Special Needlelooms for Circular Needling

By inventing circular needling technology, DILO extended needling beyond flat structures. The RONTEX process winds preneedled felt strips on a perforated stitching roll where there are needles and the tube is delivered at right angles to the infeed direction. This technology allows the production of tubes with various diameters and wall thicknesses. Apart from man-made fibres, a great number of special fibres can be processed directly from the card web. By feeding different needlefelts a multi-layer structure, also with a different density gradient from the inside to outside, can be produced efficiently. Seamless tubes made of needlefelt with diameters from 5 – 500 mm can be produced. The similar ORC process for thick-walled cylinders can produce outer diameters of max. 1600 mm at inner diameters of 10 – 300 mm. The invention of the RONTEX S 2000 allows an efficient production of needled felt tubes with stroke frequencies of up to approx.  2500 min^-1.