PROTECTIVE GLOVE WITH INNER GLOVE LIFE INDICATOR

Abstract

An inner indicator glove formed of multiple layers including a protective layer having a top surface and a bottom surface, the bottom surface facing a hand of a user when wearing the inner indicator glove, and an indicator layer supported by the top surface of the protective layer and positioned to contact protective glove when the inner indicator glove is inserted into the protective glove, wherein the indicator layer is formed of a material that changes color when exposed to a solution penetrating the protective glove.

Description

RELATED APPLICATIONS

This application claims the benefit of priority under 35 U.S.C. Section 119 to European Patent Application Serial No. 15198547.0, filed on Dec. 8, 2015, which application is incorporated herein by reference in its entirety.

BACKGROUND

The protective gloves for process industries (petrochemical, chemical, food, beverage, and pharmaceutical) are constructed to assure people safety under harsh chemical, mechanical and electrical conditions. The glove suppliers provide a big product catalog, where different types of gloves are recommended for different type of chemicals to be handled. Depending on the application and chemical products to which they are exposed, the gloves may have a different type of material and a different thickness of the layers from which they are made of.

In many countries, such as European countries, the gloves have to pass mechanical (EN 388), thermal (EN511), and chemical standards, such as a European standards (EN 374-2, EN 374-3) before they are sent to the market. In addition to these standards, the gloves should comply with the standard EN 420, which specifies general criteria for comfort, size, dexterity, labeling, and heavy metal content and pH content. Each standard defines exact test and acceptance conditions for the gloves exposed to critical mechanical, thermal, chemical agents. There may be various levels of performance specified by the different standards. For instance a first level may specify the test and acceptance conditions for the least aggressive value of the externally applied agent and the highest level may be associated with the most aggressive value of the externally applied agent.

For example, the standard EN-374-2 characterizes the permeability features of the gloves and it specifies a method for testing the protective gloves resistance to permeation of chemical products (penetration). Standard EN374-3 includes the standard. EN 374-2 requirements, and in addition, requires that the protective glove pass the performance level 2 of chemical resistance for at least three chemical products (like, methanol, sulfuric acid 96%, 40% sodium hydroxide, tetrahydrofuran, acetone, carbon disulfide, ethyl acetate, etc.) This performance level 2 for chemical resistance means that the permeation time (test made according to the standard) should be higher than or equal to 30 minutes, when the glove is exposed continuously to that chemical.

A catalog of gloves for chemical protection. during handling of acids and alkalis, for example, would include as suitable the latex gloves which can be used in harsh applications for food and beverage industry where cleaning with high concentrated cleaning agents are the most used. Such latex gloves meet the above standard and they are also accompanied by a wide list of permeation data. Related to the protective gloves described above, their use in the field is made most of the time without keeping clear evidence of the time of use during their lifetime, and so in many cases they can be used for a much shorter time with respect to their designed lifetime. On the other hand, the suppliers themselves may be conservative in specifying the level of performance, which means that even if the real level of performance may be 4, the supplier would specify 3, which is lower than 4. The reason for this conservative approach may the fact that according to the standard requirements, the supplier is testing the resistance of the gloves in 12 families of chemical agents, each represented by a certain concentration at a certain temperature, while the real breakthrough time of the glove in the field can be indicated with accuracy only for breakthrough tests performed in that real agent, at that temperature.

SUMMARY

An inner indicator glove formed of multiple layers including a protective layer having a top surface and a bottom surface, the bottom surface facing a hand of a user when wearing the inner indicator glove, and an indicator layer supported by the top surface of the protective layer and positioned to contact protective glove when the inner indicator glove is inserted into the protective glove, wherein the indicator layer is formed of a material that changes color when exposed to a solution penetrating the protective glove.

A method of forming an inner indicator glove, the method including dip coating a hand shaped former into a bath to form a protective-layer having a thickness that provides a selected protection time less than a protection time of a protective glove and forming an indicator layer on the protective layer, the indicator forming an outer layer of the inner indicator glove.

A method includes inserting an inner indicator glove into a protective glove, wherein the inner indicator glove has an indicator layer positioned to change color responsive to an end of service life of the protective glove, using the protective glove with the inserted inner indicator glove, viewing the change of color of the indicator layer, and discontinuing use of the protective glove.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram illustrating a protective outer glove and inner indicator glove for use inside the protective outer glove according to an example embodiment.

FIG. 2 is a cross section representation of a portion of an inner indicator glove according to an example embodiment.

FIG. 3 is a block diagram of a protective outer glove having a transparent patch for viewing an inner indicator glove color according to an example embodiment.

DETAILED DESCRIPTION

In the following description, reference is made to the accompanying drawings that form a part hereof, and in which is shown by way of illustration specific embodiments which may be practiced. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it is to be understood that other embodiments may be utilized and that structural, logical and electrical changes may be made without departing from the scope of the present invention. The following description of example embodiments is, therefore, not to be taken in a limited sense, and the scope of the present invention is defined by the appended claims.

Suppliers of protective gloves may be conservative in specifying the level of performance of the gloves that they sell. Even if the real level of performance may be 4, the supplier would specify 3, representing a shorter period of time than the actual performance of the glove prior to failure. A protective glove without any fabrication defects can still create injury to the user at the unknown end of its service life due to the permeation of the dangerous liquid/gases through the micro/nano pores of the glove, which can, thus, reach the skin of the user.

FIG. 1 is a representation of a protective glove 100 to be used in conjunction with an inner indicator glove 110 that fits inside of protective glove 100. The protective glove may be formed of latex or other protective material, like nitrile, chloroprene (e.g. Neoprene, butyl, polyvinyl chloride (PVC), PU, CSM, Fluoro elastomer (e.g. Viton). Off the shelf protective gloves that are unmodified may be used in some embodiment.

In order to obtain a maximum protection of the user's hands even in the situation of protective glove 100 reaching its (100%) end of service life during the working time, the inner indicator glove 110 is introduced into the outer protective glove (G2G-glove to glove). The inner indicator glove 110 is designed to indicate the permeation of harsh chemicals through the outer glove and to assure hand protection for a minimum amount of time, such as at least 10 minutes of work (performance level 1).

FIG. 2 is a cross section view of a portion 200 of the inner protective glove 110. The inner protective glove 110 in one embodiment is thin and flexible, comprising two layers, a top layer 210 and a bottom layer 220, strongly adhering one to the other, being stacked together during a fabrication process. The bottom layer 220 is formed of protective material having a thickness suitable for ensuring protection of a hand for a specified amount of time following failure of the protective glove 100, such as 10 minutes. Other times, such as 5 minutes, 15 minutes, or any other time may be selected. Note that the protective bottom layer 220 may be quite a bit thinner than the thickness of the protective glove 100.

Top layer 210 of the inner indicator glove is made of a material which changes its color due to the pH of the liquid permeating through the outer glove. Such a color changing layer can be made of universal pH indicator, and may thus respond to any type of chemical, either acid or base and its mixture.

A good example for such universal pH indicator is the bromophenol blue. According to the color change of the bromophenol blue exposed to the liquid, a yellow color is obtained for pH smaller than 3, multiple colors for pH between 3 and 4.6 (real pH indicator in this pH range) and blue color for pH greater than 4.6. The advantage of bromophenol blue is that it has the largest change in color hue, when the concentration of the observed sample increases or decreases. If for example one needs a indicator to be used for the top layer 220 of the inner indicator glove 110 immersed only in the acid baths, then one can use a color changing layer (top layer 220) based on methyl orange (C₁₄H₁₄N₃NaO₃S) which indicates the presence of acids (pH between 0 and 6), discriminating very well the strength of the acid. For other applications, where only bases are handled, one can have a color changing layer based on phenolphthalein, which is colorless below 8.2 and pink above that value up to a pH of about 13. For even stronger basic solutions, the phenolphthalein becomes colorless. The bottom layer 220 of the inner glove, which is in contact with the skin, it is made of a chemically resistant material like latex, butyl, CSM/neoprene, etc.

Such an inner indicator glove 110 with continuous color change top layer 220 above the entire hand has the advantage of identification of the starting leakage area without any harmful effect of on the skin of the user, while the outer protective glove itself has been safely used during its maximum service life, without any concerns related to its use in the last period of use.

Determining that the inner indicator glove 110 has changed color may be done in several different ways. In one embodiment, the user may simply remove the outer protective glove 100 and visually inspect the inner indicator glove 110 for color changes. In a further embodiment, a transparent or at least partially transparent or translucent patch may be provided on an alternative outer protective glove 300 as indicated at 310 in FIG. 3. The patch 310 is sufficiently transparent to allow a user to see the color of the inner indicator glove without removing the outer glove.

In a still further embodiment, the activation mechanism causing the inner indicator glove to produce a visible indication results in a flow of an indicator solution comprising vapors and liquids the external glove is exposed to, to an external surface of the protective glove. In the body of the protective gloves there are always nanopores which are filled with air, and these nanopores are at the origin of the liquid permeation process. This means that the liquid molecules can diffuse inside the protective glove via those pores and after a certain time they can penetrate the entire thickness of the protective glove, reaching the inner indicator glove. This time is called the breakdown time of the protective glove in a certain solution. The breakdown time of a protective glove will depend on its thickness, the magnitude of the permeating liquid molecule and the size of the nanopores. Exposure of the protective glove to the solution results in nanopores filling with liquid molecules, and thus the liquid gradually penetrates the protective glove. After the nanopores are filled with the solution along the entire thickness of the protective glove, the solution from the nanopores will start to dissolve the color changing indicator layer 210 containing bromophenol blue in one embodiment in the inner indicator glove 110, acting as a pH indicator or dye. This dye will start diffusing back along the nanopores via concentration gradient and capillary forces, through the protective glove 100 until visible at the outer surface of the protective glove 100.

When the dye arrives at the outer surface of protective glove 100 through a multitude of nanopores, a change in the background color of protective glove will be easily visible to a user. A background color of white for the protective glove 110 may provide for maximum contrast of the indication color. The color will be changed according to the overall pH of the liquid in the pores after glove exposure to both acids and bases, and solvents, i.e., the solution.

Three fabrication processes for the inner indicator glove are described, where a solid state pH indicator layer is deposited continuously on the entire chemically resistant layer of the inner indicator glove.

The first fabrication process is similar to a traditional dip coating process used for the protective glove. A second process is a hybrid approach where the chemically resistant layer is made by dip coating while the color changing layer is made by direct printing. The third process is an all-printing process, where both color changing layer and the chemically resistive layer are made by a method of direct printing. This G2G concept can be applied to all types of chemically protective gloves. Moreover, a universal inner indicator glove can be used for all type of gloves dedicated to acid/base/solvent combinations.

Generic standard technology for the dip coating fabrication process of the protective gloves consists of full immersion of a hand shaped former (HSF) in multiple baths where the liquid state of the future layers are present. In one embodiment, the hand shaped former is in the shape of a typical glove, having portions corresponding to an arm, palm area, four fingers and a thumb. Different HSFs may be used for each hand and multiple HSFs may be used of varying sizes corresponding to different sizes of hands and protective gloves. After each dip coating, a thermal treatment is made for the solid state consolidation of the film. At the end of the process, the gloves are peeled off from the HSF, and thus the last deposited layer on the glove will be the layer in contact with the skin. Note that in some embodiments, the glove is not reversed when peeling it off from the HSF, or may be turned inside out after peeling off. This allows the inner indicator glove to be formed by first forming the latex protective layer followed by the indicator layer.

Note that in some embodiments, the same size HSF may be used to form both the protective glove 100 and the inner indicator glove 110 such that a tight fit of the inner indicator glove 110 into the protective glove 100 is obtained. A tight fit ensures better tactile feel and dexterity for the user in utilizing the combined gloves. A tight fit may also promote better migration of color from the inner indicator glove to the outside of the protective glove for viewing by a user. In further embodiments, a slightly smaller size HSF may be used for the inner indicator glove formation.

Three alternative methods for making inner indicator glove 110 are described.

I. An example of a “standard” all-dip-coating fabrication process of a smart latex inner indicator glove 110 containing a color change layer 210 as follows:

1. Dip coating of the hand-shape former (HSF) into the “latex” bath for getting a latex film of the desired thickness.

2. Thermal treatment of the dip-coated HSF for obtaining a solid state of the thin latex film.

3. Dip-coating of the HSF from step 2 into a bath containing bromophenol blue slurry at the right viscosity.

4. Thermal treatment of the HSF from the step 3.

II. An example of the original hybrid fabrication process of smart inner indicator glove 110 based on dip-coating and direct printing may be performed as follows:

1. Dip coating of the hand-shape former (HSF) into the “latex” bath for getting a latex film of desired thickness. (about 20% of the thickness of the outer glove).

2. Thermal treatment of the dip-coated HSF from step 1 for obtaining a solid state of the first latex film.

3. Direct printing of the color changing layer. Direct printing, such as by inkjet printer allows the color changing layer to be masklessly deposited.

4. Thermal treatment of the HSF from step 3 which was direct printed for getting a solid color changing layer.

III. Finally, an example of original all-printed inner indicator glove 110 may also utilize direct printing to replace all the dip-coating processes from above.

An example of process for making the viscous bromophenol blue slurry that can be used for dip coating or inkjet printing can be as shown below:

1. Dissolve the bromophenol blue powder in a mixture of water and small amount of solvent like ethylic alcohol, dimethylformamide, or dimethylsulfoxide.

2. Add surfactants like Tween 20, Tween 40, Tween 60, Tween 80.

3. Add viscosity intensifying agent resin (like shellac, guaiac gum methyl cellulose and ethyl cellulose).

4. Obtain a homogeneous and viscous solution of the color changing agent based on bromophenol blue.

An automated factory for fabrication of all printed inner indicator gloves utilizing moving the HSF on a line from one location to another, and at each location, the HSF will receive the required process as described above. For thermal treatment the HSF can travel through a furnace with the required temperature profile, as required by the previous printed layer.

EXAMPLES

1. An inner indicator glove fanned of multiple layers comprising:

• • a protective layer having a top surface and a bottom surface, the bottom surface facing a hand of a user when wearing the inner indicator glove; and
  • an indicator layer supported by the top surface of the protective layer and positioned to contact protective glove when the inner indicator glove is inserted into the protective glove, wherein the indicator layer is formed of a material that changes color when exposed to a solution penetrating the protective glove.

2. The inner indicator glove of example 1 wherein the change in color becomes visible from an external surface of the protective glove when the inner indicator glove is inserted into the protective glove.

3. The inner indicator glove of any of examples 1-2 wherein the change in color becomes visible when a least a portion of the inner indicator glove is removed from the protective glove.

4. The inner indicator glove of any of examples 1-3 wherein the indicator layer comprises a pH indicator generating a color corresponding to a pH of the solution.

5. The inner indicator glove of example 4 wherein the pH indicator comprises bromophenol blue.

6. The inner indicator glove of any of examples 1-5 wherein the protective layer comprises natural or synthetic lattices.

7. The inner indicator glove of any of examples 1-6 wherein the indicator layer is a continuous layer.

8. The inner indicator glove of any of examples 1-7 wherein the protective layer comprises at least one of latex, nitrile, or chloroprene and the indicator layer comprises bromophenol blue.

9. The inner indicator glove of any of examples 1-8 wherein the protective layer has a thickness configured to provide approximately 10 minutes of protection when the life of the protective glove has failed and the indicator layer changes color responsive to the failure of the protective glove.

10. The inner indicator glove of any of examples 1-9 and further comprising a protective glove into which the indicator glove has been inserted.

11. The inner indicator glove of any of examples 1-10 wherein the protective glove includes a transparent patch through which the color of the indicator layer is observable.

12. A method of forming an inner indicator glove, the method comprising:

• • dip coating a hand shaped former into a bath to form a protective-layer having a thickness that provides a selected protection time less than a protection time of a protective glove; and
  • forming an indicator layer on the protective layer, the indicator forming an outer layer of the inner indicator glove.

13. The method of example 12 wherein forming an indicator layer on the protective layer comprises dip coating the hand shaped former having the first protective layer into a bath containing a bromophenol blue slurry to form the indicator layer comprising bromophenol blue.

14. The method of example 13 wherein the bromophenol blue slurry comprises bromophenol blue powder, alcohol, a surfactant, and a viscosity intensifying agent resin.

15. The method of any one of examples 12-14 wherein forming an indicator layer on the protective layer comprises printing the indicator layer.

16. A method comprising:

• • inserting an inner indicator glove into a protective glove, wherein the inner indicator glove has an indicator layer positioned to change color responsive to an end of service life of the protective glove;
  • using the protective glove with the inserted inner indicator glove;
  • viewing the change of color of the indicator layer; and
  • discontinuing use of the protective glove.

17. The method of example 16 wherein viewing the change of color of the indicator layer comprises removing a portion of the protective glove to expose the inner indicator glove such that the change of color is visible to a user.

18. The method of example 16 wherein viewing the change of color of the indicator layer comprises viewing a solution that diffused back through nanopores in the protective glove to an outer surface of the protective glove, the solution being colored by the indicator layer responsive to the solution penetrating the protective glove signifying the end of the service life of the protective glove.

19. The method of example 16 wherein viewing the change of color of the indicator layer comprises viewing the indicator layer through a transparent patch of the protective glove.

20. The method of example 16 wherein the indicator layer comprises bromophenol blue.

Although a few embodiments have been described in detail above, other modifications are possible. For example, the logic flows depicted in the figures do not require the particular order shown, or sequential order, to achieve desirable results. Other steps may be provided, or steps may be eliminated, from the described flows, and other components may be added to, or removed from, the described systems. Other embodiments may be within the scope of the following claims.

Claims

1. An inner indicator glove formed of multiple layers comprising:

a protective layer having a top surface and a bottom surface, the bottom surface facing a hand of a user when wearing the inner indicator glove; and

an indicator layer supported by the top surface of the protective layer and positioned to contact protective glove when the inner indicator glove is inserted into the protective glove, wherein the indicator layer is formed of a material that changes color when exposed to a solution penetrating the protective glove.

2. The inner indicator glove of claim 1 wherein the change in color becomes visible from an external surface of the protective glove when the inner indicator glove is inserted into the protective glove.

3. The inner indicator glove of claim 1 wherein the change in color becomes visible when a least a portion of the inner indicator glove is removed from the protective glove.

4. The inner indicator glove of claim 1 wherein the indicator layer comprises a pH indicator generating a color corresponding to a pH of the solution.

5. The inner indicator glove of claim 4 wherein the pH indicator comprises bromophenol blue.

6. The inner indicator glove of claim 1 wherein the protective layer comprises natural or synthetic lattices.

7. The inner indicator glove of claim 1 wherein the indicator layer is a continuous layer.

8. The inner indicator glove of claim 1 wherein the protective layer comprises at least one of latex, nitrile, or chloroprene and the indicator layer comprises bromophenol blue.

9. The inner indicator glove of claim 1 wherein the protective layer has a thickness configured to provide approximately 10 minutes of protection when the life of the protective glove has failed and the indicator layer changes color responsive to the failure of the protective glove.

10. The inner indicator glove of claim 1 and further comprising a protective glove into which the indicator glove has been inserted.

11. The inner indicator glove of claim 1 wherein the protective glove includes a transparent patch through which the color of the indicator layer is observable.

12. A method of forming an inner indicator glove, the method comprising:

dip coating a hand shaped former into a bath to form a protective-layer having a thickness that provides a selected protection time less than a protection time of a protective glove; and

forming an indicator layer on the protective layer, the indicator forming an outer layer of the inner indicator glove.

13. The method of claim 12 wherein forming an indicator layer on the protective layer comprises dip coating the hand shaped former having the first protective layer into a bath containing a bromophenol blue slurry to form the indicator layer comprising bromophenol blue.

14. The method of claim 13 wherein the bromophenol blue slurry comprises bromophenol blue powder, alcohol, a surfactant, and a viscosity intensifying agent resin.

15. The method of claim 12 wherein forming an indicator layer on the protective layer comprises printing the indicator layer.

16. A method comprising:

inserting an inner indicator glove into a protective glove, wherein the inner indicator glove has an indicator layer positioned to change color responsive to an end of service life of the protective glove;

using the protective glove with the inserted inner indicator glove;

viewing the change of color of the indicator layer; and

discontinuing use of the protective glove.

17. The method of claim 16 wherein viewing the change of color of the indicator layer comprises removing a portion of the protective glove to expose the inner indicator glove such that the change of color is visible to a user.

18. The method of claim 16 wherein viewing the change of color of the indicator layer comprises viewing a solution that diffused back through nanopores in the protective glove to an outer surface of the protective glove, the solution being colored by the indicator layer responsive to the solution penetrating the protective glove signifying the end of the service life of the protective glove.

19. The method of claim 16 wherein viewing the change of color of the indicator layer comprises viewing the indicator layer through a transparent patch of the protective glove.

20. The method of claim 16 wherein the indicator layer comprises bromophenol blue.