Gel-based temperature indicators

Patent metadata

Field	Value
Publication number	US-10408686-B2
Application number	US-201715402678-A
Country	US
Kind code	B2
Filing date	Jan 10, 2017
Priority date	Jan 15, 2016
Publication date	Sep 10, 2019
Grant date	Sep 10, 2019

Abstract

Disclosed herein are gel-based temperature indicators that include a first absorbent substrate having opposing first and second faces and a first gel coupled to the first face. In some embodiments, the first gel is a gel at a first temperature, and the first gel turns to liquid at a second temperature. In some embodiments, the first absorbent substrate is configured to allow the first gel upon turning to liquid to diffuse through the first face toward the second face.

First claim

The invention claimed is:

1. A gel-based temperature indicator comprising:
a first absorbent substrate having opposing first and second faces; and
a first gel coupled to the first face;
wherein the first gel is a gel at a first temperature;
wherein the first gel turns to liquid at a second temperature;
wherein the first absorbent substrate is configured to allow the first gel upon turning to liquid to diffuse through the first face toward the second face;
wherein the first gel is contained within a second absorbent substrate coupled to the first face of the first absorbent substrate, and
wherein the first gel comprises a first additive that affects the visual appearance of the first absorbent substrate when the first gel diffuses from the second absorbent substrate to the first face of the first absorbent substrate and further diffuses toward the second face; and
wherein the ratio of the area of the second face in mm 2 to the thickness of the first absorbent substrate in mm is at least 10 mm.

2. The gel-based temperature indicator of claim 1 , wherein the first absorbent substrate comprises a second additive and diffusion of the first gel comprising the first additive allows the first and second additives to react with each other in a way that affects the visual appearance of the first absorbent substrate.

3. The gel-based temperature indicator of claim 1 , wherein the first gel goes from gel to liquid with increasing temperature.

4. The gel-based temperature indicator of claim 1 , wherein the first gel goes from gel to liquid when the temperature decreases below a low temperature threshold, and the low temperature threshold is below 30° C.

5. A label for a perishable good, comprising a gel-based temperature indicator of claim 1 .

6. A method of protecting a perishable item, comprising:
coupling the perishable item with a gel-based temperature indicator of claim 1 so that the temperature condition indicator is subject to substantially the same temperature conditions as the perishable item.

7. The gel-based temperature indicator of claim 1 , wherein the first face comprises a marking that is revealed when the first gel diffuses through the first face.

8. A gel-based temperature indicator comprising:
a first absorbent substrate having opposing first and second faces;
a first gel coupled to the first face; and
a second gel coupled to the first face;
wherein the first gel is a gel at a first temperature;
wherein the first gel turns to liquid at a second temperature;
wherein the second gel is a gel at the first temperature
wherein the second gel turns to liquid at the second temperature;
wherein the first absorbent substrate is configured to allow the first and second gels upon turning to liquid to diffuse through the first face toward the second face;
wherein the first and second gels interact in the first absorbent substrate to effect a change in the visual appearance of the first absorbent substrate; and
wherein the ratio of the area of the second face in mm 2 to the thickness of the first absorbent substrate in mm is at least 10 mm.

9. The gel-based temperature indicator of claim 8 , wherein the extent of the change in visual appearance of the first absorbent substrate provides an indication of the amount of time that the indicator has been exposed to a temperature greater than or equal to the second temperature.

10. A label for a perishable good, comprising a gel-based temperature indicator of claim 8 .

11. A method of protecting a perishable item, comprising:
coupling the perishable item with a gel-based temperature indicator of claim 8 so that the temperature condition indicator is subject to substantially the same temperature conditions as the perishable item.

12. The gel-based temperature indicator of claim 8 , wherein the first gel goes from gel to liquid with increasing temperature.

13. The gel-based temperature indicator of claim 8 , wherein the first gel goes from gel to liquid when the temperature decreases below a low temperature threshold, and the low temperature threshold is below 30° C.

14. A gel-based temperature indicator comprising:
a first absorbent substrate having opposing first and second faces;
a first gel coupled to the first face;
wherein the first gel is a gel at a first temperature;
wherein the first gel turns to liquid at a second temperature;
wherein the first absorbent substrate is configured to allow the first gel upon turning to liquid to diffuse through the first face toward the second face;
wherein the first gel is contained within a second absorbent substrate having a third face positioned adjacent to the first face of the first absorbent substrate; and
wherein a first electrode and a second electrode are positioned in physical contact with the first absorbent substrate so as to not contact each other and so that current does not flow between the first electrode and the second electrode prior to the gel turning to a liquid; and
wherein the first gel comprises conductive particles such that diffusion of the first gel toward the second face allows a current to flow from the first electrode and second electrode through the first absorbent substrate.

15. The gel based temperature indicator of claim 14 , wherein the flow of current between the first and second electrodes causes a signal to be sent to a remote monitoring device.

16. The gel based temperature indicator of claim 14 , wherein the ratio of the area of the second face in mm 2 to the thickness of the first absorbent substrate in mm is at least 10 mm.

17. A label for a perishable good, comprising a gel-based temperature indicator of claim 14 .

18. A method of protecting a perishable item, comprising
coupling the perishable item with a gel-based temperature indicator of claim 14 so that the temperature condition indicator is subject to substantially the same temperature conditions as the perishable item.

19. The gel-based temperature indicator of claim 14 , wherein the first gel goes from gel to liquid with increasing temperature.

20. The gel-based temperature indicator of claim 14 , wherein the first gel goes from gel to liquid when the temperature decreases below a low temperature threshold, and the low temperature threshold is below 30° C.

21. A gel-based temperature indicator comprising:
a first absorbent substrate having opposing first and second faces;
a first gel coupled to the first face;
wherein the first gel is a gel at a first temperature;
wherein the first gel turns to liquid at a second temperature;
wherein the first absorbent substrate is configured to allow the first gel upon turning to liquid to diffuse through the first face toward the second face;
wherein the first gel is contained within a plurality of absorbent substrates sized and positioned on the first face of the first absorbent substrate to create a pattern;
wherein diffusion of the first gel toward the second face allows the pattern to be read by a digital code-reading device; and
wherein the ratio of the area of the second face in mm 2 to the thickness of the first absorbent substrate in mm is at least 10 mm.

22. A label for a perishable good, comprising a gel-based temperature indicator of claim 21 .

23. A method of protecting a perishable item, comprising:
coupling the perishable item with a gel-based temperature indicator of claim 21 so that the temperature condition indicator is subject to substantially the same temperature condit

Assignees

• Temptime Corp

Inventors

• Newport John
• Abdo Mohannad
• Smith Dawn E

Classifications

• G01K3/04

  in respect of time · CPC title

• G01K11/18

  of materials which change translucency · CPC title

• G01K11/06 Primary

  using melting, freezing, or softening · CPC title

• A23V2002/00

  Food compositions, function of food ingredients or processes for food or foodstuffs · CPC title

• A23L3/00

  Human Necessities · mapped topic