Moisture responsive stiffening members for flexible containers
US4524458A · kind A · utility
Inventors
Key dates
| Filing date | Nov 25, 1983 |
| Grant date | Jun 18, 1985 |
| Priority date | — |
| Expiry date | Nov 25, 2003 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB65D2231/004
- WIPO fieldHandling
- WIPO sectorMechanical engineering
Abstract
Flexible plastic bags used for the bulk storage and dispensing of fluids are often blocked from dispensing all the contents and/or entrap part of the contents in folds of the plastic as they shrink during dispensing. The invention is for a tongue or dip tube that is attached to the inner wall of the plastic bag near the location of the dispensing aperture. The tongue is formed of a laminate of two dissimilar materials, one non-hygroscopic and the other being hygroscopic, so that upon introduction of moisture into the bag, the hygroscopic layer will expand and the normally flat tongue will curl to form a thick tube that both prevents collapse of the bag and prevents closure of the dispensing aperture by the opposite wall of the bag.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.