METHOD FOR LASER MARKING POLYMER CONTAINERS Russian patent published in 2018 - IPC B29C71/04 B41M5/26 B44C1/22 

FIELD: packaging industry.

SUBSTANCE: invention relates to a method for manufacturing a polymeric container with a marking. At first, the resolution of l_pi image of the marking in two mutually perpendicular directions is determined from the ratio: lp_i= L_i / (d⋅k₁⋅k₂) points / mm, where L_and is linear size of the marking image on the final product, mm; d is the diameter of the waist of the laser radiation, mm; k₁ is the coefficient of increase in the diameter of the container as compared to the blank; k₂ is the coefficient of material properties of the container, defined as k₂= D / d, where D is the diameter of the spherulites formed in the near-surface layer of the container after thermomechanical action to the blank, d is the diameter of the waist of the laser radiation. Then focused laser radiation is applied to a preset pattern of the marking image on the blank of the polymer container, heated to a temperature equal to (0.3-0.4)⋅T_c, where T_c is the glass transition temperature of the container material, °C, at a laser radiation energy lower than the ablation threshold. Finally, the container is formed using thermomechanical action to the blank with the image of the marking applied.

EFFECT: method requires less energy and allows to reduce the time of applying the marking.

11 cl, 3 dwg, 1 ex