Multilayer Flexible Irrigating Hose

A method of making a multilayer flexible hose, comprising the successive steps of:

• (a) extruding a first polymer material to obtain a tubular supporting layer;
• (b) forming a first textile knitted layer with stitches of tricot type on said tubular supporting layer, to obtain a first semifinished product;
• (c) forming a second textile layer with stitches of the tricot type on said first semifinished product, to obtain a second semifinished product;
• and
• (d) extruding a second polymer material on said second semifinished product to obtain an outer layer, thereby forming a finished hose,
• wherein said first and second textile layers both include wales of stitches and lines of stitches and are formed with at least some of the lines of stitches having opposite inclinations to a longitudinal axis of the hose, both of said first and second textile layers being formed with the wales of stitches substantially parallel to said longitudinal axis, and
• wherein said steps (b) and (c) for forming said textile layers are carried out by a knitting apparatus comprising,
• an inlet for the tubular supporting layer, the tubular supporting layer being made from a first polymer material,
• a first and a second knitting unit, for forming on the tubular supporting layer the first and the second textile knitted layers respectively, with the stitches of the tricot type having the wales of stitches and the lines of stitches to form the first and the second semifinished products defining the longitudinal axis,
• an exit for the second semifinished product,
• a first and a second series of needles associated with each of said first and said second knitting units,
• a first and a second series of reels of yarn, operatively coupled to the first and the second series of needles respectively, the first and said second series of reels being susceptible of peripherally rotating about the longitudinal axis to form the first and the second textile layers on the outer surface of the tubular supporting layer as the tubular supporting layer is moved forward,
• cam means operably connecting the needles and the reels so that rotation of the reels causes a reciprocating motion of the needles in a direction substantially parallel to the longitudinal axis, and
• first and second motor means susceptible of driving into rotation the first and the second series of reels in opposite directions, so that the lines of stitches of the first and second textile knitted layers have opposite inclinations to the longitudinal axis, the needles of both the first and the second series being rotationally locked so that the wales of stitches of the corresponding textile layer are substantially parallel to the longitudinal axis.

A line for manufacturing a flexible hose comprising:

• an extrusion station configured to extrude a first polymer material to obtain a tubular supporting layer;
• at least one knitting station configured to form a first and a second textile knitted layers with stitches of tricot type, in overlapped relation, on said tubular supporting layer;
• and
• an extrusion station configured to extrude a second polymer material on a semifinished product coming out of the at least one knitting station, to obtain an outer layer, thereby forming a finished hose,
• wherein said first and second textile layers both include wales of stitches and lines of stitches, said first and second textile layers being formed with at least some of the lines of stitches having opposite inclinations to a longitudinal axis of the hose, both of said first and second textile layers being formed with the wales of stitches substantially parallel to said longitudinal axis, and
• wherein said at least one knitting station comprises an apparatus having,
• an inlet for the tubular supporting layer, the tubular supporting layer being made from a first polymer material,
• a first and a second knitting unit configured to form on the tubular supporting layer the first and the second textile layers respectively, with the stitches of the tricot type having the wales of stitches and the lines of stitches to form a semifinished product defining the longitudinal axis,
• an exit for the semifinished product,
• a first and a second series of needles associated with each of said first and said second knitting units,
• a first and a second series of reels of yarn, operatively coupled to the first and the second series of needles respectively, the first and said second series of reels being susceptible of peripherally rotating about the longitudinal axis to form the first and the second textile layers on the outer surface of the tubular supporting layer as the tubular supporting layer is moved forward,
• cam means operably connecting the needles and the reels so that rotation of the reels causes a reciprocating motion of the needles in a direction substantially parallel to the longitudinal axis, and
• first and second motor means susceptible of driving into rotation the first and the second series of reels in opposite directions, so that the lines of stitches of the first and second textile knitted layers have opposite inclinations to the longitudinal axis, the needles of both the first and the second series being rotationally locked so that the wales of stitches of the corresponding textile layer are substantially parallel to the longitudinal axis.