a length direction. The tube includes melt-processable fluororesin and when the strain of the tube is defined as , the stress at the strain is defined as (MPa) and the strain is put on the horizontal axis and the stress is put on the longitudinal axis on a coordinate graph, each of a straight line ab and a straight line cd which are defined by four coordinate points a(0.4,8.8), b(0.4,2.4), c(1.0,9.9) and d(1.0,3.2) on the graph intersects with a mechanical property curve of the tube which is obtained by carrying out a tensile test under the conditions of an ambient temperature of 60 C., an initial chuck-to-chuck distance of 220.05 mm and a tensile speed of 5 mm/sec.

The disclosure provides a tube which is rarely broken and is stable during the process of the production of a heat-shrinkable tube having tearability in a length direction. The tube includes melt-processable fluororesin and when the strain of the tube is defined as , the stress at the strain is defined as (MPa) and the strain is put on the horizontal axis and the stress is put on the longitudinal axis on a coordinate graph, each of a straight line ab and a straight line cd which are defined by four coordinate points a(0.4,8.8), b(0.4,2.4), c(1.0,9.9) and d(1.0,3.2) on the graph intersects with a mechanical property curve of the tube which is obtained by carrying out a tensile test under the conditions of an ambient temperature of 60 C., an initial chuck-to-chuck distance of 220.05 mm and a tensile speed of 5 mm/sec.