초록 ▼

A vacuumizing and sealing operation on a package comprises initially reducing the external pressure on the package, before sealing of the package, to a value at which the flexible film covering of the package is capable of ballooning, and ensuring heating of the flexible film of the package, prefera

A vacuumizing and sealing operation on a package comprises initially reducing the external pressure on the package, before sealing of the package, to a value at which the flexible film covering of the package is capable of ballooning, and ensuring heating of the flexible film of the package, preferably while an intermediate pressure is maintained (at which intermediate pressure ballooning could just be sustained without excessive evacuation to reduce the thermal capacity of the circulating air). Finally the pressure inside and outside is reduced still further before re-pressurizing.

대표청구항 ▼

A process for forming a vacuum sealed package comprising a flexible film covering at least one product article, such process comprising the steps of subjecting the unsealed package to reducing pressure to attain an intermediate pressure at which ballooning of said flexible film away from the surface

A process for forming a vacuum sealed package comprising a flexible film covering at least one product article, such process comprising the steps of subjecting the unsealed package to reducing pressure to attain an intermediate pressure at which ballooning of said flexible film away from the surface of the said at least one product article occurs; temporarily completely suspending pressure reduction around the package when the said flexible film is in the ballooned condition; heating the said ballooned flexible film while pressure reduction is so suspended; allowing the flexible film to collapse onto the surface of said at least one product article; sealing the package; and finally increasing the pressure around the sealed package.