Apparatus and process for packaging a product

Patent metadata

Field	Value
Publication number	US-10926904-B2
Application number	US-201515517549-A
Country	US
Kind code	B2
Filing date	Oct 8, 2015
Priority date	Oct 10, 2014
Publication date	Feb 23, 2021
Grant date	Feb 23, 2021

Abstract

A process for packaging a product arranged on a support comprising unrolling a film, moving the film to a packaging assembly defining at its inside a packaging chamber, progressively moving a number of supports inside the packaging chamber of the packaging assembly, closing the packaging chamber with the film sheets held above the respective support, optionally causing one or both of: a gas withdrawal from the hermetically closed packaging chamber and gas injection of a gas mixture of controlled composition, heat sealing the film to said support, wherein the heat sealing uses one or more heaters having heating surfaces which are heated for discrete and short time periods only. An apparatus for performing the above process is also disclosed.

First claim

The invention claimed is:

1. A packaging apparatus comprising:
a packaging assembly configured to receive at least one support and to tightly fix a film to the support, the packaging assembly including:
a lower tool defining a prefixed number of seats configured to receive said at least one support with a product to be packaged,
an upper tool facing and cooperating with the lower tool, said upper tool and lower tool being relatively movable at least between a first operating condition, where the upper tool and lower tool are spaced apart from one another and allow positioning of at least one film portion of said film above one or more of said at least one support, and a second operating condition, where the upper tool and lower tool are approached to one another and allow heat sealing of said film portion to the at least one support located at said one or more seats,
an inner heater carried by the upper tool and having a heating surface configured to heat at least a part of said film portion,
a peripheral heater carried by the upper tool and positioned radially outside with respect to the inner heater, the peripheral heater having a heating surface configured to heat seal to the at least one support at least a peripheral region of said film portion;

a supply unit configured to control energy supplied to said peripheral heater and to said inner heater; and
a control device acting on the supply unit and configured to command the supply unit and control a supply of energy to the peripheral heater independently from a supply of energy to the inner heater, said control device being further configured to command the supply unit to execute a heating cycle including the following steps:
increasing a temperature of the heating surface of the peripheral heater to a first temperature,
keeping the heating surface of the peripheral heater at least at the first temperature for a first discrete time interval,
reducing the temperature of the heating surface of the peripheral heater below said first temperature,
increasing a temperature of the heating surface of the inner heater to a second temperature,
keeping the heating surface of the inner heater at least at the second temperature for a second discrete time interval, wherein a start of the second discrete time interval is after a start of the first time interval, and
reducing the temperature of the heating surface of the inner heater below said second temperature.

2. The apparatus of claim 1 wherein said control device is configured to:
command the supply unit to consecutively repeat execution of said heating cycle a plurality of times, during each of said consecutive heating cycles at least one of said film portions being heat sealed to at least one respective support,
control the supply unit such that, during each heating cycle, the supply unit supplies energy to the peripheral heater only during a discrete time period followed by a time period when no energy is supplied to the peripheral heater to cause the increase and keeping of the heating surface of the peripheral heater at least at the first temperature for the first discrete time interval, and to cause a subsequent reduction of the temperature of the heating surface of the peripheral heater below said first temperature,
control the supply unit such that, during each heating cycle, the supply unit supplies energy to the inner heater only during a discrete time period followed by a time period when no energy is supplied to the inner heater to cause the increase and keeping of the heating surface of the inner heater at least at the second temperature for the second discrete time interval, and to cause a subsequent reduction of the temperature of the heating surface of the inner heater below said second temperature.

3. The apparatus of claim 1 , wherein the first discrete time interval has a duration between 0.2 and 5 seconds, and wherein the second discrete time interval has a duration between 0.2 and 5 seconds.

4. The apparatus of claim 1 , further wherein the control device is configured to command the supply unit to increase the temperature of at least one of:
the heating surface of the peripheral heater from a respective baseline temperature to the first temperature with a temperature increase rate over time higher than 1° C./msec, or
the heating surface of the inner heater from a respective baseline temperature to the second temperature with a temperature increase rate over time higher than 1° C./msec.

5. The apparatus of claim 1 , wherein:
the heating surface of said peripheral heater has an annular shape and surrounds the heating surface of the inner heater, and
when the upper and lower tools are in said second operating position, the peripheral heater is configured to heat a peripheral band of said film portion while the inner heater is configured to heat at least a part of an inner zone of the same film portion located radially inside the peripheral band.

6. The apparatus of claim 1 , wherein:
both the heating surface of the peripheral heater and the heating surface of the inner heater are flat and
at least when the upper and lower tools are in said second operating position, the heating surface of the inner heater is:
either coplanar to the heating surface of the peripheral heater or
indented with respect to the heating surface of the peripheral heater, such that when the heating surface of the peripheral heater contacts a top surface of the film portion, the heating surface of the inner heater is spaced apart by a prefixed distance from the top surface of the same film portion.

7. The apparatus of claim 1 , wherein the heating surface of the inner heater is located at a radial distance from the heating surface of the peripheral heater and extends in an area surrounded by the heating surface of the peripheral heater, said heating surface of the inner heater comprising one selected from the group consisting of:
a heating surface of annular shape,
a continuous heating surface delimited by a single closed contour line,
a heating surface including a plurality of parallel spaced apart bands connected at ends thereof by connecting portions.

8. The apparatus of claim 1 , wherein:
the peripheral heater comprises a first electrically conductive element extending along the heating surface of the peripheral heater, said first electrically conductive element being an electrically conductive annular element, and
the inner heater comprises a second electrically conductive element extending along the heating surface of the inner heater, said second conductive element being one selected in the group consisting of:
an electrically conductive annular element,
an electrically conductive continuous plate,
an electrically conductive meander element.

9. The apparatus of claim 1 , further comprising a cooling circuit associated to the upper tool and configured to cool said inner heater and said peripheral heater, said cooling circuit being controlled by the control device which is further configured to cause circulation of a cooling fluid in said cooling circuit and to regulate a cooling fluid temperature.

10. The apparatus of claim 8 , wherein the supply unit is an electric supply unit and comprises:
at least one impulse transformer,
at least one electric circuitry connecting the impulse transformer to at least one of the first electrically conductive element or the second electrically conductive element.

11. The apparatus of claim 8 , wherein the supply unit is an electric supply unit and comprises:
at least a first impulse transformer and a first electric circuitry connecting the first impulse transformer to the first electrically conductive element, and
at least

Assignees

• Cryovac Inc
• Cryovac Llc

Inventors

• Rizzi Jvanohe
• Capitani Stepfano

Classifications

• B29C65/7888 Primary

  Means for handling of moving sheets or webs · CPC title

• B65B61/06

  by cutting · CPC title

• B65B51/14

  by reciprocating or oscillating members (B65B51/148 takes precedence) · CPC title

• B65B51/10

  Applying or generating heat or pressure or combinations thereof {(welding of plastics per se B29C65/02; closing plastic tube ends in general B29C57/10)} · CPC title

• B65B31/02 Primary

  Filling, closing, or filling and closing, containers {or wrappers} in chambers maintained under vacuum or superatmospheric pressure or containing a special atmosphere, e.g. of inert gas · CPC title