Thermoplastic elastomer tubing and method to make and use same

Patent metadata

Field	Value
Publication number	US-9987784-B2
Application number	US-201615044729-A
Country	US
Kind code	B2
Filing date	Feb 16, 2016
Priority date	Jun 6, 2012
Publication date	Jun 5, 2018
Grant date	Jun 5, 2018

Abstract

A thermoplastic elastomer tube can include a thermoplastic elastomer component disposed within a matrix. In an embodiment, the thermoplastic elastomer component is disposed within the matrix in a thermoplastic elastomer phase having a number of domains. At least approximately 50% of the domains of the thermoplastic elastomer component have an aspect ratio of no greater than approximately 1.5. In a particular embodiment, the thermoplastic elastomer tube comprises at least approximately 20 wt % of the thermoplastic elastomer component and no greater than approximately 50 wt % of a polyolefin component. In some embodiments, the thermoplastic elastomer component includes styrene.

First claim

What is claimed is:

1. A process comprising:
providing a number of starting materials to a twin screw extruder, the starting materials including a thermoplastic elastomer;
mixing the starting materials in the twin screw extruder to provide a twin screw extruder output;
providing the twin screw extruder output to a pump; and
providing an output of the pump to a die to form a thermoplastic elastomer tube comprising:
a matrix including a thermoplastic elastomer phase, the thermoplastic elastomer phase comprising a plurality of domains comprising a thermoplastic elastomer component, wherein at least approximately 50% of the plurality of domains comprising the thermoplastic elastomer component have an aspect ratio of no greater than approximately 1.5, and
wherein (a) the thermoplastic elastomer tube comprises no greater than approximately 60 wt % of the thermoplastic elastomer component and at least approximately 25 wt % of the thermoplastic elastomer component, (b) an average value of a major dimension of the plurality of domains is at least 1.2 microns, or both.

2. The process of claim 1 , further comprising heating the number of starting materials in the twin screw extruder to form a melt.

3. The process of claim 2 , wherein a temperature of the melt is no greater than approximately 230° C.

4. The process of claim 1 , wherein a first portion of the number of starting materials comprises solid materials, a second portion of the number of starting materials comprises liquid materials, a third portion of the number of starting materials comprises gaseous materials, or a combination thereof.

5. The process of claim 1 , wherein a pressure at an input of the die varies by no greater than approximately 10% from a specified input pressure.

6. The process of claim 1 , wherein the output of the pump is provided to the die and mandrel via one or more filtering devices.

7. The process of claim 1 , further comprising cooling the thermoplastic elastomer tube.

8. The process of claim 7 , wherein the thermoplastic elastomer tube is cooled after providing the output of the pump to the die.

9. The process of claim 7 , wherein the thermoplastic elastomer tube is cooled via a water bath.

10. The process of claim 9 , wherein the water bath is disposed in a vacuum tank, open to the atmosphere, or both.

11. The process of claim 1 , further comprising blending the starting materials before providing the starting materials to the twin screw extruder.

12. The process of claim 1 , wherein the twin screw extruder is driven by a gear pump.

13. The process of claim 1 , wherein the pump is a positive displacement pump.

14. The process of claim 13 , wherein the positive displacement pump is a melt pump.

15. The process of claim 1 , wherein the pump is a single screw extruder.

16. The process of claim 15 , wherein the single screw extruder has a ratio of length to diameter (L/D) of no greater than approximately 24.

17. The process of claim 1 , further comprising providing one or more of the starting materials to the twin screw extruder via one or more liquid injection pumps.

18. The process of claim 1 , further comprising providing one or more of the starting materials to the twin screw extruder via one or more feeders coupled to the twin screw extruder.

19. The process of claim 1 , further comprising providing at least a portion of the starting materials to the twin screw extruder via a side feeder.

Assignees

• Saint Gobain Performance Plastics Corp

Inventors

• Siddhamalli Sridhar Krishnamurthi
• Simon Mark W
• Schrader Steven
• Kundinger Todd E

Classifications

• B29C48/69

  Filters or screens for the moulding material · CPC title

• B29C48/388

  using a screw extruder and a ram or piston · CPC title

• B29L2023/007

  Medical tubes other than catheters (catheters B29L2031/7542) · CPC title

• B29C48/919

  using a bath, e.g. extruding into an open bath to coagulate or cool the material · CPC title

• B29K2105/0038

  Plasticisers · CPC title