MOISTURE PROTECTION SHELL CORRUGATED IN FORM OF RIGID SELF-SUPPORTING SHIRRED STICKS AND METHOD FOR OBTAINING IT Russian patent published in 2017 - IPC A22C13/02 A22C13/00 B29D23/18 

FIELD: packaging industry.

SUBSTANCE: invention relates to a flexible-hose moisture protection shell for food products, corrugated in the form of rigid self-supporting shirred sticks, (co)-extruded from a melt, having a layer in contact with food that has a reduced adhesion to the contents. The shell has on the outer hose surface at least one binding water-soluble or water-dispersible (co) polymer in an amount of at least 10 g/m², ensuring the adhesive connection between the corrugated folds in the shirred sticks. The shirred sticks additionally have on their outer surface a hydrophobic component reducing the adhesion strength and represented by at least one liquid substantially non-volatile at the room temperature and substantially water-insoluble organic and/or element-organic substance. The total content of the substance on the shell surface is higher than the binder polymer content on the shell surface, and ranges from 50 to 500 mg/m². The shirred sticks are characterized by the signs: after holding for 24 hours in the free state on a smooth flat surface at 20°C and the relative humidity of 75%, their compressibility in the longitudinal direction under the action of force in 1 N does not exceed 0.5%. The shirred sticks are characterized by the absence of visible elastic bend deformation under the action of its own weight, being cantilevered, and the irreversible kink when the bending moment from 60 to 400 N⋅mm is reached; can be de-corrugated at the temperature of 20°C and RH of 60% with a speed of at least 1.5 m/s without shell ruptures. The method for manufacturing this shell corrugated in the form of rigid self-supporting shirred sticks includes the stage of extruding a flexible-hose shell of synthetic polymers, the stage of orientational drawing and thermofixing, if necessary, and the stage of its corrugating, with applying an aqueous system containing a binder polymer to the outer surface of the shell. On the outer shell surface, a hydrophobic component reducing the adhesion strength is additionally applied. The method comprises the stage of fixing the shape obtained by corrugating the shirred sticks with the fixing equipment; the stage of forced drying of the shirred sticks in the fixed state for 0.5 to 20 minutes, at which the surface temperature of these shirred sticks reaches from 45 to 75°C, and the stage of cooling to the room temperature and removal of the fixing equipment to obtain rigid self-supporting shirred sticks.

EFFECT: ensuring filling the shirred sticks on high-performance automatic equipment without the occurrence of technical problems, including defects of their shape and integrity.

36 cl, 2 tbl, 5 ex