Ultra-violet fluorescing sealant
A sealing element that visually indicates when a sealing element has been opened or corrupted without destruction of the seal. Ultraviolet light passes through a scattering layer and is absorbed by a fluorescing layer, the fluorescing layer reemitting the light in the visual spectrum and thereby allowing a user to inspect the integrity of the sealing element without otherwise destroying the seal.
1. A package having opposing first and second sides defining an interior therebetween that is adapted to be accessible when the package is in an open configuration, and inaccessible when the package is in a closed configuration, the package comprising:
a first film forming the first side and including a light scattering layer; and
a second film forming the second side and heat sealed, ultrasonic sealed, or impulse sealed to the first film at a sealing portion when the package is in the closed configuration, wherein the second film contains an optical brightener that causes the second film to fluoresce when exposed to ultraviolet light passing through the light scattering layer at the sealing portion.
2. The package of claim 1 , wherein the optical brightener is bis-stilbene.
3. The package of claim 1 , wherein the light scattering layer further contains a white pigment.
4. The package of claim 3 , wherein the white pigment is titanium dioxide.
5. The package of claim 1 , wherein the second film is clear.
6. The package of claim 1 , wherein the sealing portion is configured as a solid strip.
7. The package of claim 6 , wherein the solid strip is along at least a portion of a peripheral edges of the package.
8. The package of claim 7 , in which the package is peelable or non-peelable.
9. The package of claim 1 , wherein the light scattering layer comprises a non-woven material.
10. The package of claim 1 , wherein the second film comprises at least one of polyethylene, polyester, nylon, and/or polypropylene.
11. A method of inspecting a seal of a package having opposing first and second sides defining an interior therebetween that is adapted to be accessible when the package is in an open configuration, and inaccessible when the package is in a closed configuration, the method comprising:
heat sealing, ultrasonic sealing, or impulse sealing a first portion of a first film having a light scattering layer to a second portion of a second film to create the seal, the first film forming the first side and the second film forming the second side, the second film containing an optical brightener causing the second film to fluoresce when exposed to ultraviolet light passing through the light scattering layer at the seal when the package is in the closed configuration;
exposing the seal to an ultraviolet (UV) light source; and
detecting a fluorescence.
12. The method of claim 11 , further comprising determining the first film and the second film are in intimate contact at the seal when at least some UV light passes through the light scattering layer and is absorbed by the optical brightener.
13. The method of claim 11 , in which the detecting comprises a computerized vision inspection.
14. The method of claim 11 , in which the detecting maintains an integrity of the seal.
15. A sealing system comprising:
a package having opposing first and second sides defining an interior therebetween that is adapted to be accessible when the package is in an open configuration, and inaccessible when the package is in a closed configuration, the package including:
a first film forming the first side and including a light scattering layer;
a second film forming the second side and heat sealed, ultrasonic sealed, or impulse sealed to the first film at a sealing portion, the second film contains an optical brightener that causes the second film to fluoresce when exposed to ultraviolet light passing through the light scattering layer at the sealing portion when the package is in the closed configuration; and
a detector configured to detect a fluorescence.
16. The sealing system of claim 15 , wherein the optical brightener is bis-stilbene.
17. The sealing system of claim 15 , wherein the light scattering layer further contains a white pigment.
18. The sealing system of claim 15 , wherein the detector comprises a computerized vision inspector or a user.
19. A sealing element comprising:
a light scattering layer containing titanium dioxide; and
a fluorescing layer coupled to the light scattering layer, wherein the fluorescing layer contains an optical brightener that causes the fluorescing layer to fluoresce when exposed to ultraviolet light passing through the light scattering layer at portions of the sealing element where the light scattering layer and fluorescing layer are in contact.