Wet spinning process of an elastomeric polymer thread

Abstract

The present invention relates to a wet spinning process of an elastomeric polymer thread comprising a wet spinning phase in which a spun prepolymer is passed in equicurrent to a reactive solution to give a polymeric thread, a drying phase in which the solvent of the reactive solution is removed from the yarn and a collection phase in which said thread is wound on winding devices.

1 . A wet spinning process of an elastomeric polymer, which comprises: 
 a wet spinning phase in which a prepolymer is put in contact with a reactive solution to give a polymeric thread;    a drying phase in which the solvent of the reactive solution is removed from the thread;    a collection phase in which said thread is wound on winding devices;    wherein, in the wet spinning phase, said reactive solution moves in the direction of the thread-run in order to considerably reduce the hydrodynamic friction between the thread and reactive bath.    
     
     
         2 . The process according to  claim 1 , wherein said reactive solution moves at a rate ranging from 15 to 80 m/min.  
     
     
         3 . The process according to  claim 2 , wherein said reactive solution moves at a rate ranging from 30 to 60 m/min.  
     
     
         4 . The process according to  claim 1 , wherein said reactive solution comprises a diamine in an organic solvent.  
     
     
         5 . The process according to  claim 4 , wherein said diamine is ethylenediamine and said organic solvent is toluene.  
     
     
         6 . The process according to  claim 1 , wherein said prepolymer is an elastomer selected from the group consisting of polyester-urethanes, polyether-urethanes, or polyether/polyester-urethanes and mixtures thereof.  
     
     
         7 . The process according to  claim 1 , wherein in said wet spinning phase the prepolymer is fed to a spinning position comprising one or more dies, immersed in a reactive bath, each connected with a duct in which the thread runs in equicurrent with a flow of reactive solution.  
     
     
         8 . The process according to  claim 7 , wherein said prepolymer is polymerized while flowing in equicurrent with said reactive solution.  
     
     
         9 . The process according to  claim 1 , wherein the spinning is effected in one or more spinning positions, each of which comprises from 2 to 8 dies immersed in the same reactive bath.  
     
     
         10 . The process according to  claim 1 , wherein the reactive solution is removed from the polymeric yarn before said dry or hot phase.  
     
     
         11 . The process according to  claim 10 , wherein the removal of said reactive solution comprises squeezing of the thread.  
     
     
         12 . The process according to  claim 1 , wherein said drying phase comprises thermal curing treatment of the thread for increasing its elastic properties.  
     
     
         13 . The process according to  claim 1 , wherein said drying phase is made under heating by the passage of one or more threads on the hot surfaces of rolls.  
     
     
         14 . The process according to  claim 13 , wherein said rolls comprise grooves in each of which a single thread passes.  
     
     
         15 . The process according to  claim 1 , wherein said drying phase takes place at a temperature ranging from 180-240° C.  
     
     
         16 . The process according to  claim 1 , wherein a dried thread is lubricated before the collection phase.  
     
     
         17 . Equipment for the wet spinning of an elastomeric polymer comprising a series of spinning positions operatively independent of each other, each of which includes one or more dies arranged inside a reactive bath container.  
     
     
         18 . The equipment according to  claim 17 , wherein in each reactive bath container there are from 2 to 8 dies parallelly arranged.  
     
     
         19 . The equipment according to  claim 17 , wherein each die is connected by means of a spinning head to a device for the running of a thread in equicurrent with a reactive solution.  
     
     
         20 . The equipment according to  claim 17 , further comprising a drying section of an elastomeric yarn equipped with a pair of smooth heatable cylinders for the passage of one or more threads.