Described is an apparatus for heating end portions of pipes made of thermoplastic material, comprising an internal heating element, designed to be inserted at least partially inside an end portion of a pipe made of thermoplastic material for heating an inner cylindrical surface of the portion, the heating element comprising at least one infra-red ray radiation unit which has an operating zone designed to face at least partially the inner cylindrical surface, the operating zone extending longitudinally along a predetermined direction, parallel to a central axis of the pipe to be heated.

Described is an apparatus for heating end portions of pipes made of thermoplastic material, comprising an internal heating element, designed to be inserted at least partially inside an end portion of a pipe made of thermoplastic material for heating an inner cylindrical surface of the portion, the heating element comprising at least one infra-red ray radiation unit which has an operating zone designed to face at least partially the inner cylindrical surface, the operating zone extending longitudinally along a predetermined direction, parallel to a central axis of the pipe to be heated.

The composite tube may include a body having a longitudinal centerline axis and at least one end portion. The at least one end portion may include a plurality of segments that are angled relative to the longitudinal centerline axis and are circumferentially separated from each other by a plurality of slits. The composite tube may be implemented in a joint assembly that includes a support wedge. The support wedge may at least partially engage at least one of a radially inward surface of the at least one end portion and a radially outward surface of the at least one end portion.

The composite tube may include a body having a longitudinal centerline axis and at least one end portion. The at least one end portion may include a plurality of segments that are angled relative to the longitudinal centerline axis and are circumferentially separated from each other by a plurality of slits. The composite tube may be implemented in a joint assembly that includes a support wedge. The support wedge may at least partially engage at least one of a radially inward surface of the at least one end portion and a radially outward surface of the at least one end portion.

An object of the present invention is to provide a method of joining resin tubes, in which the degree of freedom of selecting a tube material is large, and further a defect such as stiffness and contraction at joining portions of the tubes is not developed. The method of joining resin tubes according to the present invention is a method of joining resin tubes so that a first tube is joined to a second tube, the first tube and the second tube each being made of synthetic resin, the method comprising: a surface activation step of activating each of a joining region of the first tube and a joining region of the second tube; and an adhesion step of adhering the joining region of the first tube obtained via the surface activation step with the joining region of the second tube obtained via the surface activation step to each other.

Described is an apparatus for heating end portions of pipes made of thermoplastic material, comprising an internal heating element, designed to be inserted at least partially inside an end portion of a pipe made of thermoplastic material for heating an inner cylindrical surface of the portion, the heating element comprising at least one infra-red ray radiation unit which has an operating zone designed to face at least partially the inner cylindrical surface, the operating zone extending longitudinally along a predetermined direction, parallel to a central axis of the pipe to be heated.

Described is an apparatus for heating end portions of pipes made of thermoplastic material, comprising an internal heating element, designed to be inserted at least partially inside an end portion of a pipe made of thermoplastic material for heating an inner cylindrical surface of the portion, the heating element comprising at least one infra-red ray radiation unit which has an operating zone designed to face at least partially the inner cylindrical surface, the operating zone extending longitudinally along a predetermined direction, parallel to a central axis of the pipe to be heated.

The multilayer container includes a container body having a multilayer structure and a multilayer head of the container. The multilayer body of the container has at least one barrier layer connected, on one side, to at least one thermoplastic layer and heat sealed in a longitudinal overlapping joint formed of the edges of these layers. The body has its external surface covered with a polymeric coating, and the multilayer head of the container includes at least one non-metallic barrier layer connected, on one side, to at least one thermoplastic layer and is wholly extruded in the co-extrusion process. The essence of the invention is also a method for producing such a container.

The multilayer container includes a container body having a multilayer structure and a multilayer head of the container. The multilayer body of the container has at least one barrier layer connected, on one side, to at least one thermoplastic layer and heat sealed in a longitudinal overlapping joint formed of the edges of these layers. The body has its external surface covered with a polymeric coating, and the multilayer head of the container includes at least one non-metallic barrier layer connected, on one side, to at least one thermoplastic layer and is wholly extruded in the co-extrusion process. The essence of the invention is also a method for producing such a container.

An apparatus for internal heating of end portions of pipes made of thermoplastic material having a central axis including a heating element, designed to be inserted at least partially inside an end portion of a pipe made of thermoplastic material for heating an inner cylindrical surface of the portion, the heating element including an infra-red radiation unit designed to face at least partially the inner cylindrical surface.