RU225615U1 - Device for ultrasonic welding of surgical synthetic threads with a thickness of 0.1 mm to 0.6 mm - Google Patents

Abstract

The utility model relates to the field of ultrasonic welding, in particular threads, namely surgical ones. A device for ultrasonic welding of surgical threads consists of clamps for securing the threads, a pin for forming a loop, a waveguide and an anvil, made movable and located on the same axis plane-parallel to each other. The anvil is made with a prismatic gripping groove of a trapezoidal cross-section. The quality of the welded joint is improved. 11 ill., 1 tab.

Description

The utility model relates to the field of ultrasonic welding, in particular threads, namely surgical ones.

The device can be used in various fields of the national economy, in particular in medicine for welding surgical threads, for example polyglycolide ones.

Welding occurs when the surfaces being welded are simultaneously exposed to mechanical ultrasonic vibrations and external pressure applied perpendicular to the surfaces being welded.

There are known analogues of ultrasonic welding devices for joining products made of thermoplastic materials, including a source of ultrasonic vibrations ending with a working welding tool-waveguide. To implement welding, such devices are equipped with units that provide pressure on the waveguide to the materials being welded.

There is a known analogue - an apparatus for ultrasonic welding of thread and film "Giminey-Ultra", model AUS-0.4/22-OM, which is designed for joining structural products and sheet materials using the method of continuous or step-by-step ultrasonic welding. The device consists of an electronic generator with a timer and output power regulator (30-100%), a piezoelectric oscillatory system in a metal case with forced air cooling, a set of working tools [https://dzen.ru/video/watch/6272143472a4a07ac2152673?utm_referrer=ya .ru].

The device does not allow making an extended weld on thin (surgical threads) located parallel to each other, since the threads are not positioned parallel to each other and are not located one above the other during the welding process. When welding particularly thin threads, the waveguide burns them out, since there is no way to limit the stroke of the waveguide.

The prototype is a thread welding device from KROTT & HEUTER [https://cloud.mail.ru/stock/2oMrqtMmhMC5GpCdgZjirziu], intended for welding products made of polymer materials. In particular, it is used for welding polymer threads.

The disadvantage of such a device is the unstable quality of the welded joint due to the complexity of positioning the threads and the need for an additional high-precision adjustable stop to position the movement of the waveguide, which significantly complicates the design of the known device as a whole.

The technical result is improved quality of the welded joint.

The device is designed for threads with a thickness of 0.1-0.6 mm and its design is significantly simplified in comparison with analogues.

The technical result is achieved by a device for ultrasonic welding of threads with a thickness of 0.1-0.6 mm, which consists of clamps for securing each thread, a pin for forming a loop, a waveguide and an anvil. In this case, the anvil is made with a prismatic groove of a trapezoidal cross-section, which acts as an orienting gripping device for the threads being welded, while both the anvil and the waveguide are movable and located on the same axis, plane-parallel to each other.

The quality of welding is ensured by an equally uniform weld along the entire length. The proposed technical solution makes it possible to make the working surface of the waveguide flat and does not require setting the exact stroke of the waveguide during its operation, which greatly simplifies its design, and the trapezoidal groove located on the working surface of the anvil allows for precise orientation of the threads before welding. During welding, the waveguide rests against the anvil, which is a limiter (constant stop) of the movement of the waveguide and at the same time regulates the pressure on the threads being welded, and the depth of the groove allows you to select the optimal pressure on the threads being welded. The device does not require adjustments to the pressing pressure and waveguide stroke. The pressing pressure and waveguide stroke are parameters that ensure high quality of the welded joint, and the simplification of the design occurs due to the presence on the working surface of the anvil of a prismatic groove of a trapezoidal cross-section, which allows you to orient the threads before welding and select the optimal compression force that ensures a high-quality seam.

If the pressing pressure were insufficient, the seam would be narrow and its strength would be low.

If you squeeze, the threads become thinner and break. And if the threads relative to each other are not oriented flat and parallel, then it is impossible to ensure a seam along a given length of threads.

The presence of a special groove in the anvil allows precise positioning of the threads during welding. The size of the groove is selected in such a way that the groove allows optimal orientation of the threads during the welding process. The depth of the anvil groove is selected to ensure an optimal degree of thread pressure and ultimately obtain the required seam strength without complicating the design of the device.

The developed design of the anvil and waveguide allows, on the one hand, not to create excess pressure and not burn out the threads, and on the other hand, to provide the necessary pressure for high-quality welding of the threads. The size and shape of the groove in the working surface of the anvil determines the optimal compression of the two threads, ensuring the melting of the threads at the point of contact along a given width; the depth of the groove is selected according to the size of the thread.

The groove can be trapezoidal, triangular, semicircular, or another cross-sectional shape.

The first anvil, in the process of moving towards the waveguide, orients the threads in such a way that the first thread falls into the groove completely, and the second thread only half or two-thirds of its diameter. The anvil, while moving, performs the function of orienting the threads before the welding process.

In fig. 1 shows the general unit A of the device for ultrasonic welding of threads 1.

In fig. Figure 2 shows a view of the ultrasonic unit A, which consists of a right and left clamp for securing threads 1, a pin for forming a loop 2, an anvil with a prismatic capture groove of a trapezoidal cross-section 3, a waveguide 4, a thread 5.

In fig. Figure 3 shows a view of an anvil with a groove.

In fig. Figure 4 shows a side view of an anvil with a groove.

In fig. Figure 5 shows the end view of the anvil.

Figures 6, 7, 8 show a prismatic gripper groove of a trapezoidal cross-section, which can be made of different sizes depending on the diameter of the thread.

In fig. 9 and 10 show a photo of anvil 3, which has an anvil carriage 7, bolts for attaching the carriage to the module 8 and 9, and a pin for forming a loop 2.

In fig. Figure 11 shows a device for ultrasonic welding of threads, which consists of a table 10 standing on adjustable supports 11. Inside the machine there is a built-in chassis with a compressed air filter-regulator 12. Under the table frame 10 there is a process start pedal 13. On the table there is a control panel 14, on which contains the Network button 15, the emergency button Mushroom 16, as well as the control screen itself 17. On the upper surface of the table 10 there are trays 18, a replaceable anvil 3, an ultrasonic path casing 19, an anvil carriage casing 20, buttons 21 and 22, at the bottom of the table grounding bolt 23 is located.

Device operation

The inventive device operates as follows.

The first on command, the anvil begins to move towards the waveguide. In the process of movement, due to the trapezoidal cross-section groove located on its plane, it acts as a thread catcher and, by running over them, orients the threads before welding inside the groove. After the anvil has reached its extreme position and the threads are already in the groove one above the other, the movement of the waveguide is turned on, which, resting against the anvil, compresses the threads located in the groove, and at this moment an ultrasonic pulse is applied to the waveguide. The pulse time depends on the thickness and material of the thread, and does not exceed a fraction of a second, after which the threads melt. Then there is a short-term exposure under pressure to cool the weld, approximately one to two seconds. Next, the anvil and the waveguide move to their original positions, and the thread is removed by the operator. The waveguide and anvil are driven by displacement mechanisms. In this case, pneumatic cylinders, but other actuators can also be used.

Table.

Ultrasonic welding parameters table. The exact values for each thread must be determined by the customer in a test mode to achieve maximum quality of the welded loop.

Thread name Number
anvils Pressure,
kRa Time
pulse, ms 1 PP No. 2 0.536 1 200 250 2 PLCL No. 2 0.598 1 200 250 3 PGKL No. 2 0.520 1 200 250 4 PDO No. 2 0.505 1 150 250 5 PDO No. 1 0.422 1 150 150 6 PGLK No. 1 0.428 1 150 200 7 PLCL №0 0.372 2 250 150 8 PGKL No. 0 0.376 2 250 250 9 PGKL No. 0 0.360 2 200 200 10 PDO No. 0 0.362 2 200 200 eleven PGLK No. 2 0.301 3 250 100 12 PGKL No. 3 0.232 4 250 50 13 PGKL No. 4 0.160 4 200 100

* PP - Polypropylene thread;

* PLCL - polylactide threads with ε-caprolactone in the composition, synthetic;

* PGCL - polyglycolide threads with ε-caprolactone in the composition 75:25, synthetic;

* PDO - polydioxanone threads, synthetic.

Claims (1)

A device for ultrasonic welding of surgical synthetic threads with a thickness from 0.1 mm to 0.6 mm, consisting of clamps for securing the threads, a pin for forming a loop, a waveguide and an anvil, made movable and located on the same axis plane-parallel to each other, characterized in that the anvil is made with a prismatic gripping groove of a trapezoidal cross-section.