Desiccant pack with humidity sensor and method of manufacturing the same

• US 6,324,896 B1
• Filed: 01/04/2000
• Issued: 12/04/2001
• Est. Priority Date: 09/28/1999
• Status: Expired due to Fees

• Current Assignee: Fuji-Kagaku Kenkyujo Company Limited, Asahi Shiko Co Ltd (Rengo Company Limited)
• Original Assignee: Fuji-Kagaku Kenkyujo Company Limited
• Inventors: Watanabe, Kazuo, Aoyagi, Yasutoshi
• Primary Examiner(s): Kwok, Helen
• Assistant Examiner(s): WIGGINS, JOHN DAVID
• Application Number:
  US09/477,343
• Time in Patent Office: 700 Days
• Field of Search: 73/290.1, 73/290.4, 73/290.2, 73/310.1, 73/310.5, 422/88, 340/602
• US Class Current: 73/29.01
• CPC Class Codes: G01N 31/222 for investigating moisture content

Abstract

A desiccant pack 1 with a humidity sensor comprises a pack body 10 formed by sealing the three opened sides of a package film having gas permeability and heat sealability, and a desiccant is filled inside the pack body 10. Humidity sensor substances are applied in a band or strip-shape to the surface of the pack body 10, by which humidity sensors 21, 22 and 23 are applied directly to the pack.

Claims

1. A desiccant pack with a humidity sensor comprising:

a pack body having a set of sides and corresponding edges arranged about a pack body inner surface and outer surface, each side formed by a row of two or more side portions, with one side having a portion being folded in upon itself along a lateral edge and with the other remaining sides being heat sealed along their lateral edges;

a desiccant filled inside the inner surface on said pack body; and

a humidity sensor substance being applied directly onto the outer surface of said pack body, which substance manifests an observable moisture sensitive reaction and changes its color according to a varying ambient level of relative humidity.

2. A desiccant pack with a humidity sensor defined in claim 1, wherein said humidity sensor substance is applied in the shape of a band parallel to said side portion of the pack body being folded.

3. A desiccant pack with a humidity sensor defined in claim 2, wherein said humidity sensor substance includes a plurality of substances which react to different humidity levels respectively and change their color accordingly, said plurality of substances being applied in plural bands.

4. A manufacturing device of a desiccant pack with a humidity sensor comprising:

a package film manufacturing device including a supply roll for sending out a band-shaped package film base, and a humidity sensor application device for applying a liquid-state humidity sensor substance to the surface of a package film; and

a pack manufacturing device connected to said package film manufacturing device, said pack manufacturing device including a center seal device for folding the supplied package film at the center portion in the width direction of said film and heat-sealing both side ends thereof, a hopper for measuring a desiccant and filling the same in said package film being center-sealed, an end seal device for heat-sealing the front and back side ends of said package film, and a cutter for separating said heat-sealed package film to individual packs.

5. A manufacturing device of a desiccant pack with a humidity sensor defined in claim 4, wherein said humidity sensor application device comprises a plurality of humidity sensor units, each unit comprising a container storing said liquid-state humidity sensor substance, an application roller to which said humidity sensor substance is adhered, and a backup roller opposing to said application roller, wherein said humidity sensor substance is applied onto the surface of said package film being conveyed between said application roller and said backup roller.

6. A manufacturing device of a desiccant pack with a humidity sensor defined in claim 5, wherein said manufacturing device includes an air cylinder for driving said application roller to contact to or separate from said backup roller.