A method of welding a sleeve (10) to a tube (20) includes putting onto end portions (11) of the sleeve (10) respective protective elements (40), of a material that cannot be fused with the materials of the sleeve (10) and of the outer coating (24) of the tube (20); applying on each end portion (11) of the sleeve (10) covered by a protective element (40) a respective heat-shrink element (30); supplying each heat-shrink element (30) with a quantity of heat (Q) which by heating it causes it to shrink and compress the respective end portion (11) of the sleeve (10) against the tube (20), where this quantity of heat (Q) is transmitted to the end portion (11) of the sleeve (10) to obtain a welding of the sleeve (10) to the tube (20) and produce a device (1) comprising the tube (20) with the sleeve (10).

Described is a peelable heat shrink tube composed of a fluororesin and having a determination coefficient calculated from [Equation 1] below using an elastic modulus ratio (%) of more than 0, but 0.90 or less: $\begin{array}{cc}\mathrm{Determination}\mathrm{coefficient}={\left(\mathrm{correlation}\mathrm{coefficient}\right)}^2={\left[\frac{\left(\mathrm{covariance}\right)}{\left(\mathrm{standard}\mathrm{deviation}\mathrm{of}X\right)\left(\mathrm{standard}\mathrm{deviation}\mathrm{of}Y\right)}\right]}^2& \left[\mathrm{Equation}1\right]\end{array}$
where X, Y and covariance represent the following: X: Proportion of the position of each point, where the elastic modulus was measured, from the interior of the tube Y: Elastic modulus ratio in each region Covariance: Average of the product of deviations of X and Y.

A heat shrink tube heating system includes a frame, a first and second fixture, and a heating furnace. The first fixture is installed on the frame for clamping one end of a cable product. The second fixture is installed on the frame for clamping the other end of the cable product. The heating furnace is mounted on the frame in a movable manner and has a heating channel that allows the cable product to pass through. The heating furnace is movable along an axial direction of the clamped cable product between the first fixture and the second fixture, for heating a heat shrink tube on the cable product.

For producing a pipe, a core is provided and a functional material, a fiber composite material and a shrink material forming a shrink tube are applied radially externally to the core. The pipe is thermoformed by heating of the pipe with application of radially inward pressure to the fiber composite material and radially outward pressure to the functional material, this in turn by radially inward thermal contraction of the shrink tube and/or radially outward thermal expansion of the core. At the same time consolidation of the functional material together with the fiber composite material form the pipe, and cooling to a cold temperature and demolding of the consolidated pipe from the shrink tube and from the core. The functional material has such a media resistance with respect to the medium that for a planned usage period it is less damaged by the medium than the fiber composite material.

The invention is directed to a heating assembly for catheter manufacture which includes a heating element having a central vertical passage and a plurality of gas flow passages in communication with the central passage. The passages are at an angle relative to the central passage increasing heat transfer surface area. The invention may also include an iris assembly. The iris assembly includes a plurality of discs having slits which are offset relative to another disc. The invention may also include an insulation chamber surrounding the heating element. The flow of gas previously heated by the exterior of the thermos coupler and heating element is restricted by the insulation chamber for passage through the gas flow passages and into the central passage, so that the gas receives additional heat for exposure to sheathing material to be bound to a catheter.