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EP-4741139-A1 - METHOD FOR PRINTING AND PRINTER

EP4741139A1EP 4741139 A1EP4741139 A1EP 4741139A1EP-4741139-A1

Abstract

a method for printing of an object with a printer, comprising printing the object (11) on a removal sheet (12) using a printing material; and bending the removal sheet to detach the printed object. The removal sheet is made of an elastomer having an inner bend radius of 50-800 % of the thickness of the removal sheet, as measured according to ISO 10619-1:2018, adapted method B.

Inventors

  • PRAKASH, DHAYAKUMAR RAJAN
  • KALPIO, TOMI
  • KOSKI, Timo
  • PRINSSI, Roosa
  • SÄILYNOJA, Eija

Assignees

  • Stick Tech OY

Dates

Publication Date
20260513
Application Date
20241107

Claims (15)

  1. A method for printing of an object with a printer, comprising - printing the object on a removal sheet using a printing material; and - bending the removal sheet to detach the printed object; wherein the removal sheet is made of an elastomer having an inner bend radius of 50-800 % of the thickness of the removal sheet, as measured according to ISO 10619-1:2018, adapted method B.
  2. The method according to claim 1, further comprising measuring a force of ejection when the printed object is detached.
  3. The method according to claim 1 or 2, wherein the removal sheet is at least partially coated with an adhesive prior to printing the object, wherein a peeling strength of the adhesive is lower than a shear force caused by the bending of the removal sheet, the peeling strength being measured according to ISO 11339:2022 and the shear force being measured according to ISO 13445:2003.
  4. The method according to claim 3, wherein the adhesive is selected from polylactic acid, polycaprolactone, ethylene vinyl acetate, polyethylene glycol, polyvinyl alcohol, thermoplastic polyurethane, polyethylene terephthalate glycol, polybutylene adipate terephthalate, and polybutylene succinate.
  5. The method according to any of the preceding claims, wherein the removal sheet is made of silicone, natural rubber, styrene-butadiene rubber, ethylene-propylene-diene monomer, nitrile rubber, butyl rubber, chloroprene rubber, polyurethane rubber, thermoplastic polyurethane, chlorosulfonated polyethylene, ethylene acrylic elastomer, perfluoroelastomer, polyacrylic rubber, polychloroprene, styrene-ethylene-butylene-styrene, polyether block amide, polysulfide rubber, vinyl methyl silicone rubber, liquid silicone rubber, epichlorohydrin rubber, ethylene-vinyl acetate rubber, polypropylene elastomer, fluorosilicone rubber, hydrogenated nitrile rubber, polyether polyurethane, thermoplastic polyester elastomer, acrylic rubber, ether-based polyurethane, or ester-based polyurethane.
  6. The method according to any of the preceding claims, wherein the removal sheet has a thickness of 0.1-10 mm.
  7. The method according to any of the preceding claims, wherein the object is made of a curable resin, and the curing of the printed object is carried out using ultraviolet light, infrared light, thermal curing or chemical curing.
  8. The method according to claim 7, wherein curing is carried out using ultraviolet light or infrared light, and the removal sheet is transparent or translucent to the used light.
  9. The method according to any of the preceding claims, wherein the removal sheet comprises at least one indentation, and the removal sheet has a compression set of less than 30 % when measured according to ISO 815-1:2019 at a temperature of 23 °C ± 2 °C.
  10. The method according to claim 9, further comprising at least partially filling the at least one indentation with a material capable of at least one of providing support and creating an oxygen inhibition layer on the object to be printed.
  11. A printer comprising a printer head; a removal sheet made of an elastomer having an inner bend radius of 50-800 % of the thickness of the removal sheet, as measured according to ISO 10619-1:2018, adapted method B; and means for bending the removal sheet.
  12. The printer according to claim 11, wherein the removal sheet is in the form of a conveyer belt.
  13. The printer according to claim 11, further comprising a support for the removal sheet, which support has an opening arranged at a location on which an object is configured to be printed on the removal sheet, and the means for bending the removal sheet is a movable protrusion arranged in the opening and configured to push the removal sheet to detach the printed object.
  14. The printer according to claim 11, wherein the means for bending the removal sheet is a roll arranged to bend the removal sheet.
  15. The printer according to any of the claims 11-14, further comprising means for measuring the ejection force of the printed object.

Description

FIELD The present invention relates to a method for printing of an object, comprising printing the object using a printing material. The present invention also relates to a printer comprising a printer head, and capable of carrying out the present method. BACKGROUND AND OBJECTS Printing, such as three-dimensional printing, commonly called 3D printing, is nowadays a widely used manufacturing method in dentistry and other fields of medicine. Typically, once the object is printed, it needs to be removed from the printer, either using some mechanical means or by hand. These steps typically slow down the overall process. An aim of the present invention is thus to provide a method that can be automated as far as possible, and that would need as little manual handling as possible. A further aim is to provide a printer capable of carrying out the present method. A yet further aim is to provide a method and apparatus where the finished object can be for example turned around at some point of the printing and continue printing on another side of the semi-finished object. SUMMARY OF THE INVENTION The invention is defined by the features of the independent claims. Some specific embodiments are defined in the dependent claims. According to an aspect, there is provided a method for printing of an object with a printer, comprising printing the object on a removal sheet using a printing material; andbending the removal sheet to detach the printed object; wherein the removal sheet is made of an elastomer having an inner bend radius of 50-800 % of the thickness of the removal sheet, as measured according to ISO 10619-1:2018, adapted method B. According to another aspect, there is provided a printer comprising a printer head; a removal sheet made of an elastomer having an inner bend radius of 50-800 % of the thickness of the removal sheet, as measured according to ISO 10619-1:2018, adapted method B; and means for bending the removal sheet. BRIEF DESCRIPTION OF THE DRAWINGS Figures 1a-1c illustrate part of a printer according to a first embodiment.Figures 2a and 2b illustrate a part of a printer according to a second embodiment.Figure 3 illustrates a printer according to a third embodiment.Figures 4a-4e illustrate partial side views of different removal sheets according to some embodiments.Figures 5a and 5b illustrate as top view different removal sheets according to some further embodiments.Figures 6a-6c illustrate as side view some removal sheets according to embodiments.Figures 7a-7c illustrate different removal sheets according to some embodiments.Figure 8 illustrates a part of a printer according to an embodiment.Figure 9 illustrates a part of a printer according to another embodiment.Figure 10 illustrates a part of a printer according to yet another embodiment. DETAILED DESCRIPTION According to an aspect of the present invention, there is provided a method for printing of an object with a printer, comprising printing the object on a removal sheet using a printing material; andbending the removal sheet to detach the printed object; wherein the removal sheet is made of an elastomer having an inner bend radius of 50-800 % of the thickness of the removal sheet, as measured according to ISO 10619-1:2018, adapted method B. The present method is thus based on the principle that the object is printed on a flexible removal sheet made of an elastomer and detached from this removal sheet by bending the removal sheet. The present method does thus not need any other mechanical means for detaching the finished object, such as a robot grabble. The bend radius, which is measured as the inside curvature, is the minimum radius one can bend a sheet without kinking it, damaging it, or shortening its life. The smaller the bend radius, the greater the material flexibility (as the radius of curvature decreases, the curvature increases). The bend radius is measured according to ISO 10619-1:2017, adapted method B. Indeed, the method B of ISO 10619-1:2017, while being designed for rubber and plastics hoses and tubing, can be used to derive the bend radius of the elastomer sheet. The measurement is carried out as in method B, using a test piece having a width equal to the width of the mandrel and a length adequate to provide a grip at each end in addition to a section which can be bent around the periphery of the mandrel (i.e. length as in method B). The inner bend radius is the radius at which the thickness of the elastomer sheet is reduced by 5 % compared to the original thickness, when the sheet is bent around the mandrel The bend radius of the removal sheet is 50-800 % of its thickness. For example, the bend radius can be from 50, 60, 70, 80, 90, 100, 125, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700 or 750 % of its thickness, up to 60, 70, 80, 90, 100, 125, 150, 200, 250, 300, 350, 400, 450, 500, 550, 600, 650, 700, 750 or 800 % of its thickness. The bend radius typically depends also on the manner the removal sheet is bent, suc