초록 ▼

This invention relates to the vacuum packaging of products and involves the use of a heat sealable thermoplastic bag in conjunction with a vacuum dome having a sealing edge disposed around its periphery and being connected to a source of vacuum, the thermoplastic bag being entirely closed except for

This invention relates to the vacuum packaging of products and involves the use of a heat sealable thermoplastic bag in conjunction with a vacuum dome having a sealing edge disposed around its periphery and being connected to a source of vacuum, the thermoplastic bag being entirely closed except for an integral flat vent passage disposed at one peripheral location on the bag. One half of the vent passage is made up of material from one portion of the bag, and the other half of the vent passage is made up of a precisely equal amount of material from an opposite portion of the bag, such that the interior surfaces of said vent passage can tend to adhere together. The novel method in accordance with this invention comprises the steps of placing the thermopalstic bag in a supportive device having a desired configuration, placing the vacuum dome over the vent passage so the vent passage protrudes into the interior of the vacuum dome, with the peripheral edge of the dome in contact with bag portions surrounding the vent passage, reducing the pressure inside the dome so as to cause the egress of air from the interior of the bag out through the vent passage, thereafter removing the dome from contact with the bag, with the sidewalls of the vent member sealing together temporarily, and then taking the final step of heat sealing the opening of the vent passage to effectively prevent the return of air to the interior of the bag.

대표청구항 ▼

1. The method of vacuum packaging products involving a substantially filled heat sealable thermoplastic bag utilized in conjunction with a vacuum dome having a sealing edge disposed around its periphery and being connected to a source of vacuum, said method comprising the steps of forming a flat ven

1. The method of vacuum packaging products involving a substantially filled heat sealable thermoplastic bag utilized in conjunction with a vacuum dome having a sealing edge disposed around its periphery and being connected to a source of vacuum, said method comprising the steps of forming a flat vent passage within said bag, disposed at one peripheral location on said bag with one half of said vent passage being made up of material from one portion of said bag, and the other half of said vent passage made up of a precisely equal amount of material from an opposite portion of said bag, such that the interior surfaces of said vent passage can tend to adhere together, said bag being entirely closed except for said vent passage, placing said thermoplastic bag in a supportive device having a desired configuration, placing said vacuum dome over said vent passage so said vent passage protrudes into the interior of said vacuum dome, with the peripheral edge of said dome in contact with bag portions surrounding said vent passage, reducing the pressure inside said dome, so as to cause the egress of air from the interior of said bag out through said vent passage, thereafter removing the source of vacuum from said come, and then removing said dome from contact with said bag, with the sidewalls of said vent member sealing together temporarily without letting the air back in, as a result of such precisely equal amounts of material, and then taking the final step of heat sealing the opening of said vent passage together, to effectively prevent the return of air to the interior of said bag. 2. The method as recited in claim 1 in which said dome is made in two substantially equal, closely interfitting parts, such that said vent passage need not be distinctly separated from the adjacent parts of said thermoplastic bag. 3. The method as recited in claim 1 in which said bag has at least one corner in a location adjacent said vent, which corner is cut at such time as a sample is to be taken of the contents of the bag, such corner, after the sample has been taken, is resealed, and the vacuum procedure repeated, using the vacuum dome. 4. The method of vacuum packaging products involving the use of heat sealable thermoplastic bag utilized in conjunction with a vacuum dome having a sealing edge disposed around its periphery and being connected to a source of vacuum, said thermoplastic bag being open at one end, and having an integral flat vent passage disposed at the opposite end, whose opposing interior surfaces utilizing equal amounts of material, which surfaces, tent to adhere together, said method comprising the steps of placing said thermoplastic bag in an inverted position in a supportive device having a desired configuration, with said vent passage pointed downwardly, and the open end of the bag pointed upwardly, filling the bag from its open end, sealing shut the open end, re-inverting the bag so its vent passage points upwardly, placing said vacuum dome over said vent passage so said vent passage protrudes into the interior of said vacuum dome, with the peripheral edge of said dome in contact with bag portions surrounding said vent passage, reducing the pressure inside said dome, so as to cause the egress of air from the interior of said bag out through said vent passage, thereafter removing the source of vacuum from said dome, and the removing said dome from contact with said bag, with the sidewalls of said vent member sealing together temporarily without letting the air back in, as a result of such use of equal amounts of material, and then taking the final step of heat sealing the opening of said vent passage together, to effectively prevent the return of air to the interior of said bag. 5. The method as recited in claim 4 in which said dome is made in two substantially equal, closely interfitting parts, such that said vent passage need not be distinctly separated from the adjacent parts of said thermoplastic bag. 6. The method as recited in claim 4 in which said bag has at least one corner in a location adjacent said vent, which corner is cut at such time as a sample is to be taken of the contents of the bag, such corner, after the sample has been taken, is resealed, and the vacuum procedure repeated, utilizing the vacuum dome. 7. The method of vacuum packaging products involving a heart sealable thermoplastic bag utilized in conjunction with a vacuum dome having a sealing edge disposed around its periphery and being connected to a source of vacuum, said method comprising the steps of placing a thermoplastic bag having an open end in a supportive device having a desired configuration, with the open end of the bag directed upwardly; filling the bag through its open end; thereafter clamping a fixture containing electric heating wires over the pair of edges constituting the open end of the bag, and using therewith spreader means to spread the open end of the bag; said wires being configured in such a manner as to create when current flows through the wires, a vent passage at the top of the bag, sealing said open end of the bag with said wires to form said vent passage, with the sidewalls of said vent passage, by virtue of the spreader means, being constituted by equal portions of material, so that they ten to adhere together; upon removal of the fixture, placing said vacuum dome over the newly formed vent passage so said vent passage protrudes into the interior of said vacuum dome, with the peripheral edge of said dome in contact with bag portions surrounding said vent passages; reducing the pressure inside said dome, so as to cause the egress of air from the interior of said bag out through said vent passage; thereafter removing the source of vacuum from said dome, and then removing said dome from contact with said bag, with the sidewalls of said vent member sealing together temporarily without letting the air back in, as a result of such precisely equal portions of material; and then taking the final step of heat sealing the opening of said vent passage, to effectively prevent the return of air to the interior of said bag. 8. The method as recited in claim 7 in which said dome is made in two substantially equal, closely interfitting parts, such that said vent passage need not be distinctly separated from the adjacent parts of said thermoplastic bag. 9. The method as recited in claim 7 in which said bag has at least one corner in a location adjacent said vent, which corner is cut at such time as a sample is to be taken of the contents of the bag, such corner, after the sample has been taken, is resealed, and the vacuum procedure repeated, utilizing the vacuum dome.