COMPOSITE POLYSTYRENE PROFILE AND METHOD FOR MAKING SUCH PROFILES Russian patent published in 2025 - IPC B29C44/22 B29C48/16 C08J9/228 E04F19/04 

FIELD: chemistry.

SUBSTANCE: present invention relates to a composite polystyrene profile (1) extending longitudinally from first end (10) to second end (11), comprising front surface (12) and rear surface (13) and comprising: a) a portion of core (2) comprising a polystyrene monopolymer foam extending in said longitudinal direction, said portion of the core comprising foamed polystyrene with a density in range of 160 kg/m³ to 240 kg/m³; b) a portion of shell (3) comprising/consisting of an impact-resistant polystyrene copolymer and surrounding said portion of core (2) in at least said longitudinal direction, with a density in range of 700 kg/m³ to 1300 kg/m³; wherein said polystyrene profile (1) comprises a total density in range of 200 kg/m³ to 360 kg/m³; and said portion of shell (3) comprises a non-uniform thickness in a transverse direction perpendicular to said longitudinal direction; and minimum thickness on rear surface (13) is less than minimum thickness on front surface (12). Also described is a method of producing composite polystyrene profile (1) according to any of the previous claims, comprising steps of: a) plasticising a core polymer composition in a first extruder, said core polymer composition comprising a polystyrene monopolymer, a nucleating agent and a physical foaming agent; b) plasticising in a second extruder a polymer shell composition, said polymer shell composition comprising a polystyrene copolymer; c) feeding the plasticized polymer core composition into a coextrusion mould to form a portion of core (2); d) after step (c) of feeding the polymer composition of the shell into said coextrusion mould in order to form a plastic composite having a portion of core (2) and portion of shell (3) made from said polymer composition of shell, surrounding said portion of core (2) and welded thereto; e) transferring the plastic composite obtained at the end of step (d) to a calibrating unit with cooling for cooling and stabilizing the shape of said plastic composite, wherein section of shell (3) is provided with non-uniform thickness in transverse direction perpendicular to said longitudinal direction; wherein said non-uniform thickness of said section of shell (3, 30, 31) is achieved by providing difference in flow rate of said polymer composition of shell in direction of said section of core (2). Described is a device for implementing said method.

EFFECT: technical result is improved impact resistance of the profile.

27 cl, 8 dwg