Ultrasonic packaging material flaw detection with time-limited response detection

Patent metadata

Field	Value
Publication number	US-11520026-B2
Application number	US-202016940239-A
Country	US
Kind code	B2
Filing date	Jul 27, 2020
Priority date	Sep 19, 2019
Publication date	Dec 6, 2022
Grant date	Dec 6, 2022

Abstract

A method, apparatus and program product may evaluate a packaging material to determine various metrics associated with the packaging material. A test apparatus may be used to evaluate packaging material using a take up drum capable of sensing containment force imparted upon the drum by packaging material applied thereto, and in some instances, simulated flaws may be formed in a web of packaging material to evaluate a packaging materials response to such flaws when under tension.

First claim

What is claimed is:

1. A method of detecting a flaw in a stretch wrap packaging material, the method comprising:
conveying a web of packaging material from a packaging material roll to a body through a packaging material delivery system, wherein the packaging material delivery system applies a controlled stretch to the packaging material prior to the packaging material being wrapped around the body; and
detecting a flaw in the web of packaging material while conveying the web of packaging material from the packaging material roll to the body using an ultrasonic flaw detection sensor disposed adjacent the web of packaging material, wherein the flaw includes a hole propagated in the web of packaging material as a result of application of the controlled stretch to the web of packaging material, and wherein detecting the flaw includes:
emitting an ultrasonic pulse from the ultrasonic flaw detection sensor and towards the web of packaging material;
after emitting the ultrasonic pulse towards the web of packaging material from the ultrasonic flaw detection sensor, sensing with the ultrasonic flaw detection sensor during a time-limited detection window;
determining a failure to sense, with the ultrasonic flaw detection sensor, a reflected ultrasonic signal reflected off of the web of packaging material in response to the emitted ultrasonic pulse prior to expiration of the time-limited detection window; and
reporting the detected flaw in the web of packaging material in response to determining the failure to sense.

2. The method of claim 1 , further comprising characterizing the flaw in response to detecting the flaw.

3. The method of claim 1 , wherein the ultrasonic flaw detection sensor includes an array of ultrasonic sensors extending across a width of the web of packaging material, wherein characterizing the flaw includes determining a position of the flaw along the width of the web of packaging material based on an associated position among the array of ultrasonic sensors that fails to sense a reflected ultrasonic signal during the time-limited detection window.

4. The method of claim 3 , wherein the packaging material delivery system includes a pre-stretch assembly including upstream and downstream pre-stretch rollers and first and second idle rollers disposed downstream of the downstream pre-stretch roller, and wherein the ultrasonic flaw detection sensor is disposed between two adjacent rollers among the upstream and downstream pre-stretch rollers and the first and second idle rollers.

5. The method of claim 4 , wherein the ultrasonic flaw detection sensor is disposed between the first and second idle rollers.

6. The method of claim 1 , further comprising counting a number of detected flaws detected by the ultrasonic flaw detection sensor.

7. The method of claim 1 , wherein the body comprises a take up drum, and wherein the packaging material delivery system, the take up drum and the ultrasonic flaw detection sensor are disposed in a test apparatus.

8. The method of claim 1 , wherein the body comprises a load, and wherein the packaging material delivery system and the ultrasonic flaw detection sensor are disposed in a stretch wrapping machine.

9. The method of claim 8 , further comprising generating a notification to an operator in response to detecting the flaw.

10. The method of claim 9 , wherein the notification alerts the operator that the roll of packaging material has excessive flaws.

11. The method of claim 1 , wherein the ultrasonic flaw detection sensor is positioned within about 2 inches of the web of packaging material.

12. The method of claim 1 , wherein the ultrasonic flaw detection sensor is positioned about 0.9 inches from the web of packaging material.

13. The method of claim 1 , wherein the time-limited detection window is about 1 millisecond in length.

14. The method of claim 1 , wherein the time-limited detection window is less than about 1 millisecond in length.

15. The method of claim 1 , wherein the ultrasonic flaw detection sensor includes an array of ultrasonic sensors, and wherein detecting the flaw includes:
concurrently emitting a respective ultrasonic pulse towards the web of packaging material from each ultrasonic sensor in the array of ultrasonic sensors;
after concurrently emitting the respective ultrasonic pulses towards the web of packaging material from the ultrasonic flaw detection sensor, sensing with the array of ultrasonic sensors during the time-limited detection window; and
determining a failure to sense, with a first ultrasonic sensor in the array of ultrasonic sensors, a respective reflected ultrasonic signal reflected off of the web of packaging material in response to the respective ultrasonic pulse emitted by the first ultrasonic sensor prior to expiration of the time-limited detection window.

16. The method of claim 1 , further comprising delaying a subsequent sensing cycle in response to detecting the flaw such that any reflected ultrasonic signal received by the ultrasonic flaw detection sensor outside of the time-limited detection window is not received in the subsequent sensing cycle.

17. A method of detecting a flaw in a stretch wrap packaging material, the method comprising:
conveying a web of packaging material from a packaging material roll to a body through a packaging material delivery system, wherein the packaging material delivery system applies a controlled stretch to the packaging material prior to the packaging material being wrapped around the body; and
detecting a hole associated with a flaw in the web of packaging material and propagated in the web of packaging material as a result of application of the controlled stretch to the web of packaging material while conveying the web of packaging material from the packaging material roll to the body using an ultrasonic flaw detection sensor disposed adjacent the web of packaging material, wherein detecting the hole includes:
emitting an ultrasonic pulse from the ultrasonic flaw detection sensor and towards the web of packaging material;
after emitting the ultrasonic pulse towards the web of packaging material from the ultrasonic flaw detection sensor, sensing with the ultrasonic flaw detection sensor during a time-limited detection window;
determining a failure to sense, with the ultrasonic flaw detection sensor, a reflected ultrasonic signal reflected off of the web of packaging material in response to the emitted ultrasonic pulse prior to expiration of the time-limited detection window; and
reporting the the detected hole in the web of packaging material in response to determining the failure to sense.

18. A method of controlling an apparatus to wrap a body with packaging material dispensed from a packaging material dispenser through relative rotation between the packaging material dispenser and the body, the method comprising:
detecting a packaging material hole during a wrap operation that wraps a body with packaging material as the packaging material is conveyed between a packaging material roll and the body by the packaging material dispenser using an ultrasonic flaw detection sensor, wherein detecting the packaging material hole includes emitting an ultrasonic pulse from the ultrasonic flaw detection sensor and towards the web of packaging material and determining that no reflection of the emitted ultrasonic pulse has been received by the ultrasonic flaw detection sensor within a time-limited detection window; and
during the wrap operation and in response to detecting the packaging material hole using the ultrasonic flaw detection sens

Assignees

• Lantech Com Llc

Inventors

• Mitchell Michael P

Classifications

• B65H2801/81

  Packaging machines · CPC title

• G01S7/521 Primary

  Constructional features · CPC title

• B65H2553/30

  using acoustic or ultrasonic elements · CPC title

• G01N2291/044

  Internal reflections (echoes), e.g. on walls or defects · CPC title

• B65H26/025

  responsive to web breakage · CPC title