Patent ID: 9254463
Filing Date: 2016-02-09
CPC Classification: B01D,Y10T

Claim Text:
1. A method for producing a hollow fiber membrane mat with at least one stripe-shaped area in which the walls of the hollow fiber membranes are fluid impermeable, comprising the following steps: a) providing a hollow fiber membrane mat having hollow fiber membranes arranged parallel to one another and adjacent to one another, said membranes having at least one of a porous, microporous, and semi-permeable wall and a continuous lumen, wherein the hollow fiber membranes are connected to one another by means of a plurality of linear connecting elements which are arranged spaced apart from one another and parallel to one another and said membranes are kept at a distance by the linear connecting elements and wherein the hollow fiber membranes are composed of a thermoplastic polymer, and the linear connecting elements have a melting temperature that is at least as high as the melting temperature of the thermoplastic polymer composing the hollow fiber membranes, and the linear connecting elements have a superheated steam shrinkage of at most 5% at a temperature of 121° C. and an atmospheric humidity of 100%, b) transporting the hollow fiber membrane mat by means of a transport equipment and at a transport speed in the direction of the extension of the linear connecting elements and under a tension acting in the transport direction through at least one heating device extending in the transport direction having heating elements arranged above and below the hollow fiber membrane mat and at a distance from the surface of the hollow fiber membrane mat as well as from one another via which heat is supplied to the hollow fiber membranes in a treatment zone over a width B transverse to the transport direction, whereby the hollow fiber mat is treated in a treatment area, and simultaneously c) gripping of the hollow fiber membrane mat in zones, which are located to the right and left of the at least one heating device when viewed in the transport direction, by clamping devices, which are adjustable regarding their contact pressure perpendicular to the flat extension of the hollow fiber membrane mat, by means of which clamping devices the hollow fiber membranes are held under tension transverse to the transport direction, wherein in the treatment zone the temperature is adjusted to a temperature 5 to 15% below the melting temperature of the polymer composing the hollow fiber membranes by means of the heating elements so that a shrinkage of the hollow fiber membranes is initiated in the treatment area, and wherein by adjusting the contact pressure of the clamping devices, the hollow fiber membranes are held under tension in their longitudinal extension so that the hollow fiber membranes retain a straight-line course in their longitudinal extension.