Continuous method and system for the production of at least one polymeric yarn and polymeric yarn

Patent metadata

Field	Value
Publication number	US-11021811-B2
Application number	US-201515531653-A
Country	US
Kind code	B2
Filing date	Dec 2, 2015
Priority date	Dec 2, 2014
Publication date	Jun 1, 2021
Grant date	Jun 1, 2021

Abstract

The present invention provides a continuous method for the production of at least one polymeric yarn comprising the steps of: mixing a polymer with a first solvent generating a mixture; homogenizing the mixture; rendering the mixture inert; dosing the mixture to an extruder; immersing the mixture in a quenching bath (30), wherein an air gap is maintained before the mixture achieves the surface of the liquid of the quenching bath (30) forming at least one polymeric yarn; drawing at least once the at least one polymeric yarn; washing the polymeric yarn with a second solvent that is more volatile than the first solvent; heating the at least one polymeric yarn; drawing at room temperature, at least once, the at least one polymeric yarn; and heat drawing, at least once, the at least one polymeric yarn, wherein the mixture comprises: a polymer comprising ultra-high molecular weight polyethylene, comprising an intrinsic viscosity of from 5 dL/g to 40 dL/g, and a polydispersity index of from 2 to 10; and a first solvent capable of dissolving the polymer under the process conditions, and comprising a dynamic viscosity, measured at a temperature of 37.8° C., according to ASTM D-445, greater than 10 cP. The present invention further provides a continuous system for the production of at least one polymeric yarn, comprising: means for mixing the polymer with a first solvent generating a mixture; means for homogenizing the mixture; means for rendering the mixture inert; means for dosing the mixture to an extruder; means for immersing the mixture in a quenching bath (30), wherein an air gap is maintained before the mixture achieves the surface of the liquid of the quenching bath (30) forming at least one polymeric yarn; means for drawing at least once the at least one polymeric yarn; means for washing for washing the at least one polymeric yarn with a second solvent that is more volatile than the first solvent; means for heating the at least one polymeric yarn; means for drawing at room temperature at least once the at least one polymeric yarn; and means for heat drawing at least once the at least one polymeric yarn, wherein the mixture comprises: a polymer comprising ultra-high molecular weight polyethylene, comprising an intrinsic viscosity of from 5 dL/g to 40 dL/g, and a polydispersity index of from 2 to 10; and a first solvent capable of dissolving the polymer under the process conditions and comprising a dynamic viscosity, as measured at a temperature of 37.8° C. according to the ASTM standard D-445, greater than 10 cP. Further, the present invention provides a polymeric yarn made according to the above stated method.

First claim

What is claimed is:

1. A continuous method for the production of at least one polymeric yarn comprising the steps of:
mixing a polymer with a first solvent, providing a mixture;
homogenizing the mixture;
rendering the mixture inert;
dosing the mixture in an extruder, forming a homogeneous solution;
dosing the solution in an orifice die, providing the solution with the shape of filament yarn;
immersing the solution with the shape of filament yarn in a quenching bath, wherein an air gap is maintained before the mixture achieves a surface of the liquid of a quenching bath forming at least one gel yarn;
drawing at least once the at least one gel yarn;
washing the gel yarn with a second solvent that is more volatile than the first solvent;
drying the at least one gel yarn; and
heat drawing at least once the at least one gel yarn;
the method being characterized in that in the step of dosing the solution in the orifice die:
the minimum speed of the solution at an orifice die inlet is defined by

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2. The method of claim 1 , characterized in that the mixture comprises:
a polymer comprising ultra-high molecular weight polyethylene, comprising an intrinsic viscosity of between 5 dL/g and 40 dL/g, and a polydispersity index of between 2 and 10;
a first solvent capable of dissolving the polymer under process conditions, and comprising a dynamic viscosity, as measured at a temperature of 37.8° C., according to ASTM D-445, of greater than 10 cP.

3. The method of claim 1 , characterized in that the mixture comprises:
a polymer comprising ultra-high molecular weight polyethylene, comprising an intrinsic viscosity of between 10 dL/g and 20 dL/g, and a polydispersity index of between 3 and 6; and
a first solvent capable of dissolving the polymer under process conditions, and comprising a dynamic viscosity, as measured at a temperature of 37.8° C., according to the standard ASTM D-445, of greater than 30 cP.

4. The method according to claim 1 , comprising a post drawing step in which the draw ratio is greater than 1.5 and lower than 3.

5. The method according to claim 1 , characterized in that the Survival Index is greater than 70%.

6. The method according to claim 1 , characterized in that:
the polymer is selected from the group consisting of high molecular weight polyolefin, ultra high molecular weight polyolefin, ultra-high molecular weight polyethylene, high molecular weight polypropylene and ultra high molecular weight polypropylene, ethene-propene copolymer, polyvinyl alcohol, polyesters, polyoxide ethylene, and ultra-high molecular weight polyethylene, and
the first solvent is selected from the group consisting of a mineral oil, aliphatic hydrocarbons, cyclo-aliphatic hydrocarbons, aromatic hydrocarbons, and halogenated hydrocarbons.

7. A polymeric yarn, made according to a method for the production of at least one polymeric yarn, said method comprising the steps of:
mixing a polymer with a first solvent, providing a mixture;
homogenizing the mixture;
rendering the mixture inert;
dosing the mixture in an extruder, forming a homogeneous solution;
dosing the solution in an orifice die, providing the solution with the shape of filament yarn;
immersing the solution with the shape of filament yarn in a quenching bath, wherein an air gap is maintained before the mixture achieves a surface of the liquid of a quenching bath forming at least one gel yarn;
drawing at least once the at lea

Assignees

• Braskem America Inc
• Braskem Sa

Inventors

• Bueno Marcos Roberto Paulino
• Bernardi Alessandro
• Westfahl Jr Harry

Classifications

• D10B2321/021

  polyethylene · CPC title

• D01F6/04 Primary

  from polyolefins · CPC title

• D10B2401/063

  high strength · CPC title

• D01D10/06

  Washing or drying · CPC title

• D10B2401/061

  elastic · CPC title