Method of forming a heat resistant carton
US4249978A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 19, 1979 |
| Grant date | Feb 10, 1981 |
| Priority date | — |
| Expiry date | Apr 19, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/31797
- WIPO fieldTextile and paper machines
- WIPO sectorMechanical engineering
Abstract
A method of forming a heat-sealable carton having a pair of mating surfaces to be sealed includes the steps of coating at least one of the carton surfaces with a heat-activated thermosetting adhesive, spraying a fine mist of a water-based adhesive which exhibits high contact tackiness when dry, to form a discontinuous film on the coated surface, heating the water-based adhesive coated surface to a temperature sufficient to dry the water-based adhesive and activate the thermosetting adhesive, placing the mating carton surfaces in contact with each other and applying pressure for a time sufficient to seal the contacting surfaces together. A carton formed by the method is provided with flaps sealed by the combination of thermosetting heat-activated adhesive and high tack water-based adhesive. This allows the mating surfaces to be rapidly sealed by automatic carton closing apparatus and results in a sealed carton which exhibits good seal integrity at high temperatures. A carton formed in this manner is useful, for example, as a food container which can be placed directly in an oven to heat the contents thereof, with the carton seal being unaffected by the oven heat.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.