Title:
METHOD FOR PRODUCING FRESHNESS-KEEPING BAG
Document Type and Number:
WIPO Patent Application WO/2021/039717
Kind Code:
A1
Abstract:
Provided is a method for producing a freshness-keeping bag that can keep the freshness of contents for a long period of time with very little inflow of oxygen from the outside. The present invention provides a method for producing a freshness-keeping bag that is formed from a film and has a strip-like bonding area in which the two ends of the film are joined and bonded to each other. The bonding area includes a plurality of bonding portions in which the two ends of the film are bonded to each other, and a non-bonding portion that is disposed between the adjacent bonding portions. In the non-bonding portion, the ends of the film are not bonded to each other. The non-bonding portion constitutes a non-linear air passage connecting the internal space of the bag and the outside of the bag. The method comprises the step for forming the bonding portions by ultrasonic welding. In the step for forming the bonding portions, the bonding portions are sequentially formed on the film while a disc-shaped ultrasonic welding anvil is rotated with respect to the film. The anvil has a plurality of projections that are sequentially formed at predetermined intervals on the outer periphery of the anvil so as to agree with the shapes of the bonding portions of the bag.
Inventors:
WATANABE TORU (JP)
Application Number:
PCT/JP2020/031841
Publication Date:
March 04, 2021
Filing Date:
August 24, 2020
Export Citation:
Assignee:
W & CO (JP)
International Classes:
B65B51/22; A23B9/20; A23L3/3418; B65D81/26; B65D85/50
Domestic Patent References:
| WO2018064340A1 | 2018-04-05 |
Foreign References:
| JP2019131215A | 2019-08-08 | |||
| JPH0840466A | 1996-02-13 | |||
| JP2002308292A | 2002-10-23 | |||
| JP3259166B2 | 2002-02-25 | |||
| JPS6052729B2 | 1985-11-21 |
Other References:
See also references of EP 4019418A4
Attorney, Agent or Firm:
TANAKA Shinichiro et al. (JP)
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