JP-2026514396-A - High-speed laser process for marking articles

Abstract

A material sheet marked by a pulse-raising device. The material sheet has a predetermined feature area (17) which includes a plurality of marks (12) and voids (11) of a grid pattern (16). The grid pattern (16) has a plurality of positions arranged along a series of substantially parallel columns, each position including either one mark (12) or one void (11). A pulse from the pulse-raising device forms a mark (12), and the absence of a pulse forms a void (11). The pulse-raising device is controlled by a computing device that sends a packet of instructions to the pulse-raising device, the packet of instructions comprising at least two, each individual instruction notifying the laser of pulse generation or non-pulse generation to generate a mark (12) or void (11) at each position on the grid pattern (16), respectively.

Inventors

• ジョセフ クレッグ レスター
• フィリップ アンドリュー サウィン
• スティーブン ロバート チューイ
• アンソニー オッグ

Assignees

• ザ プロクター アンド ギャンブル カンパニー

Dates

Publication Date

20260511

Application Date

20240329

Priority Date

20230330

Claims (15)

1. A material sheet marked by a pulse-raising device, wherein the material sheet is A predetermined feature portion comprising a grid pattern including a plurality of marks and voids, wherein the grid pattern includes a plurality of positions arranged along a series of substantially parallel columns, each position including either one mark or one void, The pulses from the pulse raising device form the marks, and the absence of pulses forms the voids. A material sheet wherein the pulse-raising device is controlled by a computing device that transmits instruction packets to the pulse-raising device, the instruction packets comprising at least two individual instructions, each individual instruction notifying the laser of pulse generation or non-pulse generation, thereby generating marks or voids at each position on the grid pattern, respectively.
2. The material sheet according to claim 1, wherein the grid pattern is formed by positions in columns where each position is separated by an X distance, and there are two or more parallel columns, and each adjacent pair in the parallel columns is separated by a Y distance.
3. The material sheet according to claim 1 or 2, wherein the positions between adjacent parallel rows are stacked.
4. The material sheet according to any one of claims 1 to 3, wherein the position between adjacent parallel rows is offset.
5. The material sheet according to any one of claims 1 to 4, wherein the predetermined characteristic portion includes at least one alphanumeric character.
6. The material sheet according to claim 5, wherein the alphanumeric characters have a font size in the range of 6pt to 10pt, and the Y distance is at least 1.2 times the X distance.
7. A material sheet according to any one of claims 1 to 6, further comprising a laser absorption additive, wherein the laser absorption additive is titanium dioxide ( TiO₂ ), antimony tin oxide (ATO), ATO-coated substrates such as mica, indium tin oxide (ITO), Sb₂O₃ , tin oxide, carbon black, graphite carbon, bismuth oxide, mixed metal oxides, metal nitrides, doped metal nitrides, metal carbides, metal borides, pearlescent pigments, zero-valent metals, doped tungsten oxide, tungsten oxide, doped tungsten oxide, and mixtures thereof.
8. The material sheet according to any one of claims 1 to 7, wherein the material sheet forms an article.
9. The material sheet according to claim 8, wherein the article is a garbage bag, bottle, sachet, tube, film, laminate, bag, wrap, drum, jar, cup, or cap.
10. The material sheet according to claim 1, wherein the predetermined feature portion is a UPC, QR code, data matrix, or other machine-readable code or symbol.
11. The material sheet according to any one of claims 1 to 10, wherein each of the aforementioned instructions may be any combination of marks and voids, including all marks or all voids.
12. A method for marking a material sheet using a pulse bracing device, wherein the method is A step of defining a predetermined feature portion of a grid pattern including a plurality of marks and voids, wherein the grid pattern includes a plurality of positions arranged along a series of substantially parallel columns, each position including either a mark or a void, The steps include forming the marks by pulse-driving the pulse-raising device and generating voids by not pulse-driving the pulse-raising device, A method comprising the step of controlling a pulse-raising device by a computing device that transmits a packet of instructions to the pulse-raising device, wherein the packet of instructions comprises at least two individual instructions, and each individual instruction notifies the pulse-raising device of pulse generation or non-generation, thereby generating marks or voids at each position on the grid pattern, respectively.
13. The method according to claim 12, wherein at least one of the columns is marked by two different packets.
14. The method according to claim 13, wherein at least one of the columns is marked by three different packets.
15. The method according to claim 12, wherein the instruction packet further comprises two or fewer, preferably only one, individual instructions relating to the positioning of a position within the grid pattern.

Description

This invention relates to a process for laser marking articles and a method for marking such articles. Short-pulse laser decoration utilizes energy from nano, pico, and femto short-pulse lasers across various wavelengths and energies to mark decorative patterns onto articles such as products and/or packaging. Any and all other decorative techniques applicable to products and/or packaging (i.e., labels, screen printing, digital printing, etc.) can be used in conjunction with laser marking to achieve various decorative and functional effects. Importantly, the laser technology used in short-pulse laser marking is a high-throughput technique that uses a fixed laser source, where the laser beam is directed onto the product or packaging being marked by electronically/mechanically controlled mirrors (i.e., "Garbo" sets) and lenses (i.e., F-theta and similar lenses). These mirrors and lenses steer the laser beam across the surface of the article (this steer is also called "scanning") so that the laser can impart images, such as digital images (e.g., from computer files such as PDF files), to the surface of the packaging or product. This technique has a further advantage over other decorative techniques in that the use of digital images allows for the customization and personalization of the decoration. There is considerable interest in the possibilities presented by laser-marked articles, such as those using short-pulse laser marking. For example, replacing adhesive labels on polymer containers is not only economically beneficial but also ecologically beneficial. Removing adhesive labels from polymer containers reduces the amount of petroleum-derived material per package, thereby reducing the weight of the packaging and consequently decreasing the total weight of the packaging material, which requires less fuel for transportation. Furthermore, the absence of adhesive labels makes it easier to recycle polymer containers, as adhesive labels often need to be removed before recycling due to potential impurities that could enter the recycling process. Laser marking of small items (i.e., golf balls, etc.) and/or small areas on items (i.e., date codes, address labels on finished packages) is known. While lasers are improving, and newer lasers have a variety of energies and wavelengths, these marking processes can still be slow and expensive. Furthermore, they lack the ability to mark small characters requiring high precision, such as small-font text consisting of alphanumeric characters (i.e., instructions for use, ingredient lists). For example, date codes are marked on packages by relatively fast lasers, but these use single lines of large, inaccurate, or unevenly spaced spots (ranging from 250 μm to over 800 μm in diameter) and relatively large-font characters. This is equivalent to printing stick figures that, while suitable for some purposes, are difficult for consumers to read and nearly impossible for machines to read. More specifically, large, inaccurate, or unevenly spaced single lines cannot currently be used to mark high-precision small font text or machine-readable graphics, such as UPCs or QR codes, on articles. Current state-of-the-art laser marking processes include "raster" and "vector" marking processes, which are either high-speed but have low precision and resolution, or low-speed but have high precision and resolution. A combination of high speed and high precision does not exist in prior art. This issue is particularly pronounced when marking large areas on an article, such as when using laser marking as a complete replacement for other decorative techniques, where all text and/or graphics (many of which are required for regulatory purposes) to be provided on at least one face of the article are delivered via laser marking. The raster laser marking process places individual laser marks on a grid, and the image is marked row by row, point by point by the laser. Each pulse is "gate-controlled" so that the pulse is emitted only on dark pixels of the image and not on bright pixels (or vice versa). Each pulse is individually gate-controlled, and the pulse energy of each pulse can be varied to produce a grayscale. State-of-the-art raster marking processes are practically limited to lasers with a repetition rate of about 100 kHz, considering the practical limit of the update rate of about 10 µs when signaling the laser's on/off function (i.e., "gating"). Speed increases can only be achieved by increasing the pulse interval, which may come at the expense of fine detail, such as that required to mark small font text and graphics. State-of-the-art vector marking processes can run at speeds above 100 kHz, as pulses are typically gate-open while the laser beam is "directed" (by mirrors) to the shape of the vector line being marked. Vector-marked items, including text, are often recognizable because the marked lines are typically one pulse width (unless filled in), and the pulses converge near corners where the su