Joining device for fine plastic monofilaments using ultrasound

Abstract

Device for welding fine and ultrafine plastic monofilaments using ultrasound, characterized by a horizontally aligned sonotrode and an anvil combination, wherein the anvil combination, - can be moved horizontally and - a first setting for fine adjustment of the welding gap to adapt to different diameters of the monofilaments, - and a second setting comprising a segmented or interchangeable second anvil with different heights or surface profiles to weld different monofilament types or combinations.

Description

[0001] The present invention relates to a device for ultrasonic welding of fine and ultrafine plastic monofilaments, in particular for producing connection points in technical fabrics, such as in paper machine clothing.

[0002] Ultrasonic welding devices used for welding plastic monofilaments are known from the state of the art. However, these have limitations regarding the reproducible and damage-free joining of filaments with small diameters. Incomplete or unstable welds often occur, particularly when processing filaments with diameters below 500 µm, and especially below 100 µm. Furthermore, changing the filament diameter to be welded regularly requires manual adjustment of the anvil position and the welding gap, which is associated with increased adjustment effort and time loss.

[0003] The object of the present invention is to provide a device with which fine and ultrafine plastic monofilaments can be welded reliably, reproducibly, and without damage. Furthermore, a quick change between filaments of different diameters should be enabled without complex changeover processes.

[0004] This object is achieved by a device having the features of patent claim 1.

[0005] The device according to the invention comprises a horizontally aligned ultrasonic welding system with a sonotrode and an anvil combination, wherein the anvil combination is designed to be both horizontally movable and doubly adjustable.

[0006] The horizontal mobility of the anvil combination allows for precise positioning of the anvils relative to the sonotrode. The dual adjustability includes: 1. a horizontal fine adjustment of the entire anvil combination to adapt the welding gap to different diameters of the monofilaments to be welded and 2. a segmented or replaceable second anvil surface with different height levels or surface profiles for targeted adaptation to different filament types or filament combinations.

[0007] The design allows for easy and quick adaptation of the device to changing material requirements without complete replacement or manual conversion of the anvil combination.

[0008] The invention is characterized in particular by the following advantages: • Reproducible and damage-free welds for filament diameters smaller than 500 µm, especially 100 µm • Tool-free and adjustment-free change between different monofilament diameters • Time and cost savings through reduced adjustment times • Suitable for industrial applications with frequently varying production parameters, particularly in the field of technical fabrics and paper machine clothing. • • The following claims relate to a device for welding plastic monofilaments using ultrasound, in particular for the damage-free and reproducible joining of fine and ultrafine filaments. The invention is characterized by a multiply adaptable anvil combination, which allows flexible handling of different filament diameters and types without complex conversion processes. The device is particularly suitable for applications in industrial fabrics, such as paper machine clothing. Description accompanying drawing

[0009] Fig.1 shows a schematic representation of an apparatus according to the invention for ultrasonic welding of monofilaments in a side view.

[0010] The device comprises a sonotrode (1) equipped with welding surfaces (4, 5) and support surfaces (4b, 5b). The sonotrode is permanently mounted on an oscillating unit (converter) and an anvil combination (2) that can be moved horizontally along a guide rail (3).

[0011] The anvil combination (2) has two adjustment mechanisms (6, 6a): • Two horizontal fine adjustments (6, 6a) with which the welding gap can be adjusted exactly to the diameter of the monofilament to be welded (7, 7a). • A segmented anvil surface (5a) that can be adapted to different filament types by horizontal movement or by using interchangeable modules. In the illustrated design, this anvil surface (5a) cooperates with the opposite support surface (5b) to fix the filaments (7a) in the sonotrode (1).

[0012] In addition, the fine adjustment (6) of the entire anvil combination can be carried out, for example, by motor or via a fine thread (6a) and can be reproducibly positioned on the stop (6b).

[0013] This arrangement enables highly precise, reproducible welds for changing material requirements - without any significant setup effort. List of reference symbols 1 sonotrode 2 anvil combination 3 guide rail 4 Welding surface 5 Welding surface 4a Anvil surface 5a Anvil surface 4b Support surface 5b Support surface 6 Adjustment mechanism 6a Adjustment mechanism 6b stop 7 filaments 7a Filament

Claims

[1] Device for welding fine and ultrafine plastic monofilaments using ultrasound, characterized by , a horizontally aligned sonotrode and an anvil combination, wherein the anvil combination, - can be moved horizontally and - a first setting for fine adjustment of the welding gap to adapt to different diameters of the monofilaments, - and a second setting comprising a segmented or interchangeable second anvil with different heights or surface profiles to weld different monofilament types or combinations. [2] Device according to claim 1, characterized by that the anvil combination has several areas arranged one above the other, each with different welding gap widths, between which you can switch by horizontal movement. [3] Device according to one of claims 1 or 2, characterized by that the fine adjustment of the anvil combination is carried out by motor or by means of a fine thread. [4] Device according to one of claims 1 to 3, characterized by that the anvil surfaces are made of a wear-resistant material with a low coefficient of friction in order to minimize thermal impairment of the monofilaments during the welding process. [5] Device according to one of claims 1 to 4, characterized by that the ultrasonic welding parameters, in particular amplitude, frequency and welding time, are automatically adjusted depending on the set position of the anvil combination.

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