INNOVATION IN BURNING METHOD FOR LASER MARKING MACHINES

Technical Field

The present disclosure is related to burning fabrics by using laser technology in order to distress them.

The present disclosure is particularly related to the method to be followed to guide the laser on the fabric while burning (marking) the fabric by means of scanner heads to burn point-based images prepared to give the fabric a natural old look.

Prior Art

Nowadays, the laser technology is guided on the fabric by means of various scanner heads and the surface of the fabric is burned with laser beams. As a result of this burning process, color changes are achieved particularly on jeans fabric and products manufactured from this fabric. Digital pictures or images which create a distressed impression on the fabric are point-based, and laser beams are guided on the fabric in predetermined different durations according to intended color values.

Various color tones are created on the fabric, which is exposed to a little or large amounts of laser beams, in proportion to the intensity of beams. Design programs are used to preview the look of the burning process on the fabric and adjust its position. Thanks to design programs, the image to be burned is brought on the area intended to be burned on the computer screen. Design programs allow users to utilize various parameters, and the burning process is carried out according to these parameters. While burning point-based digital images on fabric, vertical and/or horizontal scanning parameters are entered according to the placement of the scanner head, and the image to be burned is processed on the fabric as rows or columns according to this parameters.

The design program prompts the users to define the DPI parameter in order to determine the beam power or in other words, the color toning of the image to be burned on the fabric. DPI parameter refers to the number of points on a length of one inch. Furthermore, this parameter prevents quality loss due to low resolution of the image to be burned.

However, methods used today do not meet the distressed look expectation properly. A natural look cannot be given particularly in dark washed jeans products and lower tones.

Therefore, textile products processed with laser technology are exposed to manual processing or require re-processing with various chemicals. Such processes increase the use of labor and raw materials as well as costs per product.

Furthermore, workers are exposed to chemicals and powders for longer durations for a more natural look, and risky situations occur in terms of their health. Our environment is also polluted as a result of more water and chemical use.

Thanks to this new method we found, more natural results have been achieved by using laser technology on clothes manufactured particularly from jeans fabric or indigo colored fabric and thereby, costs and damages to the environment have been reduced. Products that cannot be manufactured by using laser technology can be manufactured with laser technology thanks to this new method.

A known art document TR 201 1/12573 describes a method to make marking and pattern design on jeans fabric by using laser beam. Mentioned method allows using more than two mannequins and more than one stand and making marking with laser beam both on products on the stand and on products on mannequins. The system has laser units which can run independently from each other. While one of laser units is making marking on products on the mannequin, the other one can make marking on the stand. However, said document does not describe carrying out the laser burning process according to bump angle of the fabric surface.

Another prior art document KR20080069152A describes a fabric model for processing special patterns with laser marking without any extra cost and loss of functionality and meeting aesthetical wishes of users. In mentioned document, computer image is transferred to the laser marking machine. The laser copies the image of the line beam automatically as a form of the image received by transferring the laser beam. Such products as textile or leather products may be given an image pattern, light and shadow. However, said document does not describe spacing between rows by carrying out the laser burning process according to bump angle of the fabric surface. As a result, it was required to engage into a new development in the related technical field due to above-mentioned problems and insufficiency of current solutions on the issue.

Objective of Invention

The invention aims to solve the troubles mentioned above by taking inspiration from the current situations.

The main aim of the invention is to achieve a natural burned look by putting space between rows according to the weaving direction during the process of burning with laser.

Another aim of the invention is to achieve a marking with a natural look by defining the scanning angle of the image to be burned as well as the row and column values with DPI parameter.

To achieve the objective mentioned above, the invention is a method to guide the laser on the product to be burned during the process of burning point-based burning patterns, which are prepared to give a natural distressed look to the fabric, with laser on the product to be burned by means of scanner heads, wherein it comprises the steps of, a. determining the placement angle of the burn pattern which compose after positioning the burn pattern on the product or on computer screen without the product to be burned by means of a design program by,,

for horizontal and vertical axes on the product to be burned by the design program,

b. calculating the scanning angle, which is the angle of processing the burn pattern on the product to be burned, by means of burned angle which is equal to the bump angle of the fabric surface,

c. determining the quantity of number strings indicating the number of rows in the burn pattern and the number of dots in the row for which the resolution is defined by means of determination of row spacing values , d. determining the content of number strings which will allow processing the burn pattern on the product to be burned with the scanning angle, e. processing the burn pattern on the product to be burned by transferring number strings to the scanner head.

Structural and characteristic specifications and all advantages of the invention will be understood more clearly with the figures provided below and the detailed description written with reference to these figures, and thus, evaluation should be made by considering these figures and detailed description.

Figures to Help to Clarify the Invention

Figure 1 shows a distressed fabric by marking.

Figure 2 shows the look of recessed and protruding surfaces, due to abrasion.

Figure 3 shows a representative image of weaving lines and recesses and protrusions formed on the natural structure of the fabric.

Figure 4 is the view of a sample burn pattern.

Figure 5 is the screenshot of the design program.

Figure 6 is the view of placement angles according to x and y axes.

Figure 7 is the view of the scanning angle and placement angle of which x axis is from right to left and from top to down respectively according to the stance of the operator using the machine.

Figure 8 is the view of the burn pattern parameters on the product to be burned.

Figure 9 is the view showing the determination of the angle to be burned.

Figure 10 is the view of the flow diagram run for the preparation of number strings.

Description of Part References

1. Burn pattern

2. Product to be burned

3. Row spacing

a. Fabric surface bump angle

b. Placement angle

D. Scanning angle Detailed Description of the Invention

In this detailed description, preferred embodiments of the burning method developed for laser marking machines of the invention are described for a better understanding of the subject matter.

As a natural result of the weaving method, recesses and protrusion with an angle of 45 degrees as far as the weaving direction on the surface of the fabrics manufactured for clothing purposes and particularly of jeans fabrics. Mentioned recesses and protrusions may be within the proximity of 45 degrees to +/- 15 degrees. As seen on Figure 2, in the current distressing methods, protruding surfaces are subject to more abrasion, and their colors are seen white or lighter in color compared to the background. Recessed surfaces has less abrasion and the color becomes darker compared to protruding surfaces, and these abrasion differences are easily seen by human eye.

The new method proposed in our invention allows likening the burn patterns (1 ), which are processed digitally on a pixel basis on the product to be burned (2) by means of laser beams guided by a scanner head to achieve an distressed look, to recesses and protrusions in the natural structure due to the weaving of the fabric.

Preview of the burn pattern (1 ) at a certain scale is moved on the product to be burned (2) or on the empty background color of the design program by means of the design program, and the placement of the burn pattern (1 ) is adjusted. This program may be installed on a computer placed on the machine or on a design computer which is independent from the machine.

In the most general sense, our invention is a method to guide the laser on the product to be burned (2) during the process of burning point-based burning patterns (1 ), which are prepared to give a natural distressed look to the fabric, with laser on the product to be burned (2) by means of scanner heads. Firstly, mentioned burn pattern (1 ) is moved and positioned on the product to be burned (2) or on the empty background color of the design program by means of the design program. The placement angle (b) of the burn pattern (1 ) as far as horizontal and vertical axes on the product to be burned (2) is determined via the design program. The scanning angle (D), which is the angle of processing the burn pattern (1 ) on the product to be burned (2), is calculated by means of burned angle which is equal to the bump angle (a) of the fabric surface. Prefably, the burn pattern (1 ) can be rotated with an scanning angle (D) in order to make scanning the burn pattern (1 ) with the scanning angle (A).The operator enters values of row spacing (3). The quantity of number strings indicating the number of rows in the burn pattern (1 ) and the number of dots in the row for which indicating the resolution are determined. The content of number strings which will allow processing the burn pattern (1 ) on the product to be burned (2) with the scanning angle (D) is determined. The burn pattern (1 ) is processed on the product to be burned (2) by transmitting the number strings to the scanner head and if burn pattern (1 ) is rotated with the scanning angle (D) prefably, number strings obtained from the image rotated with the scanning angle (D) rotated back to the required scanning angle (D).. These stages mentioned are detailed and exemplified below. On the computer screen, the following formula is used to determine, the pixel change, i.e. sliding of the burn pattern (1 ) effect on the change of the scanner head in the burning area.

Equation 1 :

/(Pixel Change) x (MaxBits) x (MaxDistance)

V MaxPixelDistance

Distance = x (Orientation Factor)

MaxBits

In the equation 1 :

Distance: Change in axis (mm),

Pixel Change: The number of pixels which are subject to sliding on one axis on the screen, MaxBits: The maximum scanning area that can be scanned by the scanner head,

MaxDistance: The maximum length area that can be scanned by the scanner head (mm),

MaPixelDistance: The maximum pixel distance that can move on the axis on the screen,

Orientation Factor: The factor value for suitable orientation of the movement on the computer screen in the burning area.

For example, the change in the burning area caused by a change of 5 pixels on x axis on the computer screen;

The minimum bits value on x axis for the scanner head: -32768

The maximum bits value on x axis for the scanner head: 32768 MaxBitsX = 32786 ^* 2= 65536 bits will be obtained from the communication protocol.

MaxDistance = 1200 mm selection may be made. It changes depending on the machine and burning head.

MaxPixelDistance = 700 pixels will be obtained from the design program.

Orientation Factor = 1 will be obtained from the construction of the machine.

Distance X (mm) = (((( 5 ^* 65536 ) / 700 ) ^* 1200 ) / 65536 ) ^* 1

Distance X (mm) = 8.571428571 mm

Axes of the scanner head may vary depending on the placement of the scanner head in the burning area and the parameters checking the scanner head and selected in the design program.

After the burn pattern (1 ) is adjusted to the position to be burned, the placement angle (b) of the burn pattern (1 ) on the product to be burned (2) is obtained. After its position to be burned is adjusted, mentioned placement angle (b) is determined on horizontal and vertical axes on the design program.

Then, the burning angle is found for the new method. Mentioned burning angle is same as the fabric surface bump angle (a) mentioned above. (45 +/- 15)

The following formula is used to find the scanning angle.

Equation 2:

D = b - (F ^* orientation factor)

Wherein:

F : Natural burning angle according to weaving direction of the fabric or the new method's angle 45 (+/- 15)

b : Angle of the burn pattern (1 ) after the position adjustment on the product to be burned (2) - placement angle

Orientation Factor: The factor used according to x or y axis of the burning area or according to the scanning angle (D).

The scanning angle (D) - 180 or scanning angle (D) + 180 may be used depending on the scanning axis. This situationdepends on the placement of the scanner head. According to the stance of the operator using the machine, the placement angle (b) of the burn pattern (1 ) to be burned desired from right to left on the x axis may be assumed as 180 degrees. With the new method found;

the scanning angle (D) may be found as = 180 - (45 ^* (-1 )) = 225 or 225 - 180 = 45 degrees. Herein, the orientation factor expressed as -1 changes according to the construction of the machine.

According to the stance of the operator using the x axis machine, the placement angle (b) of the burn pattern (1 ) to be burned desired from top to down on the may be assumed as 180 degrees.

With the new method found;

the scanning angle may be found as (D) = 270 - (45 ^* (-1 )) = 225 or 225 - 180 = 45 degrees. Herein, the orientation factor expressed as 1 changes according to the construction of the machine.

Images prepared on a pixel basis digitally with an distressed look consist of black and white toning. It has 255 tones. It defines the power of the laser on the point selected for the scanner head and burning time of the laser on that point depending on the toning of that point. Thereby, grey tones and patterns seen on the burn pattern (1 ) become visible on the product to be burned (2) with laser beam, particularly on clothing manufactured with jeans fabric.

Another parameter which has an effect on the power (impact, whiteness, depth) of toning on textile products is DPI. DPI parameter is defined by the operator using the machine. The burn pattern (1 ) is divided into rows and columns by means of the DPI parameter and number strings are created.

In the method proposed by the invention, DPI parameter of rows and columns are not the same.

In a preferred embodiment of the invention, row spacing (3) is selected as 24 DPI for providing a more natural look.

In a preferred embodiment of the invention, row spacing (3) is selected as 16 DPI to 28 DPI.

The formula used to find the quantity of the number strings;

Quantity of number strings = y length ^* DPI (Equation 3) The formula used to find the quantity of dots in the number strings;

Quantity of dots in the row = x length ^* DPI (Equation 4)

The edge length of the burn pattern (1 ) on x and y axes are in inch and it indicates the edge length of the burn pattern (1 ) on the relevant axis.

After the determined of the quantity of row strings and content numbers indicating the resolution within the row, the burn pattern (1 ) is examined and the content of the strings is filled up.

After the calculations, mentioned number strings are prepared as follows;

• the initial value is assigned as 0 for the y position variable,

• if the y position variable exceeds the quantity of number strings calculated, it is determined the entire image is scanned and the number strings are prepared for sending to the scanner head,

• if the y position variable does not exceed the quantity of number strings calculated, the initial value is assigned as 0 for the x position variable,

• new number string is created,

• if x position variable does not exceed the number of dots in the row, the point in the coordinates of x position variable and y position variable is added to the numbers list and x position variable is increased 1 , and the same step is queries again for checking whether the x position variable exceeds the number of dots in the row,

• if x position variable exceeds the number of dots in the row, coordinates are added to the number string, they are prepared for sending to the scanner head and y position variable is increased 1 , and the 2nd step is queries again in order to check whether y position variable exceeds the quantity of number strings.

For the number strings and contents prepared, strings or dots within strings which are not necessary to burn with laser may be removed for a shorter and faster process. To make tones of the burn pattern (1 ) visible on the textile product to be burned, the number strings which indicate the tone of dots is sent to the scanner head.

With the new method proposed by the invention, after positioning the scanner head, the burn pattern (1 ) prepared digitally, and the product to be burned (2), the new method to be followed is obtained for number strings scanned with the scanning angle (D) and with row spacing (3). In a preferred embodiment of the invention, after the scanning angle (D, )which is the angle of processing the burn pattern (1 ) on the product to be burned (2), calculating by means of burn angle which is equal to bump angle (a) of the fabric surface, the burn pattern (1 ) may be rotated as much as the scanning angle (D). The following 3 ^* 3 matrix may be used for this operation.

Wherein, x’ and y’ indicate input values of horizontal and vertical axes, x and y indicate output values of horizontal and vertical axes, and tx and ty indicates the shifts on axes.

The following expression may be used for rotating operation. This is because the input and output values become the same if 0 is entered for tx and ty in the matrix. When cos is entered instead of 1 , rotated outputs are obtained.

Furthermore, "Rotate()” and "RotateAtO” commands used in design programs may also be used in rotating operation. (See: "Matrix. RotateAt Method or Matrix. Rotate Method from docs.microsoft.com web page)

After the burn pattern (1 ) is rotated, the method steps proceed with determination of number strings.

If it is preferred to rotate the burn pattern (1 ), after the burn pattern (1 ) is processed on the product to be burned (2) by transmitting the number strings to the scanner head, number strings obtained from the image rotated with the scanning angle (D) for the purpose of examining the pattern in rows and columns, are rotated back to the scanning angle (D) to allow the scanner head process with the newly found method The following formula is used for this operation.

If the number strings are obtained without rotating, there will be no need to rotate the number strings obtained back again.