Irradiation and post-cure processing of elastomers

Patent metadata

Field	Value
Publication number	US-9994688-B2
Application number	US-201615204958-A
Country	US
Kind code	B2
Filing date	Jul 7, 2016
Priority date	Apr 16, 2015
Publication date	Jun 12, 2018
Grant date	Jun 12, 2018

Abstract

Processing methods are described for improving the physical properties of elastomeric materials including elastomeric tubing. The methods include heating tubing in a post-cured step for a specified time and at a specified temperature. The methods also include irradiating the tubing with a desired dose of radiation. Embodiments can include treatment of silicon-based elastomers and/or non-silicon-based elastomers. The improved elastomers can be utilized in pumps.

First claim

The invention claimed is:

1. A method, comprising:
providing elastomeric tubing already having had a first exposure to heat, and having a radial strength equal to a first radial strength;
heating the elastomeric tubing with a second exposure to heat; and
increasing the radial strength by irradiating the elastomeric tubing with a dose of seventy-five kilogray to a second radial strength that is greater than the first radial strength.

2. The method of claim 1 , wherein the heating comprises heating the elastomeric tubing for approximately two hours at a temperature of approximately four hundred degrees Fahrenheit.

3. The method of claim 1 , wherein the heating comprises heating the elastomeric tubing for approximately two hours at a temperature of approximately four hundred degrees Fahrenheit.

4. The method of claim 1 , wherein the elastomeric tubing comprises a silicon-based elastomer or a polydimethyl siloxane (PDMS).

5. The method of claim 1 , further comprising coupling the irradiated elastomeric tubing having the second radial strength to a pump.

6. The method of claim 1 , wherein the irradiating comprises applying gamma-ray irradiation to the elastomeric tubing.

7. The method of claim 1 , wherein the irradiating comprises applying E-beam irradiation to the elastomeric tubing.

8. A method of strengthening elastomeric tubing, the method comprising:
providing a segment of the elastomeric tubing already having had a first exposure to heat, and having a first radial strength;
increasing the first radial strength by irradiating the segment with seventy-five kilogray of gamma-ray irradiation; and
providing the irradiated segment as a strengthened segment of elastomeric tubing having a second radial strength greater than the first radial strength.

9. The method of claim 8 , wherein the irradiating comprises irradiating the segment with less than fifty kilogray of the gamma-ray irradiation.

10. The method of claim 8 , further comprising, prior to the irradiation, heating the segment with a second exposure to heat.

11. The method of claim 10 , wherein the heating comprises heating the segment for at least two hours at a temperature of approximately four hundred degrees Fahrenheit.

12. The method of claim 8 , further comprising, following the irradiation, heating the segment with a second exposure to heat.

13. The method of claim 12 , wherein the heating comprises heating the segment for at least two hours at a temperature of approximately four hundred degrees Fahrenheit.

14. A method, comprising:
providing elastomeric tubing already having had a first exposure to heat, and having a first radial strength;
increasing the first radial strength by irradiating the elastomeric tubing with seventy-five kilogray of E-beam irradiation; and
providing the irradiated elastomeric tubing as a strengthened elastomeric tubing having a second radial strength greater than the first radial strength.

15. The method of claim 14 , wherein the irradiating comprises irradiating the elastomeric tubing with less than fifty kilogray of the E-beam irradiation.

16. The method of claim 14 , further comprising heating the elastomeric tubing with at least a second exposure to heat.

17. The method of claim 16 , wherein the heating comprises heating the elastomeric tubing for at least two hours at a temperature of approximately four hundred degrees Fahrenheit.

18. The method of claim 16 , wherein the irradiating and the heating comprise intermittently heating and irradiating the elastomeric tubing.

19. The method of claim 16 , wherein the heating comprises heating the elastomeric tubing during the irradiating.

Assignees

• Carefusion 303 Inc

Inventors

• Bavaro Vincent

Classifications

• C08L83/04

  Polysiloxanes · CPC title

• A61L29/06

  obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds · CPC title

• C08J7/08

  Heat treatment · CPC title

• B29C2035/085

  using gamma-ray · CPC title

• C08G77/32

  Post-polymerisation treatment · CPC title