Patent ES-448620-A1 (ES)
Title: Random laid bonded continuous filament cloth
IPC: B32B5/02
Filed: 1976-06-05
Abstract: This application discloses a cloth structure comprising preferably generally continuous melt spun organic polymer filaments dispersed and laid to provide frequent random filament crossings, subsequently bonded to form a coherent cloth. In accordance with one aspect of the disclosed invention, a stream of filaments is melt spun through a linear spinnerette having a plurality of spinnerette orifices or rows of orifices offset to enable interleaving of the extruded filaments into a planar single row stream of filaments which are mechanically drawn to textile denier while still arranged in such single row stream on a draw roll having its surface in alignment with the axis of the spinnerette and then forwarded in such single row stream to a formation location closely coupled with a porous collection surface whereat the filaments are dispersed randomly or in directed formation onto the porous collection surface. In accordance with this aspect of the invention the controlled spinning, drawing and forwarding and the close coupling provide a precisely defined focus or divergence point for laydown of each filament in the stream and a limited and controlled excursion of each filament symmetrically about its focus. In accordance with another aspect of the disclosed invention at least some of the dispersed filaments are random laid to form an unbonded web on a porous woven fabric having generally uniform knuckle heights and the unbonded web comprised thereof is carried while still on the fabric and together therewith through a heated bonding nip to emboss the fabric knuckles into the web, providing spaced apart spot bond points and a textured surface to the bonded cloth produced thereby. In accordance with yet another aspect of the disclosed invention, there are provided at least two types of preferably generally continuous filaments, at least one of which is relatively elastomeric, at least one of which is generally uniformly dispersed and random laid to provide frequent random filament crossings, at least some of which are bonded, preferably autogenously, to form a coherent bonded cloth. In accordance with this aspect of the invention the fibers are selected to have differing stretch characteristics such that, under a given common percent elongation, inelastic or permanent deformation will be produced in at least one fiber type in the cloth and elastic or non-permanent deformation will be produced in at least one other type of fiber in the cloth. In accordance with yet still another aspect of this invention, such a coherent bonded cloth containing at least one relatively elastomeric filament type and one elongatable but relatively non-elastic filament type is then mechanically worked after bonding, as by stretching, beyond the elastic limit of the non-elastic filaments followed by relaxation of the relatively elastomeric filaments to develop the cloth to a low modulus of elasticity in the direction or directions of stretch. Yet still another aspect of the disclosed invention is the production of bonded cloth by control of the extent of orientation and extent of drawdown of melt spun filaments. Other aspects of the Disclosed invention are methods and apparatus for producing the bonded cloths hereof.