Claims
- 1. A method for sealing a bag of foraminous material that encloses a predetermined quantity of particulated substance capable of releasing an agent in a body of fluid to impart to the body of fluid a desired property, in a sealed condition said bag of foraminous material constituting a confining barrier preventing said particulated substance in a dry state to freely sift-out of said bag, said bag including a pair of walls of non-woven fibrous material, one of said walls comprising:
- i) a first fiber layer including bond-forming fibers fusible at a certain temperature; and
- ii) a second fiber layer including fibers of a material in a substantially solid phase at said certain temperature, another one of said walls comprising a layer of fibers of a material in a substantially solid phase at said certain temperature, said method including the steps of:
- a) pressing superposed portions of said walls against one another whereby said first fiber layer is located between said second fiber layer and said another wall;
- b) driving into said superposed portions a plurality of spaced apart heated projections at such depth as to establish direct contact between said heated projections and said first layer in order to elevate a temperature of said bond-forming fibers at least in a vicinity of said heated projections to said certain temperature for causing said superposed portions to bond to one another.
- 2. A method as defined in claim 1, wherein said another wall further includes a layer of bond-forming fibers fusible at said certain temperature, said method including the step of pressing the layers of bond-forming fibers of said superposed portions against one another and driving into said superposed portions said heated projections.
- 3. A method as defined in claim 1, comprising the step of compressing said superposed portions between a pair of opposed sealing members, one of said members including said plurality of projections.
- 4. A method as defined in claim 3, comprising the step of passing said superposed portions between a pair of rotating sealing rolls, one of said sealing rolls including said plurality of projections, whereby rotation of said sealing rolls causes a progressive formation of said joint area.
Parent Case Info
This is a division of application Ser. No. 08/126,938, filed Sep. 24, 1993, now U.S. Pat. No. 5,456,055, which is hereby incorporated by reference.
US Referenced Citations (5)
Divisions (1)
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Number |
Date |
Country |
Parent |
126938 |
Sep 1993 |
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