DE102016121414A1 - Method of working a needle - Google Patents

Abstract

In a method for processing a needle (2), a region (21) of the needle (2) is modified by a pulsed laser beam (4) with a pulse duration below 30 ps. In particular, a line structure in the surface of the needle (2) can be generated by the laser beam (4) in the region (21). In the modified region (21), the needle (2) is then connected to a further component (3). In particular, the needle (2) in the modified region (21) with a plastic of the further component (3) are molded. Due to the ultrashort laser pulses, lines of comparatively great depth (27) and small edge width (26) can be generated. Thereby, a mechanical Verkrallung between the needle (2) and the plastic of the other component (3) is improved. The needle (2) may in particular be a hollow needle or a solid needle.

Description

The invention relates to a method of processing a needle by which a connection between the needle and at least one further component is improved.

In many devices in various fields of technology, needles are components of these devices. It is often necessary for the correct, reliable and secure operation of such devices to provide a durable, strong and secure connection between the needle and at least one other component of such a device guarantee. Important examples of such devices are found in the field of medical applications of needles, without the present invention being restricted to this area.

For example, hollow needles are used for syringes for administering injections or for taking samples. Such hollow needles can be plugged with a, usually made of plastic, adapter to the syringe. Likewise, the hollow needle can be connected directly to the syringe. For a safe use of the syringe, a reliable connection between the hollow needle and adapter or between the hollow needle and syringe is of particular importance, since only so the hollow needle can be safely guided over the syringe and leaks between the needle and adapter or syringe can be avoided. The adapter or the syringe in this example represent the at least one further component with which the needle, in this case the hollow needle, is to be connected. An example in which a full needle is used is a lancing device for taking a blood drop (e.g., for blood glucose measurements). The needle is to be securely connected to a guide carriage which is e.g. can be accelerated by a spring. Further examples will be discussed later in this application.

If the at least one further component, with which the needle is to be connected, consists of plastic, then this further component is frequently produced and connected to the needle, that the needle is injection molded with the plastic in an injection molding process, or that the needle with the glued separately prepared further component. The bonding with the needle is also suitable for those other components which are made of a material other than plastic, such as glass. However, the surface of the needle, which is normally made of metal, is comparatively smooth, so that the plastic of the further component or also the adhesive used for the bonding adheres at best moderately to it. To improve this adhesion, it is already known to modify the surface of the needle. This modification aims at producing structures on the surface of the needle which lead to a mechanical engagement with the plastic or adhesive. Suitable plastics are known to those skilled in the art, such as, but not limited to, cycloolefin polymers (COP) or cycloolefin copolymers (COC).

To modify the surface of the needle, sand blasting or the introduction of a line structure into the surface by means of a laser beam are used in the prior art. Both types of processes are basically ablative processes, yet undesirable local enlargement of the outer diameter of the needle can occur. This can result in damage to the precision machined injection molding tool, or the resulting bond between the other component and the needle is unsatisfactory. Problems can also already occur during the separation of the needles for feeding to the injection molding tool. When sandblasting, for example, sand particles may stick to the needle, or metal of the needle may be bent out of the surface, but not completely removed. In the known structuring by means of laser, in addition to a removal of material, a deposit of material initially melted, ejected from the processing site, is generated around the processing site. If the extent of these deposits is to be limited, the depth of the structures introduced into the surface of the needle must be limited. The local melting of material of the needle also means that it is impossible to produce structures with steep flanks, since the material flow associated with the presence of melted material unfolds a leveling effect, thus increasing flank widths and reducing flank heights. A limited depth of the structures introduced into the surface and flat flanks of these structures mean that a desired clawing of the plastic of the further component with the needle is only moderate.

It is therefore an object of the invention to provide a method for processing a needle, by which the mechanical anchoring between the needle and the at least one further component is improved.

In the method according to the invention, a needle to be connected with at least one further component is provided. An area of a surface of the needle is modified by at least one laser beam, that is, structures are formed in the surface of the needle in this area. The needle is then connected in the modified area with the at least one further component. According to the invention, the at least a laser beam which modifies the area of the surface of the needle, a pulsed laser beam with a pulse duration less than 30 ps. The pulse width is considered to be the full width of the pulse at half the height of the pulse. In particular, the method according to the invention can be carried out with a diode-pumped solid-state laser in which further pulse compression is carried out. Alternative laser types which are likewise suitable for carrying out the process according to the invention are apparent to the person skilled in the art from the disclosure content of this application.

The short pulse duration below 30 ps of the ultrashort laser pulses causes a material removal at the processing location, without there being any ejection of molten material. Thus, eliminating the need to reduce the ejection and to limit the depth of the generated structures. Since there are no, or at least no significant, amounts of molten material at the edge of the processing location, there is no material flow which levels flanks of structures. Thus, structures can be created that have flanks that are significantly steeper than flanks of structures produced by the laser-based methods of the prior art. In general, the dimensions and shape of the structures can be produced more precisely in the needle than is possible with conventional methods. Also, no local enlargement of the outer diameter of the needle occurs because no molten material is ejected and deposited around the processing site. The possibility of producing precisely shaped structures in the needle makes it possible to match the shape of these structures very well with the material properties, in particular the filling behavior, of the plastic used for the at least one further component. In this way, the mechanical anchoring between the needle and the at least one further component is significantly improved. As a result, a significantly higher pull-out force of the needle from the further component can be achieved than is possible with methods according to the prior art. The connection between the needle and the at least one further component is thus more resilient, more durable and therefore more reliable.

The method according to the invention makes it possible to form a wide variety of structures precisely in the material of the needle. In one embodiment, the area of the surface of the needle is modified by introducing a line structure into the surface of the needle. In particular, this line structure may comprise a plurality of parallel lines. The lines can be aligned, for example, perpendicular to a longitudinal axis of the needle. Another example is that the lines enclose an acute angle with a longitudinal axis of the needle. A similar structure can be achieved by inserting a line in the form of a helical line in the surface of the needle. However, the invention is expressly not limited to these examples.

Furthermore, in one embodiment, the spacing of adjacent lines of the plurality of lines is between 20 μm and 60 μm. In this case, but also independently thereof, a width of a line of the plurality of lines may be in the range of 50 μm to 100 μm. In one embodiment, the width of an edge of a line of the plurality of lines is less than 5 μm. In one embodiment, a depth of a line of the plurality of lines is in the range of 30 μm to 500 μm; In particular, the depth of a line in the range of 30 microns to 300 microns, or even in the range of 30 microns to 100 microns. However, the method according to the invention is not limited to producing general line structures or especially line structures with the dimensions mentioned.

The adhesion between the plastic of the at least one further component and the needle can be further improved if the surface of the needle in the modified region is activated and / or cleaned by a plasma. In particular, the plasma used for activation and / or purification can be generated by the pulsed laser beam acting on the material of the needle. This eliminates separate devices and methods for generating and guiding the plasma.

• 1A zeigt eine Hohlnadel mit Adapter.
• 1B zeigt eine Hohlnadel mit dem Zylinder einer Spritze.
• 2 zeigt einen schematischen Längsschnitt eines modifizierten Bereichs einer Hohlnadel.
• 3 zeigt eine dreidimensionale Ansicht eines Teils eines modifizierten Bereichs einer Hohlnadel.
• 4 zeigt eine dreidimensionale Ansicht eines Teils eines modifizierten Bereichs einer Hohlnadel.
• 5 zeigt die Einwirkung eines Laserstrahls auf das Material einer Nadel.
• 6 zeigt eine Venenverweilkanüle.
• 7 zeigt einen Kapselinhalator.

In the following, the invention and its advantages will be explained in more detail with reference to specific embodiments and associated schematic drawings. The embodiments illustrated in the drawings and explained in the associated description of the figures represent only examples to explain how the invention may be configured, and are not to be construed as limiting the invention.

• 1A shows a hollow needle with adapter.
• 1B shows a hollow needle with the cylinder of a syringe.
• 2 shows a schematic longitudinal section of a modified portion of a hollow needle.
• 3 shows a three-dimensional view of a portion of a modified portion of a hollow needle.
• 4 shows a three-dimensional view of a portion of a modified portion of a hollow needle.
• 5 shows the action of a laser beam on the material of a needle.
• 6 shows a venous indwelling cannula.
• 7 shows a capsule inhaler.

In the drawings, for purposes of clarity, some elements are not drawn to scale. Like reference numerals are used for the same or corresponding elements of the invention in various embodiments.

1A shows a hollow needle 2 and another component 3 in the form of an adapter. The adapter 3 is in one area 21 the hollow needle 2 with the hollow needle 2 connected. By means of the adapter 3 becomes the hollow needle 2 attached in a known manner to a syringe. Also shown is a longitudinal axis 22 the hollow needle 2 ,

1B shows a hollow needle 2 with another component 3 in the form of a cylinder of a syringe. The cylinder 3 the syringe is made in this example in one piece by an injection molding of plastic and the hollow needle 2 connected. The connection between hollow needle 2 and cylinders 3 is achieved in this example that an area (not shown here) of the hollow needle 2 during production of the cylinder 3 with the plastic for the cylinder 3 was overmoulded.

2 shows a longitudinal section through a hollow needle 2 in a modified according to the invention range 21 , Also shown is the longitudinal axis 22 the hollow needle 2 , In the illustrated embodiment is in a wall 23 the hollow needle 2 a line structure has been generated. The lines run parallel to each other around the circumference of the hollow needle 2 around and perpendicular to the longitudinal axis 22 , The lines are marked by line spacing 24 , Line width 25 , Flank width 26 , and line depth 27 ,

The method according to the invention allows lines with more precisely defined dimensions in the surface of a needle, in the example shown in the wall 23 the hollow needle 2 to generate, as is possible with methods of the prior art. Since the ejection of molten material over the prior art is eliminated, one must be at the line depth 27 do not restrict for the purpose of reducing the ejection. Since there is no appreciable melt, which has a leveling effect in the prior art, lines with smaller flank width can be used 26 be prepared, as is possible in the prior art. Great line depth 27 and low edge width 26 improve the mechanical Verkrallung the plastic of at least one other component 3 , about the adapter 3 out 1A or the cylinder 3 the syringe off 1B , with the hollow needle 2 and thus increase the pull-out force of the hollow needle 2 from the at least one further component 3 ,

In non-limiting embodiments, the line spacing is 24 in the range 20 microns to 60 microns, the line width 25 in the range 50 microns to 100 microns, and the edge width 26 is less than 5 μm. The line depth 27 may be, but not limited to, in the range of 30 .mu.m to 500 .mu.m, in particular in the ranges of 30 .mu.m to 300 .mu.m or 30 .mu.m to 100 .mu.m.

The invention is not limited to regular line structures. In particular, different line widths and / or line distances can be generated on a given needle.

3 shows a three-dimensional view of a part of the modified area 21 a hollow needle 2 , In the wall 23 the hollow needle 2 is a line structure generated. The lines of the line structure are parallel to each other and perpendicular to the longitudinal axis 22 the hollow needle 2 ,

4 shows a three-dimensional view of a part of the modified area 21 a hollow needle 2 , In the wall 23 the hollow needle 2 is a line structure generated. The lines of the line structure run parallel to each other and close with the longitudinal axis 22 the hollow needle 2 an acute angle.

5 shows a section of a needle 2 , With a pulsed laser beam 4 be in the material of the needle 2 Line structures generated, and so an area 21 the surface of the needle 2 modified. By the action of the laser beam 4 on the material of the needle 2 arises at the processing site a plasma 5 , Through the plasma 5 becomes the surface of the needle 2 activated in the vicinity of the processing location; this contributes to an improvement in the adhesion of the plastic of the at least one further component to the needle 2 at. The plasma 5 can also have a cleansing effect on the surface of the needle 2 in the vicinity of the processing location, whereby the adhesion of the plastic of the at least one further component to the needle 2 is also improved.

6 shows a venous indwelling cannula 6 with hollow needle 2 , The hollow needle 2 is with a retaining element 3 , which in this embodiment represents the at least one further component, at one end of the venous indwelling cannula 6 used in this. It can be seen that in this device, the contact surface between the hollow needle 2 and the holding element 3 is comparatively low. In venous indwelling cannulas of the prior art, therefore, there is a risk that the hollow needle during preparation, piercing into the body of the patient or when removing from the vein slip or even completely from the holding element 3 and possibly the venous indwelling cannula 6 is pulled. In a processed according to the inventive method and accordingly with the holding element 3 connected hollow needle 2 this danger is eliminated.

7 shows a cross section through a Kaspelinhalator 7 , In the reusable device is a capsule 71 used, which contains a drug in the form of a powder. By pressing push button 72 will be at least one needle, in this example two needles 2 , in the capsule 71 stabbed. This will cause the powder in the capsule 71 released and can be inhaled by the patient. The needles 2 , which are full needles are in holding elements 3 used, which in turn with the push button 72 are connected and represent in this application example, the other components in the context of this application. In prior art capsule inhalers, repeated piercing of the needles into a capsule, ie, repeated use of the inhaler, may result in needles from the holding elements 3 be pulled, making the inhaler unusable. As in accordance with the invention processed needles 2 , which accordingly with the respective holding elements 3 connected, the connection between needle 2 and further component, ie here holding element 3 , is improved, the likelihood of pulling out the needles 2 from the holding elements 3 reduces the life, as measured in number of punctures, the inhaler 7 extended.

For the skilled person, many other application examples are apparent from the present disclosure, in which a needle processed according to the invention can be advantageously used. Another such non-limiting example is, for example, an infusion set for administering an active agent, such as insulin.

LIST OF REFERENCE NUMBERS

2

needle

21

Area of the needle

22

Longitudinal axis of the needle

23

Wall of the hollow needle

24

line spacing

25

linewidth

26

flank width

27

line depth

3

further component

4

laser beam

5

plasma

6

IV catheter

7

Kapselinhalator

71

capsule

72

push-button

Claims (15)

A method of processing a needle (2), comprising the steps of: providing a needle (2); Modifying a region (21) of a surface of the needle (2) by at least one laser beam (4); and connecting the needle (2) to at least one further component (3) in the modified region (21); characterized in that the at least one laser beam is a pulsed laser beam (4) with a pulse duration of less than 30 ps. Method according to Claim 1 in that the area (21) of the surface of the needle (2) is modified by introducing a line structure into the surface of the needle (2). Method according to Claim 2 wherein the line structure comprises a plurality of parallel lines. Method according to Claim 3 , wherein the plurality of lines are aligned perpendicular to a longitudinal axis (22) of the needle (2). Method according to Claim 3 wherein the plurality of lines having an elongated axis (22) of the needle (2) forms an acute angle. Method according to one of Claims 3 to 5 wherein a distance (24) of adjacent lines of the plurality of lines is between 20 μm and 60 μm. Method according to one of Claims 3 to 6 wherein a width (25) of a line of the plurality of lines is in the range of 50 μm to 100 μm. Method according to one of Claims 3 to 7 wherein a width (26) of an edge of a line of the plurality of lines is smaller than 5 μm. Method according to one of Claims 3 to 8th wherein a depth (27) of a line of the plurality of lines is in the range of 30 μm to 500 μm. Method according to one of the preceding claims, wherein the surface of the needle (2) in the modified region (21) by a plasma (5) is activated and / or purified. Method according to one of the preceding claims, wherein the connection of the needle (2) with at least one further component (3) in the modified region (21) takes place in that the needle (2) in the modified region (21) with the further component (3 ) is sprayed or glued. Method according to one of Claims 1 to 11 wherein the needle (2) is a hollow needle. Method according to one of Claims 1 to 11 , wherein the needle (2) is a solid needle. Method according to one of Claims 1 to 12 wherein the at least one further component (3) is a cylinder of a syringe or an adapter for attaching the needle (2) to a syringe, or a component of a venous indwelling cannula (6) or an infusion set. Method according to one of Claims 1 to 11 and 13 , wherein the at least one further component (3) is a component of a lancing device or a capsule inhaler (7).

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