| 摘要 |
<p>PROBLEM TO BE SOLVED: To form a paperboard carton by a single process work and to make appropriate protection possible for food by a method wherein moistureproof barrier property is given to the internal surface with aqueous copolymeric emulsion having stability and soluble extract value smaller than a specified value under specified conditions such as temperature. SOLUTION: To the internal surface of a carton 2 comprising of a tray 4 composed of a bottom panel 6 and side walls 8 and a cover 14, aqueous emulsion coating 18 is applied at the coating rate of 6-12 pounds in dry weight per 3000 ft<2> ream. The aqueous emulsion has mass stability at the temperature lower than 400 deg.F while being available for tack jointing at the temperature of 250 deg.F or above and chloroform soluble extract level therefor does not exceed, when exposed for two hours to a solvent at the temperature of 150 deg.F, a value of 0.5 mg/in<2> at the surface contacting with food. Furthermore, the carton has flexibility resistive against bending in crossing direction applied with a 2-point male ruler and a 0.62 inch channel and capable of keeping the crack length ratio at 0.1 or below. The cartons also develop blocking resistance when piled up under a load of 0.5 pounds/in<2> or above.</p> |
