Device and method for continuously blow molding fiber-reinforced thermoplastic hollow profiles having a constant or changing cross-section

A device for the semi-continuous blow moulding of fiber-reinforced, thermoplastic, endless, hollow-profile components with cross sections that are constant or varying in the longitudinal direction, consisting of at least one consolidating tool which, in the closed state, encloses a preform, which encloses an elastically deformable pressure chamber, wherein:

• a) a preforming unit and the consolidating tool are arranged directly one after the other;
• b) the preforming unit provides the endless preform;
• c) the preform enclosed by the consolidation tool is a preform segment;
• d) the central axis of the preforming unit, the consolidation tool, the preform segment, and the pressure chamber are arranged congruently;
• e) the consolidating tool is designed in at least two parts;
• and
• f) the consolidation tool corresponds to the contour of the component;
• wherein:
• the consolidation tool has at least two independently isothermal-tempered tool segments, and in that the tool segments are arranged along the middle axis;
• the dimensions of the consolidation tool, the pressure chamber, and the preform segment for processing are identical along the central axis;
• the device has a feed device which is capable of repeatedly moving the preform by the amount of the length of a tool segment into a machining direction directed along the central axis;
• the pressure chamber is formed from:
• an endless, deformable pressure membrane and sealing elements, or
• a pressure membrane that is a deformable hose firmly attached to sealing elements;
• and
• the pressure chamber is pressurizable.

A method for the semi-continuous blow moulding of fibre-reinforced thermoplastic hollow profiles with cross-sections that are constant or varying in longitudinal direction, comprising at least the steps:

• a) providing a tubular pressure membrane which is coated or enclosed with a preform comprising thermoplastic matrix material;
• b) providing a device for the semi-continuous blow moulding of fiber-reinforced, thermoplastic, endless, hollow-profile components with cross sections that are constant or varying in the longitudinal direction, consisting of at least one consolidating tool which, in the closed state, encloses a preform, which encloses an elastically deformable pressure chamber;
• c) positioning of the tubular pressure membrane and the preform such that it extends over the entire length of the consolidating tool and covers the sealing elements,
• d) closing the consolidating tool;
• e) compressing the preform segment by enlarging the diameter of the pressure membrane through pressurization, and nestling the preform segment against the inner wall of the consolidating tool;
• f) heating a first preform segment in the first tool segment of the consolidating tool to a temperature below the melting temperature of the thermoplastic, preferably simultaneously, heating a second preform segment in the second tool segment of the consolidating tool to a temperature which at least reaches the melting temperature of the matrix material, preferably simultaneously, cooling and shaping a third preform segment in a third tool segment of the consolidating tool to a temperature which is below the solidification temperature of the matrix material;
• g) terminating the pressurization of the pressure membrane;
• h) opening the consolidating tool and, subsequently, advancing the preform by the length of one tool segment and subsequently closing the consolidating tool;
• and
• i) repeating steps e) to h).