WO2019105623A1 - Method for printing a flexible product - Google Patents

Abstract

The present invention relates to a method for printing at least one first layer (10) of a flexible product (1), preferably an elastic product (1), particularly preferably an elastomeric product (1), having at least the steps: • providing of the first layer (10) which has a first surface (11), • treating of at least one section (12) of the first surface (11), and • printing of at least the treated section (12) of the first surface (11) at least in sections with an electrically conductive flexible material.

Description

 description

Method of printing a flexible product

The present invention relates to a method for printing a flexible product according to the patent claim 1 and a correspondingly produced flexible product according to the patent claim 11. There are long known various products which comprise at least one elastomeric material or consist of at least one elastomeric material. Such products may also have at least one flexible strength member. These include e.g. Tires, conveyor belts, air springs, drive belts, foils, hoses and the like.

Depending on the application, it may be of interest to process the surface of the elastomeric product or the surface of an elastomeric layer of a multilayer elastomeric product. In particular, it may be relevant to print such a surface.

The disadvantage here is that elastomeric products or layers usually have such a rough surface that it is not or only partially suitable for printing processes. In particular, in printing processes with very fine structures, a rough surface can hinder even at comparatively low roughness. In addition to the roughness of the surface of an elastomeric product or an elastomeric layer is to be noted that components of the elastomeric mixture such as waxes or plasticizers can diffuse out of the mixture and settle on the surface. This can lead to the formation of a so-called vulcanization skin in the context of a vulcanization process, which can cover the surface partially or completely. The vulcanization skin may have, for example, sulfur and peroxydic residues. This can also interfere with printing on the surface, because these substances can influence the surface tension of the surface. As a result, the surface during printing can not be deformed or pressed so that printing substrates can find a sufficient to optimal surface.

An object of the present invention is to provide a flexible product of the type described above, so that its surface is better suited than previously known for printing. This should be achieved in particular for printing processes with very fine structures. At least an alternative to known such flexible products should be created.

The object is achieved by a method with the features of the patent entitlement 1 and by a flexible product with the features of claim 11. Advantageous developments are described in the subclaims.

Thus, the present invention relates to a process for printing at least a first layer of a flexible product, preferably an elastic product, more preferably an elastomeric product. A product is understood to mean an object which is the result of a manufacturing process. The flexible product has at least one first layer, which is at least partially, preferably completely, made of a flexible, preferably of an elastic, particularly preferably of an elastomeric, material. The elastomeric material of the first layer has preferably already been vulcanized. Also, corresponding plastics can be used as a flexible material. The property of flexibility of the product is to be understood as a material property which can be achieved by the use of a flexible material, preferably by the use of an elastic material, and more preferably by the use of an elastomeric material, preferably rubber. The product may be completely, apart from the further inventive features, consist of this material or at least substantially comprise this material, so that the flexible material property of the product can be achieved.

The method according to the invention has at least the steps:

 Providing the first layer, which has at least one first surface,

Treating at least a portion of the first surface, and

 • printing on at least the treated portion of the first surface

 at least in sections with an electrically conductive flexible material. On the one hand, the present invention is based on the recognition that by treating at least one section of the first surface in this area, the quality of the surface can be improved in terms of its suitability by various measures together or alternatively, as described in more detail below becomes.

In particular, in the case of an elastomeric material of the first layer on the untreated sections of the first surface, a vulcanization skin with a comparatively low surface tension may usually still be present. In this case, in the printing process, primarily the portions of the first surface may be printed with the printing material, such as a printing medium. be wetted with a paste, which for the removal or to reduce the

Vulcanization skin were pretreated and thus have a higher surface tension than the vulcanization skin.

On the other hand, the present invention is based on the recognition that by printing the first layer with an electrically conductive flexible material, electrically conductive structures can be formed there which, on account of their Material properties at the same time can be sufficiently flexible to follow the movements of the first layer sufficiently without being damaged or destroyed. As a result, the functionality of the electrically conductive structures also in

Deformations of the first layer are retained, so that electrically conductive structures can be printed on a flexible surface and used as permanently as possible.

The respective surface properties can be checked before, during and / or after the treatment step via different sensor systems. In this way, insights can be gained as to how intensively the subsequent treatment should take place, how intensively the ongoing treatment should take place or how intensively the previous treatment has taken place. In this way, the subsequent or ongoing treatment step can be influenced in its intensity to improve the result of this step. Further, the subsequent printing can be adjusted to the obtained result of the previous treatment.

According to one aspect of the present invention, the portion of the first surface is smoothed at least in sections by the treatment. In other words, the roughness of the first surface in this area is reduced. This can be achieved both by removing bumps, ripples and bumps and depressions such. Craters are made, which e.g. can be formed by a vulcanization skin. Likewise, a reduction in surface tensions may smooth the first surface of the first layer. The treatment can be carried out uniformly for the section so that the same effect can be achieved over the entire section. The treatment may, however, be varied in intensity within the section, so that the effect of the treatment within the section may be different.

According to another aspect of the present invention, the portion of the first surface is recessed at least in sections by the treatment. As a result, a structure obtained by printing with the electrically conductive flexible material can be created such as a trace and or or or an electrical

Component, as will be described later, are arranged and protected by the recessed arrangement against external influences. Also, another electrical component, which can be manufactured independently and placed on the first surface of the first layer and usually has a certain height, are protected by the recessed arrangement against external influences. This is especially true for protection against mechanical damage such as Scratch.

According to another aspect of the present invention, the treatment is carried out as grinding. As a grinder, a cutting blade for accurate demarcations or a cylindrical grinder can be used, which covers the entire surface structure

accordingly abraded. For the grinding process also disc milling cutters can be used, which mill only a narrow slit. It can also be milled offset, so that milling patterns similar to broken lines can be created. Depending on the application, the section of the first surface can be abraded at least in sections, as described above. In addition, cavities, corners or edges can be ground, whose contour can vary depending on the application.

According to a further aspect of the present invention, the treatment is carried out as a laser treatment. A laser treatment is understood to mean laser ablation, which can lead to a reduction in thickness and / or to a structuring of the first surfaces. As a result, the advantages of the previously described grinding can alternatively be achieved. However, a laser can still engrave targeted edges, boundaries or areas. Respective laser engraving processes can be introduced in the Ro 11-to-roll process subareas. As a laser tool, a high-precision laser method can be used, which is applied directly for the coating and printing technology shaping. Advantageous is an on-the-fly laser process.

According to a further aspect of the present invention, the treatment is carried out as plasma treatment. The treatment can be done with a plasma and / or photonic surface technique. The plasma treatment is a collective term for all Plasma processes that can be used for surface treatment. These are in particular the plasma cleaning of surfaces, the plasma activation for increasing the surface tension, the plasma etching for the surface enlargement, for matting and structuring as well as the plasma coating for the application of structures.

According to a further aspect of the present invention, at least one conductor track and / or at least one electrical component is or are formed by the printing on the treated portion of the first surface. A conductor track is understood to be a conductor track of an electronic circuit. Under an electrical component is another component of an electronic

Circuit understood. Preferably, the electrical component or the electronic circuit is one which has previously been embodied as a chip module as a potted electrical component or as a potted electronic circuit rigid as a board. The electrical component or the electronic circuit can, for example, a sensor or a sensor element such. be a probe. The sensor or the

 Sensor element may e.g. Capacitive and or or work inductively and or or can detect an ohmic resistance. For example, temperature, force,

Pressure and / or acceleration sensors are formed. The electrical component or the electronic circuit can also be an actuator or an actuator component. The electrical component or the electronic circuit can furthermore be a battery or a rechargeable accumulator. Also, the electrical component or the electronic circuit may be processing electronics or a computing unit, which can process signals and / or data. Likewise, the electrical component or the electronic circuit a

Signal transmission unit, preferably a wireless signal transmission unit with or without antenna such as NEC (Near Field Communication) or RFID (Radio Frequency IDentification), which can receive and / or send signal. This also heating and / or cooling elements can be formed. According to another aspect of the present invention, the first layer comprises an elastomeric material, preferably consists of an elastomeric material, wherein the first layer is provided in a vulcanized state. In this way, a first layer can be provided which can be treated as described above to achieve the desired properties. Also, if necessary, can be dispensed with a subsequent vulcanization step to the electrically conductive flexible material or the thus formed structures such as

Conductors and / or electrical components to protect from the heat of vulcanization.

According to another aspect of the present invention, the method comprises at least the step before providing:

 • Rolling of the first surface of the first layer in an unvulcanized state by means of a counter roll with an at least partially formed S ilikonob it surface.

As a result of this pretreatment of the first surface of the first layer, in the case of an elastomeric first layer, its surface tension can already be changed and, in particular, reduced before the treatment described above takes place. For this purpose, the first layer with its first surface, e.g. in a calendering process via a silicone surface such as e.g. be guided over a counter roll with silicone foil. As a result, the first surface of the first layer can be given a very low surface tension. The counter roll with silicone film can also have a structuring, which can bring about desired changes in the surface tension only in certain places. The silicone structures can prevent the printing process from leaving residues of printing materials such as e.g. functional inks or pastes on

unwanted portions of the first surface can adhere. Thus, this can lead to a sharp separation between adherent and non-adherent first surface.

According to another aspect of the present invention, the method comprises at least the further step: Applying at least a second layer at least in sections to the first surface of the first layer,

wherein the electrically conductive flexible material is at least partially covered by the second layer.

As a result, the electrically conductive flexible material on the first surface of the first layer can be better kept and protected against external influences.

The present invention also relates to a flexible product, which is characterized in that the flexible product has been produced by a method as described above. As a result, the properties and advantages described there can be used on a product.

According to another aspect of the present invention, the flexible product is a flexible sensor, preferably an elastic sensor, more preferably an elastomeric sensor. In this way, a sensor may be formed as a flexible body, preferably for use in other flexible bodies such as e.g. a tire, a drive belt, a conveyor belt, a foil, an air spring or a hose to be used.

According to another aspect of the present invention, the flexible product is a tire, a drive belt, a conveyor belt, a foil, an air spring or a hose. This allows a direct integration into the flexible product already at its

Manufacture done.

The advantages of the various aspects of the present invention described above are, in particular, to be seen in the fact that an ideally ideally flat, i. Smooth, as well as flat surface with a reduced or optimized surface tension of a partial surface or the total area can be created. Also, the

Representing a sharp separation between adherent and non-adherent portions of the first surface can be achieved. In this case, it is advantageous in particular that no laser trimming can be required after ink printing since the structures were printed cleanly. This can be ideal for encapsulation process, because by plane surfaces very many adhesive surfaces or

Air pockets can be used, which can mean a quality optimization.

By a clear delimitation by a depression or other surface tension, the printed image can be further improved. Since with an elastomeric first layer on other points of the surface structure a vulcanization skin with little surface tension can still be present, in the printing process the spots are wetted with paste, which have been pretreated. This can lead to a longer life expectancy of the flexible product.

An embodiment and further advantages of the invention are explained below in connection with the following figures. It shows:

 1 is a perspective schematic representation of a first surface of a

 provided first layer of a flexible product;

 Fig. 2 shows the illustration of Figure 1 with a treated portion of the first

 Surface of the first layer;

 FIG. 3 shows the illustration of FIG. 2 with a printed portion of the first surface of the first layer; FIG. and

 Fig. 4 shows the illustration of Figure 3 with a second layer.

The description of the o.g. Figures take place in Cartesian coordinates with a longitudinal direction X, a transverse direction Y perpendicular to the longitudinal direction X, and a vertical direction Z perpendicular to both the longitudinal direction X and the transverse direction Y. The longitudinal direction X can also be referred to as depth X and transverse direction Y as well as width Y and the vertical direction Z are also referred to as height Z.

1 shows a perspective schematic representation of a first surface 11 of a provided first layer 10 of a flexible product 1. The first layer 10 consists of a vulcanized elastomeric material, so that the first layer 10 is flexible. The first layer 10 extends substantially in the plane of the longitudinal direction X and the transverse direction Y and is in the height Z comparatively small, ie thin, formed.

Viewed at the height Z from the top, the first layer 10 has the first surface 11, which extends substantially in the horizontal, which is formed by the longitudinal direction X and by the transverse direction Y. The first surface 11 has a certain roughness and a vulcanization skin.

According to the invention, the first surface 11 is ground in sections, so that the roughness in this region of the first surface 11 can be reduced. Furthermore, this can reduce the surface tension. FIG. 2 shows the representation of FIG. 1 with a treated section 12 of the first surface 11 of the first layer 10.

The treated portion 12 of the first surface 11 of the first layer 10 is then printed in sections with an electrically conductive flexible material. For this purpose, suitable known printing methods can be used. Two interconnects 13 and an electrical component 14 are formed so that correspondingly flexible electrical structures 13, 14 can be formed on the first surface 11 of the first layer 10 as a flexible substrate, see FIG flexible product 1 can withstand better than conventional rigid conductor tracks 13 and electrical components 14th

Subsequently, a second elastomeric layer 15 is applied to the first surface 11 of the first layer 10, see FIG. 4, to cover the conductor tracks 13 and the electrical component 14. Further, the flexible elastomeric product 1 is vulcanized to obtain its final material properties. List of Reference Numerals (part of the description)

X longitudinal direction; depth

Y transverse direction; width

 Z vertical direction; height

1 flexible product; elastic product; elastomeric product; Sensor; Tire;

 Drive belt; Conveyor belt; Foil; Air suspension; tube

10 first shift

11 first surface of the first layer 10

12 treated portion of the first surface 11th

 13 trace

 14 electrical component

15 second shift

Claims

claims Method for printing at least one first layer (10) of a flexible product (1), preferably an elastic product (1), particularly preferably an elastomeric product (1), having at least the following steps:  Providing the first layer (10) having at least a first surface (11),  Treating at least a portion (12) of the first surface (11), and printing at least the treated portion (12) of the first surface (11) at least in sections with an electrically conductive flexible material. 2. The method according to claim 1, characterized in that  the section (12) of the first surface (11) is smoothed by the treatment at least in sections. 3. The method according to claim 1 or 2, characterized in that  the section (12) of the first surface (11) is recessed at least in sections by the treatment. 4. The method according to any one of the preceding claims, characterized in that the treatment takes place as grinding. 5. The method according to any one of the preceding claims, characterized in that the treatment is carried out as a laser treatment. 6. The method according to any one of the preceding claims, characterized in that the treatment is carried out as a plasma treatment. Method according to one of the preceding claims, characterized in that by printing on the treated portion (12) of the first surface (11) at least one conductor track (13) and / or at least one electrical component (14) is / are formed. Method according to one of the preceding claims, characterized in that the first layer (10) comprises an elastomeric material, preferably consists of an elastomeric material,  wherein the first layer (10) is provided in a vulcanized state. Method according to one of the preceding claims, with at least the step before providing:  Rolling the first surface (11) of the first layer (10) in an unvulcanized state by means of a counter-roller with an at least sectionally  trained silicone surface. 10. The method according to any one of the preceding claims, with at least the other  Step:  Applying at least a second layer (15) at least in sections to the first surface (11) of the first layer (10),  wherein the electrically conductive flexible material is at least partially covered by the second layer (15). 11. Flexible product (1), characterized in that  the flexible product (1) has been produced by a method according to one of the preceding claims. 12. Flexible product (1) according to claim 11, characterized in that the flexible product (1) is a flexible sensor (1), preferably an elastic sensor (1), particularly preferably an elastomeric sensor (1). 13. Flexible product (1) according to claim 11, characterized in that  the flexible product (1) is a tire (1), a drive belt (1), a conveyor belt (1), a film (1), an air spring (1) or a hose (1).