Method of producing mat comprising filament loop aggregate

A method of producing a mat including a three dimensional filament loop aggregate, the method comprising the steps of:

• extruding molten thermoplastic synthetic resin from a die to form a plurality of filaments including outer filaments and remaining filaments, the plurality of filaments descending from the die onto the surface of cooling liquid between first and second rotatable rolls wherein the first rotatable roll and the second rotatable roll are fully submerged in the cooling liquid;
• cooling the plurality of filaments simultaneously in the cooling liquid, the outer filaments forming first loops and the remaining filaments forming second loops on the surface of the cooling liquid;
• supporting the first loops on a top of the first rotatable roll such that the first loops lie substantially horizontally on the top and thereafter move around upon rotation of the first rotatable roll to a substantially vertical plane;
• providing a supporting roll in the cooling liquid below the first and second rotatable rolls, the first rotatable roll, the second rotatable roll and the supporting roll each having an axis and the first rotatable roll, the second rotatable roll and the supporting roll being arranged so that the axis of the first rotatable roll, the axis of the second rotatable roll and the axis of the supporting roll define an acute triangle, the first and second rotatable rolls and the supporting roll defining a zone for receiving the first and second loops with the first and second loops being integrated in said zone to form the filament loop aggregate wherein the filament loop aggregate is at least partially supported from below by the supporting roll;
• transporting the filament loop aggregate first between the first and second rotatable rolls and thereafter between the supporting roll and the second rotatable roll to regulate the width and density of the filament loop aggregate;
• providing an auxiliary roll;
• and
• transporting the filament loop aggregate between the supporting roll and the auxiliary roll.