FIELD: paper.
SUBSTANCE: group of inventions relates to methods of producing laminated biodegradable cellulose cardboard for packaging food products. According to the first version of the invention, after feeding the continuous cardboard web from the first unwinder, preliminary infrared heating and preliminary ultrasonic treatment of the cardboard supplied from the first unwinder are carried out. It is subjected to corona treatment with the help of spaced aluminium electrodes with charges of 12 kW. Using a co-extruder, layers of a melt containing polyethylene and a biodegradable composition are applied onto the cardboard from the first unwinder at a temperature of not more than 320 °C, at a speed of not less than 150 m/min. Continuous cardboard web is fed from the second unwinder. It is preliminarily treated with the help of a ceramic electrode with charge of 8 kW. Layers of melt containing polyethylene and biodegradable composition are applied on at least one surface of cardboard web supplied from the second unwinder by means of a co-extruder at temperature of not more than 220 °C at a rate of not less than 150 m/min. Obtained laminated cardboard from the first unwinder is connected to the obtained laminated cardboard from the second unwinder. Coronary treatment of the obtained laminated cardboard is carried out with the help of spaced aluminium electrodes with charges of 8 kW. Using an extruder, a layer of a melt containing polyethylene and a biodegradable composition is applied on the surface of the obtained laminated cardboard at a temperature of not more than 320 °C. Obtained material is cooled and its surface is subjected to corona treatment by means of an aluminium electrode with charge of 12 kW. According to the second version of the invention, the cardboard supplied from the unwinder is subjected to preliminary infrared heating and preliminary ultrasonic treatment. Coronary treatment is carried out with the help of spaced aluminium electrodes with charges of 12 kW. Further, using a co-extruder, layers of a melt containing polyethylene and a biodegradable composition are applied onto the cardboard at a temperature of not more than 320 °C, at a speed of not less than 150 m/min. Coronary treatment of the obtained laminated cardboard is carried out with the help of spaced aluminium electrodes, with charges of 8 kW. Using an extruder, a layer of a melt containing polyethylene and a biodegradable composition is applied on the surface of the obtained laminated cardboard at a temperature of not more than 320 °C. Obtained material is cooled and its surface is subjected to corona treatment by means of an aluminium electrode with charge of 12 kW. According to the third version of the invention, after feeding the continuous cardboard web from the unwinder, its preliminary corona treatment is carried out using a ceramic electrode with charge of 8 kW. Layers of the melt containing polyethylene and the biodegradable composition are applied using a co-extruder at a temperature of not more than 220 °C at a rate of not less than 150 m/min. Coronary treatment of the obtained laminated cardboard is carried out with the help of spaced aluminium electrodes, with charges of 8 kW. Using an extruder, a layer of a melt containing polyethylene and a biodegradable composition is applied on the surface of the obtained laminated cardboard at a temperature of not more than 320 °C. Obtained material is cooled and its surface is subjected to corona treatment by means of an aluminium electrode with charge of 12 kW.
EFFECT: invention increases strength and improves barrier properties of biodegradable laminar material based on cellulose cardboard without deterioration of its biodegradation process.
3 cl, 1 dwg
