FR3088431A1 - METHOD AND INSTALLATION FOR EVALUATING THE ADHESIVE CHARACTERISTICS OF AN ADHESIVE TAPE, METHOD AND INSTALLATION FOR PRODUCING AN ADHESIVE TAPE - Google Patents

Abstract

Evaluation method for evaluating an adhesive character of an adhesive substance on a substrate (2) of an adhesive strip (1), the evaluation method providing for: - running the adhesive strip (1) in a direction of scrolling (L), - putting a contact member (21) in contact with the adhesive substance of the adhesive strip (1), and - measuring a longitudinal component according to the direction of travel of forces exerted on the contact member ( 21) by the adhesive strip (1), the longitudinal component being representative of the adhesive nature of the adhesive substance.

Description

Method and installation for evaluating the adhesive nature of an adhesive strip, method and installation for manufacturing an adhesive strip

The invention relates to an evaluation method and installation for measuring an adhesive character of an adhesive substance on a substrate of an adhesive tape as well as to a method and an installation for manufacturing an adhesive tape using implements such an evaluation method and such an evaluation installation respectively.

Currently, the properties of an adhesive substance of an adhesive strip are measured from tests carried out on a sample of adhesive strip previously taken from an installation for manufacturing the adhesive strip.

The measurements are therefore carried out indirectly, with a time lag which can in particular cause loss of adhesive tape when a defect is detected on one or more of the properties of the adhesive substance.

In addition, measurements are made to determine properties, such as viscosity and elasticity, in a dissociated manner. These measurements do not offer a simple and rapid characterization of an adhesive character, or in Anglo-Saxon tack or tackiness terms, of the adhesive substance.

The invention aims to overcome the problems mentioned above.

To this end, according to a first aspect, the invention provides an evaluation method for evaluating an adhesive nature of an adhesive substance on a substrate of an adhesive strip, the measurement method providing for:

- scroll the adhesive strip in a running direction,

- put a contact member in contact with the adhesive substance of the adhesive strip, and

- Measure a longitudinal component in the direction of movement of forces exerted on the contact member by the adhesive strip, the longitudinal component being representative of the adhesive nature of the adhesive substance.

By adhesive character is meant in the sense of the present invention the property of a product or a material capable of being bonded or of adhering to a support.

Thus, the invention provides a continuous dynamic evaluation, on a moving adhesive strip, of the adhesive nature of the adhesive substance. It further provides a simple and rapid way of characterizing the adhesive character of the adhesive substance.

The invention can be applied to the manufacturing control of the adhesive tape to intervene as soon as a defect is detected and thus limit losses.

It can also be applied "in the laboratory", upstream of the application of the adhesive substance during the manufacture of the adhesive strip, to develop a formulation of an adhesive substance. The evaluation process thus makes it possible to establish a close link with the rheological properties measured elsewhere in order to create a predictive model of the properties of the adhesive substance during implementation.

The evaluation method may include measuring a contact force exerted by the contact member on the adhesive strip, and determining the longitudinal component as a function of the contact force.

The evaluation method may provide for moving the contact member and the adhesive strip relative to each other in a vertical direction perpendicular to the direction of travel, and to choose a value of the contact force in a range of contact force values.

According to specific provisions, the evaluation process can take into account the industrial conditions of implementation of the adhesive strip.

In particular, the evaluation method may provide for measuring an ambient temperature in the vicinity of the adhesive strip, and for determining the longitudinal component as a function of the ambient temperature.

Complementarily or alternatively, the evaluation method may provide for measuring a speed of travel of the adhesive strip, and of determining the longitudinal component as a function of the speed of travel.

In this regard, the evaluation method can provide for choosing a value of the scrolling speed within a range of values of the scrolling speed.

The evaluation process may include comparing the measured longitudinal component to a reference longitudinal component.

The contact member may be transparent and the evaluation process may include visualizing the adhesive substance through the contact member. These provisions make it possible to combine the measurements carried out with a visual control, if necessary supplemented with an adapted image processing, of an area of the adhesive strip. Such a visualization can be used to understand and interpret the measurement of the longitudinal component as well as a method of detachment of the adhesive substance.

According to a second aspect, the invention proposes a method of manufacturing an adhesive strip providing for:

- provide a substrate,

- coat a surface of the substrate with an adhesive substance,

- implement the evaluation process as defined above.

When the manufacturing process plans to compare the measured longitudinal component to a reference longitudinal component, the manufacturing process can plan to stop running the adhesive strip when a difference between the measured longitudinal component and the reference longitudinal component reaches a determined threshold.

According to a third aspect, the invention proposes an evaluation installation for the implementation of the evaluation method as defined above, the evaluation installation comprising:

- a chassis,

- a drive system mounted on the chassis and configured to run the adhesive strip in a running direction,

- a contact member mounted on the chassis and configured to be in contact with the adhesive substance of the adhesive strip,

- A detection device configured to measure a longitudinal component in the direction of movement of forces exerted on the contact member by the adhesive strip, the longitudinal component being representative of the adhesive nature of the adhesive substance.

The detection device may include a longitudinal force sensor mounted on the contact member so as to directly measure the longitudinal component.

The detection device may include a torque sensor mounted on the contact member so as to measure a torque exerted on the contact member under the effect of the longitudinal component.

The contact member may comprise a contact surface intended to be in contact with the adhesive substance of the adhesive strip, the contact surface being cylindrical around a central axis perpendicular to the direction of travel, the contact member being pivotally mounted on the chassis along the central axis.

The drive system may include a drive roller having a cylindrical drive surface around a drive axis perpendicular to the direction of travel, the drive surface being intended to be in contact with the adhesive tape to be opposite the contact surface of the contact member.

The detection device may include a vertical force sensor configured to measure a contact force exerted by the contact member on the adhesive strip, the detection device being configured to determine the longitudinal component as a function of the contact force. The detection device can impose the value of the contact force exerted by the contact member on the adhesive strip.

The contact member can be mounted movable on the chassis in a vertical direction perpendicular to the running direction so as to vary the contact force within a range of values of the contact force.

The detection device may include a temperature sensor configured to measure an ambient temperature in the vicinity of the adhesive strip, the detection device being configured to determine the longitudinal component as a function of the ambient temperature.

The detection device may include a speed sensor configured to measure a speed of travel of the adhesive tape, the detection device being configured to determine the longitudinal component as a function of the speed of travel.

The drive system can be configured to vary the frame rate within a range of frame rate values.

The detection device can be configured to compare the longitudinal component measured with a longitudinal reference component.

The contact member may be transparent and the detection device may further comprise a display member configured to view the adhesive substance through the contact member.

According to a fourth aspect, the invention proposes an installation for manufacturing an adhesive strip comprising:

- a substrate loading station,

- a coating station configured to coat a surface of the substrate with an adhesive substance,

- an evaluation facility as defined above.

When the detection device is configured to compare the measured longitudinal component to a reference longitudinal component, the detection device can be configured to stop the tape from running when a difference between the measured longitudinal component and the reference longitudinal component reaches a determined threshold.

Other objects and advantages of the invention will appear on reading the following description of particular embodiments of the invention given by way of non-limiting example, the description being made with reference to the accompanying drawings in which:

FIG. 1 is a schematic perspective representation according to a first orientation of an installation for manufacturing an adhesive strip comprising an installation for evaluating an adhesive nature of an adhesive substance on a substrate of the adhesive strip,

FIG. 2 is a schematic perspective representation in a second orientation, opposite to the first orientation, of the evaluation installation of the manufacturing installation of FIG. 1,

- Figures 3 to 6 are representations of a first example of experimentation implementing the evaluation installation of Figure 1, Figures 4 to 6 illustrating data obtained during the experiment on a first strip reference adhesive shown diagrammatically in FIG. 3, the first reference adhesive strip comprising blocks of adhesive substances of different compositions, the data being relative to a longitudinal component of forces exerted by the adhesive strip on a contact member brought into contact with the adhesive substance, the longitudinal component being representative of the adhesive character of the adhesive substance, FIG. 4 representing a variation of the longitudinal component over time, FIG. 5 representing the maximum and average values of the longitudinal component for the different compositions at first and second scrolling speeds, FIG. 6 representing a variation of the longitudinal component as a function of adhesion and rheological properties of two of the compositions of the adhesive substance evaluated by an elastic modulus G ’and by a tanô loss factor characterizing a dissipation,

- Figures 7 to 9 are representations of a second example of experimentation implementing the evaluation installation of Figure 1, Figures 8 and 9 illustrating data obtained during the experiment on a second strip reference adhesive shown diagrammatically in FIG. 7, the first reference adhesive strip comprising blocks of adhesive substances of different thicknesses, the data relating to the longitudinal component of the forces exerted by the adhesive strip on the contact member, the FIG. 8 representing a variation of the longitudinal component over time, FIG. 9 representing the maximum and average values of the longitudinal component for the different thicknesses,

- Figures 10 to 16 are representations of a third example of experimentation implementing the evaluation installation of Figure 1, Figures 14 to 16 illustrating data obtained during the experiment on a third strip reference adhesive shown in FIG. 13, the third reference adhesive strip comprising blocks of adhesive substances of different compositions, the data relating to a longitudinal component of forces exerted by the adhesive strip on a contact member brought into contact with the adhesive substance, as well as at a speed of rotation of the contact member driven by the adhesive strip, the speed of rotation of the contact member being measured by means of an experimental device shown in FIGS. 10 to 12 and using an external display device.

In the figures, the same references designate identical or analogous elements.

FIG. 1 schematically represents an installation 5 for manufacturing an adhesive strip 1 according to an embodiment of the invention.

The manufacturing installation 5 comprises a frame 6 resting on a ground surface S and on which are mounted a loading station 7 of a substrate 2 and a coating station 8 configured to coat a surface 3 of the substrate 2 with a adhesive substance and, in particular, a pressure-sensitive adhesive.

A drive system 10 is also provided for scrolling the substrate 2 and the adhesive strip 1 in a running direction L.

The drive system 10 comprises a drive roller 11 having a cylindrical drive surface 12 around a drive axis 13 parallel to the ground surface S and extending in a transverse direction T, perpendicular to the running direction L. The drive roller 11 is pivotally mounted on the chassis 6 around the drive axis 13 and connected to a motorization device 14 adapted to drive the drive roller 11 in rotation along the axis drive 13. The drive surface 12 of the drive roller is in contact with a surface of the substrate 2 opposite the surface 3 coated with adhesive substance to move the substrate 2 and the adhesive strip 1 when it is driven in rotation. The drive system 10 can also include one or more guide rollers 15 pivotally mounted on the chassis and on respective cylindrical outer surfaces from which the substrate 2 and the adhesive strip 1 can rest to ensure sufficient guidance and tension.

The drive system 10 may include an electronic control unit, for example integrated with an electronic control unit 9 of the manufacturing installation 5 which can also control the loading station 7 and the coating station 8. The device motor 14 is connected to the control unit 9 so as to be able to vary a running speed with which the adhesive strip 1 is driven in a range of values of the running speed.

According to the invention, the manufacturing installation 5 also includes an evaluation installation 20 for evaluating an adhesive nature of the adhesive substance on the substrate 2 of the adhesive strip 1.

In the embodiment shown, the evaluation installation 20 is integrated into the manufacturing installation 5 of the adhesive strip 1 of which it shares, as will appear below, the chassis 6, the drive system 10 and the control unit 9. As a variant, the evaluation installation 20 could be independent of the manufacturing installation 5 and include its own chassis, its own drive system and its own control unit.

As shown in more detail in FIG. 2, the evaluation installation 20 comprises a contact member 21 having a cylindrical contact surface 22 around a central axis 23 parallel to the ground surface S and extending along the transverse direction T. The contact member 21 is mounted to rotate freely along the central axis 23 on a support 24 mounted on the chassis 6 and movable in a vertical direction V, perpendicular to the direction of travel L and to the transverse direction T. The support 24 is arranged in such a way that the central axis 23 and the drive axis 13 are superimposed in the vertical direction V. Thus, the contact surface 22 of the contact member 21 can be brought into contact, with a contact force, normal to the contact surface 22, that is to say vertical in the embodiment shown, with the adhesive strip 1, opposite the drive surface 12 of the roller 11, i.e. in contact with the surf ace 3 coated with adhesive substance of the substrate 2. The movement of the support 24, controlled by the control unit 9, relative to the drive roller 11 makes it possible to vary the contact force of the contact member 21 on the adhesive tape 1 within a range of contact force values.

The contact member 21 can be made of any suitable material and in particular steel. Advantageously, the contact member 21 can however be made of a transparent material making it possible to view the area of the adhesive strip with which it is in contact.

The evaluation installation 20 also comprises a detection device 25 configured in particular to measure a longitudinal component in the direction of travel L of the forces exerted on the contact member 21 by the adhesive strip 1. When the surface 3 coated with adhesive substance of the substrate 2 runs in contact with the contact surface 22 of the contact member 21, adhesion forces of the adhesive substance which act on the contact member 21 are found in the longitudinal component of the 'all the forces exerted on the contact member 21. The longitudinal component of the forces exerted on the contact member 21 is therefore representative of the adhesive nature of the adhesive substance.

To do this, the detection device 25 may include one or more longitudinal force sensors 26 mounted on the contact member 21 so as to directly measure the longitudinal component. Complementarily or alternatively, the detection device 25 may comprise a torque sensor (not shown) mounted on the contact member 21 so as to measure a torque exerted on the contact member 21 under the effect of the longitudinal component of the forces exerted on the contact member 21.

The evaluation of the adhesive character of the adhesive substance is carried out continuously directly on the manufacturing installation 5. Under these conditions, it may prove useful to combine this evaluation with measurements of parameters likely to influence the component. longitudinal of the forces exerted on the contact member 21.

The detection device 25 thus comprises one or more vertical force sensors 27 configured to measure the contact force exerted by the contact member 21 on the adhesive strip 1. In the embodiment shown, two vertical force sensors 27 are mounted on the support 24 at a distance from each other in the transverse direction T.

The detection device 25 may also include a temperature sensor 28 configured to measure an ambient temperature in the vicinity of the adhesive strip, as well as a speed sensor 29 configured to measure a speed of movement of the adhesive strip 1. The unit 9 can then determine the longitudinal component as a function of the ambient temperature in the vicinity of the adhesive strip and / or of the running speed of the adhesive strip 1.

The detection device 25 comprises a processing unit to which the various aforementioned sensors are connected. In the embodiment shown, without being limited thereto, the processing unit of the detection device 25 is integrated into the control unit of the measurement installation and therefore into the control unit 9 of the installation of manufacturing 5. The control unit 9 can then determine the longitudinal component as a function of at least one of the following factors which are the contact force, the ambient temperature and the running speed.

When the contact member 21 is made of a transparent material, the detection device 25 may further comprise a display member, such as a camera, configured to view and / or acquire, through the contact member 21 at least one image of the area of the adhesive strip with which the contact member 21 is in contact.

An external display member can also be added to the manufacturing installation 5, at the level of the contact member 21 in order to see the shape of the contact obtained when the member 21 comes into contact with the adhesive strip 1 .

The manufacturing installation 5 described above allows the implementation of a process for manufacturing an adhesive strip 1 including an evaluation process for evaluating the adhesive nature of the adhesive substance on the substrate 2 of the adhesive strip 1.

A strip of substrate 2 is secured to the drive system 10.

A value of the frame rate in the range of frame rate can be chosen by an operator. In addition, a value of the contact force in the range of values of the contact force can be chosen by the operator. This value of the contact force can in particular be chosen as a function of the type of adhesive strip and therefore of substrate 2 and of adhesive substance. The contact force as well as the running speed can vary during the process.

The contact member 21 is moved towards the drive roller 11 so that it can come into contact with the surface 3 of the substrate 2 intended to be coated with adhesive substance until the chosen contact force is reached.

The drive system 10 is activated to first scroll the substrate 2 in a direction of travel, materialized by an arrow SD, from the travel direction L from the loading station 7 to the coating station 8 where one 3 of its surfaces is coated with the adhesive substance. The adhesive strip 1 thus formed continues to run in the running direction L under the effect of the drive system 10 at the running speed until the evaluation installation 20.

The detection device 25 measures the longitudinal component in the direction of travel L of the forces exerted on the contact member 21 by the adhesive strip 1, the ambient temperature in the vicinity of the adhesive strip 1, the speed of travel of the adhesive strip 1, in order to determine the longitudinal component as a function of at least one of the following factors, which are the contact force, the ambient temperature and the speed of travel. Where appropriate, the area of the adhesive substance in contact with the contact member 21 is displayed and images are acquired thereof through the contact member 21.

The control unit 9 can also compare the longitudinal component measured with a longitudinal reference component obtained empirically by prior tests and, for example, stop scrolling the adhesive strip 1 when a difference between the longitudinal component measured and the longitudinal reference component reaches a determined threshold.

The implementation of the evaluation installation 20 makes it possible to evaluate an adhesive character, at variable running speed, ranging for example from 1 m / min to 26 m / min, and at variable temperature, ranging for example from ambient temperature up to 120 ° C., by controlling the contact force and measuring the longitudinal component of the forces exerted on the contact member 21 and generated by the adhesive nature of the adhesive substance.

In connection with FIGS. 3 to 16, examples of experiments implementing the evaluation installation 20 are described. The experimental examples are provided for illustrative and non-limiting purposes.

EXAMPLE 1 silicone masses having different compositions

In this first example, to measure the longitudinal component of the forces exerted on the contact member 21, the evaluation installation 20 implements a longitudinal force sensor 26 sold under the name TME F108TC IdaN. Furthermore, to measure the contact force, the evaluation installation 20 implements a vertical force sensor 27 sold under the name TME F108TC 25daN.

In FIG. 3, a first reference adhesive strip 1 is prepared. It comprises a pattern consisting of four rows of blocks of adhesive substance spaced apart from one another in the direction of travel L. Each row comprises five blocks of adhesive substance 30 juxtaposed in the transverse direction T. Each block of adhesive substance has a length of 9 cm in the direction of travel L, a width of 3 cm in the transverse direction T and a thickness of 0.3 mm in the vertical direction V.

The adhesive substance is a silicone of known and controlled rheology obtained by the mixture of variable concentrations of two compounds A and B of Silpuran®2114 A / B from Wacker Chimie SAS.

In a first row referenced RI in FIG. 3, the mass ratio of compound A to compound B is 0.8 / 1.2. In a second row referenced R2 in FIG. 3, the mass ratio of compound A on compound B is 0.85 / 1.15. In a third row referenced R3 in FIG. 3, the mass ratio of compound A to compound B is 0.9 / 1.1. In a fourth row referenced R4 in FIG. 3, the mass ratio of compound A to compound B is 0.95 / 1.05. Compounds A and B are mixed with a spatula at room temperature in the appropriate proportions for 5 minutes. A template of specific geometry is placed beforehand on the polyester strip with a thickness of 50 microns before pouring the A / B mixture onto it. The mixture is poured so as to completely fill the free volume left by the template. The mixture is then left for two days at room temperature so that it gels and hardens. After this time, the template is carefully peeled off from the strip.

FIG. 4 illustrates a variation in the longitudinal component of the forces exerted on the contact member 21 during a PI approach phase, where the speed of travel of the adhesive strip 1 is zero, then when the adhesive strip 1 is driven at first VI and second V2 frame rates. For example, the first scrolling speed VI is 1 m / min and the second scrolling speed V2 is 10 m / min. The longitudinal component varies according to the row of blocks of adhesive substance concerned at the same speed. The passage of a row of blocks of adhesive substance on the contact member 21 is characterized by a force peak in the signal measured by the longitudinal force sensor 26. The first VI and second V2 run speeds are imposed on 5 turns.

For each of the rows RI, R2, R3 and R4, a maximum value corresponding to the force peak (Fmax) and a value of the average (Fmoy) of the longitudinal component is measured on each pass.

FIG. 5 illustrates the maximum and average values of the longitudinal component of the forces exerted on the contact member 21 for each row of blocks of adhesive substance and for each of the first VI and second V2 running speeds. The maximum and average values of the longitudinal component vary according to the speed of travel.

FIG. 6 represents a variation in the average value of the longitudinal component as a function of an adhesion work, also called adhesiveness, measured by a so-called tack test, and of rheological properties of two of the compositions of the adhesive substance evaluated by an elastic modulus G 'and by a tanô loss factor characterizing a dissipation. It is found that the more the composition of the adhesive substance has a low elastic modulus G ’, characterizing a soft adhesive substance, and a high loss factor, characterizing a dissipative adhesive substance, the greater the longitudinal component. At the same time, the tackiness measured by the tack test increases.

EXAMPLE 2 Elastomeric masses having different thicknesses

In this second example, the composition of the adhesive substance was prepared using the following constituents in the proportions, expressed as a percentage by weight, mentioned in table 1 below.

Elastomer: block copolymer of poly (styrene-ethylene-butylene-styrene) (abbreviated SEBS): - KRATON® G 1654 ES

Plasticizer: Pionier 2076P mineral oil sold by Hansen & Rosenthal

Vaseline: Codex® A petroleum jelly sold by the company AIGLON

Antioxidant: IRGANOX® 1010 marketed by BASF

Hydrocolloid: Carboxymethylcellulose sodium CMC BLANOSE® 7H4XF sold by the company ASHLAND,

Resin: ExcoreMobil Escorez 5380 cycloaliphatic resin

Active: potassium sucrose octsulfate sold by the company Euticals

Composition manufacturing

The carboxymethylcellulose, potassium sucrose octasulfate and SEPINOV EMT 10 are premixed and sieved at 400 μm.

The oil is introduced into a kneader at a set temperature of 90 ° C, at a speed of 60 to 70 rotations per minute (rpm), then the powders of carboxymethylcellulose, SEPINOV EMT 10 and potassium sucrose octasulfate are introduced. sifted. We knead for 5 minutes.

The set temperature is increased to 140 ° C. We then introduce the elastomer and the antioxidant. Mix for 45 minutes (until a smooth and homogeneous mixture is obtained). The resin is introduced 15 minutes before the end of the mixing step.

The composition was then allowed to cool, then the mixer was drained.

Ex. 2 Ref. commercial % weight SEBS (Kraton G1654 ES from Kraton Polymer) 6.0 White mineral oil (Pionier 2076P) 32.38 Carboxymethyl cellulose sodium (CMC Blanose 7H4XF from Aschland) 14.0 T etraki s3 - (3,5 -di-tert-butyl-4hydroxyphenyl) pentacrythitol propionate (BASF Irganox 1010) 0.12 copolymer of the salt of 2-methyl-2 [(loxo-2-propenyl) amino] -1-propanesulfonic acid and of the 2-hydroxyethyl ester of propenoic acid (Sepinov EMT 10 from SEPPIC) 5 Euticals potassium octasulfate sucrose 7.5 Cycloaliphatic resin (Escorez 5380) 35.0

In a second reference adhesive strip, the mass according to example 2 is then shaped in a press at 90 ° C. in templates in order to obtain three blocks having a length of 11 cm in the direction of travel L, a width 12 cm 5 in the transverse direction T and a thickness of:

- 0.014 cm for a first row RI,

- 0.019 cm for a second row R2,

- 0.024 cm for a third row R3.

Each of these blocks is placed on a polyester substrate with a thickness of 50 microns according to the same arrangement as in the previous example.

The running speed during the approach phase is V = 0 m / min. Once the adhesive strip 1 in contact with the contact member 21, a speed VI of 1 m / min is imposed over 2 turns.

For each block, a maximum value corresponding to the force peak (Fmax) and a value of the average (Fmoy) of the longitudinal component is measured at each passage. We subtract the baseline from these values. For each thickness, the different measurements made during the two passes are then averaged.

FIG. 8 represents a variation of the longitudinal component over time. Figure 9 shows the maximum and average values of the longitudinal component for the different thicknesses. It can be seen that the more the thickness increases, the greater the longitudinal component.

EXAMPLE 3: Online Adhesive Assessment

In this third example, the measurements of the longitudinal component of the forces exerted by a third reference adhesive strip 1 on the contact member 21 are correlated with measurements of instantaneous speeds of rotation of the contact member from video.

The speed of rotation of the contact member is measured by means of an experimental device shown in FIGS. 10 to 12 and using an external display member.

The external display member, in the form of a camera, is installed so as to display a part of the contact surface 22 of the contact member 21 and the adhesive strip 1. On the contact member 21, a measuring strip comprising white markers numbered from 1 to 15 and separated by 0.2 cm black bands is placed on the contact member for the calibration of the images. During the experiment, the pixels of the images acquired by the camera will change from white to black during the rotation of the contact member 21.

In FIG. 12, the third reference adhesive strip 1 is detected on the images acquired by the camera by means of a first pixel PI and a second pixel P2 of a reference line.

The third reference adhesive strip has three blocks of adhesive substance having a length of 2 cm in the direction of travel L, a width of 9 cm in the transverse direction T and a thickness of 0.3 mm. The blocks associated with liners respectively are placed on the substrate in such a way that the blocks are interposed between the liners and the substrate.

Each block includes an adhesive substance of varying concentrations of two compounds A and B from Silpuran®2114 A / B from Wacker Chimie SAS. In a first row referenced RI in FIG. 13, the mass ratio of compound A on compound B is 0.85 / 1.15. In a second row referenced R2 in FIG. 13, the mass ratio of compound A on compound B is 0.9 / 1.1. In a third row referenced R3 in FIG. 13, the mass ratio of compound A on compound B is

0.95 / 1.05. Thus, from row RI to row R3, the adhesive substance goes from elastic to dissipative.

The contact member is placed in contact with the adhesive strip with a contact force of 0.1 N, then the adhesive strip is driven at a fixed speed. For the same speed, several laps are made before increasing the speed.

FIG. 14 represents the variation of the longitudinal component of the forces exerted by the adhesive strip 1 on the contact member 21 as well as the ordinates yP1 and yP2 of the first PI and second P2 pixels as a function of the images acquired by the camera. The difference of the ordinates yP1 and yP2 of the first PI and second P2 pixels corresponds to a spacing of the liner and the substrate which are not glued on all their facing surfaces. As can be seen from this figure, the maximum value of the longitudinal component corresponding to the force peak is well correlated with the adhesion of the adhesive strip to the contact member which causes a displacement of the contact member.

FIG. 15 represents the variation of the longitudinal component of the forces exerted by the adhesive strip 1 on the contact member 21, and of the change of state of the pixels corresponding to the marks 3, 7, 11 and 15 as a function of the images acquired by the camera. Contact of the adhesive strip with the contact member causes its movement and an increase in the signal from the sensors. As soon as the contact member stops rotating, the longitudinal component returns to its baseline.

FIG. 16 represents the variation of the longitudinal component of the forces exerted by the adhesive strip 1 on the contact member 21, and of the speed of rotation of the contact member as a function of the images acquired by the camera. It appears that the speed of rotation of the contact member is independent of the adhesive substance composition and remains substantially constant over the entire length of the adhesive substance pad.

Claims (24)

1. Evaluation method for evaluating an adhesive nature of an adhesive substance on a substrate (2) of an adhesive strip (1), the evaluation method providing for: - scroll the adhesive strip (1) in a direction of travel (L), - bringing a contact member (21) into contact with the adhesive substance of the adhesive strip (1), and - Measure a longitudinal component in the direction of travel (L) of forces exerted on the contact member (21) by the adhesive strip (1), the longitudinal component being representative of the adhesive nature of the adhesive substance. 2. Evaluation method according to claim 1, providing for measuring a contact force exerted by the contact member on the adhesive strip (1), and for determining the longitudinal component as a function of the contact force. 3. Evaluation method according to claim 2, providing for moving the contact member (21) and the adhesive strip (1) relative to each other in a vertical direction (V) perpendicular to the direction of scroll (L), and choose a contact force value from a range of contact force values. 4. Evaluation method according to any one of claims 1 to 3, providing for measuring an ambient temperature in the vicinity of the adhesive strip (1), and for determining the longitudinal component as a function of the ambient temperature. 5. Evaluation method according to any one of claims 1 to 4, providing for measuring a running speed of the adhesive strip (1), and determining the longitudinal component as a function of the running speed. 6. Evaluation method according to claim 5, providing for choosing a value of the scrolling speed within a range of values of the scrolling speed. 7. Evaluation method according to any one of claims 1 to 6, providing for comparing the longitudinal component measured with a longitudinal reference component. 8. Evaluation method according to any one of claims 1 to 7, wherein the contact member (21) is transparent and providing to visualize the adhesive substance through the contact member (21). 9. Method of manufacturing an adhesive tape providing for: - provide a substrate (2), - coating a surface (3) of the substrate (2) with an adhesive substance, - implementing the evaluation method according to any one of claims 1 to 8. 10. The manufacturing method according to claim 9 when it depends on claim 7, providing to stop scrolling the adhesive strip (1) when a difference between the measured longitudinal component and the longitudinal reference component reaches a determined threshold. . 11. Evaluation installation (20) for implementing the evaluation method according to any one of claims 1 to 8, the evaluation installation comprising: - a chassis (6), - a drive system (10) mounted on the chassis (6) and configured to run the adhesive strip (1) in a running direction (L), a contact member (21) mounted on the chassis (6) and configured to be in contact with the adhesive substance of the adhesive strip (1), - a detection device (25) configured to measure a longitudinal component in the direction of travel (L) of forces exerted on the contact member (21) by the adhesive strip (1), the longitudinal component being representative of the character adhesive of the adhesive substance. 12. Evaluation installation (20) according to claim 11, wherein the detection device (25) comprises a longitudinal force sensor mounted on the contact member (21) so as to directly measure the longitudinal component. 13. Evaluation installation (20) according to any one of claims 11 and 12, wherein the detection device (25) comprises a torque sensor (26) mounted on the contact member (21) so as to measure a torque exerted on the contact member (21) under the effect of the longitudinal component. 14. Evaluation installation (20) according to any one of claims 11 to 13, in which the contact member (21) comprises a contact surface (22) intended to be in contact with the adhesive substance of the adhesive strip (1), the contact surface (22) being cylindrical around a central axis (23) perpendicular to the direction of travel (L), the contact member (21) being pivotally mounted on the frame (6) along the central axis (23). 15. Evaluation installation (20) according to claim 14, wherein the drive system (10) comprises a drive roller (11) having a drive surface (12) cylindrical around an axis of drive (13) perpendicular to the direction of travel (L), the drive surface (12) being intended to be in contact with the adhesive strip (1) opposite the contact surface (22) of the contact member (21). 16. Evaluation installation (20) according to any one of claims 11 to 15, in which the detection device (25) comprises a vertical force sensor (27) configured to measure a contact force exerted by the member contact (21) on the adhesive strip (1), the detection device being configured to determine the longitudinal component as a function of the contact force. 17. Evaluation installation (20) according to claim 16, wherein the contact member (21) is movably mounted on the frame (6) in a vertical direction (V) perpendicular to the direction of travel (L) of so as to vary the contact force within a range of values of the contact force. 18. Evaluation installation (20) according to any one of claims 11 to 17, in which the detection device (25) comprises a temperature sensor (28) configured to measure an ambient temperature in the vicinity of the adhesive strip (1), the detection device (25) being configured to determine the longitudinal component in depending on the ambient temperature. 19. Evaluation installation (20) according to any one of claims 11 to 18, in which the detection device (25) comprises a speed sensor (29) configured to measure a running speed of the adhesive strip (1), the detection device (25) being configured to determine the longitudinal component as a function scrolling speed. 20. An evaluation installation (20) according to claim 19, in which the drive system (10) is configured to vary the scrolling speed within a range of values of the scrolling speed. 21. Evaluation installation (20) according to any one of claims 11 to 20, in which the detection device (25) is configured to compare the longitudinal component measured with a longitudinal reference component. 22. Evaluation installation (20) according to any one of claims 11 to 21, in which the contact member (21) is transparent and the detection device (25) further comprises a display member configured to display the adhesive substance through the contact member (21). 23. Manufacturing installation (5) of an adhesive strip (1) comprising: - a loading station (7) of a substrate (2), - a coating station (8) configured to coat a surface (3) of the substrate (2) with an adhesive substance, - an evaluation installation (20) according to any one of claims 11 to 22. 5 24. Manufacturing installation (5) according to claim 23 when dependent on claim 21, wherein the detection device (25) is configured to stop scrolling the adhesive tape (1) when a difference between the component longitudinal measured and the longitudinal reference component reaches a determined threshold.