Mold for manufacturing at least one marking stamp, stamp and associated process

Abstract

Mold for manufacturing at least one marking stamp for at least one test sample, the mold comprising a body having at least: - A base having a first principal face and a second principal face, - At least one side extending from the base to form at least partially a peripheral border of the base, the first principal face of the base thus forming a bottom of the body, at least one hundred holes extending in at least one area of ​​the base so as to open at one end onto the first principal face and to be blind at a second end opposite the first end, the holes being arranged according to a predetermined pattern. Corresponding stamp and method. FIGURE IN ABRIDGED: Fig. 1

Description

Title of the invention: Mold for manufacturing at least one marking pad, pad and associated method

[0001] The invention relates to a mold for manufacturing at least one marking pad, said pad being able to be used to mark samples used in mechanical and / or physical tests.

[0002] The invention also relates to a method for manufacturing such a mold.

[0003] The invention also relates to a pad manufactured by such a mold.

[0004] BACKGROUND OF THE INVENTION

[0005] Mechanical and / or physical tests are commonly used to characterize the behavior, damage, and failure of a material and / or structure. For this purpose, mechanical, thermal, electromagnetic, chemical, electrical, or coupled stresses are applied to samples, and the local strain field is measured on the surface of the material or structure.

[0006] It is increasingly common to ensure measurement of local deformations and / or monitoring of damage or cracking by analysis of digital images taken on the surface of the sample during the test.

[0007] For this purpose, said surface must be covered with a marking highlighting contrasts of grey levels: the movement of the marking patterns during the test makes it possible to characterize the field of deformations on the observed surface.

[0008] This marking most often consists of spots, made with spray paint or an airbrush. It is then called mottling.

[0009] Unfortunately, a speckled pattern can exhibit defects such as a large disparity in the size of paint spots, a disparity inherent to the application method. This size disparity makes image analysis less precise.

[0010] SUBJECT OF THE INVENTION

[0011] One object of the invention is to propose a solution enabling the improvement of the quality of an image analysis of a sample subjected to any kind of stress (mechanical, physical, chemical ...), inducing deformations, damage, cracking or other measurable surface damage. Summary of the invention

[0012] To this end, according to the invention, a mold is provided for manufacturing at least one marking pad for at least one test sample, the mold comprising a body including at least: - A base with a first main face and a second main face, - At least one flank extending from the base to form at least partially a peripheral border of the base, the first main face of the base thus forming a bottom of the body,

[0013] at least one hundred holes extending in at least one area of ​​the base so as to open at one end onto the first main face and to be blind at a second end opposite to the first end, the holes being arranged according to a predetermined pattern.

[0014] In this way, the invention makes it possible to manufacture a marking pad directly incorporating studs (each stud corresponding to one of the holes in the mold): it then becomes easy to mark a test sample by applying ink or paint to the pad and then applying the pad to the sample.

[0015] The marking thus obtained is much more controlled than with prior art processes, which makes it easier to follow the movement of said marking, directly linked to the deformation of the test sample.

[0016] Optionally, the holes all have the same diameter.

[0017] Optionally, at least one of the holes has a diameter of less than 350 micrometers.

[0018] Optionally, a cross-section of at least one of the holes is circular.

[0019] Optionally, at least the body is made of resin.

[0020] Optionally, the holes cover at least 10% of the base area.

[0021] Optionally, the holes are arranged randomly on the base area.

[0022] Optionally, the holes are all disjoint.

[0023] The invention also relates to a method for manufacturing a mold as mentioned above, comprising the step of producing the body by additive method.

[0024] The invention also relates to a pad manufactured by a mold such as the one mentioned above, in which the pad is made of or based on silicone.

[0025] Other features and advantages of the invention will become apparent from the following description of a particular, non-limiting embodiment of the invention. Brief description of the drawings

[0026] Reference will be made to the attached drawings, among which:

[0027] [Fig-1] is a three-dimensional view of a mold according to an embodiment particular of the invention;

[0028] [Fig.2] is a front view of part of the bottom of the mold shown in [Fig.1];

[0029] [Fig.3] is a three-dimensional view of a pad obtained using the mold represented in [Fig.1];

[0030] [Fig.4] represents a marking of a surface obtained using the pad illustrated in the [Fig.l]. DETAILED DESCRIPTION OF THE INVENTION

[0031] Figures 1 and 2 illustrate a mold 1 for manufacturing at least one marking pad 100.

[0032] The mold 1 comprises a body 2 having at least one base 3. The base 3 is provided with a first principal face 3a and a second principal face 3b opposite the first principal face 3a. The two faces 3a, 3b each extend in a plane.

[0033] The two principal faces 3a, 3b are parallel to each other and to a plane comprising a first axis X and a second axis Y orthogonal to the first axis X. The two principal faces 3a, 3b are, for example, identical. The two principal faces 3a, 3b are, for example, shaped into a rectangle. Each principal face 3a, 3b thus has a length defined along the first axis X and a width defined along the second axis Y. The base 3 therefore has a thickness defined along a third axis Z, which is orthogonal to the first axis X and the second axis Y. The base 3 is thus shaped such that its thickness is less than its length and width. Defined in this way, the base 3 is shaped into a rectangular parallelepiped. In the present case, the base 3 is shaped into a plate.

[0034] Furthermore, the body 2 has at least one side extending from the base 3 to form at least partially a peripheral border of the base 3. In this case, the mold 1 has as many sides as there are sides to the base 3, so that each side forms the border of its corresponding side. In this case, the mold 1 has four sides. In particular, the mold 1 has two longitudinal sides 4 forming borders of the two long sides of the base 3 and two lateral sides 5 forming borders of the two short sides of the base 3.

[0035] The four sides 4, 5 together form a closed frame. Said frame extends over the entire periphery of the base 2. Preferably, each side 4, 5 extends from the second main face 3b (without exceeding it) until it extends beyond the first main face 3a.

[0036] The various flanks 4, 5 are preferably of the same thickness. The flanks 4, 5 preferably have a small thickness and for example a thickness between 1 and 5 millimeters.

[0037] In this way, the first main face 3a of the base 3 forms a bottom of the body 2, a bottom surrounded by the peripheral frame drawn by the sides 4, 5.

[0038] Furthermore, the base 3 has a plurality of holes 6 (only a part of which is referenced in Figures 1 and 2) arranged in at least one area of ​​the base 3. In the present case, said area extends over the whole of the base 3.

[0039] Each hole 6 extends longitudinally so as to open at one longitudinal end onto the first main face 3a and to be blind at its second longitudinal end. It is therefore understood that each hole 6 extends in this way without opening onto the second main face 3b.

[0040] For example, the various holes 6 are arranged so as to extend parallel to each other.

[0041] Preferably, the holes 6 are provided in the aforementioned area so as to extend into at least 10% of said area and so as to extend preferably into at least 20% of said area and so as to extend preferably into at least 30% of said area.

[0042] It is therefore understood that the holes 6 are particularly numerous. The mold 1 thus comprises at least one hundred holes (at least one hundred) and preferably at least several hundred holes.

[0043] The holes 6 are also arranged according to a predetermined pattern. This pattern is defined before the mold is manufactured, for example by an operator and / or by an algorithm.

[0044] In the present case, the pattern is such that the holes 6 are arranged so as to be disjoint from each other i.e. the holes 6 do not open into each other.

[0045] In the present case, the pattern is such that the 6 holes are arranged randomly in the aforementioned area. Thus, the 6 holes do not form any specific alignment or geometric figure, and in particular no line, column, checkerboard, staggered pattern, etc.

[0046] In the present case, the pattern is such that the different holes 6 are all identical to each other.

[0047] Optionally, the design is such that the various holes 6 all have the same diameter. The term "diameter" is to be taken here in its broadest sense, namely the upper bound of the set of distances between any two points of a cross-section of the hole 6 in question. The holes 6 therefore do not necessarily have a circular cross-section.

[0048] In the present case, the pattern is such that the different holes 6 all have the same diameter optionally to a percentage error less (in absolute value) than 5% and preferably less (in absolute value) than 2.5%.

[0049] In the present case, the pattern is such that the diameter of the different holes 6 is less than 350 micrometers and for example is less than 300 micrometers and for example is less than 250 micrometers and for example is less than 220 micrometers.

[0050] In the present case, the pattern is such that the various holes 6 have a circular cross-section.

[0051] In the present case, the pattern is such that the different holes 6 all have an identical cross-section in dimensions and shape over the entire length of the hole 6 considered.

[0052] The mold 1 thus described is preferably made of a single piece. The sides 4, 5 and the base 3 are in particular made of a single piece.

[0053] At least the base 3, and preferably the assembly formed by the base 3 and the sides 4, 5, and preferably the whole mold 1, is made of or based on resin.

[0054] Optionally, the mold 1 thus described is of small dimensions. By "small dimensions" it is understood that the width of the mold 1 is less than 4 centimeters and for example less than 3 centimeters and / or that the length of the mold 1 is less than 8 centimeters and for example less than 5 centimeters.

[0055] The mold 1 thus described proves to be simple in structure.

[0056] The mold 1 thus described proves to be reusable.

[0057] The mold 1 thus described proves to be relatively simple to manufacture.

[0058] A method for manufacturing such a mold 1 will now be described.

[0059] In a first step, a file for printing by additive manufacturing is generated. This file includes, in particular, the diameter and depth of the holes 6 as well as their positioning relative to each other. It is therefore understood that this file contains the predetermined pattern.

[0060] In a second step, the mold 1 is produced by additive manufacturing from the aforementioned file. For example, the mold 1 is produced by three-dimensional printing, for instance, using at least one resin. It should be noted that the base 3 and the sides 4, 5 are printed together. In this way, the mold 1 proves to be robust.

[0061] From mold 1, it is possible to manufacture 100 marking stamps, it being understood that the same mold 1 allows a large number of stamps 100 to be manufactured in series.

[0062] For this purpose, a liquid or semi-liquid material is poured into the mold 1. It is understood that said material will also flow inside the various holes 6 of the mold 1.

[0063] The material is poured so that it reaches the top of the upper ends of the sides 4, 5 or so that it falls below said ends. For example, the poured material is silicone-based or made of silicone.

[0064] After the solidification of said material, a completed pad 100 can be removed from the mold 1.

[0065] Demolding is facilitated by the presence of the sides 4, 5.

[0066] Optionally, at least one of the flanks may include at least one step. Such a step thus locally reduces the thickness of the flank in which it is formed.

[0067] Such a detachment further facilitates the removal of the pad 100 from the mold 1.

[0068] Optionally, the mold 1 has two recesses formed respectively on two opposite sides. For example, the mold 1 has a first recess 10 formed in one of the two lateral sides 5 and a second recess 10 formed in the other of the two lateral sides 5. The two recesses 10 are, for example, identical.

[0069] Optionally, at least one step 10 is centered on the length of the associated flank.

[0070] Optionally, at least one recess 10 is provided so that it is turned only towards the inside of the mold 1. Such a recess 10 therefore does not open onto the outside of the closed frame.

[0071] Optionally, at least one step 10 is provided so as not to extend to the base 3.

[0072] Optionally, at least one step 10 is provided so as to extend from a free surface of the associated flank in the direction of the base 3.

[0073] Fig. 3 illustrates a buffer 100 obtained by the mold 1 described previously.

[0074] The buffer 100 has a support 101. The support 101 is shaped according to the space defined by the first main face 3a and the flanks 4, 5 surrounding it. In the present case, the support 101 is shaped into a rectangular parallelepiped and, for example, is shaped into a plate.

[0075] It is understood that if one or more notches are present in the mold 1, the pad 100 may optionally include one or more corresponding extensions. At least one extension may be retained and / or at least one extension may be removed after demolding (by laser cutting, for example).

[0076] The support 101 thus comprises two principal faces opposite each other. Each principal face is flat. These faces extend, for example, parallel to each other.

[0077] The first main face 101a is smooth, while bumps 102 (only part of which is referenced) extend from the second main face 101b. These bumps 102 correspond to the flow of the liquid or semi-liquid material into the holes 6 of the mold 1.

[0078] Consequently, the pins 102 all extend from the second main face 101b of the support 101.

[0079] Each pin 102 extends longitudinally from the second main face 101b of the support 101 outwards from the support 101. Each pin 102 extends longitudinally, for example, along a normal to the second main face 101b.

[0080] The different pins 102 are independent of each other, i.e. the pins 102 do not touch each other.

[0081] For example, the different pins 102 are arranged parallel to each other.

[0082] Preferably, the pins 102 are arranged so as to cover at least 10% of the second main face 101b of the support 101 and preferably so as to cover at least 20% of said second main face 101b of the support 101 and preferably so as to cover at least 30% of said second main face 101b of the support 101.

[0083] For example, the pegs 102 are arranged randomly on the second main face 101b of the support 101. Thus, the pegs 102 do not form any specific alignment or geometric figure, and in particular no line, column, checkerboard, staggered pattern...

[0084] For example, the different pins 102 are all identical to each other.

[0085] Optionally, the various pins 102 all have the same diameter. The term "diameter" is to be taken here in its broadest sense, namely the upper bound of the set of distances between any two points on a cross-section of the pin 102 under consideration. The pins 102 therefore do not necessarily have a circular cross-section.

[0086] For example, the different pins 102 all have the same diameter to a percentage error of less than (in absolute value) 5% and preferably less than (in absolute value) 2.5%.

[0087] For example the diameter of the different pins 102 is less than 350 micrometers and for example is less than 300 micrometers and for example is less than 250 micrometers and for example is less than 220 micrometers.

[0088] Optionally, the various pins 102 have a circular cross-section.

[0089] Optionally, the different pins 102 all have an identical cross-section in dimensions and shape over the entire length of the pin 102 considered.

[0090] The pad 100 (formed of the support assembly 101 and pins 102) is for example made of or based on silicone.

[0091] The pad 100 is preferably one piece. In particular, the support 101 and the pins 102 are preferably one piece.

[0092] The pad 100 thus described is optionally of small dimensions. By "small dimensions" it is meant that the width of the pad 100 is less than 4 centimeters and for example less than 3 centimeters and / or that the length of the pad 100 is less than 8 centimeters and for example less than 5 centimeters (it being understood that the dimensions of the stamp 100 are necessarily smaller than those of the mold 1).

[0093] With such a stamp 100 it is thus possible to mark a test sample 200.

[0094] For this purpose, an ink or paint or any other equivalent product is deposited on the free ends of the pins 102. The pad 100 is then applied once or several times to at least a portion of the sample 200 that one wishes to study. For example, the pad 100 is applied to the sample 200 and then a weight is placed on the pad 100 for a predetermined time interval.

[0095] Optionally, a manipulator is attached to the buffer 100 and, for example, is attached to the first main face 101a of the buffer 100.

[0096] The manipulator is, for example, a handle or a roller. Once attached to the manipulator, the pad 100 can either retain its previously described shape or deform to conform to the shape of the manipulator. The pad 100 is attached to the manipulator by gluing, screwing, etc.

[0097] This makes it easier to apply the 100 buffer to the sample.

[0098] As seen in [Fig.4], the portion of the sample 200 is then marked by marking points 201 (only part of which is referenced), each point 201 corresponding to the apposition of the free end of one of the pins 102 on the portion of the sample 200.

[0099] Preferably, points 201 are arranged so as to cover at least 10% of the aforementioned portion of sample 200 and preferably so as to cover at least 20% of said portion and preferably so as to cover at least 30% of said portion.

[0100] Advantageously, having a high density of points 201 improves the accuracy of the measurement.

[0101] In the present case, the points 201 are arranged randomly on said portion. Thus, the points 201 do not form any alignment or specific geometric figure, and in particular no line, column, checkerboard, quincunx...

[0102] Advantageously, having points 201 arranged randomly on a portion facilitates the visualization of small deformations and / or small deteriorations.

[0103] In the present case, the different points 201 all have the same diameter. The term "diameter" is to be taken here in the broadest sense, namely the upper bound of the set of distances from any two points 201 of a cross-section of the point 201 under consideration.

[0104] For example, the different points 201 all have the same diameter to a percentage error of less than (in absolute value) 5% and preferably less than (in absolute value) 2.5%.

[0105] Advantageously, having points 201 of homogeneous dimensions improves the accuracy of the measurement.

[0106] For example the diameter of the different points 201 is less than 350 micrometers and for example is less than 300 micrometers and for example is less than 250 micrometers and for example is less than 220 micrometers.

[0107] Optionally, the various points 201 have a circular cross-section.

[0108] It is thus possible to carry out one or more mechanical and / or physical tests (for example temperature rise, exposure to a magnetic field) on the sample 200 and to follow the corresponding deformations or degradations (propagation of cracks, blistering, etc.) by studying the points 201.

[0109] For example, an optical sensor can capture images and an analysis of the images makes it possible to study the movements of points 201, movements directly related to deformations or crack propagation in the sample 200.

[0110] Furthermore, each pixel of the optical sensor can be associated with a window of the portion of the sample 200. The windows can be of the same dimensions or of different dimensions.

[0111] In the present case, thanks to the high point density 201, it is possible to define windows, each comprising between three and five marking points, that are small in size. By small size, we mean that each window forms a polygon (for example, a regular polygon, for example, a square) whose longest side is less than 600 micrometers and preferably less than 500 micrometers. This also improves the accuracy of the measurement.

[0112] Of course, the invention is not limited to the embodiment described but encompasses any variant falling within the scope of the invention as defined by the claims.

[0113] In particular, although here all the holes (and therefore the pins) have a circular cross-section, at least one hole (and therefore the associated pin) may have another cross-section such as, for example, an ellipse, a square, a star, a triangle, ...

[0114] In particular, although here all the holes are disjoint, at least two holes may partially overlap to be connected.

[0115] In particular, although here all the holes are of the same diameter, at least two holes may have different diameters. This will allow, for example, the hole density to be varied according to a specific area of ​​the sample being studied.

[0116] In particular, although here all the holes (and therefore the pins) are arranged in a disorderly manner, at least some of the holes (and therefore the pins) may be arranged in an orderly fashion. This will be particularly advantageous for monitoring large deformations.

[0117] In particular, although here all the holes (and therefore the pins) have an identical cross-section in dimensions and shape along the entire length of the hole in question, at least two holes (and their pins) may be arranged so as to have a different cross-section in dimensions and / or shape along the length of the hole in question. For example, at least one of the holes may widen or narrow from its blind end to its end opening onto the base (the pin will then narrow or widen respectively towards its free end).

[0118] Generally any pattern of holes can be used, adapting the pattern to the intended application.

[0119] A polymer other than silicone may be used to manufacture the pad. Before pouring the material into the mold, the material may undergo one or more processing steps, such as a degassing step.

[0120] Although here the mold and the stamp are of small dimensions, the mold and the stamp may be of larger dimensions.

[0121] Although here all the windows form a regular polygon, at least one of the windows may form a non-regular polygon or may form another closed shape such as a circle.

Claims

Demands

1. Mold for manufacturing at least one marking stamp of at least one test sample, the mold comprising a body (2) having at least: - A base (3) having a first principal face (3a) and a second principal face (3b), - At least one side extending from the base to form at least in part a peripheral border of the base, the first principal face of the base thus forming a bottom of the body, at least one hundred holes extending in at least one area of ​​the base so as to open at a first end on the first principal face and to be blind at a second end opposite to the first end, the holes being arranged according to a predetermined pattern.

2. Mold according to claim 1, in which the holes (6) all have the same diameter.

3. Mold according to claim 1 or claim 2, wherein at least one of the holes (6) has a diameter of less than 350 micrometers.

4. Mold according to any one of claims 1 to 3, wherein a cross-section of at least one of the holes (6) is circular.

5. Molds according to any one of claims 1 to 4, wherein at least the body (2) is made of resin.

6. Mold according to any one of the preceding claims, wherein the holes (6) cover at least 10% of the area of ​​the base (3).

7. Mold according to any one of the preceding claims wherein the holes (6) are arranged randomly on the base area.

8. Mold according to any one of the preceding claims, wherein the holes (6) are all disjoint.

9. A method for manufacturing a mold according to any one of the preceding claims, comprising the step of producing the body (2) by additive method.

10. Pad manufactured by a mold according to any one of claims 1 to 8, wherein the pad is made of or based on silicone.

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