Apparatus for sealing a web of film in a packaging

• US 4,856,260 A
• Filed: 10/17/1988
• Issued: 08/15/1989
• Est. Priority Date: 10/17/1988
• Status: Expired due to Term

• Current Assignee: Baxter International Inc.
• Original Assignee: Baxter International Inc.
• Inventors: Ling, Michael T. K., Woo, Lecon
• Primary Examiner(s): Culver, Horace M.
• Application Number:
  US07/258,943
• Time in Patent Office: 302 Days
• Field of Search: 53/552, 53/551, 53/373, 156/583.1, 156/583.2, 219/241, 219/251, 219/516
• US Class Current: 53/374.8
• CPC Class Codes: B29C 65/18 using heated tools
• CPC Class Codes: B29C 65/227 said cross-section being hollow
• CPC Class Codes: B29C 65/38 Impulse heating
• CPC Class Codes: B29C 65/743 using the same tool for both joining and severing, said tool being monobloc or formed by several parts mounted together and forming a monobloc B29C65/2046 takes precedence
• CPC Class Codes: B29C 66/004 Preventing sticking together, e.g. of some areas of the parts to be joined
• CPC Class Codes: B29C 66/1122 Single lap to lap joints, i.e. overlap joints B29C66/45, B29C66/472, B29C66/52272 take precedence
• CPC Class Codes: B29C 66/3494 while keeping the welding zone under pressure
• CPC Class Codes: B29C 66/431 Joining the articles to themselves B29C66/4322 and B29C66/4332 take precedence
• CPC Class Codes: B29C 66/73921 characterised by the materials of both parts being thermoplastics
• CPC Class Codes: B29C 66/80 General aspects of machine operations or constructions and parts thereof
• CPC Class Codes: B29C 66/81261 Thermal properties, e.g. thermal conductivity, thermal expansion coefficient
• CPC Class Codes: B29C 66/81417 being V-shaped
• CPC Class Codes: B29C 66/81427 comprising a single ridge, e.g. for making a weakening line; comprising a single tooth
• CPC Class Codes: B29C 66/81457 comprising a block or layer of deformable material, e.g. sponge, foam, rubber pressing elements supported or backed-up by resilient material B29C66/8161
• CPC Class Codes: B29C 66/81811 of the welding jaws
• CPC Class Codes: B29C 66/8242 Pneumatic or hydraulic drives using fluid pressure directly acting on the parts to be joined B29C66/8266
• CPC Class Codes: B29C 66/8322 Joining or pressing tools reciprocating along one axis
• CPC Class Codes: B29C 66/91212 involving measurement means being part of the welding jaws, e.g. integrated in the welding jaws
• CPC Class Codes: B29C 66/91221 of the parts to be joined
• CPC Class Codes: B29C 66/91411 of the parts to be joined, e.g. the joining process taking the temperature of the parts to be joined into account
• CPC Class Codes: B29C 66/91421 : of the joining tools
• CPC Class Codes: B29C 66/91443 : following a temperature-time profile B29C65/38 takes precedence
• CPC Class Codes: B29C 66/9161 : by controlling or regulating the heat or the thermal flux, i.e. the heat flux
• CPC Class Codes: B29C 66/961 : involving a feedback loop mechanism, e.g. comparison with a desired value
• CPC Class Codes: B65B 2051/105 : Heat seal temperature control
• CPC Class Codes: B65B 51/303 : reciprocating along only one axis

Abstract

An apparatus for sealing a web of film in a packaging machine. The apparatus includes a sealing bar for heating a web of film to a temperature sufficient to melt at least a portion of the web of film. The sealing bar includes a surface that directly contacts the web of film and does not include a release layer. The surface includes thereon a measuring member for measuring the temperature of the molten area of the film. The apparatus further includes a cooling member for cooling the melted portion of the film to its crystallization point during a cycle time of the packaging machine.

Claims

1. An apparatus for sealing a web of film in a packaging machine comprising:

a sealing bar for heating a web of film to a temperature sufficient to melt at least a portion of the web of film, the sealing bar including a surface that directly contacts the web of film and does not include a release layer;

means for heating the sealing bar;

means for cooling the sealing bar;

the means for heating and the means for cooling functioning to heat and cool the sealing bar during a cycle of the packaging machine;

and means for measuring the temperature of a portion of the web of film located on the surface of the sealing bar.

2. The apparatus of claim 1 wherein the sealing bar includes a channel and the means for cooling includes fluid that is fed into the channel.

3. The apparatus of claim 1 wherein the means for measuring is a thermocouple.

4. The apparatus of claim 1 including means for regulating the temperature of the sealing bar, the means for measuring cooperating with the means for regulating.

5. The apparatus of claim 1 wherein the sealing bar includes means for severing the web of film.

6. An apparatus for sealing a web of film in a form, fill, seal packaging machine comprising:

a sealing bar for heating a web of film to a temperature sufficient to melt at least a portion of the web of film, the sealing bar including a surface that directly contacts the portion of the web of film, the sealing bar being coupled to means for heating the sealing bar, the sealing bar further including a channel for receiving a fluid for cooling the sealing bar to a temperature sufficient to prevent the portion of the film from sticking to the sealing bar after the sealing bar melts the portion of the web of film;

and means for measuring the temperature of the portion of the film and regulating the temperature of the sealing bar located on the surface of the sealing bar.

7. The apparatus of claim 6 wherein the means for heating and fluid for cooling cooperate to heat the sealing bar to a temperature sufficient to melt the portion of the film and cool the sealing bar to a temperature sufficient to cause the melted portion of the film to crystallize during a cycle of the form, fill, seal packaging machine.

8. The apparatus of claim 6 wherein the means for measuring is a thermocouple.

9. The apparatus of claim 8 wherein the thermocouple has a cross-sectional thickness of approximately 0.005 to about 0.0001 of an inch.

10. The apparatus of claim 6 wherein the sealing bar is substantially hollow.

11. The apparatus of claim 10 wherein the sealing bar has walls having a cross-sectional thickness of approximately 0.02 to about 0.003 of an inch.

12. The apparatus of claim 6 wherein the sealing bar includes means for severing the web of film.

13. The apparatus of claim 6 wherein the apparatus seals a web of film in less than approximately three seconds.

14. The apparatus of claim 12 wherein the means for severing includes a raised portion on the sealing bar.

15. The apparatus of claim 8 wherein the thermocouple is secured to the sealing bar by a ceramic adhesive.

16. The apparatus of claim 8 wherein the thermocouple is an iron constantan or copper constantan thermocouple.

24. The apparatus of claim 16 wherein the thermocouple is an iron constantan or copper constantan thermocouple.

17. An apparatus for sealing and severing a web of film in a form, fill, seal packaging machine comprising:

an impulse sealing bar for heating a web of film to a temperature sufficient to melt at least a portion of the web of film, the sealing bar including a surface that directly contacts the portion of the web of film, the sealing bar is coupled to an electrical source for heating the sealing bar, the sealing bar further including a channel for receiving a fluid for cooling the sealing bar to a temperature sufficient to prevent the portion of the film from sticking to the sealing bar after the sealing bar melts the portion of the web of film and means for severing the web of film; and

a thermocouple for measuring the temperature of the portion of the film and through feedback control means regulating the temperature of the sealing bar secured to a surface of the sealing bar.

18. The apparatus of claim 17 wherein the thermocouple has a thickness of approximately 0.005 to about 0.0001 of an inch.

19. The apparatus of claim 17 wherein the sealing bar is substantially hollow.

20. The apparatus of claim 19 wherein the sealing bar has walls having a cross-sectional thickness of approximately 0.02 to about 0.003 of an inch.

21. The apparatus of claim 17 wherein the apparatus seals a web of film in less than approximately three seconds.

22. The apparatus of claim 17 wherein the means for severing includes a raised portion on the sealing bar.

23. The apparatus of claim 17 wherein the thermocouple is secured to the sealing bar by a ceramic adhesive.