Composite material comprising ultrasonically welded seams which combine strands, method for its manufacture, and apparatus for the carrying out of the method

A composite material comprising:

• an upper layer;
• a lower layer secured to the upper layer along substantially parallel, spaced apart, ultrasonically welded seams;
• and
• an intermediate layer comprised of individual strands of material which are plurally subdivided, at least partially, in the transverse direction thereof and which lie substantially parallel to said welded seams and between said seams in respective channels formed by said upper and lower layers and said welded seams.

A method for producing a composite material wherein two webs of ultrasonically weldable material form an upper layer and a lower layer, comprising the steps of:

• continuously welding together said layers along substantially parallel weld seams spaced apart from each other;
• feeding strands of material forming an intermediate layer between the weld seams during said welding step such that said intermediate layer is inserted between the upper layer and the lower layer so as to continuously form said composite material, wherein said strands of material have one of a melting temperature point and a melting temperature range which is below that of the upper and lower layers;
• and
• subdividing said strands in the transverse direction thereof in at least a partial cross-section of said strands by a brief pressing against the composite material of a heated die, said die being at a temperature below the respective one of the melting temperature point and melting temperature range of the upper and lower layers and being at a temperature equal to or greater than the respective one of the melting temperature point and melting temperature range of the strands of material to be subdivided.

An apparatus for producing a composite material of the type having an upper layer, a lower layer and an intermediate layer comprised of a plurality of elongated strands of material disposed between said upper layer and said lower layer, comprising:

• a plurality of parallel, spaced apart, intermittently engaging anvil plates;
• an oscillating body for ultrasonically welding said upper layer to said lower layer along substantially parallel, spaced apart weld seams, between said anvil plates and said oscillating body;
• and
• guide means for feeding said strands of material of said intermediate layer between said spaced apart, intermittently engaging anvil plates and said oscillating body and between said weld seams so as to continuously form said composite material.