FOOD SERVICE ARTICLES BEARING DECORATIVE MARKINGS, IMAGES AND/OR CUSTOM CONTENT AND METHOD THEREFOR
A plastic food service article bearing a decorative mark or image and method therefor is disclosed. The method includes providing an article made from a colored plastic such as polystyrene, polypropylene, polyethylene, PET, PLA, ABS, etc., that discolors when irradiated with a laser beam; applying a laser beam to cause localized surface discoloration; and controlling the deflection and amplitude of the beam to form a surface decoration and/or image. In embodiments, the laser is a YAG or Fiber laser, the markings emulate silver or gold or pewter without applying metals, inks, or coatings to the plastic articles. The markings are clearly visible against both light and dark backgrounds, and can be placed in food-contact areas of the articles. The technique can be used for marking customized and personalized designs, images, and photographs on food service articles. Embodiments can be used to decorate plates and/or cutlery.
1 . A method for decorating a disposable plastic foodservice article, comprising:
providing a disposable plastic foodservice article made of a colorant-containing plastic material that is discolored when locally heated;
exposing a surface of the article to a laser beam, the beam having sufficient intensity to cause localized discoloration of plastic on the surface; and
controlling the location of the beam using a software-controlled beam director, thereby forming a marking pattern on the surface of the food service article that provides the appearance of a permanentware article; said marking pattern being characterized by its suitability for food contact without an overcoat.
2 . The method of claim 1 , wherein the laser beam is produced by a YAG laser.
3 . The method of claim 1 , wherein the laser beam is produced by a Fiber laser.
4 . The method of claim 1 , wherein the plastic material is one of general-purpose polystyrene, high-impact polystyrene, polypropylene, polycarbonate, ABS, SAN, PMMA, and SBC.
5 . The method of claim 1 , wherein the plastic includes at least one of general-purpose polystyrene, high-impact polystyrene, polypropylene, polyethylene, polycarbonate, acrylonitrile-butadiene-styrene (ABS), SAN, PMMA, styrene-butadiene-copolymer (SBC) and a copolymer thereof.
6 . The method of claim 1 , wherein the plastic food service article is a plate.
7 . The method of claim 1 , wherein the plastic is tinted to resemble china dinnerware.
8 . The method of claim 1 , wherein the localized discoloration of plastic on the surface is difficult to detect by touch.
9 . The method of claim 1 , wherein the discoloration on the surface provides an appearance similar to a metal.
10 . The method of claim 1 , wherein at least a portion of the marking pattern is applied to a region of the food service article that is not flat.
11 . The method of claim 1 , wherein at least a portion of the marking pattern is applied to a region that is generally intended for food contact.
12 . The method of claim 1 , wherein the marking pattern can be changed by providing appropriate software instructions to the beam director.
13 . The method of claim 12 , further comprising automatically delivering and removing a plurality of plastic food service articles from a laser-marking location using an automated delivery and removal system.
14 . The method of claim 13 , wherein the marking pattern can be changed as frequently as every article during the automated decoration.
15 . The method of claim 1 , wherein at least one of a focus of the laser beam and an intensity of the laser beam is controlled by the software.