Application nozzle for the manual application of a pasty adhesive

Abstract

A nozzle for the manual application of a pasty adhesive, characterized in that, in the discharge direction (12) towards an application surface (15) of the pasty adhesive, it first comprises a shaft (8) with an internal thread (10) for mounting the shaft (8) onto a corresponding external thread of a material supply opening, an intermediate piece (4) adjoining the shaft (8), and an application part (5) directly adjoining the intermediate piece (4), which is provided with two discharge openings (6, 7), wherein the open flow cross-section of the intermediate piece (4) decreases in the direction of the application part (5), and the cross-sectional shape of the open flow cross-section changes from round to a shape other than round, wherein the discharge opening (7) is arranged on a side of the application part (5) facing away from a guide direction (13) of the nozzle, and with the discharge opening (6)) is directly connected, wherein the discharge opening (6.) at the front end of the application part (5.) of the application nozzle is formed by edges of the application nozzle which are guided on the application surface (15.) during the application of the pasty adhesive, wherein the edge of the discharge opening (6.) formed by these edges is reinforced with a bead-shaped first contact ring (1.) which runs in a U-shape around the discharge opening (6.), wherein the first contact ring (1.) is made of an abrasion-resistant material or of a material from which the remaining nozzle parts are also made, wherein edges of the first contact ring (1.) are chamfered or rounded, and wherein further U-shaped contact rings (1.) are provided which, at regular intervals and parallel to the first contact ring (1.), encompass the application part (5.) with a stiffening effect, wherein the side of the further contact rings (1.) facing the application surface (15.)) as a cutting edge for shortening the applied part (5.) in order to reduce the size of the exit opening (7.), wherein for the purpose of assigning the individual contact rings (1.), they are identified numerically, alphabetically or by color stripes.".

Description

[0001] In automotive engineering, aviation, and construction, as well as in many other areas of technology, plastic adhesives in paste form, also known as "assembly or construction adhesives," find versatile applications. These adhesives, used as process materials, are mostly moisture-curing polyaddition adhesives whose polymerization is induced by atmospheric moisture. With regard to viscosity, sliding properties during material feeding, adhesion behavior, and plastic stability, they are designed so that they can be applied under pressure via an application nozzle to the material to be bonded. After application, these materials adhere quickly to the bonding surface. In practice, tapered plastic nozzles "A" are commonly used for single-strand adhesive application; these are screwed onto a round material feed opening with an external thread. Due to their thin walls, or rather...Due to the use of a suitably soft plastic, these nozzles can be easily cut to the desired opening size with a sharp blade using a simple manual cut. They are usually used only once (disposable nozzle) and are therefore flexible in their handling.

[0002] With this type of dispensing nozzle, precise definition of the opening size and the gate angle is only possible with relatively high effort. The resulting outlet opening is either round or oval (depending on the gate angle) and its profile defines the shape and quantity (also dependent on the feed pressure) of the applied adhesive.

[0003] Even if step cut planes are planned in the profile by means of corresponding notch rings pre-marked on the outer surface (a kind of “break points”), in practice these are only met imprecisely and it is therefore not possible to implement the two-surface opening shape (“B”) described below.

[0004] When applying the adhesive, these application nozzles "A" only have limited and relatively undefined contact with the material to be bonded because, as previously described, the distance is controlled manually, usually freehand. This makes precise shaping of the adhesive bead only partially possible. In some cases, the applied bead breaks.

[0005] Especially on non-horizontal surfaces, the adhesive requires direct contact to bond. This allows the emerging, still-soft adhesive flow to form an adhesive surface, establishing initial contact. In practice, this is often achieved by maintaining a small distance between the nozzle opening and the surface or by slightly tilting the nozzle onto the surface. As a result, the application process is relatively laborious and time-consuming, and the application pattern is uneven. Another disadvantage is that tilting the nozzle on rough surfaces (e.g., masonry) can wear down the contact surfaces of the nozzle opening edges. This alters the opening cross-section and may render the nozzle unusable. Furthermore, some applications specify application rates for different materials with varying loads.Adherence to such requirements is only possible to a limited extent.

[0006] However, in technical applications, "B" dispensing nozzles are known that operate with two opening surfaces simultaneously. These nozzles are used in stationary, industrial systems for the manual application of large quantities or for specialized bonding applications, such as the manual installation of windshields. The opening surfaces (cross-sections) are adjacent to each other so that the dispensed adhesive stream is not split but exits in two directions. As the material flows out of the nozzle, they are usually guided mechanically so that they directly contact the material to be bonded, creating a contact surface that secures the initial adhesion. Simultaneously, the actual adhesive stream exits through the second opening, which is located opposite to the guide direction, and is applied with a relatively constant cross-section.Due to the two nozzle openings, the adhesive bead adheres and is applied in a combined manner. Key process parameters are the angle of the nozzle axis to the application surface and the pressure / flow rate of the adhesive stream, or the speed at which the nozzle is moved. These types of application nozzles, which have a fixed area ratio between the two previously described opening cross-sections that can only be changed with considerable effort, are sometimes manufactured from relatively high-quality materials specifically for the respective application. This makes them expensive, or even when they are produced more cost-effectively as disposable items (e.g., for bonding windshields), they are inflexible with regard to the application quantity. The only remaining controllable parameter is the material flow pressure, which can be adjusted within certain limits.If one were to use this nozzle type "B" as a replacement for the previously described nozzle type "A", several versions would have to be kept on hand. This is impractical and therefore increases costs. An alternative, precise cutting of the nozzle "on-site" (as with nozzle type "A") to achieve an exact definition of the opening size and the cutting angle is only feasible with relatively high technical effort.

[0007] An application nozzle is known (according to patent no. DE 10 2008 007 306 A1) whose main function is easy resealing. Accordingly, this nozzle has a mechanical locking system. Furthermore, various versions of the application opening 51 (or 56) were developed, wherein the Fig. 6. A U-shaped opening is selected. This U-shaped opening is provided with a brush edge 53. This edge is relatively narrow and angular. Due to this edge profile, the associated mechanical properties regarding easy sliding behavior are expected to be poor. With this brush edge profile 53, a direct sliding application of the pasty adhesive will not be possible, especially on rough surfaces.

[0008] Furthermore, the size of the free cross-section of this nozzle, which regulates the flow volume of the adhesive bead during application, can be changed by adjusting the opening mechanism. However, the technology used in the nozzle for this purpose is relatively complex. Ultimately, the variable adhesive bead cross-section can only be achieved by offering different types of this nozzle, which differ in the design of the opening cross-section that forms the adhesive bead.

[0009] The state of the art includes a nozzle according to publication no. WO 97 / 41 968 A1. A key feature of this nozzle design is that it is intended for a spread or even application of adhesive. Due to the design of the nozzle head, which has an outlet opening in the center of a contact surface, no adhesive bead is formed; instead, a more or less defined cushion of material is created on which the nozzle head glides during application. As a result, this nozzle leaves an evenly distributed application of material. An additional variant of this nozzle is also available (see [reference]). Fig. 7 u. Fig. 8), for which a U-shaped opening is selected. This U-shaped opening is provided with a brushing edge 4'. The brushing edge 4' is relatively narrow and angular in design, comparable to the application nozzle (according to DE 10 2008 007 306 A1). The associated mechanical properties with regard to easy sliding behavior are nevertheless to be expected to be moderate due to this edge profile design. A direct sliding application process of the pasty adhesive will not be possible with this profile of the brushing edge 4', especially on rough surfaces.

[0010] Similar to the nozzle shape “A” described in the introduction, the nozzle is designed according to document Az. US 2 981 449 A. However, the stepped gate planes are not incorporated into the profile by corresponding pre-marked notch rings (a kind of “break-off point”) on the outer surface, but rather by profile rings applied from the outside (cf. Fig. 3. Items 19, 20, and 21). These serve as pre-markings for cutting, allowing the nozzle to be shortened at different cutting planes. This achieves various predefined opening cross-sections. However, the resulting shape of the application opening necessitates manually guiding the nozzle at a certain distance from the application surface onto which the adhesive is applied. Directly placing the nozzle on the application surface would simply close the opening, even if attempts were made to circumvent this by tilting the nozzle. Consequently, a defined bead of adhesive that is intended to adhere immediately upon application (e.g., when applying "overhead" or to vertical application surfaces) is not possible.

[0011] For applying silicone or PE sealant, a nozzle is available according to German patent application DE 297 19 428 U1. This nozzle is designed exclusively for sealing corner joints and has a triangular application opening for this purpose. It does not feature any special sliding surfaces. Therefore, this nozzle can be considered unsuitable for applying a pasty adhesive to a surface that is predefined as flat.

[0012] The state of the art includes a nozzle according to document no. GB ​​2 553 866 B. This document specifies various nozzle head designs. The illustrations Fig. 2(a), Fig. 2(b) and Fig.The nozzle head design shown in Figure 2(c) is designed for application to a flat or curved surface, specifically for the penetration of an adhesive between the overlapping seam of a pipe sheath. For this purpose, the nozzle head itself is manufactured as a section of pipe that is cut in half or at an angle along its longitudinal axis. The application medium is fed to one end of the cut pipe by an angled feeder. The other end is open. This creates an application that first adheres and is then formed by the open end of the pipe. To improve the sliding properties, the circumferential edges of the cut pipe are flattened and designed as sliding surfaces. From a fluid dynamics perspective, such a nozzle design results in only a low adhesive pressure of the applied adhesive, as the main flow direction is longitudinal to the application portion of the nozzle body.

[0013] This is insignificant for the intended application area of ​​this nozzle, but is an essential requirement for its function when using pasty adhesives that are also used on vertical or "overhead" application surfaces.

[0014] The challenge was therefore to create a cost-effective device that, with manual and flexible handling, could produce a definable material flow as a paste-like adhesive strand within a certain tolerance range. The material flow would be regulated by adhesion, ensuring that it adheres to the application surfaces upon initial contact, even when vertical. Simultaneously, a fast, precise, and ideally smooth application was required. Furthermore, the abrasion of the application nozzle's contact surfaces was to be minimized.

[0015] This is achieved by the application nozzle according to the invention for the manual application of a pasty adhesive, in such a way that, similar to the disposable nozzle "A" described above, it is manufactured from a soft, cost-effective plastic or from a similar material with comparable material properties. Furthermore, this nozzle is also placed on a round material feed opening, the fixed connection being formed, for example, with a corresponding external thread or a suitable internal thread in the shaft (8.) of the nozzle (M16 in the example nozzle). In the first part of the intermediate piece (4.), the round cross-section tapers so that a certain pressure build-up of the adhesive material is generated inside. However, the nozzle shape changes in an intermediate piece (4.) in the adhesive flow feed.The cross-section changes from a tubular shape to a rectangular design, the edges of which may be rounded for aerodynamic reasons. In practice, the rectangular cross-sectional shape with rounded edges proved to be the most practical, although other geometries are also conceivable.

[0016] Even with the change in cross-section (from round to rectangular), the open flow cross-section continues to decrease. The intermediate piece (4) connects directly to the application part (5), which continues to have a rectangular cross-section. Other cross-sectional shapes are also conceivable here. In the exemplary embodiment, the end of the application part is manufactured with a common application angle (for example, 70°) in the delivered form, i.e., the nozzle axis is aligned with the contact surface (2) at an angle of 70° to the application surface. This has proven practical in tests, but other application angles are possible. Similar to the industrial nozzle "B", the application nozzle according to the invention operates with two outlet openings (6) and (7). Due to the two outlet openings, a combination of adhesion and deposition of the adhesive strand (14) occurs. Process control parameters also include the pressure and flow rate of the supplied adhesive (16).), or the guiding speed.

[0017] Thus, on the side facing away from the guide direction (13), a further rectangular outlet opening (7) is formed. During the feeding process, the adhesive flow is forced from the outlet opening (6) directly onto the application surface (15) for adhesion and simultaneously exits the nozzle to the rear via the outlet opening (7). This ensures that the adhesive bead (14) is evenly distributed onto the application surface (15) and is shaped by the rectangular outlet opening (7). Other geometric shapes for the outlet opening are also possible, depending on the desired profile of the adhesive bead (14). A particular advantage is that this allows for relatively high profile shapes of the adhesive, because such pasty adhesives can compensate for unevenness in the bonding surface by filling in irregularities.

[0018] The common techniques that generate the pressure / flow rate of the supplied adhesive (16.) in practice ensure a certain stability of these parameters, which, with continuous guidance of the nozzle, makes it relatively easy to produce a constant shape of the adhesive strand (14.) after exiting within a certain tolerance range.

[0019] In the application nozzle according to the invention, the rectangular outlet opening (7.) has an area of, for example, 160 mm² in the delivered state. 2Furthermore, the edge of the nozzle's guide surface is reinforced with an annular, bead-shaped contact ring (1.) that runs in a U-shape around the outlet opening (6.). This contact ring (1.) is made of an abrasion-resistant material, for example, a metal or a correspondingly hard plastic. However, it is also conceivable that, for cost reasons, it is made of the same material as the other nozzle parts. This reinforcement of the contact surface (2.) reduces abrasion (as described for nozzle type "A") on rough application surfaces and facilitates clean nozzle guidance during adhesive application. Simultaneously, a certain sealing effect occurs, minimizing uncontrolled lateral adhesive leakage. The edges of the contact ring (1.) are rounded or chamfered to ensure uniform nozzle guidance on the application surface.In particular, this allows for rapid manual application because the contact surfaces (2.) are easily guided on the application surface (15.) and a lubricating film forms during application (similar to an air cushion). Due to this design, the initial adhesive contact remains stable during rapid application with the appropriate application pressure, and the adhesive bead (14.) maintains consistently good dimensional stability within a certain tolerance range.

[0020] The application part (5.) has further contact rings (1.) of this type, which are parallel to the first, i.e., also at the selected application angle or at regular intervals, and are connected to the base body of the application part (5.). In the exemplary embodiment, three more of these contact rings (1.) follow.

[0021] This makes it possible to shorten the application part (5) of the application nozzle at defined intervals using a sharp blade by making a simple manual cut along the side of these contact rings (1) facing the application surface (15). The cut edge can be marked with colored stripes (3) to indicate the corresponding opening sizes. The upper edge of the contact rings (1) facing the application surface serves to guide the cut cleanly. At the same time, the contact rings (1) provide additional stability to the application part (5), enabling a precise cut without deformation of the application part (5) under cutting pressure.

[0022] Thus, the exit opening (7.) that gives the adhesive strand (14.) its contour can be adjusted in the exemplary embodiment in steps of 40 mm. 2 reduce, i.e. this nozzle can be easily adjusted to outlet openings of either 160 mm 2 , 120 mm 2 , 80 mm 2and 40 mm 2 Adaptable. Depending on the viscosity, adhesion properties, and application area of ​​the adhesives, an application nozzle can be manufactured that, for example, for one and the same adhesive, is graduated according to the type of stress on the bond and ensures tabulated, predefined application quantities. For easy identification and classification, the contact rings (1.) are to be externally marked with numerical or alphabetical designations. Identification and classification solely by color stripes (3.), as in the exemplary embodiment, is also possible. "Reference symbol list" 1. Contact ring 2. Contact surface inclined at the application angle 3. Color stripes 4. Intermediate piece 5. Order Part 6.1 Exit opening 7.2 Exit opening; side facing away from the direction of travel. 8. Shaft 9. Material supply 10. (Non-visible) internal thread 11. Exit direction towards the side opposite the direction of travel 12. Exit direction towards the adhesive surface 13. Direction of guidance 14. Shaped / dimensioned adhesive strand 15. Application area 16. Added adhesive

Claims

[1] Application nozzle for the manual application of a pasty adhesive characterized by, that in the exit direction (12.) to an application surface (15.) of the pasty adhesive, this has first a shaft (8.) with an internal thread (10.) for mounting the shaft (8.) onto a corresponding external thread of a material supply opening, an intermediate piece (4.) adjoining the shaft (8.), and an application part (5.) directly adjoining the intermediate piece (4.), which is provided with two outlet openings (6., 7.), wherein the open flow cross-section of the intermediate piece (4.) decreases in the direction of the application part (5.), and the cross-sectional shape of the open flow cross-section changes from round to a shape other than round, wherein the outlet opening (7.) is arranged on a side of the application part (5.) facing away from a guide direction (13.) of the application nozzle, and is directly connected to the outlet opening (6.), wherein the outlet opening (6.) is located at the front End of the order section (5.) the application nozzle is formed by edges of the application nozzle which are guided during the application of the pasty adhesive onto the application surface (15.), wherein the edge of the discharge opening (6.) formed by these edges is reinforced with a bead-shaped first contact ring (1.) which runs in a U-shape around the discharge opening (6.), wherein the first contact ring (1.) is made of an abrasion-resistant material or of a material from which the remaining nozzle parts are also made, wherein edges of the first contact ring (1.) are chamfered or rounded, and wherein further U-shaped contact rings (1.) are provided which, at regular intervals and parallel to the first contact ring (1.), encompass the application part (5.) with a stiffening effect, wherein the side of the further contact rings (1.) facing the application surface (15.) serves as a cutting edge for shortening the application part (5.) to reduce the size of the discharge opening (7.) to reduce, wherein for the purpose of assigning the individual contact rings (1.), they are identified numerically, alphabetically or by color stripes."

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