Thermoplastic films and bags with color changing indicators and methods of making the same

Abstract

The present disclosure relates to a thermoplastic film that includes a layer of thermoplastic material and a color indicator applied to the thermoplastic material. The color indicator can be configured to change color in response to a trigger. For example, the color indicator can change color (e.g., change from a first color to a second color) in response to a color change trigger, such as exposure to malodor particles, absorption of moisture, a length of time, or as a result of oxidation. In one or more embodiments, the thermoplastic film further includes an odor control component configured to mask, neutralize, or otherwise control malodors. The color indicator can change its color appearance as the odor control component performs to control any present malodors, thus signaling the performance of the odor control component.

What is claimed is: 
     
         1 . A film, comprising:
 a layer of thermoplastic material; and   a color indicator applied to the layer of thermoplastic material, wherein the color indicator is configured to change from a first color to a second color in response to exposure to odor particles and to change from the second color to a third color in response to exposure to additional odor particles.   
     
     
         2 . The film of  claim 1 , wherein the first color, the second color, and the third color are non-clear. 
     
     
         3 . The film of  claim 2 , wherein:
 the first color is yellow or brown;   the second color is green; and   the third color is purple.   
     
     
         4 . The film of  claim 1 , wherein:
 the color indicator is configured to change from the first color to the second color in response to exposure to odor particles having a first chemical structure; and   the color indicator is configured to change from the second color to the third color in response to exposure to odor particles having a second chemical structure.   
     
     
         5 . The film of  claim 1 , wherein:
 the color indicator is configured to change from the first color to the second color in response to exposure to odor particles having a first pH value; and   the color indicator is configured to change from the second color to the third color in response to exposure to odor particles having a second pH value.   
     
     
         6 . The film of  claim 1 , further comprising an odor control component applied to the layer of thermoplastic material, wherein a rate of color change of the color indicator is controlled based on one or more of a chemistry of the odor control component or a concentration of the odor control component. 
     
     
         7 . The film of  claim 1 , wherein the color indicator is applied as a pattern onto a surface of the layer of thermoplastic material. 
     
     
         8 . The film of  claim 1 , wherein the layer of thermoplastic material is formed into a thermoplastic bag. 
     
     
         9 . The film of  claim 1 , further comprising a second layer of thermoplastic material adjacent to the layer of thermoplastic material, wherein the color indicator is disposed between the layer of thermoplastic material and the second layer of thermoplastic material. 
     
     
         10 . The film of  claim 1 , wherein the color indicator is embedded within the layer of thermoplastic material. 
     
     
         11 . A thermoplastic bag, comprising:
 a first sidewall;   a second sidewall opposite the first sidewall and joined with the first sidewall along a first side edge, an opposite second side edge, and a bottom edge; and   a color indicator applied to the first sidewall, wherein the color indicator is configured to change from a first color to a second color in response to exposure to odor particles and to change from the second color to a third color in response to exposure to additional odor particles.   
     
     
         12 . The thermoplastic bag of  claim 11 , wherein the first color, the second color, and the third color are non-clear. 
     
     
         13 . The thermoplastic bag of  claim 12 , wherein:
 the first color is yellow or brown;   the second color is green; and   the third color is purple.   
     
     
         14 . The thermoplastic bag of  claim 11 , wherein:
 the color indicator is configured to change from the first color to the second color in response to exposure to odor particles having a first chemical structure; and   the color indicator is configured to change from the second color to the third color in response to exposure to odor particles having a second chemical structure.   
     
     
         15 . The thermoplastic bag of  claim 11 , wherein the color indicator is embedded within the first sidewall. 
     
     
         16 . The thermoplastic bag of  claim 11 , further comprising an odor control component applied to the thermoplastic bag. 
     
     
         17 . The thermoplastic bag of  claim 16 , wherein a rate of color change of the color indicator is controlled based on one or more of a chemistry of the odor control component or a concentration of the odor control component. 
     
     
         18 . The thermoplastic bag of  claim 11 , wherein the first sidewall comprises a first film of thermoplastic material and a second film of thermoplastic material, and the color indicator is disposed between the first film of thermoplastic material and the second film of thermoplastic material. 
     
     
         19 . The thermoplastic bag of  claim 11 , wherein the first sidewall comprises a hem channel and the color indicator is disposed within the hem channel. 
     
     
         20 . The thermoplastic bag of  claim 19 , wherein placement within the hem channel prevents color changes before malodor sources are placed within the thermoplastic bag.