CA2474284C - Method for vitrescent marking - Google Patents
Method for vitrescent marking Download PDFInfo
- Publication number
- CA2474284C CA2474284C CA 2474284 CA2474284A CA2474284C CA 2474284 C CA2474284 C CA 2474284C CA 2474284 CA2474284 CA 2474284 CA 2474284 A CA2474284 A CA 2474284A CA 2474284 C CA2474284 C CA 2474284C
- Authority
- CA
- Canada
- Prior art keywords
- substrate
- marking material
- marking
- laser beam
- vitrescent
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 238000000034 method Methods 0.000 title claims abstract description 77
- 239000000758 substrate Substances 0.000 claims abstract description 140
- 239000000463 material Substances 0.000 claims abstract description 115
- 238000004017 vitrification Methods 0.000 claims abstract description 33
- 239000011449 brick Substances 0.000 claims abstract description 32
- 230000001678 irradiating effect Effects 0.000 claims abstract description 13
- 239000011521 glass Substances 0.000 claims description 21
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 claims description 11
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 11
- 239000004927 clay Substances 0.000 claims description 9
- 239000011888 foil Substances 0.000 claims description 9
- 239000000203 mixture Substances 0.000 claims description 9
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 7
- 229910044991 metal oxide Inorganic materials 0.000 claims description 7
- 150000004706 metal oxides Chemical class 0.000 claims description 7
- 239000001301 oxygen Substances 0.000 claims description 7
- 229910052760 oxygen Inorganic materials 0.000 claims description 7
- 229910052782 aluminium Inorganic materials 0.000 claims description 6
- 229910052759 nickel Inorganic materials 0.000 claims description 6
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 claims description 5
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 5
- 229910052804 chromium Inorganic materials 0.000 claims description 5
- 239000011651 chromium Substances 0.000 claims description 5
- 150000001875 compounds Chemical class 0.000 claims description 5
- 229910052751 metal Inorganic materials 0.000 claims description 5
- 239000002184 metal Substances 0.000 claims description 5
- 239000000843 powder Substances 0.000 claims description 5
- 235000012239 silicon dioxide Nutrition 0.000 claims description 5
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 claims description 4
- 239000000919 ceramic Substances 0.000 claims description 4
- 229910052802 copper Inorganic materials 0.000 claims description 4
- 239000010949 copper Substances 0.000 claims description 4
- 229910002026 crystalline silica Inorganic materials 0.000 claims description 4
- 238000010438 heat treatment Methods 0.000 claims description 4
- 239000003795 chemical substances by application Substances 0.000 claims description 3
- 229910017052 cobalt Inorganic materials 0.000 claims description 3
- 239000010941 cobalt Substances 0.000 claims description 3
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 claims description 3
- 238000007598 dipping method Methods 0.000 claims description 3
- 238000001035 drying Methods 0.000 claims description 3
- 239000001023 inorganic pigment Substances 0.000 claims description 3
- 229910003455 mixed metal oxide Inorganic materials 0.000 claims description 3
- 229910011255 B2O3 Inorganic materials 0.000 claims description 2
- KRHYYFGTRYWZRS-UHFFFAOYSA-M Fluoride anion Chemical compound [F-] KRHYYFGTRYWZRS-UHFFFAOYSA-M 0.000 claims description 2
- 230000001680 brushing effect Effects 0.000 claims description 2
- 239000004568 cement Substances 0.000 claims description 2
- 229910052570 clay Inorganic materials 0.000 claims description 2
- JKWMSGQKBLHBQQ-UHFFFAOYSA-N diboron trioxide Chemical compound O=BOB=O JKWMSGQKBLHBQQ-UHFFFAOYSA-N 0.000 claims description 2
- 230000005484 gravity Effects 0.000 claims description 2
- 239000005337 ground glass Substances 0.000 claims description 2
- WPBNNNQJVZRUHP-UHFFFAOYSA-L manganese(2+);methyl n-[[2-(methoxycarbonylcarbamothioylamino)phenyl]carbamothioyl]carbamate;n-[2-(sulfidocarbothioylamino)ethyl]carbamodithioate Chemical compound [Mn+2].[S-]C(=S)NCCNC([S-])=S.COC(=O)NC(=S)NC1=CC=CC=C1NC(=S)NC(=O)OC WPBNNNQJVZRUHP-UHFFFAOYSA-L 0.000 claims description 2
- 239000005078 molybdenum compound Substances 0.000 claims description 2
- 150000002752 molybdenum compounds Chemical class 0.000 claims description 2
- 238000005507 spraying Methods 0.000 claims description 2
- 239000004575 stone Substances 0.000 claims description 2
- 150000003755 zirconium compounds Chemical class 0.000 claims description 2
- 210000003298 dental enamel Anatomy 0.000 claims 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims 1
- 239000011324 bead Substances 0.000 claims 1
- 150000001642 boronic acid derivatives Chemical class 0.000 claims 1
- 239000010439 graphite Substances 0.000 claims 1
- 229910002804 graphite Inorganic materials 0.000 claims 1
- 229910052573 porcelain Inorganic materials 0.000 claims 1
- 229910052566 spinel group Inorganic materials 0.000 claims 1
- 239000003086 colorant Substances 0.000 description 19
- UQSXHKLRYXJYBZ-UHFFFAOYSA-N Iron oxide Chemical compound [Fe]=O UQSXHKLRYXJYBZ-UHFFFAOYSA-N 0.000 description 6
- 230000008569 process Effects 0.000 description 6
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 5
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 description 4
- TZCXTZWJZNENPQ-UHFFFAOYSA-L barium sulfate Chemical compound [Ba+2].[O-]S([O-])(=O)=O TZCXTZWJZNENPQ-UHFFFAOYSA-L 0.000 description 4
- 235000013980 iron oxide Nutrition 0.000 description 4
- 239000000049 pigment Substances 0.000 description 4
- RTAQQCXQSZGOHL-UHFFFAOYSA-N Titanium Chemical compound [Ti] RTAQQCXQSZGOHL-UHFFFAOYSA-N 0.000 description 3
- FRLJSGOEGLARCA-UHFFFAOYSA-N cadmium sulfide Chemical class [S-2].[Cd+2] FRLJSGOEGLARCA-UHFFFAOYSA-N 0.000 description 3
- 239000011248 coating agent Substances 0.000 description 3
- 238000000576 coating method Methods 0.000 description 3
- 229910052742 iron Inorganic materials 0.000 description 3
- 239000002243 precursor Substances 0.000 description 3
- 239000000126 substance Substances 0.000 description 3
- XOLBLPGZBRYERU-UHFFFAOYSA-N tin dioxide Chemical compound O=[Sn]=O XOLBLPGZBRYERU-UHFFFAOYSA-N 0.000 description 3
- 229910001887 tin oxide Inorganic materials 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Chemical compound O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- QPLDLSVMHZLSFG-UHFFFAOYSA-N Copper oxide Chemical compound [Cu]=O QPLDLSVMHZLSFG-UHFFFAOYSA-N 0.000 description 2
- 239000005751 Copper oxide Substances 0.000 description 2
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 2
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 2
- CDBYLPFSWZWCQE-UHFFFAOYSA-L Sodium Carbonate Chemical compound [Na+].[Na+].[O-]C([O-])=O CDBYLPFSWZWCQE-UHFFFAOYSA-L 0.000 description 2
- XLOMVQKBTHCTTD-UHFFFAOYSA-N Zinc monoxide Chemical compound [Zn]=O XLOMVQKBTHCTTD-UHFFFAOYSA-N 0.000 description 2
- QCWXUUIWCKQGHC-UHFFFAOYSA-N Zirconium Chemical compound [Zr] QCWXUUIWCKQGHC-UHFFFAOYSA-N 0.000 description 2
- NDUKHFILUDZSHZ-UHFFFAOYSA-N [Fe].[Zr] Chemical compound [Fe].[Zr] NDUKHFILUDZSHZ-UHFFFAOYSA-N 0.000 description 2
- DIVGJYVPMOCBKD-UHFFFAOYSA-N [V].[Zr] Chemical compound [V].[Zr] DIVGJYVPMOCBKD-UHFFFAOYSA-N 0.000 description 2
- 229910052946 acanthite Inorganic materials 0.000 description 2
- 229910052787 antimony Inorganic materials 0.000 description 2
- 239000012298 atmosphere Substances 0.000 description 2
- 239000000969 carrier Substances 0.000 description 2
- 229910000431 copper oxide Inorganic materials 0.000 description 2
- -1 copper-red Substances 0.000 description 2
- 238000005336 cracking Methods 0.000 description 2
- PGWFQHBXMJMAPN-UHFFFAOYSA-N ctk4b5078 Chemical class [Cd].OS(=O)(=O)[Se]S(O)(=O)=O PGWFQHBXMJMAPN-UHFFFAOYSA-N 0.000 description 2
- 230000004927 fusion Effects 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- UGKDIUIOSMUOAW-UHFFFAOYSA-N iron nickel Chemical compound [Fe].[Ni] UGKDIUIOSMUOAW-UHFFFAOYSA-N 0.000 description 2
- KFZAUHNPPZCSCR-UHFFFAOYSA-N iron zinc Chemical compound [Fe].[Zn] KFZAUHNPPZCSCR-UHFFFAOYSA-N 0.000 description 2
- VBMVTYDPPZVILR-UHFFFAOYSA-N iron(2+);oxygen(2-) Chemical class [O-2].[Fe+2] VBMVTYDPPZVILR-UHFFFAOYSA-N 0.000 description 2
- 238000010330 laser marking Methods 0.000 description 2
- 229910052748 manganese Inorganic materials 0.000 description 2
- 239000011572 manganese Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000002480 mineral oil Substances 0.000 description 2
- 235000010446 mineral oil Nutrition 0.000 description 2
- RVTZCBVAJQQJTK-UHFFFAOYSA-N oxygen(2-);zirconium(4+) Chemical compound [O-2].[O-2].[Zr+4] RVTZCBVAJQQJTK-UHFFFAOYSA-N 0.000 description 2
- KHJHBFLMOSTPIC-UHFFFAOYSA-N prop-2-enylidenechromium Chemical compound C(=C)C=[Cr] KHJHBFLMOSTPIC-UHFFFAOYSA-N 0.000 description 2
- 239000004576 sand Substances 0.000 description 2
- 239000000377 silicon dioxide Substances 0.000 description 2
- XUARKZBEFFVFRG-UHFFFAOYSA-N silver sulfide Chemical compound [S-2].[Ag+].[Ag+] XUARKZBEFFVFRG-UHFFFAOYSA-N 0.000 description 2
- 229940056910 silver sulfide Drugs 0.000 description 2
- 230000008646 thermal stress Effects 0.000 description 2
- 239000004408 titanium dioxide Substances 0.000 description 2
- 229910052726 zirconium Inorganic materials 0.000 description 2
- 229910001928 zirconium oxide Inorganic materials 0.000 description 2
- GFQYVLUOOAAOGM-UHFFFAOYSA-N zirconium(iv) silicate Chemical compound [Zr+4].[O-][Si]([O-])([O-])[O-] GFQYVLUOOAAOGM-UHFFFAOYSA-N 0.000 description 2
- 239000005995 Aluminium silicate Substances 0.000 description 1
- 229910001369 Brass Inorganic materials 0.000 description 1
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 1
- MBMLMWLHJBBADN-UHFFFAOYSA-N Ferrous sulfide Chemical compound [Fe]=S MBMLMWLHJBBADN-UHFFFAOYSA-N 0.000 description 1
- 241000594011 Leuciscus leuciscus Species 0.000 description 1
- 241000233855 Orchidaceae Species 0.000 description 1
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 1
- QEFDIAQGSDRHQW-UHFFFAOYSA-N [O-2].[Cr+3].[Fe+2] Chemical class [O-2].[Cr+3].[Fe+2] QEFDIAQGSDRHQW-UHFFFAOYSA-N 0.000 description 1
- UKUJCSBWRBWNAV-UHFFFAOYSA-N [Sn].[V] Chemical compound [Sn].[V] UKUJCSBWRBWNAV-UHFFFAOYSA-N 0.000 description 1
- DVKNZOANXCZDCP-UHFFFAOYSA-N [Ti].[Ni].[Sb] Chemical compound [Ti].[Ni].[Sb] DVKNZOANXCZDCP-UHFFFAOYSA-N 0.000 description 1
- 238000005299 abrasion Methods 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 230000009471 action Effects 0.000 description 1
- 230000032683 aging Effects 0.000 description 1
- 229910000272 alkali metal oxide Inorganic materials 0.000 description 1
- 229910000287 alkaline earth metal oxide Inorganic materials 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- 235000012211 aluminium silicate Nutrition 0.000 description 1
- OOBNORVQFIAGPT-UHFFFAOYSA-N antimony manganese Chemical compound [Mn].[Sb] OOBNORVQFIAGPT-UHFFFAOYSA-N 0.000 description 1
- TUFZVLHKHTYNTN-UHFFFAOYSA-N antimony;nickel Chemical compound [Sb]#[Ni] TUFZVLHKHTYNTN-UHFFFAOYSA-N 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 229910000416 bismuth oxide Inorganic materials 0.000 description 1
- 229910021538 borax Inorganic materials 0.000 description 1
- 239000010951 brass Substances 0.000 description 1
- 239000001058 brown pigment Substances 0.000 description 1
- 239000004566 building material Substances 0.000 description 1
- 229910052793 cadmium Inorganic materials 0.000 description 1
- BDOSMKKIYDKNTQ-UHFFFAOYSA-N cadmium atom Chemical compound [Cd] BDOSMKKIYDKNTQ-UHFFFAOYSA-N 0.000 description 1
- AXCZMVOFGPJBDE-UHFFFAOYSA-L calcium dihydroxide Chemical compound [OH-].[OH-].[Ca+2] AXCZMVOFGPJBDE-UHFFFAOYSA-L 0.000 description 1
- 239000000920 calcium hydroxide Substances 0.000 description 1
- 229910001861 calcium hydroxide Inorganic materials 0.000 description 1
- 230000000711 cancerogenic effect Effects 0.000 description 1
- 231100000315 carcinogenic Toxicity 0.000 description 1
- DVRDHUBQLOKMHZ-UHFFFAOYSA-N chalcopyrite Chemical compound [S-2].[S-2].[Fe+2].[Cu+2] DVRDHUBQLOKMHZ-UHFFFAOYSA-N 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 230000005465 channeling Effects 0.000 description 1
- 150000001845 chromium compounds Chemical class 0.000 description 1
- 150000001869 cobalt compounds Chemical class 0.000 description 1
- NXFVVSIQVKXUDM-UHFFFAOYSA-N cobalt(2+) oxido(oxo)chromium Chemical compound [Co++].[O-][Cr]=O.[O-][Cr]=O NXFVVSIQVKXUDM-UHFFFAOYSA-N 0.000 description 1
- 239000004567 concrete Substances 0.000 description 1
- 238000009833 condensation Methods 0.000 description 1
- 230000005494 condensation Effects 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 239000013078 crystal Substances 0.000 description 1
- TYIXMATWDRGMPF-UHFFFAOYSA-N dibismuth;oxygen(2-) Chemical compound [O-2].[O-2].[O-2].[Bi+3].[Bi+3] TYIXMATWDRGMPF-UHFFFAOYSA-N 0.000 description 1
- 229910001882 dioxygen Inorganic materials 0.000 description 1
- 238000002845 discoloration Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 239000003623 enhancer Substances 0.000 description 1
- 239000010433 feldspar Substances 0.000 description 1
- 150000002222 fluorine compounds Chemical class 0.000 description 1
- 230000008014 freezing Effects 0.000 description 1
- 238000007710 freezing Methods 0.000 description 1
- 239000000499 gel Substances 0.000 description 1
- 235000011187 glycerol Nutrition 0.000 description 1
- 238000007646 gravure printing Methods 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- 150000002500 ions Chemical class 0.000 description 1
- 229910000358 iron sulfate Inorganic materials 0.000 description 1
- BAUYGSIQEAFULO-UHFFFAOYSA-L iron(2+) sulfate (anhydrous) Chemical compound [Fe+2].[O-]S([O-])(=O)=O BAUYGSIQEAFULO-UHFFFAOYSA-L 0.000 description 1
- NLYAJNPCOHFWQQ-UHFFFAOYSA-N kaolin Chemical compound O.O.O=[Al]O[Si](=O)O[Si](=O)O[Al]=O NLYAJNPCOHFWQQ-UHFFFAOYSA-N 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 230000000873 masking effect Effects 0.000 description 1
- 229910052976 metal sulfide Inorganic materials 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 238000003801 milling Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 239000006060 molten glass Substances 0.000 description 1
- 239000012768 molten material Substances 0.000 description 1
- 239000012860 organic pigment Substances 0.000 description 1
- 125000002524 organometallic group Chemical group 0.000 description 1
- 238000007649 pad printing Methods 0.000 description 1
- 230000035515 penetration Effects 0.000 description 1
- 230000002093 peripheral effect Effects 0.000 description 1
- 238000012802 pre-warming Methods 0.000 description 1
- 238000002203 pretreatment Methods 0.000 description 1
- 238000007639 printing Methods 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- 238000007712 rapid solidification Methods 0.000 description 1
- 229910052761 rare earth metal Inorganic materials 0.000 description 1
- 150000002910 rare earth metals Chemical class 0.000 description 1
- 238000007650 screen-printing Methods 0.000 description 1
- 238000012216 screening Methods 0.000 description 1
- 238000005201 scrubbing Methods 0.000 description 1
- 239000000565 sealant Substances 0.000 description 1
- 229910052709 silver Inorganic materials 0.000 description 1
- 239000004332 silver Substances 0.000 description 1
- 239000002002 slurry Substances 0.000 description 1
- 229910000029 sodium carbonate Inorganic materials 0.000 description 1
- 235000010339 sodium tetraborate Nutrition 0.000 description 1
- 239000002904 solvent Substances 0.000 description 1
- 238000010186 staining Methods 0.000 description 1
- 229910052723 transition metal Inorganic materials 0.000 description 1
- 229910000314 transition metal oxide Inorganic materials 0.000 description 1
- 150000003624 transition metals Chemical class 0.000 description 1
- BSVBQGMMJUBVOD-UHFFFAOYSA-N trisodium borate Chemical compound [Na+].[Na+].[Na+].[O-]B([O-])[O-] BSVBQGMMJUBVOD-UHFFFAOYSA-N 0.000 description 1
- 230000000007 visual effect Effects 0.000 description 1
- 239000000037 vitreous enamel Substances 0.000 description 1
- 238000010792 warming Methods 0.000 description 1
- 239000011787 zinc oxide Substances 0.000 description 1
Landscapes
- Thermal Transfer Or Thermal Recording In General (AREA)
- Laser Beam Processing (AREA)
Abstract
Methods for vitrescent marking of substrates, likes bricks, are described that include placing the substrate to be marked and at least one marking material in reactive contact with each other and vitrifying the substrate and the marking material to form a marking below the outer surface of the substrate. The vitrification may be accomplished by irradiating the marking material and the substrate with a radiant energy beam that has a wavelength and an energy level sufficient to vitrify the marking material and the substrate for form a vitrescent marking that is below the outer surface of the substrate.
Description
METHODS FOR VITRESCENT MARKING
S
BACKGROUND OF THE INVENTION
This invention relates the field of marking materials using lasers. More specifically, this invention relates to the field of marking materials using laser vitrification techniques.
The widespread usage of bricks as building materials on highly visible areas such as walkways and building fronts has led artisans to attempt to decorate or mark bricks with letters or graphical patters. As such, the laser marking of brick, payers, terra-cotta tiles, and other high clay content materials is known in the art.
Currently, surface coating techniques utilize marking mediums, which include either a glass frit containing an energy absorbing enhancer, or a mixed metal oxide or a mixed organic pigment. Using current methods, the marking medium is placed in physical contact with the brick, or other substrate, and the medium is irradiated using a low-energy laser. The irradiation causes the marking material to solidify, and a raised, marking layer is formed on the top surface of the substrate. The non-irradiated portion of the marking material is then removed from the substrate.
Using surface-marking methods, the substrate is not damaged. A raised marking layer is formed on the surface of the substrate. This raised marking layer is thereby subject to damage from cracking due to wear, impacts, thermal stresses and the like.
Therefore, a permanent marking technique is needed that produces a marking that is not susceptible to damage from cracking due to wear, impacts, thermal stresses and the like.
SUMMARY OF THE INVENTION
In one aspect, a method for vitrescent marking of a substrate is provided that comprises placing the substrate to be marked and at least one marking material in reactive contact with each other, wherein the substrate has an outer surface, and vitrifying the substrate and the marking material to form a vitrescent marking below the outer surface of the substrate, wherein the vitrification comprises irradiating the marking material and the substrate with a radiant energy beam, wherein the radiant energy beam has a wavelength and energy level suffcient to vitrify the at least one marking material and the substrate to form a vitrescent marking below the outer surface of the substrate;
In another aspect, a method for vitrescent marking of a substrate is provided that comprises placing a substrate and at least one marking material in reactive contact with each other, wherein the substrate has an outer surface, and irradiating the marking material and the substrate with a continuous wave laser beam having an energy level ranging between about 60 watts and about 100 watts, wherein the laser beam has a wavelength of about 1064 nanometers and is adapted to vitrify the at least one marking material and the substrate to form a vitrescent marking between about one sixty-forth of an inch and about one-eighth of an inch below~the outer surface of the substrate;
In yet another aspect of the invention, a method for vitrescent marking of a substrate is provided that comprises placing at least one marking material onto an outer surface of a brick and vitrifying the brick and the marking material to form a vitrescent marking below the surface of the brick, wherein the vitrification comprises irradiating the at least one marking material and the brick with a laser beam, wherein said vitrescent marking produced is at a depth between about one sixty-fourth of an inch and about one-eighth of an inch below the outer surface of the brick, wherein the laser beam has a wavelength of about 1064 nanometers, wherein the laser beam has a beam width expansion factor of about 1.6x to about 5.0x, wherein the laser beam irradiates the substrate and the marking material with a continuous wave, and wherein the laser beam has an energy level ranging between about 60 watts and about 80 watts.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure l illustrates a method of permanent vitrescent marking of a surface in accordance with the methods of the invention;
Figure 2 is an illustration of the colorant carrier in an open-faced package;
and Figure 2a is a cross-sectional view of the colorant carrier in a sealed package.
DETAILED DESCRIPTION
New and useful methods for permanent vitrescent marking of a substrate have been discovered that include placing the substrate and at least one marking material in reactive contact with each other, and vitrifying the substrate and the marking material to form a vitrescent marking below the surface of the substrate. According to the methods of the invention, and with reference to Figure 1, the marking material and the substrate are irradiated with a radiant energy beam having a wavelength and energy level adapted to vitrify both the marking material and the substrate to form a vitrescent marking below the surface of the substrate. In opposite to current marking methods that apply the marking material to the surface of the substrate, the inventive methods described herein act to produce a mark below the surface of the substrate. The radiant energy beam is used to vitrify the marking material and the substrate by applying heat and energy thereon, thereby fusing them together to form a glass below the surface of the substrate.
As such, the radiant energy beam utilized has a wavelength adapted to vitrify the marking material and the substrate below the surface of the substrate. The vitrified surface area, inclusive of the colorant, is integrally formed into the surrounding material of the substrate and cannot be readily worn off While the lettering or graphical patterns are very visible, very little channeling occurs in the substrate, and the pattern colors are a natural result of the glassification process. The vitrification process is more resistant to freezing and abrasion, as well.
The glass formed is permanent, and lies below the surface of the substrate. As such, the substrate must be adapted such that some vitrification is possible.
Unlike the prior art methods, however, the substrate need not have a material content that allows for complete glassification of an image during vitrification. Rather, the substrate need only have sufficient material content to allow for partial vitrification wherein the vitrified portion remains below the surface of the substrate. Having a vitrescent marking below the surface of the substrate reduces subsequent wear and tear on the marking and prevents debris and other contamination from affecting the appearance of the marked substrate.
As used herein, the term "vitrify" refers to the act of converting materials into a glass or glassy substance by heat and/or fusion. Accoifdingly, the term "vitrification," as used herein, refers to the process of converting materials into glass or glassy substances using heat and/or fusion.
According to the methods of the invention, at least one marking material and a substrate to be marked are placed in reactive contact with each other prior to vitrification.
As used herein, the phrase "reactive contact" means contact su~cient to allow vitrification to take place. As such, it is not critical that the substrate and the marking material be in physical contact with each other, or that the marking material be applied directly onto the surface of the substrate. The substrate and marking material may be adjacent to, in partial physical contact with, or within a su~cient distance from each other such that the marking material and the substrate can be melted and fused together by the radiant energy beam. The marking material may be in various forms, including but not limited to powder, paste and sheet forms. The marking material may also be pre-applied to a carrier prior to vitrification. The amount of marking material employed varies. Generally, however the marking material is applied at a thickness of about 0.0005 inch to about .100 inch thick. The materials may be brought into reactive contact with each other by any known method, including, but not limited to direct application, brushing and dipping. The materials may be mixed in various media, including, but not limited to water, mineral oil, glycerin, other solvents or sol gels. The materials may be in sheet form, or incorporated into a tape or decal. The materials may also be brought into contact with each other by methods including, but not limited to silk screen printing, pad Page S
printing, gravure printing, gravity feed, centrifugal force, roll coating, spraying, brush, dipping, and flow coating. ~
The substrate may be any material for which marking is desired. In one embodiment, the substrate is a brick. A typical brick suited for use in the methods of the invention may comprise a varied mixture of clay, sand and grog. Grog is broken up pieces of brick placed back into the mix to manufacture new bricks. The general contents of a brick, however, will vary by lot and color. No specific brick from any particular manufacturer has been found to be more preferable over any other. However, the different bricks are susceptible to vitrification in varying degrees depending upon such factors as the clay, sand and grog content, and overall color. In another embodiment, the substrate is a ceramic. In yet another embodiment, the substrate comprises cement. In a further embodiment, the substrate is concrete or stone.
The marking material employed may comprise a glass frit material such as lead or lead-free frit, precursors of glass frit materials, metal oxides, mixed metal oxides, or combinations or mixtures thereof. As used herein, the term "glass frit" means pre-fused glass material, which is typically produced by rapid solidification of molten material followed by grinding or milling to the desired powder size. Glass frit is generally composed of alkali metal oxides, alkaline earth metal oxides, silica, boric oxide and transition metal oxides. Examples of glass frit materials include, but are not limited to metal oxides and glass formers, such as silica, zinc oxide, bismuth oxide, sodium borate, sodium carbonate, feldspars, fluorides and the like. Finely ground glass substrate materials are also suitable marking materials, as well as inorganic pigments and precursors thereof. Metal powders such as iron, copper, nickel, silver, chromium and the like may be used, as well as organometallic materials of various metals.
Examples of suitable marking materials also include silver sulfide, copper, copper oxide;
barium sulfate, iron sulfide, calcium hydroxide and crystalline silica, silver sulfide, copper oxide, copper-iron sulfide and kaolin clay, barium sulfate, iron sulfate, iron oxide, lead S borosilicate cobalt compounds, iron oxide chromium compounds, nickel, manganese and chromium compounds and iron oxides. Further examples of inorganic marking materials suitable for use in the present invention include zirconium silicate, zirconium oxide or tin oxide; the crystal lattice of which contains ions of transition metals or rare earth metals, as e.g., in zirconium vanadium blue, in zirconium preseodyme yellow and in zirconium iron pink, or the cadmium sulfides and cadmium sulfosetenides,.as well as inclusion pigments containing such compounds. In specific embodiments of the invention, zirconium vanadium yellow, preseodyme yellow, titanium dioxide, titanates, cadmium sulfides and cadmium sulfoselenides, as well as inclusion pigments containing such compounds, are employed.
Typical ceramic colorants that are suitable for use in the masking material of the invention include, but are not limited to cobalt atuminates, chrome tin pink sphere, chrome tin orchid cassitorite, zirconium preseodyme yellow, zirconium iron pink, tin vanadium yellow, cadmium sulfoselenides, cadmium sulfides, and the inclusion compounds containing them, such as zirconium silicate, tin oxide, zirconium oxide or quartz, copper-red, manganese pink, cotcothar, the iron oxide brown pigments such as iron oxides, iron-chrome-atumina spinets, manganese-alumina spinets, wine-chrome spinets, iron-atumina spinets, zinc-iron spinets, nickel-iron spinets, manganese-chrome spinets, zinc-iron chrome spinets, tin oxide, titanium dioxide and titanates, such as nickel-antimony titanate, chrome-antimony titanate and manganese-antimony titanate.
The glass substance produced via vitrification can vary in color depending upon the color and type of brick, or other substrate, and the marking material employed. For instance, a reddish brick is found to produce a darker vitrescent marking.
Lighter shades of bricks, including for instance gray and ivory, have been shown to produce more of a greenish vitrescent marking. In each case, the vitrified patterns are easily visible below the surface of the brick. Changing the laser type configuration and power might also change the appearance of the vitrification area and its appearance.
In various embodiments of the invention, additional marking enhancement agents are placed in reactive contact with the marking material and the substrate prior to, or after, vitrification. Some marking enhancement agents include, but are not limited to, porcelain enamel mixtures. These mixtures may include, but are not limited to oxides of chromium, cobalt, aluminum and manganese, fluoride containing compounds, soluble molybdenum compounds, crystalline silica, copper, nickel and zirconium compound, spinets, for example cobalt chromite blue-green spinet (Co (Al, Cr~04), chrome iron nickel black spinet ((Ni, Fe)(Cr, Fe) z04: Mn0), and pigments such as nickel antimony titanium yellow rutile (Ti,Ni, Sb)Oz.
The marking materials of the invention may be used alone, or in combination.
For example, a combination of metal oxides with glass frit, metal oxides with metal sulfides, or inorganic pigments with glass frits may be used.
A radiant energy beam is used to vitrify the marking material and the substrate to form a vitrescent marking below the surface of the substrate. According to the methods of 1 i the invention, the radiant energy beam heats specific areas of the surface of the substrate to vitrify, or glassify, the marking material and the substrate. Any radiant energy beam having a wavelength adapted to vitrify the marking material and the substrate to form a vitrescent marking below the surface of the substrate may be employed.
In a specific embodiment of the invention, a carrier is employed to introduce the marking material to the substrate. The marking material may be introduced to the carrier by any known method of accomplishing such. The marking material may be introduced to the carrier using any of the methods described herein for introducing the marking material and the substrate together. Some examples of methods of introducing the carrier to the marking material include, but are not limited to pad printing, silk screening and gravure.
Any carrier may be employed so long as the carrier is capable of carrying the marking material and allows the marking materials and the substrate to fuse during vitrification. In a more specific embodiment, the carrier is non-metallic. In another more specific embodiment, the carrier is formed from a clean metal-based foil wherein pigment colorants are added to react with the metal oxide formed during vitrification.
Examples of suitable metal based carriers, include, but are not limited to nickel, brass, aluminum and the like that are capable of being placed into a foil. Such carriers, upon absorption of laser energy, generally form reactive oxides. In one embodiment, aluminum foil is employed as a carrier. A commercially available aluminum foil that is suitable for use in the methods of the invention is manufactured by All-Foils, Inc., and has a gauge between 0.00025 inch and 0.0059 inch.
In one embodiment, the radiant energy beam is a laser beam. The laser beam can be made steerable via computer controlled steering mirrors, and can also be guided manually. Programs may then be utilized to steer the beam in the shape of letters or graphical characters across the face of the substrate. The programs are written so that different methods of tracing letters or graphical patterns will optimize the laser beam width and intensity. The markings may also be produced by manually guiding the radiant energy beam, or laser beam.
Any laser beam having a wavelength and energy level adapted to vitrify the marking material and the substrate to form a vitrescent marking below the surface of the substrate may be employed. Generally, a high-powered laser is employed so that the marking material and the substrate are melted and fused below the surface of the substrate. In one embodiment, an Nd:Yag laser with a wavelength of 1064 manometers is employed that utilizes a continuous wave beam that has an energy level ranging between about 40W and 250W. A continuous wave beam is preferable because it provides sufficient power to quickly mark the surface of the substrate. The continuous wave beam is also preferable because it produces a smoother mark due to its non-pulsing action upon the surface of the substrate. In another embodiment, an Nd:Yag laser with a wavelength of about 1064 manometers is employed that utilizes a continuous wave beam having an energy level ranging between about 60W and about 100W. In yet another embodiment, an Nd:Yag laser with a wavelength of 1064 manometers is employed that utilizes a continuous wave beam having an energy level ranging between about 60 watts and about 80 watts.
Generally, and in one embodiment of the invention, the Nd:Yag laser is equipped with a 10-inch or larger objective lens and a beam telescope or collimator.
The collimator or beam expander, such as those available from Rodenstock Precision Optics, Inc., expands the beam in a range of 2x - 8x that of the original beam width emanating from the laser. Modification of the standard collimator so as to produce a beam that is expanded by a factor of about 1.6x to about S.Ox wide will unexpectedly improve the resultant intensity of the laser beam, thereby resulting in more efficient marking of objects, particularly in a mass production situation. In a specific embodiment, a beam width expansion factor in the range of 1.6x - S.Ox is utilized with a 254 mm objective lens. In a more specif c embodiment, a beam width expansion factor of 3.Ox is utilized.
In certain embodiments, a Q-switch is incorporated inside the Nd:Yag laser to cause a delay between laser pulses. This allows the power of the emitted beam to build up to a greater power density between each pulse. It is contemplated, however, that other lasers could be used, including a C02 laser, which operates at a continuous wavelength of 10,640 nanometers and a variety of energy levels.
In the specific embodiment of the invention illustrated in Figure 1, one galvanometer motor 2 is connected to an X-axis rotating mirror 6, and another galvanometer motor 4 is connected to a Y-axis rotating mirror 8. Each mirror 6, 8 is used in conjunction with the other and the laser is fitted with a flat-filled lens 14. A laser beam 12 is directed, using a computer-controlled device, in a pattern across the surface of the substrate 10. Upon contact of the laser beam 12 with the substrate 10, a portion of the substrate 10 vitrifies, or turns to glass. The irradiation may take place at any rate. In one embodiment, the irradiation takes place at a rate of about 10 to about 500 millimeters ("mm") per second. In another embodiment, the irradiation takes place at a rate of about 50 mm per second. The irradiation may take dace repeated times to achieve the desired vitrification depth and overall appearance. The laser may make one pass over the desired image, or multiple passes depending on the specific marking material and substrate employed, as well as the desired marking.
The substrates of the invention may be irradiated in accordance with the methods of the invention with little or no pre-treatment. However, it has been found that in order to achieve optimum vitrification, some substrates, such as bricks, must be almost completely dry prior to vitrification. When moisture is present, the laser energy necessary for vitrification is lost converting water to steam. As the steam escapes through the molten glass, it causes bubbles to form. Moisture also takes heat away from the surface causing poor penetration of the beam and resulting in very poor marking qualities. Drying optimizes the glass formation so as to produce a very smooth and glassy appearance of the marked area.
The average moisture content of a high quality clay brick payer as received from commercial sources is approximately 2 to 8 percent, by weight. This moisture can be acquired from rain, snow, condensation, factory applied water based sealants, as well as from other sources. Moisture content must be reduced to about 0.75 percent or less to achieve optimum laser vitrification. When a brick is dry, most of the laser energy will be able to be used to vitrify the clay surface to glass and the remainder into heating the clay body.
Accordingly, in a specific embodiment of the invention, the substrate is dried and/or warmed to a temperature of 100°F or more prior to irradiation.
Drying can be accomplished using a kiln, oven, microwave or infrared heat source. Pre-warming can also be accomplished with a batch warming o~ien or an infrared heat source, by use of a laser beam, or by heating the marking material before vitrification.
In one embodiment, a sealed colorant package that allows the methods of the invention to be practiced without handling various marking materials is provided. The sealed colorant package would be placed in physical contact with the substrate to be marked and irradiated. The sealed colorant package would then be removed from the surface of the substrate and discarded, or recycled. With reference to Figure 2, the colorant carrier 34 is positioned over the surface 32 of the brick 30 with the marking enhancement materials placed on top of the foil 34. The colorant carrier holding the marking material during the irradiation step, the foil forming a metal oxide for use in the vitrification composition.
Figure 2a is a cross-sectional side view depicting a brick 30 having a substrate surface 32 wherein the colorant carrier 40 is a sealed package having a top 42, bottom 44, and a peripheral sealed edge 46. The colorant, for example, glass frit precursors 48, is distributed within the sealed package, either homogeneously or in a predetermined distribution patter, allowing prepackaged shipment of the colorant carrier. In this embodiment, the colorant may be admixed with a liquid, such as mineral oil to form a paste or slurry, which typically results in a staining of the surrounding area requiring a labor intensive scrubbing of the vitrified object. Failure to remove the colorant from the surrounding area can lead to an unsightly discoloration. Further, even if most of the colorant is removed, trace amounts can discolor over time due to ultra violet exposure or normal aging. In a preferred embodiment, the top and bottom sheets are made from foil and the colorant composition is sealed within the package. During the laser marking process, only the area that is used in the vitrifibation step is removed and the laser beam is adjusted so that the package is essentially resealed during the step. Thus, if a dry powder colorant composition is employed, exposure to such items as crystalline silica, which is a known carcinogenic, is reduced or eliminated.
In a particular embodiment of the invention, an oxygen gas assist is incorporated in the process is order to create an oxygen enriched atmosphere on the surface of the substrate prior to vitrification. While not wishing to be bound to any particular theory, it appears that the inclusion of oxygen increases the apparent beam intensity at the interface of the focal point of the laser beam and the surface of the substrate. This apparent increase in intensity provides more depth, width and visual appeal to the finished vitrified surface without compromising the marking speed. Many methods for creating an oxygen-enriched atmosphere are known in the art. Any of those methods may be employed in accordance with the invention. One method for creating an oxygen-enriched environment involves incorporating a gas supply manifold to the surface of the substrate during laser vitrification. The inclusion of oxygen yields improvements in both marking quality and efficiency of the process, per se.
The oxygen can also be introduced to a substrate using flexible hoses and a diffuser, which flood the surface of the clay body with a continuous stream.
Heating the gas prior to delivery to the work surface has also been shown to result in improved performance and efficiency.
All patents arid publications mentioned in this specification are hereby incorporated by reference to the same extent a~a if each individual publication were specifically and individually indicated to be incorporated by reference.
It is to be understood that while certain embodiments of the invention are described and illustrated herein, the invention is not to be limited to the specific form or arrangement described and shown herein. It will be apparent to those skilled in the art that various changes may be made without departing from the scope and spirit of the invention and the invention is not to be considered limited to what is shown and described herein.
S
BACKGROUND OF THE INVENTION
This invention relates the field of marking materials using lasers. More specifically, this invention relates to the field of marking materials using laser vitrification techniques.
The widespread usage of bricks as building materials on highly visible areas such as walkways and building fronts has led artisans to attempt to decorate or mark bricks with letters or graphical patters. As such, the laser marking of brick, payers, terra-cotta tiles, and other high clay content materials is known in the art.
Currently, surface coating techniques utilize marking mediums, which include either a glass frit containing an energy absorbing enhancer, or a mixed metal oxide or a mixed organic pigment. Using current methods, the marking medium is placed in physical contact with the brick, or other substrate, and the medium is irradiated using a low-energy laser. The irradiation causes the marking material to solidify, and a raised, marking layer is formed on the top surface of the substrate. The non-irradiated portion of the marking material is then removed from the substrate.
Using surface-marking methods, the substrate is not damaged. A raised marking layer is formed on the surface of the substrate. This raised marking layer is thereby subject to damage from cracking due to wear, impacts, thermal stresses and the like.
Therefore, a permanent marking technique is needed that produces a marking that is not susceptible to damage from cracking due to wear, impacts, thermal stresses and the like.
SUMMARY OF THE INVENTION
In one aspect, a method for vitrescent marking of a substrate is provided that comprises placing the substrate to be marked and at least one marking material in reactive contact with each other, wherein the substrate has an outer surface, and vitrifying the substrate and the marking material to form a vitrescent marking below the outer surface of the substrate, wherein the vitrification comprises irradiating the marking material and the substrate with a radiant energy beam, wherein the radiant energy beam has a wavelength and energy level suffcient to vitrify the at least one marking material and the substrate to form a vitrescent marking below the outer surface of the substrate;
In another aspect, a method for vitrescent marking of a substrate is provided that comprises placing a substrate and at least one marking material in reactive contact with each other, wherein the substrate has an outer surface, and irradiating the marking material and the substrate with a continuous wave laser beam having an energy level ranging between about 60 watts and about 100 watts, wherein the laser beam has a wavelength of about 1064 nanometers and is adapted to vitrify the at least one marking material and the substrate to form a vitrescent marking between about one sixty-forth of an inch and about one-eighth of an inch below~the outer surface of the substrate;
In yet another aspect of the invention, a method for vitrescent marking of a substrate is provided that comprises placing at least one marking material onto an outer surface of a brick and vitrifying the brick and the marking material to form a vitrescent marking below the surface of the brick, wherein the vitrification comprises irradiating the at least one marking material and the brick with a laser beam, wherein said vitrescent marking produced is at a depth between about one sixty-fourth of an inch and about one-eighth of an inch below the outer surface of the brick, wherein the laser beam has a wavelength of about 1064 nanometers, wherein the laser beam has a beam width expansion factor of about 1.6x to about 5.0x, wherein the laser beam irradiates the substrate and the marking material with a continuous wave, and wherein the laser beam has an energy level ranging between about 60 watts and about 80 watts.
BRIEF DESCRIPTION OF THE DRAWINGS
Figure l illustrates a method of permanent vitrescent marking of a surface in accordance with the methods of the invention;
Figure 2 is an illustration of the colorant carrier in an open-faced package;
and Figure 2a is a cross-sectional view of the colorant carrier in a sealed package.
DETAILED DESCRIPTION
New and useful methods for permanent vitrescent marking of a substrate have been discovered that include placing the substrate and at least one marking material in reactive contact with each other, and vitrifying the substrate and the marking material to form a vitrescent marking below the surface of the substrate. According to the methods of the invention, and with reference to Figure 1, the marking material and the substrate are irradiated with a radiant energy beam having a wavelength and energy level adapted to vitrify both the marking material and the substrate to form a vitrescent marking below the surface of the substrate. In opposite to current marking methods that apply the marking material to the surface of the substrate, the inventive methods described herein act to produce a mark below the surface of the substrate. The radiant energy beam is used to vitrify the marking material and the substrate by applying heat and energy thereon, thereby fusing them together to form a glass below the surface of the substrate.
As such, the radiant energy beam utilized has a wavelength adapted to vitrify the marking material and the substrate below the surface of the substrate. The vitrified surface area, inclusive of the colorant, is integrally formed into the surrounding material of the substrate and cannot be readily worn off While the lettering or graphical patterns are very visible, very little channeling occurs in the substrate, and the pattern colors are a natural result of the glassification process. The vitrification process is more resistant to freezing and abrasion, as well.
The glass formed is permanent, and lies below the surface of the substrate. As such, the substrate must be adapted such that some vitrification is possible.
Unlike the prior art methods, however, the substrate need not have a material content that allows for complete glassification of an image during vitrification. Rather, the substrate need only have sufficient material content to allow for partial vitrification wherein the vitrified portion remains below the surface of the substrate. Having a vitrescent marking below the surface of the substrate reduces subsequent wear and tear on the marking and prevents debris and other contamination from affecting the appearance of the marked substrate.
As used herein, the term "vitrify" refers to the act of converting materials into a glass or glassy substance by heat and/or fusion. Accoifdingly, the term "vitrification," as used herein, refers to the process of converting materials into glass or glassy substances using heat and/or fusion.
According to the methods of the invention, at least one marking material and a substrate to be marked are placed in reactive contact with each other prior to vitrification.
As used herein, the phrase "reactive contact" means contact su~cient to allow vitrification to take place. As such, it is not critical that the substrate and the marking material be in physical contact with each other, or that the marking material be applied directly onto the surface of the substrate. The substrate and marking material may be adjacent to, in partial physical contact with, or within a su~cient distance from each other such that the marking material and the substrate can be melted and fused together by the radiant energy beam. The marking material may be in various forms, including but not limited to powder, paste and sheet forms. The marking material may also be pre-applied to a carrier prior to vitrification. The amount of marking material employed varies. Generally, however the marking material is applied at a thickness of about 0.0005 inch to about .100 inch thick. The materials may be brought into reactive contact with each other by any known method, including, but not limited to direct application, brushing and dipping. The materials may be mixed in various media, including, but not limited to water, mineral oil, glycerin, other solvents or sol gels. The materials may be in sheet form, or incorporated into a tape or decal. The materials may also be brought into contact with each other by methods including, but not limited to silk screen printing, pad Page S
printing, gravure printing, gravity feed, centrifugal force, roll coating, spraying, brush, dipping, and flow coating. ~
The substrate may be any material for which marking is desired. In one embodiment, the substrate is a brick. A typical brick suited for use in the methods of the invention may comprise a varied mixture of clay, sand and grog. Grog is broken up pieces of brick placed back into the mix to manufacture new bricks. The general contents of a brick, however, will vary by lot and color. No specific brick from any particular manufacturer has been found to be more preferable over any other. However, the different bricks are susceptible to vitrification in varying degrees depending upon such factors as the clay, sand and grog content, and overall color. In another embodiment, the substrate is a ceramic. In yet another embodiment, the substrate comprises cement. In a further embodiment, the substrate is concrete or stone.
The marking material employed may comprise a glass frit material such as lead or lead-free frit, precursors of glass frit materials, metal oxides, mixed metal oxides, or combinations or mixtures thereof. As used herein, the term "glass frit" means pre-fused glass material, which is typically produced by rapid solidification of molten material followed by grinding or milling to the desired powder size. Glass frit is generally composed of alkali metal oxides, alkaline earth metal oxides, silica, boric oxide and transition metal oxides. Examples of glass frit materials include, but are not limited to metal oxides and glass formers, such as silica, zinc oxide, bismuth oxide, sodium borate, sodium carbonate, feldspars, fluorides and the like. Finely ground glass substrate materials are also suitable marking materials, as well as inorganic pigments and precursors thereof. Metal powders such as iron, copper, nickel, silver, chromium and the like may be used, as well as organometallic materials of various metals.
Examples of suitable marking materials also include silver sulfide, copper, copper oxide;
barium sulfate, iron sulfide, calcium hydroxide and crystalline silica, silver sulfide, copper oxide, copper-iron sulfide and kaolin clay, barium sulfate, iron sulfate, iron oxide, lead S borosilicate cobalt compounds, iron oxide chromium compounds, nickel, manganese and chromium compounds and iron oxides. Further examples of inorganic marking materials suitable for use in the present invention include zirconium silicate, zirconium oxide or tin oxide; the crystal lattice of which contains ions of transition metals or rare earth metals, as e.g., in zirconium vanadium blue, in zirconium preseodyme yellow and in zirconium iron pink, or the cadmium sulfides and cadmium sulfosetenides,.as well as inclusion pigments containing such compounds. In specific embodiments of the invention, zirconium vanadium yellow, preseodyme yellow, titanium dioxide, titanates, cadmium sulfides and cadmium sulfoselenides, as well as inclusion pigments containing such compounds, are employed.
Typical ceramic colorants that are suitable for use in the masking material of the invention include, but are not limited to cobalt atuminates, chrome tin pink sphere, chrome tin orchid cassitorite, zirconium preseodyme yellow, zirconium iron pink, tin vanadium yellow, cadmium sulfoselenides, cadmium sulfides, and the inclusion compounds containing them, such as zirconium silicate, tin oxide, zirconium oxide or quartz, copper-red, manganese pink, cotcothar, the iron oxide brown pigments such as iron oxides, iron-chrome-atumina spinets, manganese-alumina spinets, wine-chrome spinets, iron-atumina spinets, zinc-iron spinets, nickel-iron spinets, manganese-chrome spinets, zinc-iron chrome spinets, tin oxide, titanium dioxide and titanates, such as nickel-antimony titanate, chrome-antimony titanate and manganese-antimony titanate.
The glass substance produced via vitrification can vary in color depending upon the color and type of brick, or other substrate, and the marking material employed. For instance, a reddish brick is found to produce a darker vitrescent marking.
Lighter shades of bricks, including for instance gray and ivory, have been shown to produce more of a greenish vitrescent marking. In each case, the vitrified patterns are easily visible below the surface of the brick. Changing the laser type configuration and power might also change the appearance of the vitrification area and its appearance.
In various embodiments of the invention, additional marking enhancement agents are placed in reactive contact with the marking material and the substrate prior to, or after, vitrification. Some marking enhancement agents include, but are not limited to, porcelain enamel mixtures. These mixtures may include, but are not limited to oxides of chromium, cobalt, aluminum and manganese, fluoride containing compounds, soluble molybdenum compounds, crystalline silica, copper, nickel and zirconium compound, spinets, for example cobalt chromite blue-green spinet (Co (Al, Cr~04), chrome iron nickel black spinet ((Ni, Fe)(Cr, Fe) z04: Mn0), and pigments such as nickel antimony titanium yellow rutile (Ti,Ni, Sb)Oz.
The marking materials of the invention may be used alone, or in combination.
For example, a combination of metal oxides with glass frit, metal oxides with metal sulfides, or inorganic pigments with glass frits may be used.
A radiant energy beam is used to vitrify the marking material and the substrate to form a vitrescent marking below the surface of the substrate. According to the methods of 1 i the invention, the radiant energy beam heats specific areas of the surface of the substrate to vitrify, or glassify, the marking material and the substrate. Any radiant energy beam having a wavelength adapted to vitrify the marking material and the substrate to form a vitrescent marking below the surface of the substrate may be employed.
In a specific embodiment of the invention, a carrier is employed to introduce the marking material to the substrate. The marking material may be introduced to the carrier by any known method of accomplishing such. The marking material may be introduced to the carrier using any of the methods described herein for introducing the marking material and the substrate together. Some examples of methods of introducing the carrier to the marking material include, but are not limited to pad printing, silk screening and gravure.
Any carrier may be employed so long as the carrier is capable of carrying the marking material and allows the marking materials and the substrate to fuse during vitrification. In a more specific embodiment, the carrier is non-metallic. In another more specific embodiment, the carrier is formed from a clean metal-based foil wherein pigment colorants are added to react with the metal oxide formed during vitrification.
Examples of suitable metal based carriers, include, but are not limited to nickel, brass, aluminum and the like that are capable of being placed into a foil. Such carriers, upon absorption of laser energy, generally form reactive oxides. In one embodiment, aluminum foil is employed as a carrier. A commercially available aluminum foil that is suitable for use in the methods of the invention is manufactured by All-Foils, Inc., and has a gauge between 0.00025 inch and 0.0059 inch.
In one embodiment, the radiant energy beam is a laser beam. The laser beam can be made steerable via computer controlled steering mirrors, and can also be guided manually. Programs may then be utilized to steer the beam in the shape of letters or graphical characters across the face of the substrate. The programs are written so that different methods of tracing letters or graphical patterns will optimize the laser beam width and intensity. The markings may also be produced by manually guiding the radiant energy beam, or laser beam.
Any laser beam having a wavelength and energy level adapted to vitrify the marking material and the substrate to form a vitrescent marking below the surface of the substrate may be employed. Generally, a high-powered laser is employed so that the marking material and the substrate are melted and fused below the surface of the substrate. In one embodiment, an Nd:Yag laser with a wavelength of 1064 manometers is employed that utilizes a continuous wave beam that has an energy level ranging between about 40W and 250W. A continuous wave beam is preferable because it provides sufficient power to quickly mark the surface of the substrate. The continuous wave beam is also preferable because it produces a smoother mark due to its non-pulsing action upon the surface of the substrate. In another embodiment, an Nd:Yag laser with a wavelength of about 1064 manometers is employed that utilizes a continuous wave beam having an energy level ranging between about 60W and about 100W. In yet another embodiment, an Nd:Yag laser with a wavelength of 1064 manometers is employed that utilizes a continuous wave beam having an energy level ranging between about 60 watts and about 80 watts.
Generally, and in one embodiment of the invention, the Nd:Yag laser is equipped with a 10-inch or larger objective lens and a beam telescope or collimator.
The collimator or beam expander, such as those available from Rodenstock Precision Optics, Inc., expands the beam in a range of 2x - 8x that of the original beam width emanating from the laser. Modification of the standard collimator so as to produce a beam that is expanded by a factor of about 1.6x to about S.Ox wide will unexpectedly improve the resultant intensity of the laser beam, thereby resulting in more efficient marking of objects, particularly in a mass production situation. In a specific embodiment, a beam width expansion factor in the range of 1.6x - S.Ox is utilized with a 254 mm objective lens. In a more specif c embodiment, a beam width expansion factor of 3.Ox is utilized.
In certain embodiments, a Q-switch is incorporated inside the Nd:Yag laser to cause a delay between laser pulses. This allows the power of the emitted beam to build up to a greater power density between each pulse. It is contemplated, however, that other lasers could be used, including a C02 laser, which operates at a continuous wavelength of 10,640 nanometers and a variety of energy levels.
In the specific embodiment of the invention illustrated in Figure 1, one galvanometer motor 2 is connected to an X-axis rotating mirror 6, and another galvanometer motor 4 is connected to a Y-axis rotating mirror 8. Each mirror 6, 8 is used in conjunction with the other and the laser is fitted with a flat-filled lens 14. A laser beam 12 is directed, using a computer-controlled device, in a pattern across the surface of the substrate 10. Upon contact of the laser beam 12 with the substrate 10, a portion of the substrate 10 vitrifies, or turns to glass. The irradiation may take place at any rate. In one embodiment, the irradiation takes place at a rate of about 10 to about 500 millimeters ("mm") per second. In another embodiment, the irradiation takes place at a rate of about 50 mm per second. The irradiation may take dace repeated times to achieve the desired vitrification depth and overall appearance. The laser may make one pass over the desired image, or multiple passes depending on the specific marking material and substrate employed, as well as the desired marking.
The substrates of the invention may be irradiated in accordance with the methods of the invention with little or no pre-treatment. However, it has been found that in order to achieve optimum vitrification, some substrates, such as bricks, must be almost completely dry prior to vitrification. When moisture is present, the laser energy necessary for vitrification is lost converting water to steam. As the steam escapes through the molten glass, it causes bubbles to form. Moisture also takes heat away from the surface causing poor penetration of the beam and resulting in very poor marking qualities. Drying optimizes the glass formation so as to produce a very smooth and glassy appearance of the marked area.
The average moisture content of a high quality clay brick payer as received from commercial sources is approximately 2 to 8 percent, by weight. This moisture can be acquired from rain, snow, condensation, factory applied water based sealants, as well as from other sources. Moisture content must be reduced to about 0.75 percent or less to achieve optimum laser vitrification. When a brick is dry, most of the laser energy will be able to be used to vitrify the clay surface to glass and the remainder into heating the clay body.
Accordingly, in a specific embodiment of the invention, the substrate is dried and/or warmed to a temperature of 100°F or more prior to irradiation.
Drying can be accomplished using a kiln, oven, microwave or infrared heat source. Pre-warming can also be accomplished with a batch warming o~ien or an infrared heat source, by use of a laser beam, or by heating the marking material before vitrification.
In one embodiment, a sealed colorant package that allows the methods of the invention to be practiced without handling various marking materials is provided. The sealed colorant package would be placed in physical contact with the substrate to be marked and irradiated. The sealed colorant package would then be removed from the surface of the substrate and discarded, or recycled. With reference to Figure 2, the colorant carrier 34 is positioned over the surface 32 of the brick 30 with the marking enhancement materials placed on top of the foil 34. The colorant carrier holding the marking material during the irradiation step, the foil forming a metal oxide for use in the vitrification composition.
Figure 2a is a cross-sectional side view depicting a brick 30 having a substrate surface 32 wherein the colorant carrier 40 is a sealed package having a top 42, bottom 44, and a peripheral sealed edge 46. The colorant, for example, glass frit precursors 48, is distributed within the sealed package, either homogeneously or in a predetermined distribution patter, allowing prepackaged shipment of the colorant carrier. In this embodiment, the colorant may be admixed with a liquid, such as mineral oil to form a paste or slurry, which typically results in a staining of the surrounding area requiring a labor intensive scrubbing of the vitrified object. Failure to remove the colorant from the surrounding area can lead to an unsightly discoloration. Further, even if most of the colorant is removed, trace amounts can discolor over time due to ultra violet exposure or normal aging. In a preferred embodiment, the top and bottom sheets are made from foil and the colorant composition is sealed within the package. During the laser marking process, only the area that is used in the vitrifibation step is removed and the laser beam is adjusted so that the package is essentially resealed during the step. Thus, if a dry powder colorant composition is employed, exposure to such items as crystalline silica, which is a known carcinogenic, is reduced or eliminated.
In a particular embodiment of the invention, an oxygen gas assist is incorporated in the process is order to create an oxygen enriched atmosphere on the surface of the substrate prior to vitrification. While not wishing to be bound to any particular theory, it appears that the inclusion of oxygen increases the apparent beam intensity at the interface of the focal point of the laser beam and the surface of the substrate. This apparent increase in intensity provides more depth, width and visual appeal to the finished vitrified surface without compromising the marking speed. Many methods for creating an oxygen-enriched atmosphere are known in the art. Any of those methods may be employed in accordance with the invention. One method for creating an oxygen-enriched environment involves incorporating a gas supply manifold to the surface of the substrate during laser vitrification. The inclusion of oxygen yields improvements in both marking quality and efficiency of the process, per se.
The oxygen can also be introduced to a substrate using flexible hoses and a diffuser, which flood the surface of the clay body with a continuous stream.
Heating the gas prior to delivery to the work surface has also been shown to result in improved performance and efficiency.
All patents arid publications mentioned in this specification are hereby incorporated by reference to the same extent a~a if each individual publication were specifically and individually indicated to be incorporated by reference.
It is to be understood that while certain embodiments of the invention are described and illustrated herein, the invention is not to be limited to the specific form or arrangement described and shown herein. It will be apparent to those skilled in the art that various changes may be made without departing from the scope and spirit of the invention and the invention is not to be considered limited to what is shown and described herein.
Claims (38)
1. A method for vitrescent marking of a substrate comprising:
placing a substrate to be marked and at least one marking material in reactive contact with each other, wherein the substrate has an outer surface; and vitrifying the substrate and the at least one marking material to form a vitrescent marking below the outer surface of the substrate, wherein said vitrification comprises irradiating the at least one marking material and the substrate with a radiant energy beam, wherein the radiant energy beam has a wavelength and energy level sufficient to vitrify the at least one marking material and the substrate to form a vitrescent marking below the outer surface of the substrate.
placing a substrate to be marked and at least one marking material in reactive contact with each other, wherein the substrate has an outer surface; and vitrifying the substrate and the at least one marking material to form a vitrescent marking below the outer surface of the substrate, wherein said vitrification comprises irradiating the at least one marking material and the substrate with a radiant energy beam, wherein the radiant energy beam has a wavelength and energy level sufficient to vitrify the at least one marking material and the substrate to form a vitrescent marking below the outer surface of the substrate.
2. The method of claim 1 further comprising removing the moisture from the substrate prior to vitrification.
3. The method of claim 2 comprising drying the substrate prior to vitrification.
4. The method of claim 2 further comprising heating the substrate prior to vitrification.
5. The method of claim 1 wherein the substrate to be marked and at least one marking material are placed in reactive contact with each other by brushing the marking material onto the outer surface of the substrate.
6. The method of claim 1 wherein the substrate to be marked and at least one marking material are placed in reactive contact with each other by spraying the marking material onto the outer surface of the substrate.
7. The method of claim 1 wherein the substrate to be marked and at least one marking material are placed in reactive contact with each other by dipping the substrate in the marking material.
8. The method of claim 1 wherein the substrate to be marked and at least one marking material are placed in reactive contact with each other by centrifugal force.
9. The method of claim 1 wherein the substrate to be marked and at least one marking material are placed in reactive contact with each other by gravity feed.
10. The method of claim 1 wherein said marking material comprises additional marking enhancement agents.
11. The method of claim 1 wherein said substrate is a brick.
12. The method of claim 1 wherein said step of irradiating the at least one marking material and the substrate with a radiant energy beam comprises irradiating the at least one marking material and the substrate with a laser beam.
13. The method of claim 12 wherein said laser beam is applied in a continuous wave.
14. The method of claim 12 wherein laser beam has an energy level ranging between about 40 watts and about 500 watts.
15. The method of claim 14 wherein the laser beam has an energy level ranging between about 60 watts and about 100 watts.
16. The method of claim 14 wherein the laser beam has an energy level ranging between about 60 watts and about 80 watts.
17. The method of claim 14 wherein the vitrification is accomplished in an oxygen-enriched environment.
18. The method of claim 1 wherein the radiant energy beam expansion factor is about 1.6x to about 5.0x wide.
19. The method of claim 1 wherein said at least one marking material is at least one selected from the group consisting of metal oxides, mixed metal oxides, clay, porcelain enamels, ceramic enamels, glass frits, inorganic pigments, boric oxide, borate compounds, powdered graphite, glass beads, ground glass, aluminum, chromium, cobalt, manganese, fluoride containing compounds, soluble molybdenum compounds, crystalline silica, copper, nickel, zirconium compounds, spinels, combinations and mixtures thereof.
20. The method of claim 1 wherein said step of irradiating the at least one marking material and the substrate comprises steering the radiant energy beam over the at least one marking material and the outer surface of the substrate at a rate of about 10 to about 500 millimeters per second.
21. The method of claim 12 wherein said Laser beam is emitted from a Nd: Yag laser.
22. The method of claim 1 wherein said step of placing the substrate and at least one marking material in reactive contact with each other comprises applying the at least one marking material onto the outer surface of the substrate.
23. The method of claim 22 wherein the at least one marking material is in powder form.
24. The method of claim 22 wherein the at least one marking material is in paste form.
25. The method of claim 22 wherein the at least one marking material is in sheet form.
26. The method of claim 1 wherein said step of irradiating the at least one marking material and the substrate with a radiant energy beam comprises irradiating the at least one marking material and the substrate at a depth of between about one sixty-forth of an inch and about one-eighth of an inch below the outer surface of the substrate.
27. The method of claim 1 wherein said at least one marking material is placed on a carrier prior to being placed in reactive contact with the substrate to be marked.
28. The method of claim 27 wherein the carrier is a metal foil.
29. The method of claim 12 wherein said laser beam is applied in a pulsed wave.
30. The method of claim 12 wherein said laser beam has a wavelength of about 1064 nanometers.
31. The method of claim 12 wherein said laser beam is emitted from a CO2 laser.
32. The method of claim 1 wherein the substrate is a ceramic.
33. The method of claim 1 wherein the substrate comprises cement.
34. The method of claim 1 wherein the marking material is applied about 0.0005 inch to about .100 inch thick.
35. The method of claim 1 wherein the substrate comprises stone.
36. A method for vitrescent marking of a substrate comprising:
placing a substrate and at least one marking material in reactive contact with each other, wherein the substrate has an outer surface; and irradiating the at least one marking material and the substrate with a continuous wave laser beam having an energy level ranging between about 60 watts and about 100 watts, wherein the laser beam has a wavelength of about 1064 nanometers and is adapted to vitrify the at least one marking material and the substrate to form a vitrescent marking between about one sixty-forth of an inch and about one-eighth of an inch below the outer surface of the substrate.
placing a substrate and at least one marking material in reactive contact with each other, wherein the substrate has an outer surface; and irradiating the at least one marking material and the substrate with a continuous wave laser beam having an energy level ranging between about 60 watts and about 100 watts, wherein the laser beam has a wavelength of about 1064 nanometers and is adapted to vitrify the at least one marking material and the substrate to form a vitrescent marking between about one sixty-forth of an inch and about one-eighth of an inch below the outer surface of the substrate.
37. A method for vitrescent marking of a substrate comprising:
placing at least one marking material onto an outer surface of a brick; and vitrifying the brick and the at least one marking material to form a vitrescent marking below the surface of the brick, wherein said vitrification comprises irradiating the at least one marking material and the brick with a laser beam, wherein said marking material is applied about 0.0005 inch to about .100 inch thick;
wherein said vitrescent marking produced is a at a depth of between about one sixty-forth of an inch and about one-eighth of an inch below the outer surface of the brick, wherein the laser beam has a wavelength of about 1064 nanometers, wherein the laser beam irradiates the substrate and the marking material with a continuous wave, and wherein the laser beam has an energy level ranging between about 60 watts and about 80 watts.
placing at least one marking material onto an outer surface of a brick; and vitrifying the brick and the at least one marking material to form a vitrescent marking below the surface of the brick, wherein said vitrification comprises irradiating the at least one marking material and the brick with a laser beam, wherein said marking material is applied about 0.0005 inch to about .100 inch thick;
wherein said vitrescent marking produced is a at a depth of between about one sixty-forth of an inch and about one-eighth of an inch below the outer surface of the brick, wherein the laser beam has a wavelength of about 1064 nanometers, wherein the laser beam irradiates the substrate and the marking material with a continuous wave, and wherein the laser beam has an energy level ranging between about 60 watts and about 80 watts.
38. A method for vitrescent marking of a substrate comprising:
placing a substrate and at least one marking material in reactive contact with each other, wherein the substrate has an outer surface; and irradiating the at least one marking material and the substrate with a pulsed wave laser beam having an energy level ranging between about 60 watts and about 100 watts, wherein the laser beam has a wavelength of about 1064 nanometers and is adapted to vitrify the at least one marking material and the substrate to form a vitrescent marking between about one sixty-forth of an inch and about one-eighth of an inch below the outer surface of the substrate.
placing a substrate and at least one marking material in reactive contact with each other, wherein the substrate has an outer surface; and irradiating the at least one marking material and the substrate with a pulsed wave laser beam having an energy level ranging between about 60 watts and about 100 watts, wherein the laser beam has a wavelength of about 1064 nanometers and is adapted to vitrify the at least one marking material and the substrate to form a vitrescent marking between about one sixty-forth of an inch and about one-eighth of an inch below the outer surface of the substrate.
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US10/638,136 | 2003-08-08 | ||
US10/638,136 US7238396B2 (en) | 2002-08-02 | 2003-08-08 | Methods for vitrescent marking |
Publications (2)
Publication Number | Publication Date |
---|---|
CA2474284A1 CA2474284A1 (en) | 2005-02-08 |
CA2474284C true CA2474284C (en) | 2010-06-29 |
Family
ID=34135640
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
CA 2474284 Expired - Fee Related CA2474284C (en) | 2003-08-08 | 2004-07-14 | Method for vitrescent marking |
Country Status (1)
Country | Link |
---|---|
CA (1) | CA2474284C (en) |
-
2004
- 2004-07-14 CA CA 2474284 patent/CA2474284C/en not_active Expired - Fee Related
Also Published As
Publication number | Publication date |
---|---|
CA2474284A1 (en) | 2005-02-08 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6238847B1 (en) | Laser marking method and apparatus | |
US20060112729A1 (en) | Screen printing process | |
JP6445194B2 (en) | Laser absorbing compound | |
AU741717B2 (en) | Laser marking method | |
US5554335A (en) | Process for engraving ceramic surfaces using local laser vitrification | |
US6064034A (en) | Laser marking process for vitrification of bricks and other vitrescent objects | |
US9487435B2 (en) | Laser marking compositions and related methods | |
WO1999025562A1 (en) | Laser marking method and material | |
JPS62183981A (en) | Laser masking method of ceramic material, glaze, glass ceramic and glass | |
US6635846B1 (en) | Selective laser compounding for vitrescent markings | |
US7238396B2 (en) | Methods for vitrescent marking | |
WO2000078554A1 (en) | Laser marking compositions and method | |
US20040137201A1 (en) | Method for creating a colored, engraved mark on a brick | |
JP2010526018A (en) | Laser pigments for ceramics | |
ES2220357T3 (en) | COMPOSITION OF ENAMEL, MANUFACTURING PROCEDURE AND ENAMELED PRODUCTS OBTAINED. | |
CA2474284C (en) | Method for vitrescent marking | |
AU2021391364A1 (en) | Method for erasing a laser-induced marking of glass sheets as well as method and devices for marking and unmarking glass sheets, preferably basic glass sheets, preferably float glass sheets | |
US20180355187A1 (en) | Laser marking compositions and methods of making and using the same | |
AU767732B2 (en) | High contrast surface marking | |
AU767680B2 (en) | High contrast surface marking | |
MXPA00002378A (en) | Laser marking method | |
AU6555201A (en) | High contrast surface marking |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
EEER | Examination request | ||
MKLA | Lapsed |
Effective date: 20170714 |