Protective packaging longitudinal heat sealer

Patent metadata

Field	Value
Publication number	US-11524475-B2
Application number	US-202117222617-A
Country	US
Kind code	B2
Filing date	Apr 5, 2021
Priority date	Mar 30, 2016
Publication date	Dec 13, 2022
Grant date	Dec 13, 2022

Abstract

A protective packaging formation device is provided herein. The device includes an inflation assembly having a fluid conduit that directs fluid between overlapping plies of a polymeric web. The device also includes a driving mechanism that drives the film in a downstream direction. The device also includes a sealing mechanism that includes a thin film heater that heats the plies to create a longitudinal seal that seals the plies of film together. The driving mechanism drives the web such that the web slides across the heating assembly in a downstream direction to trap fluid between the plies.

First claim

What is claimed is:

1. A protective packaging formation device, comprising:
an inflation assembly having a fluid conduit that directs fluid between first and second overlapping flexible web plies of a flexible structure;
a driving mechanism that drives the structure in a downstream direction; and
a sealing mechanism that includes a heating assembly having a thin-film heater that heats the plies to create a longitudinal seal that seals the first and second plies of the structure together, trapping the fluid therebetween, wherein the thin-film heater includes:
a substrate, and
a heat trace on the substrate that has a waveform shape having an amplitude that determines the width of the longitudinal seal, wherein the heat trace is configured to produce sufficient heat, in response to electrical current applied to the heat trace, to create the longitudinal seal.

2. The protective packaging formation device of claim 1 , wherein the waveform shape is sinusoidal.

3. The protective packaging formation device of claim 1 , wherein the waveform shape is a square wave.

4. The protective packaging formation device of claim 1 , wherein each of the heat trace and the substrate is between about 1 and about 3 mils thick.

5. The protective packaging formation device of claim 1 , wherein the thin-film heater is between about 2 and about 9 mils thick.

6. The protective packaging formation device of claim 1 , wherein the thin-film heater includes two contacts that are electrically connected to opposite sides of the heat trace.

7. The protective packaging formation device of claim 6 , wherein the contacts are transversely wider than the amplitude of the waveform shape.

8. The protective packaging formation device of claim 6 , wherein the contacts are at least three times as wide as the amplitude of the waveform shape.

9. The protective packaging formation device of claim 1 , wherein a majority of the waveform has a substantially consistent amplitude.

10. The protective packaging formation device of claim 1 , wherein the heat trace has opposing edges that define the waveform, each of the opposing edges having opposing peaks and valleys.

11. The protective packaging formation device of claim 1 , wherein the thin-film heater is mounted in the heating assembly to remain stationary as the structure moves across the heating assembly.

12. The protective packaging formation device of claim 1 , wherein the heating assembly further comprises a low-friction layer positioned between the structure and the thin-film heater.

13. The protective packaging formation device of claim 12 , wherein the structure directly engages against the heating assembly and moves across the low-friction layer of the heating assembly.

14. The protective packaging formation device of claim 1 , wherein:
the heating assembly comprises a roller; and
the thin-film heater is mounted on the roller to rotate as the structure is moved past the roller.

15. The protective packaging formation device of claim 1 , wherein:
the substrate comprises a first layer and a second layer; and
the heat trace is sandwiched between the first and second layers.

16. The protective packaging formation device of claim 15 , wherein the first layer, second layer, and heat trace are bonded to one another.

17. The protective packaging formation device of claim 15 , wherein the first and second layers are made of polyimide.

18. The protective packaging formation device of claim 15 , wherein the substrate encapsulates the heat trace.

19. The protective packaging formation device of claim 1 , wherein the waveform shape of the heat trace is configured to reduce longitudinal thermal expansion of the thin-film heater.

20. The protective packaging formation device of claim 19 , wherein the heating assembly includes a spring associated with the thin-film heater to retain tension in the thin-film heater during thermal expansion.

21. The protective packaging formation device of claim 19 , wherein:
the heating assembly includes a support structure that supports the thin-film heater; and
the thin-film heater is mounted directly to the support structure without a spring.

22. The protective packaging formation device of claim 19 , wherein the waveform shape is configured to expand or contract to accommodate thermal expansion of the thin-film heater.

23. A protective packaging formation device, comprising:
an inflation assembly having a fluid conduit that directs fluid between first and second overlapping flexible web plies of a flexible structure;
a driving mechanism that drives the structure in a downstream direction; and
a sealing mechanism that includes a heating assembly having:
a roller that rotates as the structure moves past the roller; and
a thin-film heater mounted to the roller that heats the plies to create a longitudinal seal that seals the first and second plies together trapping the fluid therebetween, wherein the thin-film heater comprises:
a first layer and a second layer; and
a heat trace sandwiched between the first and second layers.

24. The protective packaging formation device of claim 23 , wherein the thin-film heater includes a spring tensioning mechanism that retains tension in the thin-film heater during thermal expansion.

25. A method of inflating protective packaging, comprising:
directing a fluid between overlapping plies of a flexible structure to inflate inflatable chambers that are defined by a seal pattern between the overlapping plies and that are arranged in a longitudinal series;
driving the overlapping plies with the inflated chambers longitudinally through a pinch area in which a compression element compresses the overlapping plies together sufficiently tightly to retain the fluid between the plies; and
providing electrical current to a heating element adjacent the pinch area, which heating element includes:
a substrate, and
a heat trace disposed on the substrate and having a waveform shape that has an amplitude,
wherein the electrical current is provided through the heat trace to cause the heat trace to heat the overlapping plies in the pinch area sufficiently to heat seal the overlapping plies together, forming a longitudinal seal between the overlapping plies that seals the fluid in the inflated chambers, such that the longitudinal seal has a width determined by the amplitude.

Assignees

• Pregis Innovative Packaging Llc

Inventors

• Wetsch Thomas D
• Ostwald Paul F
• Watts William J

Classifications

• B29C66/439

  Joining sheets for making inflated articles without using a mould · CPC title

• B29C66/223

  being in the form of a triangle wave or of a sawtooth wave, e.g. zigzagged · CPC title

• B29C65/228

  characterised by the means for electrically connecting the ends of said heated wire, resistive ribbon, resistive band or resistive strip · CPC title

• B29C65/224

  being a resistive ribbon, a resistive band or a resistive strip · CPC title

• B29C66/1122

  Single lap to lap joints, i.e. overlap joints (B29C66/45, B29C66/472, B29C66/52272 take precedence) · CPC title