RU2575521C2 - Cutting of plastic articles arranged in continuous plastic band for application in medicine - Google Patents

Abstract

FIELD: process engineering.

SUBSTANCE: invention relates to cutting of plastic articles arranged in a continuous plastic band for application in medicine. First, positions of interrelated plastic articles built in continuous plastic band are defined with the help of optical device for data acquisition and cutting pattern is calculated. The laser is adjusted by appropriate control system composed of adjustable focusing optical system, adjustable deflection device and beam-forming device. Subject to defined position parameters of said focal point position and intensity of the laser are adjusted. Interrelated plastic articles in said plastic band are cut in compliance with calculated cutting pattern. Plastic articles or plastic article packages are cut at their temperature of 60-155°C.

EFFECT: higher efficiency of cutting.

12 cl, 2 dwg

Description

The present invention relates to a method and apparatus for cutting plastic products placed in a continuous plastic tape, in which the individual plastic products are connected to each other, for use in the medical field, comprising at least one laser, at least one laser control system, at least one optical device for collecting and processing data, and a quality control device with an integrated pressure sensor for detecting incorrect or insufficient laser cuts. In addition, the present invention is directed to a device for the manufacture of plastic products, in particular the manufacture of filled or filled plastic products for use in the medical field, including a device for cutting plastic products placed in a continuous plastic tape connected to each other. Also provided is a method of cutting plastic products in a continuous plastic tape in which individual plastic products are connected to each other.

It is known that lasers can be used, for example, for cutting, welding or engraving. The prototype examined various approaches. Patent application DE 102007046142 A1 describes a device with an electronically controlled robot having a laser cutting head that can be moved to a predetermined initial position. Another method of laser engraving is described in patent document DE 10148759 A1. In this method, the laser is focused on the substrate, and the substrate is moved in the x-y axes. Another welding method is described in DE 102005035495 B4.

US 5,231,262 A discloses a laser cutting device including a laser, a positioning system, an image processing processor, and a laser control system in the form of mirrors, optical shutters, objective lenses, and a rotary console. Patent application US 4,328,411 A describes a method for cutting an amorphous metal by laser crystallization. Also presented is a punching machine in combination with a mold that cuts a workpiece previously cut from amorphous metal.

The objective of the present invention is to provide a device that further improves the prototype and improves productivity when cutting plastic products placed in a continuous tape for use in the medical field.

This problem is solved by the present invention using a cutting device according to paragraph 1 of the claims, and a cutting method according to paragraph 7 of the claims.

Additional preferred embodiments follow from the dependent claims, examples, figures and descriptions.

It was unexpectedly discovered that a device comprising at least one laser, at least one laser control system, at least one optical device for collecting and processing data, and a quality control device with an integrated pressure sensor for detecting incorrect laser cuts provides an increased the effectiveness when cutting plastic products placed in a continuous tape, in which individual plastic products are connected to each other, for use in the medical field.

The functional principle of the device according to the invention is as follows: an optical data acquisition device determines the positional parameters of plastic products placed in a continuous tape and connected to each other. Positional parameters are used to calculate the cutting pattern, which is transmitted to the laser control system. In accordance with the cutting scheme, the focusing optics and the deflecting device adjust the position, intensity and focal point of at least one laser beam.

According to the present invention, gas lasers, solid state lasers and / or dye lasers can be used. Lasers included in the group of gas lasers include an excimer laser, an inert gas ion laser, a metal vapor laser, or a molecular gas laser.

The group of excimer lasers includes, but is not limited to, an H ₂ laser (116/123 nm), an Ar ₂ laser (126 nm), an F ₂ laser (157 nm), an Xe ₂ laser (172 nm), and ArF laser (193 nm), KrF laser (248 nm), XeBr laser (282 nm), XeCl laser (308 nm) and XeF laser (351 nm). Inert gas ion lasers include, but are not limited to, an (Ar) ⁺ laser (including ~ 460 nm, 480 nm, 500 nm, 520 nm), a (Kr) ⁺ laser (650 nm), and a He-Cd laser (325 nm, 440 nm).

The group of metal vapor lasers includes, but is not limited to, a Cu laser (500 nm, 545 nm) and an Au laser (310 nm, 605 nm). The group of molecular gas lasers includes a CO laser (6-8 μm), a CO ₂ laser (9 μm, 10.6 μm, 11 μm) and an N ₂ laser (337 nm).

Solid-state lasers can be selected from a ruby Cr ³⁺ : Al ₂ O ₃ laser (694 nm), a neodymium glass laser (Nd: glass) (1062 nm), a neodymium laser based on yttrium-aluminum garnet (YAG) (1064 nm) , alexandrite laser (755 nm), AlGaN / GaN laser (400-500 nm), InGaAs / GaAs laser (700-880 nm), InGaAsP / InP laser (900-1100 nm) and Pb chalcogenide laser (2 6-30 microns). The group of dye lasers includes, among others, stilbenes, coumarins and rhodamines, covering the entire spectral region from ~ 300 nm to 1300 nm.

In further embodiments, the cutting process may be performed in parallel, synchronously or sequentially by multiple lasers. The cutting process is preferably carried out by two lasers, more preferably three lasers, and most preferably four lasers. There are no restrictions on the number of lasers. The number of lasers can be adapted accordingly and depends on the complexity of the cutting scheme and the size and dimensional characteristics of plastic products placed in a continuous tape. It is also possible to split the laser beam with a beam splitter into multiple beams, and control each beam independently for the cutting process. Preferred are a CO ₂ laser and a UV laser. In particular, CO ₂ lasers with a wavelength of 9.4 μm, more preferably with 10.3 μm or 10.6 μm, with a preferred output of 200 W or between 180 W and 220 W, respectively, are preferred. Preferred UV lasers include solid-state lasers based on Nd: YAG, YLF (yttrium lithium fluoride) or Nd: VO4, where a third harmonic is generated by converting frequency with nonlinear crystals with a wavelength of 355 nm or close to it. These lasers allow extremely precise focusing of the laser beam, which is suitable for cutting or separating or perforating narrow joints between plastic components in whole or in part.

According to the present invention, a focused laser beam is conducted along the contours of plastic products placed in a continuous tape to melt or vaporize the material between the products and / or the continuous tape. A Gaussian distribution of the intensity over the cross section of the laser beam ensures that the laser radiation melts the material at the edges and no burr formation occurs. This has the advantage that sharp edges do not form on the edge of the plastic products, which can damage, for example, sterile gloves used in medical practice, or even lead to cuts in the hands of an employee working with cut plastic products. Laser beam separation offers clear advantages over mechanical separation devices, such as die cuts, since the use of mechanical devices obviously leads to burrs or sharp edges. The sharpness of the resulting burrs and / or cutting edge directly depends on the hardness / stiffness of the plastic material.

The plastics are preferably selected from the group consisting of polyamides, polyolefins or copolymers, as well as combinations of such plastics or copolymers in the form of composite materials. The plastic is preferably polyethylene (PE), even more preferably polypropylene (PP), or any other plastic with at least the same as polypropylene (PP), hardness / stiffness, tensile strength, torsion modulus, Young's modulus and / or melting temperature range. According to the present invention, preferably any plastic that is at least as hard or even harder or harder than PP can be cut.

Additional plastics that can be used in the device according to the invention can be selected from the group consisting of or comprising: polyvalerolactones, poly-ε-decalactones, polylactic acid, polyglycolic acid, polylactides, polyglycolides, copolymers of polylactides and polyglycolides, poly-ε-caprolactone , polyhydroxybutyric acid, polyhydroxybutyrates, polyhydroxyvalerates, copolymers of hydroxybutyrates and hydroxyvalerates, poly (1,4-dioxan-2,3-dione), poly (1,3-dioxan-2-ones), poly-para-dioxanones, polyanhydrides, to such as polymaleic anhydrides, polyhydroxymethacrylates, fibrin, polycyanoacrylates, polycaprolactone dimethacrylates, poly-b-maleic acid, polycaprolacton butyl acrylates, multiblock copolymers, such as those formed from oligocaprolacton diols, polyethylene polyethylene glycol polyethylene, polyethylene polyethylene, polyethylene, polyethylene, polyethylene, polyglycolic acid trimethyl carbonates, polycaprolactone glycolides, poly-g-ethylglutamate, poly (DTH-iminocarbonate), (DTH = deaminosyrosyltir zinghexyl ether), poly (DTE-co-DT-carbonate) (DTE = desaminothyrosyl tyrosine ethyl ether, and DT = desaminothyrosyl tyrosine), poly (bisphenol-A-iminocarbonate), polyorthoesters, polyglycolic acid trimethyl carbonates, poly (trimethyl carbonates), ) pyrrolidone, polyvinyl alcohols, polyester amides, glycolated polyesters, polyphosphoesters, polyphosphazenes, poly [(para-carboxyphenoxy) propane], polyhydroxyvaleric acid, polyanhydrides, ethylene oxide-propylene oxide copolymer, polyurethanes, copolymer ethers and esters, such as polyethylene oxide, polyalkenoxalates, polyorthoesters, as well as their copolymers, carrageenans, collagen, polyhydroxyalkanoates, pectic acid, actinic acid, carboxymethyl sulfate, collagen, collagen-N-hydroxysuccinimide, polyacrylmethyl acrylate, polyacrylate , polyacrylonitrile, polyamides, polyether amides, polyethylene amines, polyimides, polycarbonates, polycarbonate-urethane, polyvinyl ketones, polyvinyl halides, polyvinylidene halides, are simple f polyvinyl esters, polyvinyl aromatic compounds, polyvinyl esters, polyvinyl pyrrolidone, polyoxymethylene, polybutylene, polytetrafluoroethylene, polyolefin elastomers, polyisobutylene, ethylene-propylene-diene (EPDM) rubber, fluorosiliconetilethylene arylated, polyethersulfones, epoxies, acrylonitrile butadiene styrene (ABS) copolymers, silicones such as polysiloxanes, polyvinyl halide, and copolymers and / or with mixtures of the aforementioned polymers, and also laminated and multilayer systems of the aforementioned polymers.

Plastic products made of polypropylene have the greatest advantage over plastic products made of polyethylene, as they can be autoclaved and sterilized at temperatures of 121 ° C or higher. This is especially important in the medical field, where a guarantee is surely needed that all microorganisms are killed. Due to the higher temperatures necessary for processing polypropylene, plastic products must be cooled for a longer distance and / or for a longer time before plastic products can be cut from a continuous tape in which individual plastic products are connected to each other . Moreover, PP is much harder than PE, and naturally, mechanical cutting or punching leads to even sharper burrs and / or cutting edges.

Using the device according to the invention, plastics can be cut at a high technological temperature immediately after processing. At the same time, not only is there no need to wait until the plastic cools, but there is no need to mount long conveyor belts to cool plastic products during transportation to a temperature at which plastic products can be cut off. Therefore, it is also preferable to cut plastics that have a high Young's modulus and thereby tend to form sharp burrs and / or edges when they are cut or cut mechanically. Polypropylene, which has the standard characteristics of a melting range between 160 ° C and 170 ° C and a Young's modulus of about 1520 N / mm ^{2, is} particularly preferred. Thus, those plastics that have a melting range above 160 ° C, more preferably above 180 ° C, further preferably above 200 ° C, and particularly preferably above 220 ° C, are preferred and can be autoclaved in the usual manner at temperatures 121 ° C or higher without manifestation of deformation. In addition, those plastics that have an operating temperature above 100 ° C, more preferably above 110 ° C, and / or with a Young's modulus above 1500 N / mm ² , more preferably above 1700 N / mm ² , and further preferably above, are preferred. 1900 N / mm ² . A particularly preferred plastic that can be cut using the device of the invention is polypropylene and any other plastic characterized by a range of melting points, tensile strength, torsion modulus or hardness / stiffness, in the range of polypropylene, the expression “in the range” being defined as ± 10% of the corresponding value for polypropylene, that is, a value as for polypropylene, with a deviation from -10% to + 10%.

The device according to the invention uses a laser to cut plastic products placed in a continuous ribbon of plastic. A cooling channel for hot plastic products is not required, since the laser can reliably and accurately cut hot material, or hot material during its cooling, respectively. This is especially advantageous when cutting plastic products for the medical field at elevated temperatures, immediately or shortly after the plastic products leave the molding roll when they already begin to harden. Additionally, it is possible to fully or partially perforate narrow joints between plastic components, or to create predefined breakpoints that facilitate the separation of plastic products from each other. This is particularly advantageous when the plastic products are made of polypropylene, which is extremely viscous after cooling, which makes it difficult to manually separate the plastic products without any additional mechanical device, such as scissors.

Therefore, the laser cutting apparatus according to the invention is particularly useful for cutting warm or hot polymers and plastics, that is, cutting polymers or plastics with a temperature of at least 60 ° C, preferably at least 80 ° C, further preferably at least 100 ° C, more preferably at least 115 ° C, more preferably at least 125 ° C, even more preferably at least 135 ° C, further preferably 145 ° C, and more preferably at least 155 ° C, thanks making plastics and / or polymers can be cut even at temperatures of from 200 ° C to 250 ° C. In addition, the device according to the invention is preferably used for cutting plastic products that are in the process of cooling or heating, at which the temperature of the segment being cut at the beginning of the cutting process is different from the temperature at the end of the cutting process. The word "segment" should be understood as a section, for example, in a continuous tape, which is recognized in the duty cycle by an optical device for collecting data, and where the cutting pattern is determined. Laser cutting is very accurate even when there is a temperature gradient, that is, the temperature changes during cutting in a plastic product or in a plastic segment, respectively. The device according to the invention correctly recognizes and processes the cutting pattern for plastic products in the temperature range from -100 ° C to + 300 ° C. Any changes in the temperature of the plastic up to 1 ° C per second can be detected and processed by the device according to the invention. This also includes changes to consecutive cutting patterns and cutting modes, as well as changes in plastic materials during cutting according to a cutting pattern, or for consecutive segments and cutting patterns.

The term “cutting” or “laser cutting”, as used here, should be understood as cutting through a laser beam through a plastic material, preferably polypropylene and similar polymers or polyethylene, also including perforation, that is, alternating sections with through cutting and uncut sections, as well as cutting partially through or with the formation of thinned sections, which means that the material at the cutting point is not completely cut through, but only with a reduction in thickness, that is, the binding of the material is still there it can be, but can be mechanically separated with less effort. Thus, the term “cutting” or “laser cutting” describes the complete cutting through of a plastic material along the entire cutting pattern, or only at specified points in the cutting pattern, as well as the perforation of plastic material along the entire cutting pattern or only at specified points in the cutting pattern, there are, completely cut through sections are interspersed with uncut sections.

The term “cutting pattern” should be understood as the totality of all cut sections that are recognized by an optical device for collecting data in one detection stage. The cutting pattern can be positioned in the continuous tape segment of interconnected plastic products. Thus, if it is intended to cut plastic products in a continuous strip or tape of interconnected plastic products, the optical data acquisition device will gradually recognize a portion (i.e., a segment) of a continuous strip or tape of interconnected plastic products, which is fed to the device of the invention and then cut according to the scheme cutting. The cutting pattern includes plastic products recognized by the optical data acquisition device, which are usually three-dimensional and are located above and below the plane, and are defined by a continuous strip or continuous tape, which may include additional user-defined and thereby predefined information regarding the cutting mode. An optical data acquisition device can detect, for example, where cutting should be performed. The cutting mode (fully, partially, with perforation, etc.) can be predefined by the user. Alternatively or additionally, the optical data acquisition device can detect corresponding markings, which not only provide information on where the cuts should be made, but can also include a cutting mode as information. Naturally, a combination of the above characteristics is possible, that is, a combination of predefined patterns and automatic detection of the cutting mode and / or cutting pattern is possible. Instead of a continuous strip or continuous tape, it is also possible that the optical data acquisition device detects single blocks or only sections of continuous tape, only there are isolated segments.

The cutting pattern and, ultimately, the cutting mode, is again determined by the optical device for collecting data before cutting a specific section, or a specific section of a continuous strip or continuous tape, thereby it is possible to implement a variety of cutting patterns and cutting modes in random order. This is a clear advantage over mechanical cutting and / or punching methods. A tool for mechanical cutting or mechanical cutting is rigidly determined for a given cutting scheme or a given cutting mode and cannot adapt to changes in alternating segments with different cutting schemes and cutting modes. A laser cutting apparatus according to the invention can realize up to ten different cutting patterns with different cutting modes, which cannot be achieved with a mechanical cutting or punching tool. Even if you use various tools for cutting or cutting, there is still only a limited number of patterns that can be implemented. The device according to the invention is independent of the exact cutting pattern, that is, it is not limited to a specific pattern, but can detect and implement any cutting pattern.

The cutting pattern is determined using suitable markings that are detected by the optical data acquisition device. These may include color tags, volumetric tags, as well as radioactive tags.

Color tags include, for example, colored tags in the visible, infrared or UV region, and can be inserted into or attached to the plastic. This also applies to other materials that can be inserted into or attached to the plastic and differ from the plastic material, such as thin threads, wires or microparticles. Volume marks, on the other hand, can be made as protrusions, dents or holes in the plastic material. Radioactive tags are radioactive substances introduced into or attached to a plastic material, moreover, a labeled substance or solution in a plastic product can serve as a tag.

The data processing device determines which sections of the cutting circuit should be completely cut by the laser or only perforated, made thinner and / or should not be processed. Thus, the laser is able to cut through specific sections completely, perforate them, reduce the thickness of the material to a predetermined degree, and / or skip predetermined sections, all within the cutting circuit detected and / or predefined by an optical data acquisition device, depending on which mode cutting was predefined by the user or marked in the cutting pattern or segment, respectively. The laser is controlled by the data processing device and is guided according to the cutting pattern detected by the optical data acquisition device and a predetermined cutting mode.

The use of a laser beam for precise cutting of plastic products is determined by an optical device for data collection, which determines the positional parameters of interconnected plastic products placed in a continuous plastic tape. Positional parameters may include information about the shapes, sizes, shapes, geometric configurations, laser marks, shadow projection, color recognition, light / dark areas or reflections that are detected by the optical data acquisition device.

In a preferred embodiment, the optical data acquisition device includes a camera. In another preferred embodiment, a laser scanner is used together with the detector to determine positional parameters by measuring interconnected plastic products placed in a continuous plastic tape. The laser can be deflected by a system of mirrors to image the full surface profile of plastic products.

Positional parameters are transferred to a data processing device, for example, a programmable microprocessor, where they are further processed. The term “processed” should be understood in such a way that actually defined positional parameters are compared with the positional parameters stored in the data processing device. For each combination of positional parameters, a cutting circuit is stored in the data processing device, which is transmitted to the laser control system to direct the laser.

This has the advantage that exact adherence to the dimensions of the plastic products placed in the tape is not required, since the optical data acquisition device detects the corresponding actual state of the plastic products. In particular, high temperatures are usually used to make plastic products. The resulting temperature-dependent expansion and / or contraction of the plastic makes, for example, mechanical cutting possible only at fixed lower temperatures. The use of a device according to the invention eliminates this problem, and plastic products can be precisely cut at different temperatures. Moreover, it follows that when cutting a variety of different plastic products, complex reconfiguration of the device is not required, since only cutting patterns should be changed for positional parameters.

In another preferred embodiment, the positional parameters are not compared with the stored positional parameters, but the data processing device calculates the corresponding cutting pattern from the collected positional parameters and transfers the calculated cutting pattern to the laser control system for guiding the laser.

In a further preferred embodiment, positional parameters are stored in the memory, as well as cutting patterns that are adjusted by the respective actual positioning parameters, resulting in an adapted cutting pattern that is transmitted to the laser control system to direct the laser.

The laser control system preferably consists of an adjustable focusing optical system, an adjustable deflecting device, and a beam-forming device. In this context, the term "adjustable" should be understood so that the focusing optical system and the deflecting device can be adjusted according to the cutting schemes calculated in the device for processing data, and additionally that the data is transmitted in a suitable format. The beam-forming device collimates the laser beam and reduces beam divergence for better focusing. In accordance with certain positional parameters, the focus position and the intensity at the focal point of at least one laser are controlled using an adjustable focusing optical system and an adjustable deflecting device. If more than one laser is used, then preferably each laser is controlled by another laser control system.

In one embodiment, the laser control system includes a beam-forming device that collimates the laser beam, a telescopic lens system that reduces beam divergence for better focusing, a deflecting mirror system that directs the laser beam in two or three dimensions around interconnected plastic products according to a predefined pattern a cutting, focusing optical system that focuses the laser beam so that the plastic material evaporates while moving the laser ray, and electronic device with program control, which converts the data for cutting a moving mirror circuit.

In a preferred embodiment, the adjustable deflecting device is a scanner with a galvanometric mirror, deflecting the direction of the laser beam using mirrors. In more preferred embodiments, the scanner with a galvanometric mirror deflects the laser beam through two or more mirrors. One or more adjustable deflecting devices may be used depending on the geometric characteristics of the plastic products. In one preferred embodiment, no movement occurs between the plastic product and the laser optics, that is, the laser optics are fixed and stationary, and the laser beam is controlled only by an adjustable deflecting device.

In yet another embodiment, the laser beam is not deflected by an adjustable deflecting device, but the laser optics or part of the laser optics is moved relative to the plastic product to perform the cutting process. The term "laser optics" includes all the components necessary for the formation, focusing, regulation or amplification of a laser beam. For example, with respect to a plastic product, only a lens and a system of mirrors can move, or only a lens, or only a system of mirrors, or the entire laser optics as a whole.

In a particularly preferred embodiment, the laser beam is controlled by a movable adjustable deflecting device. The term "movable" in this context means that the adjustable deflecting device can move along the x-, y- and z-axes. This ensures that the laser beam can also reach and cut through areas that are difficult to access.

An additional advantage is that an adjustable deflecting device can also be used for simultaneous marking of ampoules, thereby cutting and marking are performed in one technological stage.

The focusing optical system is preferably a lens or mirror, more preferably a collecting lens or a focusing concave mirror. A concave mirror provides an additional advantage in that each laser wavelength can be focused at the same point without the need for special optical materials.

In one embodiment, the device includes a transport device for interconnected plastic products placed in a continuous tape. This transport device preferably consists of a feeding device that extends interconnected plastic products placed in a continuous tape, under a laser and an optical data acquisition device. This allows you to achieve high productivity and fully automate the cutting of plastic products placed in a continuous tape.

In other embodiments, the transport device is a conveyor belt on which interconnected plastic products are transported.

One of the significant advantages of laser separation of plastic products, for example, ampoules, bags or other containers, is the creation of a fused edge, as opposed to a sharp edge after mechanical separation. This is especially important when cutting plastic products for use in the medical field, since a sharp edge can cause damage to sterile gloves or even injure the hand of a doctor or hospital staff when using such ampoules. Mechanically cut plastic products always have sharp edges due to the fact that there will be a sharp edge on the side where the cutting blade leaves the cut line.

The conventional fixed-beam laser cutting method and focusing through a process gas nozzle can also lead to burrs at the edges. It is better to cut the ampoules with a moving beam, for example, using a galvanoscanner, since this method can be carried out more precisely by fine-tuning the parameters of the laser and beam-forming elements, such as telescopes and lenses, and moving the scanner so that the edges are melted at the joints. To achieve this, a sensor and a control system are required as provided by the present invention.

However, even with this type of separation, it may be that the cut plastic products, such as ampoules, do not separate at the fused edges. This is a situation where the ampoules are held together by just a perceptible sharp edge. When the ampoules are then finally separated, sharp edges still remain. Such sharp edges may result from a slight fluctuation in laser power or a barely detectable variation in beam direction.

Since ampoules are placed inside an ampoule package with very narrow connections, the quality of a laser incision can usually only be assessed using a very sophisticated image recognition system and special cameras. Such a system slows down the entire technological process, is initially expensive and prone to failures, and cannot be easily integrated into existing systems.

Therefore, the device according to the invention further includes a quality control device with an integrated pressure sensor for extruding cut plastic products. The interconnected plastic products housed in a continuous plastic tape are preferably not completely separated by a laser from the residual material, i.e. the frame, so that the cut plastic products can be transported inside the surrounding material until a final separation occurs. During laser cutting, precisely defined narrow joints remain between the plastic products and the surrounding residual material. For the final separation stage, plastic products are transported under a quality control device with an integrated pressure sensor. A stamp with the shape of the ampoule package or a stamp with a certain number of pins that strike at predetermined positions on a separate plastic product or section of a continuous plastic tape, that is, an adapted stamp, extrudes plastic products and especially the material between the narrowed sections of the ampoules, that is, the material between the neck areas of adjacent ampoules, from the residual surrounding material. If the pressure or force required to push the ampoules from the surrounding material and / or material between the narrowed sections exceeds a predetermined first adjustable value, this is an indication that the plastic products are not sufficiently separated and are still connected to the surrounding material, that is, all still connected to the tape or between each other.

Instead of a stamp that actually hits plastic products, or blocks, or packs of plastic products to separate them, a gas stream, such as an air stream or multiple air flows generated by one or multiple nozzles, can be used to apply a specific pressure of the gas stream to plastic products, or blocks, or bundles of plastic products. To do this, create single gas jets with a certain pressure, which again shows the quality of laser cutting in the sense that it can be determined whether the gas jet or gas jets were sufficient to separate single plastic products, or blocks, or packs of plastic products. Instead of gas, a qualified person can also use a liquid such as water for the same purpose.

Thus, a quality control device with an integrated pressure sensor is designed to extrude laser-cut plastic products from the surrounding residual material of a continuous tape, thereby forming separate plastic products, or blocks of plastic products that are still attached to each other but are already perforated, preferably by the laser used in the cutting device, so that the separation can be done easily without the formation of sharp edges. This is usually done using an adapted mold in the form of an ampoule or package of ampoules. Additionally, narrow dies may be included that push the residual material between the narrowed portions, that is, the area between the neck portions of two adjacent ampoules. If the pre-set first adjustable value is exceeded, then the laser cutting was insufficient, and these plastic products are assembled separately. This has the advantage that insufficiently cut plastic products can be collected separately from correctly cut plastic products, and then subsequently processed again, and thus not be lost. Thus, in one embodiment, a quality control device with an integrated pressure sensor consists of a mold adapted to the shape of ampoules, which accurately extrudes plastic products from the surrounding residual material.

In addition, a quality control device with an integrated pressure sensor can monitor the quality of laser cutting, that is, the quality of the intended separation, by measuring the resistance and / or force that is needed to extrude plastic products from the surrounding residual material. The pressure / force required to push the ampoules out of the surrounding material and / or narrowed portions of the ampoules, i.e. the material between the portions of the necks of adjacent ampoules, provides direct information on whether the laser cutting has sufficiently melted the material at the edges so that no sharp burrs occur.

The applicant found that when laser cutting, for example, polypropylene ampoules, the following is true:

if the pressure sensor does not detect any resistance, the ampoules separate correctly and the edges are completely melted around the ampoules

if the pressure sensor detects resistance up to 0.5 N to push the ampoules out of the surrounding residual material, then only a negligible rib is formed, and the use of the ampoules is safe.

if the pressure sensor registers a resistance of more than 0.5 N to eject the ampoules from the surrounding residual material, a significant sharp edge has formed, and the ampoules may be harmless and will be sorted.

Thus, if the required pressure required to eject plastic products, such as bags, vials, cans, ampoules or other containers, from the surrounding residual material and / or narrowed sections of the ampoules, that is, the material between the neck portions of adjacent ampoules, exceeds the second threshold value, but still less than the first threshold value, this indicates that laser cutting is unsatisfactory, and there is a potential dangerous formation of sharp edges or burrs in the plastic product.

In an additional embodiment, quality control is performed on the material between the narrowed sections, that is, in the area between the sections of the necks of two adjacent ampoules.

Thus, the force required to eject the plastic products from the surrounding residual material provides information on whether the plastic product is correctly cut, that is, whether the plastic products can be ejected from the surrounding material or not. In addition, the required force indicates whether faces are safe or if any edges have formed that could be potentially hazardous.

It will be clear to a person skilled in the art who is familiar with the description of this quality control device with an integrated pressure sensor that the exact first and second values or threshold values for pressure / force depend on factors such as the grade of cut plastic, the thickness of the material, the temperature, at which cutting is performed, the laser output, and / or the geometric shape or size of the plastic products, and the like. It is within the competence of a qualified specialist to determine, with minimal experimental work, which pressure or threshold force is indicative of plastic products in a continuous tape. Thus, it is completely uncomplicated and even non-patentable to find out the proper pressure range, which for a given plastic product shows flawless cutting or unacceptable cutting so that it is necessary to adjust the laser.

In yet another embodiment, a quality control device with an integrated pressure sensor determines the quality of laser cutting by applying reduced pressure to a plastic product, such as an ampoule, ampoule packaging and / or narrowed portion, that is, the material between portions of the neck of the ampoule. The principle of operation is similar to the embodiment described above, however, the force required to separate the ampoule, package the ampoules and / or narrowed portion from the surrounding residual material is not measured here. Instead, a quality control device with an integrated pressure sensor measures the force required to apply a certain reduced pressure, such as a specific vacuum.

While pressure or force is applied from above to the upper side of individual plastic products or a package or package of plastic products, a reduced pressure or vacuum is applied from below to individual plastic products or a package or package of plastic products to separate individual plastic products or a package or package of plastic products from continuous plastic tape and from other individual plastic products or other packages or packages of plastic products.

In a third embodiment of the invention, a quality control device with an integrated pressure sensor exerts a pulling force that can be determined to evaluate the quality of the laser cutting. Such a pulling force can be applied by means of a device that grips individual plastic products or a package or bag of plastic products and separates them from a continuous plastic tape and from other individual plastic products or other packages or packages of plastic products. The force required to separate individual plastic products or packaging or a package of plastic products can be measured and is also an indicator of the quality of laser cutting to evaluate whether laser cutting was flawless or insufficient.

Thus, according to the present invention, it is unimportant whether separate plastic products or individual packages or individual plastic product bags are separated by applying a pushing force, such as pressure, or pulling force or reduced pressure, such as vacuum.

In an additional embodiment, the device includes a system for compensating for the effects of long-term drift of the laser beam and an adjustable deflecting device. This may occur due to changes in temperature, humidity, vibration, mechanical stress and aging of the components, and may adversely affect the accuracy of the laser beam. The system for compensating for the effects of long-term laser beam drift ensures that laser accuracy is always optimal, reducing production losses to an absolute minimum by keeping the device in working condition.

In one embodiment, a thermal imaging camera is used to record selective heating on a surface of a material lying outside the cutting pattern, but still within the deflection range of the mirrors of the adjustable deflector. Selective heating takes place as a result of the short-term direction of the beam to this surface of the material for a specific period of time. This short-term heating can, for example, be performed while the feed device extends the following interconnected plastic products placed in a continuous tape, under the laser and the optical data acquisition device. The thermal imaging camera compares the position on the receiver with the previously programmed adjusted / design positions. The collected data is then transmitted to the laser control system to adjust and adjust the cutting pattern. This control mechanism can take place both in each cutting process and in front of it, or at certain predetermined intervals. A camera for recording thermal images can also simultaneously determine the surface temperature of a heated material and from these data draw a conclusion about the laser power used to cut plastic products. Then, according to this, the laser power can be adjusted.

In yet another embodiment, the tape lying outside the cutting pattern, but still within the deflection range of the mirror system of the adjustable deflecting device, is pulled together with the plastic tape inside or outside it, whereby the laser removes the amount of material in the tape in the form of a dot. The camera compares the position of this point with the programmed control point, and any deviations are transmitted as correction data to the laser control system, similar to the process described above.

The interconnected plastic products for medical use housed in a continuous plastic tape are preferably vials, bags or containers, and even more preferably ampoules. In addition, according to the invention, medical devices or parts of medical devices, such as syringes, tubes, hollow fibers for dialyzers, or parts of powder inhalers can be cut off.

Particularly advantageous is the use of a device for cutting multilayer plastic products, such as products made by coextrusion blow molding. These multilayer plastic products combine the positive properties of various plastics and are usually characterized by a barrier layer that is placed between two carrier layers that are interconnected by a binder. These multilayer plastic products are preferably used in applications where improved gas barrier performance is needed. Mechanical cutting methods have particular problems at the junctions of multilayer plastic products. Naturally, at the joints, the barrier layer is not very effective, and there is an increased risk that the barrier layer is destroyed as a result of mechanical cutting in these areas. The device according to the invention has the advantage that individual layers in multilayer plastic products are welded together at the joints and along the edges during laser cutting. Thus, the barrier properties at the joints, at the edges or at the seams remain unharmed and even improve, compared with methods of mechanical cutting.

The method for separating plastic products placed in or surrounded by plastic can be applied and performed in principle in a similar manner using the described laser control system for other plastic products, such as consumer goods or industrial parts.

In a particularly preferred embodiment, the device according to the invention operates in combination with a device manufacturing plastic products under the conditions of the BFS process (blow-fill-seal process). Such devices are well known and described, for example, in patent EP 1626903 B1.

The device according to the invention is particularly advantageous for cutting plastic ampoules interconnected, connected to each other and / or coupled together. These ampoules, for example, can be filled during the BFS process (blow-fill-seal process), but empty ampoules can also be processed. When plastic ampoules are made in a BFS process (“blow-fill-seal” process), the ampoules exit the loading machine in the form of rows of interconnected, connected to each other and / or ampoules joined together in a continuous tape. In this continuous tape, one row of ampoules interconnected, connected to each other and / or joined together follows another row of ampoules, and all rows are embedded in a continuous tape and surrounded by residual plastic material. In order to obtain as many ampoules as possible inside a continuous plastic tape, the ampoules are placed very close to each other, and thus the separation of the ampoules is very difficult. This is especially true for the narrowed part at the neck of the ampoule. The narrowed part at the neck of the ampoule is a critical area during mechanical cutting, as there is only a very small area that needs to be cut precisely, and often only partial separation is achieved. Thus, when opening or separating a single ampoule, there is a constant danger that an adjacent ampoule will be accidentally opened due to incomplete separation between the narrowed sections of the ampoules. The device of the invention can separate these ampoule sections reliably without risk of damage when opening the ampoules.

Ampoules in the medical field are usually produced in the form of packages, that is, a certain number of interconnected ampoules are cut mechanically from a continuous tape. However, ampoules, especially those made of polypropylene, tend to form sharp edges during mechanical cutting, or when one ampoule is manually separated from the ampoule packaging.

Unlike mechanical cutting, cutting using the device according to the invention has the following advantages. Plastic ampoules do not need cooling and can be cut off at higher temperatures. Differences in the size of the ampoules, which are initially inherent or inevitable when the ampoules are made at high temperatures, and during the shrinkage of the ampoules, when they are cooled, are detected by the device, and the laser beam is adjusted accordingly. In addition, when cutting with a laser, sharp edges and / or burrs are avoided, and with a laser, the ampoules can be provided with perforations or break points between or in plastic products, thereby facilitating their separation from each other.

The combination of the device according to the invention with a machine for the production of plastic products under the conditions of the BFS process (process "blow-fill-seal") is particularly advantageous, since there is no longer a need to build a cooling channel, and plastic products can be cut at higher temperatures immediately after manufacturing. Together with the aforementioned benefits, this leads to increased productivity, reliability and economy.

The present invention also includes a method according to the invention for cutting interconnected plastic products for use in the medical field, placed in a continuous plastic tape, which includes the following stages in which:

a) create interconnected plastic products embedded in a continuous tape of plastic,

b) determine the positional parameters of the interconnected plastic products embedded in the continuous plastic tape using an optical data acquisition device and calculate the cutting pattern in the data processing device,

c) adjust the laser using a laser control system consisting of an adjustable focusing optical system, an adjustable deflecting device and a beam-forming device, and depending on certain positional parameters, the position and intensity of the focal point of at least one laser is adjusted,

d) cut interconnected plastic products placed in a continuous tape of plastic, according to the calculated cutting pattern.

In a preferred embodiment, plastic products or packages of plastic products are cut at temperatures of plastic products or packages of plastic products from 60 ° C to 155 ° C

In further embodiments, the method may further include one of the following steps e) -e ″), in which:

e) carry out a quality test with a quality control device with an integrated pressure sensor that measures the force required to eject cut plastic products or packages of cut plastic products.

e ') carry out a quality test using a quality control device with an integrated pressure sensor that measures the reduced pressure required to separate the cut plastic products or packages of cut plastic products.

e '') perform a quality test using a quality control device with an integrated pressure sensor that measures the pulling force required to separate the cut plastic products or packages of cut plastic products.

In this way, a built-in pressure sensor measures force, reduced pressure, pulling force, or any other force that is required to separate the plastic products from the surrounding residual material. Pressure, or force, or reduced pressure (such as vacuum), below a certain value (for example, value A) shows correct and flawless cutting without sharp edges, while pressure, or force, or reduced pressure is higher than a certain value (for example, value B ) shows incorrect or defective cutting, so that plastic products cannot be separated, or cannot be easily separated, or cannot be separated without sharp edges. The pressure, or force, or reduced pressure between the value A and the value B indicates insufficient cutting, where the plastic products can still be separated, but could have sharp edges. Depending on the plastic product, the type of plastic used, and the use of the plastic product in medicine, cut plastic products obtained within the range between the value A and the value B could be sold as the correct medical products, or could be rejected as an irreparable manufacturing defect. Moreover, depending on the plastic product, the type of plastic used and the use of the plastic product in medicine, the value of A can be identical or almost identical to the value of B.

In a preferred embodiment, when the force for separating the plastic products from the surrounding material reaches the first predetermined adjustable value, this indicates that the plastic products are still connected to the tape and have not been successfully separated, that is, the force was insufficient. This also implies that when this first threshold value or first value has been reached, no additional force is applied to separate the plastic products. This is important because, if the plastic products are still firmly connected to the surrounding residual material, the application of an unlimited amount of force could damage the tape and then the plastic products, for example, if the (hot) tape is too stretched.

In addition, you can pre-set the second value / threshold value, which is near or below the first value. If the force required to separate the plastic products from the surrounding residual material exceeds this second value, but still is less than the first value, the plastic products have been successfully separated, but this is an indication of unsatisfactory and potentially dangerous formation of sharp edges or burrs. If the required force remains below this second value / threshold, then the laser cutting quality is satisfactory and there is no danger of sharp edges and / or burrs.

As described above, it is clear to a person skilled in the art that the exact first and second values or thresholds for pressure / force depend on factors such as the type of plastic being cut, the thickness of the material, the temperature at which the cutting is performed, the laser output and / or the geometric shape or the size of plastic products, and the like. It is within the competence of a qualified person to determine, with minimal experimental work, which pressure or threshold force is indicative of plastic products in a continuous tape. Thus, it is completely uncomplicated and even non-patentable to find out the proper pressure range, which for a given plastic product shows flawless cutting or unacceptable cutting so that it is necessary to adjust the laser.

In a preferred embodiment, the ampoule tape (1) is pulled and positioned using a feeding device (2) under at least one adjustable deflecting device (5) and an optical data acquisition device (5a). The optical device (5a) for collecting data recognizes the positional parameters of at least one track (II) of ampoules, and the data processing device calculates from the positional parameters a cutting circuit for cutting ampoules (III) individually or in packages of several ampoules from at least one track (II) ampoules. At least one focused laser beam (IV) is modified by the beam forming device (4) so that the laser beam is suitable for separating ampoules by vaporizing material between and / or around the ampoules. An adjustable deflecting device (5) and an adjustable focusing optical system (5b) adjust at least one focused laser beam (IV) according to the cutting scheme calculated by the data processing device for cutting ampoules individually or in packages of several ampoules. After the cutting process, the tape (1) of the ampoules is pulled further by the feeding device (2), and the next track (II) of the ampoules is positioned under the adjustable deflecting device (5) and the optical device (5a) for data collection. The cut-off ampoules (III) are still located in the tape (1) of the ampoules and are now placed under the device (7) for quality control with an integrated pressure sensor and a knife (8) for separating the tracks. A quality control device (7) with an integrated pressure sensor and a knife (8) for separating the tracks are activated, and the separated material between the narrowed sections is collected in a separate container (14). Ampoules (III) are now completely separated from the tape (1) of ampoules and transported in an upright position on an inclined plane to the external conveyor (9) for further processing. A knife (8) separates the residual material (10) of the track from the tape and collects the residual material in a container (15). When the quality control device (7) with integrated pressure sensor is activated to extrude the ampoules (III) from the tape, it simultaneously measures the required pressure. If one or more ampoules do not separate as planned, then the pressure required to squeeze the ampoules (III) out of the tape exceeds a predetermined adjustable threshold value, as a result, the shutter (11) opens, and the residual material with filled ampoules (12) drops into container (16). If the laser cutting device completely fails, then two shutters (13) are activated, and the feeding device (2) transports the remaining tape (1) of ampoules uncut from the device for later cutting.

In yet another embodiment, a device according to the invention separates the container products from the frame and / or from each other and consists of at least one laser with at least one laser control system and at least one optoelectronic system for image recognition and image processing, which determines the position of the container products in the frame and / or relative to each other and transmits this data to at least one laser control system, resulting in at least one laser and / whether the laser beam is directed so that the product container is separated from the frame and / or from each other. The other embodiments and examples described in accordance with the invention in this application are advantageously applicable also in this embodiment.

The method of cutting plastic products at varying temperatures

The present invention, in addition, is directed to a method for cutting plastic products placed in a continuous tape, consisting of segments cut by a single laser cut, for use in the medical field, and the method allows the cutting of plastic products placed in a continuous tape at varying temperatures.

Patent application WO200930311 A1 describes a cutting device for cutting single containers placed in a plastic tape, characterized by a freely falling mechanical punching device that separates individual containers from the surrounding material in free fall. In yet another application WO 2009106219 A1, the mechanical cutting device is driven by an electric motor, which drives the cutting device from its initial position to the cutting position.

When plastic products come out of the mold, they usually need to be cooled before it can be separated from the surrounding residual material. During the cooling process, plastic products undergo temperature-dependent changes in their size (shrinkage). Thus, prototype mechanical punching devices depend on a predetermined temperature at which plastic products can be separated, since only at this temperature the size of the plastic products in a continuous tape is consistent with the shape of the punching tool. This means that the mechanical punching device is placed at a fixed distance from the device for manufacturing plastic products, for example, devices for blowing-filling-sealing, so that the plastic products have an exact predetermined temperature when they enter the mechanical punching device. However, if any discrepancies, minor deviations and / or delays occur during the manufacturing process, then the plastic products no longer have the required temperature, and thus the calculated size of the plastic products is no longer valid. As a result of this, subsequent mechanical cutting down inevitably causes damage and / or destruction of plastic products when they are “cut down” from the surrounding residual material. Thus, almost all mechanical punching devices according to the prototype for plastic products used in the medical field operate at room temperature, where the plastic product made at higher temperatures was completely cooled so that no size variation would occur anymore. If the mechanical cutting process is carried out at elevated temperatures, mechanical cutting devices require the supply of cut interconnected plastic products that have an almost identical temperature, due to the fact that a change in temperature of the plastic products will cause a change in their geometric shape and size. Mechanical cutting devices are unable to follow these changes in geometric shape and size, so that cuts at different temperatures will result in inaccurate or incorrect cuts, thereby making an irreparable defect. Therefore, we need a method that can cut plastic products from a segment of interconnected plastic products at any temperature or in any temperature range between 30 ° C and 155 ° C.

Thus, an additional objective of the present invention is to provide a method for cutting plastic products or cutting segments of plastic products placed in a continuous tape, for use in the medical field, and the method allows the cutting of plastic products or their segments placed in a continuous tape at varying temperatures .

This goal is achieved by the cutting method according to paragraph 12 of the patent claims. Additional preferred embodiments follow from the dependent claims, examples, figures and description.

Thus, a method is presented for cutting plastic products for use in the medical field, placed in a continuous tape of plastic, consisting of laser-cut segments, comprising the following stages, in which:

a) create interconnected plastic products embedded in a continuous strip of plastic, consisting of segments cut by a laser, each segment being cooled, being cut by a laser, and when cutting has any temperature within the range of 30 ° C and 155 ° C,

b) determine the positional parameters of interconnected plastic products embedded in a continuous plastic tape in one segment using an optical data acquisition device and calculate the cutting pattern in the data processing device,

c) adjust the laser using a laser control system consisting of an adjustable focusing optical system, an adjustable deflecting device and a beam-forming device, and depending on certain positional parameters, the position and intensity of the focal point of at least one laser is adjusted,

d) carry out laser cutting of interconnected, cooling plastic products placed in a continuous plastic tape in one segment according to the calculated cutting pattern.

Therefore, the method according to the invention is applicable for cutting warm or hot polymers and plastics, that is, cutting polymers or plastics with a temperature of at least 30 ° C, preferably at least 60 ° C, preferably at least 80 ° C, further preferably at least at least 100 ° C, more preferably at least 115 ° C, more preferably at least 125 ° C, even more preferably at least 135 ° C, further preferably 145 ° C, and more preferably at least 155 ° C, due to why face and and / or polymers can be cut even at temperatures of from 200 ° C to 250 ° C. Thus, at the beginning of laser cutting, the temperature of the segment has at least one of the above temperatures.

In additional embodiments, when starting laser cutting, the segment has any temperature ranging from 30 ° C to 155 ° C, preferably from 35 ° C to 125 ° C, more preferably from 40 ° C to 110 ° C, even more preferably from 45 ° C to 100 ° C, even more preferably from 50 ° C to 90 ° C, and most preferably from 55 ° C to 80 ° C.

Thus, the method according to the invention allows the cutting of plastic products placed in a continuous tape or inside segments of a continuous tape at any temperature, and is completely independent of any changes in the size of plastic products due to shrinkage, for example, as a result of cooling. Depending on the shape and size of plastic products, the exact type of plastic used and some other factors, the temperature of plastic products can vary, which makes mechanical cutting at a predetermined temperature possible only for a very narrow range of applications, namely, only in conditions of one fixed production process for one product. Each change in one of these parameters inevitably makes it necessary to readjust the production line, which not only includes a change in the cutting form itself, but also provides for the reinstallation of the entire cutting device. This could be the case when another type of plastic is used, which has a higher processing temperature and thus needs to be cooled for a longer period of time before mechanical cutting is possible. In some situations, the re-adjustment of the production line might even become impossible due to the simple limited availability of the production area. Without the need to change the cutting forms, readjustment of the production line and the construction of a long cooling channel, the method presented has much higher technological flexibility, is more economical and saves a lot of space.

The term “interconnected plastic products placed in a continuous tape” should be understood as an endless tape with a certain width into which interconnected plastic products are embedded, that is, surrounded by residual material.

The term "segment" should be understood as a section, for example, in a continuous tape, which is recognized in one separate technological cycle by an optical device for collecting data, and where the cutting pattern is determined. Thus, the “segment” has a certain length and width, with a certain number of interconnected plastic products. Therefore, the proportions of the segments directly depend on the settings of the optical device for collecting data. The term “segment” should not be understood in the physical sense in the sense that, for example, there are previously cut sections or markings in a continuous tape, but it is solely determined by the recognition field of the optical device for collecting data. A “segment” is preferably that part of a continuous tape that is detected or snatched by an optical data acquisition device and a data processing device in one production cycle, and which preferably contains a certain number of interconnected plastic products. However, dividing or dividing a continuous tape into segments is more of a theoretical concept in view of the fact that the continuous tape does not contain markers denoting segments, and in view of the fact that the position of the segments can be arbitrarily selected. Moreover, it is possible that two segments overlap, or that two consecutive segments are not directly adjacent to each other.

Accordingly, using the method according to the invention, it is possible to cut one segment that has a certain temperature, and immediately after that to cut a subsequent segment that may have a different temperature. Thus, each segment can be cut precisely, regardless of its temperature and the temperature of the preceding or subsequent segment, with plastic products in a continuous tape. In the case of a mechanical cutting device, such precise cutting at variable temperatures is not possible. Plastic products would have different sizes due to different temperatures and thus could not be cut mechanically.

Thus, the method according to the invention is preferably used for cutting plastic products that are in the process of cooling or heating, the temperature of the segment being cut is different at the beginning of the cutting process compared to the temperature at the end of the cutting process. Laser cutting is very accurate even when there is a temperature gradient, that is, temperature changes during cutting in a plastic product or in a plastic segment, respectively. The cutting pattern for plastic products can be formed and executed correctly in the temperature range from -30 ° C to + 300 ° C, and preferably from + 30 ° C to + 300 ° C. Any changes in plastic temperature up to 1 ° C per second can be recognized and processed. This also includes changes to sequential cutting patterns and cutting modes, as well as changes in the grade of plastic materials during cutting according to a cutting pattern or for sequential segments and cutting patterns.

Thus, in one embodiment, at least one segment with interconnected plastic products has a varying temperature than any of the preceding segments with interconnected plastic products. The term "varying temperature" should be understood as including any temperature differences that exceed at least 0.5 ° C. This is particularly advantageous if it is associated with delays and / or minor discrepancies during the manufacturing process. In such cases, it is still possible to cut the next segment with interconnected plastic products that are placed in a continuous tape, even if the size of the plastic products has changed due to excessive cooling time. Thus, in the method according to the invention, it is preferable to cut interconnected plastic products placed in a continuous tape, which have a cooling rate of from 0.01 ° C to 5 ° C per minute. In a preferred embodiment, the interconnected plastic products placed in the continuous tape are composed of polypropylene and / or polyethylene.

In yet another embodiment, the incompletely or incorrectly cut segments are fed again and then cut again at a lower temperature. Incomplete or incorrectly cut segments are usually discarded, since it is impossible to cut these segments again, since these segments are completely cooled and no longer correspond to machines for mechanical cutting, which are configured to cut segments with a higher temperature. In the case of the method according to the invention, these segments can be fed again and then cut accordingly.

The method according to the invention can be performed using a device comprising at least one laser, at least one laser control system, at least one optical data acquisition device and a data processing device, and, optionally, a quality control device with integrated a pressure sensor to detect irregular laser cuts.

An optical device for collecting data determines in the segment the positional parameters of plastic products placed in a continuous tape and connected to each other. The positional parameters in the segment are used to calculate the cutting pattern, which is transmitted to the laser control system. In accordance with the cutting scheme, the focusing optics and the deflecting device adjust the position, intensity and focal point of at least one laser beam.

Accordingly, gas lasers, solid state lasers and / or dye lasers can be used. Lasers included in the group of gas lasers include an excimer laser, an inert gas ion laser, a metal vapor laser, or a molecular gas laser.

The group of excimer lasers includes, but is not limited to, an H ₂ laser (116/123 nm), an Ar ₂ laser (126 nm), an F ₂ laser (157 nm), an Xe ₂ laser (172 nm), and ArF laser (193 nm), KrF laser (248 nm), XeBr laser (282 nm), XeCl laser (308 nm) and XeF laser (351 nm). Inert gas ion lasers include, but are not limited to, an (Ar) ⁺ laser (including ~ 460 nm, 480 nm, 500 nm, 520 nm), a (Kr) ⁺ laser (650 nm), and a He-Cd laser (325 nm, 440 nm).

The group of metal vapor lasers includes, but is not limited to, a Cu laser (500 nm, 545 nm) and an Au laser (310 nm, 605 nm). The group of molecular gas lasers includes a CO laser (6-8 μm), a CO ₂ laser (9 μm, 10.6 μm, 11 μm) and an N ₂ laser (337 nm).

Solid-state lasers can be selected from a ruby Cr ³⁺ : Al ₂ O ₃ laser (694 nm), a neodymium glass laser (Nd: glass) (1062 nm), a neodymium laser based on yttrium-aluminum garnet (YAG) (1064 nm) , alexandrite laser (755 nm), AlGaN / GaN laser (400-500 nm), InGaAs / GaAs laser (700-880 nm), InGaAsP / InP laser (900-1100 nm) and Pb chalcogenide laser (2 6-30 microns). The group of dye lasers includes, among others, stilbenes, coumarins and rhodamines, covering the entire spectral region from ~ 300 nm to 1300 nm.

In additional embodiments, the cutting process or laser cut can be performed in parallel, synchronously or sequentially with multiple lasers. The cutting process or laser cut is preferably carried out by two lasers, more preferably three lasers, and most preferably four lasers. There are no restrictions on the number of lasers. The number of lasers can be adapted accordingly and depends on the complexity of the cutting scheme and the size and dimensional characteristics of plastic products placed in a continuous tape. It is also possible to split the laser beam with a beam splitter into multiple beams, and control each beam independently for the cutting process. Preferred are a CO ₂ laser and a UV laser. In particular, CO ₂ lasers with a wavelength of 9.4 μm, more preferably with 10.3 μm or 10.6 μm, with a preferred output of 200 W or between 180 W and 220 W, respectively, are preferred. Preferred UV lasers include Nd: YAG, YLF, or Nd: VO4 based solid state lasers, where a third harmonic with or near a wavelength of 355 nm is generated by frequency conversion by non-linear crystals. These lasers allow extremely precise focusing of the laser beam, which is suitable for cutting or separating or perforating narrow joints between plastic components in whole or in part.

According to a method according to the invention, a focused laser beam is conducted along the contours of plastic products in a segment placed in a continuous tape to melt or vaporize the material between the products and / or the continuous tape. A Gaussian distribution of the intensity over the cross section of the laser beam ensures that the laser radiation melts the material at the edges and no burr formation occurs. This has the advantage that sharp edges do not form on the edge of the plastic products, which can damage, for example, sterile gloves used in medical practice, or even lead to cuts in the hands of an employee working with cut plastic products. Laser beam separation offers clear advantages over mechanical separation devices, such as die cuts, since the use of mechanical devices obviously leads to burrs or sharp edges. The sharpness of the resulting burrs and / or cutting edge directly depends on the hardness / stiffness of the plastic material.

The plastics are preferably selected from the group consisting of polyamides, polyolefins or copolymers, as well as combinations of such plastics or copolymers in the form of composite materials. The plastic is preferably polyethylene (PE), even more preferably polypropylene (PP), or any other plastic with at least the same as polypropylene (PP), hardness / stiffness, tensile strength, torsion modulus, Young's modulus and / or melting range. According to the present invention, preferably any plastic that is at least as hard or even harder or harder than PP can be cut.

Laser section of the segment, or laser cutting of polypropylene (PP) is performed at any temperature between 30 ° C to 155 ° C, preferably between 35 ° C to 125 ° C, more preferably between 40 ° C to 110 ° C, even more preferably between 45 ° C to 100 ° C, even more preferably between 50 ° C to 90 ° C, and most preferably between 55 ° C to 80 ° C.

Additional plastics that can be used can be selected from the group consisting of or comprising: polyvalerolactones, poly-ε-decalactones, polylactic acid, polyglycolic acid, polylactides, polyglycolides, copolymers of polylactides and polyglycolides, poly-ε-caprolactone, polyhydroxybutyric acid, polyhydroxybutyrates, polyhydroxyvalerates, copolymers of hydroxybutyrates and hydroxyvalerates, poly (1,4-dioxan-2,3-diones), poly (1,3-dioxan-2-ones), poly-para-dioxanones, polyanhydrides such as polymaleic anhydrides, polygon hydroxymethacrylates, fibrin, polycyanoacrylates, polycaprolactone dimethacrylates, poly-b-maleic acid, polycaprolactone butyl acrylates, multiblock copolymers, such as those formed from oligocaprolacton diols, oligodioxanone di polyethylene, polyethylene polyethylene glycol polyethylene polyethylene glycol polyethylene polycaprolactone glycolides, poly-g-ethylglutamate, poly (DTH-iminocarbonate), poly (DTE-co-DT-carbonate), poly (bisphenol-A-iminocarbonate), poly orthoesters, polyglycolic acid trimethyl carbonates, polytrimethyl carbonates, polyiminocarbonates, poly (N-vinyl) pyrrolidone, polyvinyl alcohols, polyetheramides, glycated polyesters, polyphosphoesters, polyphosphazenes, poly [(para-carboxyphenoxy) propanoylpropanide, polypropylene, polyanilide, polypropylene, polyanilide, polypropylene, polyanilide, propylene, and propylene oxide, polyurethanes, copolymers of ethers and esters, such as polyethylene oxide, polyalkenoxalates, polyorthoesters, as well as their copolymers, carrageenans, collagen, polyhydroxy canoates, pectic acid, actinic acid, carboxymethyl sulfate, collagen, collagen-N-hydroxysuccinimide, polyacrylic acid, polyacrylates, polymethyl methacrylate, polybutyl methacrylate, polyacrylamide, polyacrylonitrile, polyamide, polyamide, polyamide polyvinylidene halides, polyvinyl ethers, polyvinyl aromatic compounds, polyvinyl esters, polyvinyl pyrrolidone, polyoxymethylene, polybutyl n, polytetrafluoroethylene, polyolefin elastomers, polyisobutylene, ethylene-propylene-diene (EPDM) rubber, fluorosilicon, carboxymethylchitosan, polyethylene terephthalate, polyvalerate, ethylene-vinyl acetate copolymers, polysulfones, simple polyethersulfonyl copolymers, epoxide, epoxide silicones such as polysiloxanes, polyvinyl halide, and copolymers and / or mixtures of the aforementioned polymers, as well as laminated and multilayer systems of the aforementioned polymers.

Plastic products made of polypropylene have the greatest advantage over plastic products made of polyethylene, as they can be autoclaved and sterilized at temperatures of 121 ° C or higher. This is especially important in the medical field, where a guarantee is surely needed that all microorganisms are killed. Due to the higher temperatures necessary for processing polypropylene, plastic products must be cooled for a longer distance and / or for a longer time before plastic products can be cut from a continuous tape in which individual plastic products are connected to each other . Moreover, PP is much harder than PE, and naturally, mechanical cutting or punching leads to even sharper burrs and / or cutting edges.

Using the method according to the invention, plastics, in particular PP, can be cut at a high process temperature immediately after processing. At the same time, not only is there no need to wait until the plastic cools, but there is no need to mount long conveyor belts to cool plastic products during transportation to a temperature at which plastic products can be cut off. Therefore, it is also preferable to cut plastics that have a high Young's modulus and thereby tend to form sharp burrs and / or edges when they are cut or cut mechanically. Polypropylene, which has the standard characteristics of a melting range between 160 ° C and 170 ° C and a Young's modulus of about 1520 N / mm ^{2, is} particularly preferred. Thus, those plastics that have a melting range above 160 ° C, more preferably above 180 ° C, further preferably above 200 ° C, and particularly preferably above 220 ° C, are preferred and can be autoclaved in the usual manner at temperatures 121 ° C or higher without manifestation of deformation. In addition, those plastics that have an operating temperature above 100 ° C, more preferably above 110 ° C, and / or with a Young's modulus above 1500 N / mm ² , more preferably above 1700 N / mm ² , and further preferably above, are preferred. 1900 N / mm ² . A particularly preferred plastic that can be cut using the device of the invention is polypropylene and any other plastics characterized by a range of melting points, tensile strength, torsion modulus or hardness / stiffness, in the range of polypropylene, the expression “in the range” being defined as ± 10% of the corresponding value for polypropylene, that is, a value as for polypropylene, with a deviation from -10% to + 10%.

In the method according to the invention, a laser is used to cut plastic products placed in a continuous plastic tape. A cooling channel for hot plastic products is not required, since the laser can reliably and accurately cut hot material, or hot material during its cooling, respectively. This is especially advantageous when cutting plastic products for the medical field at elevated temperatures, immediately or shortly after the plastic products leave the molding roll when they already begin to harden. Additionally, it is possible to fully or partially perforate narrow joints between plastic components, or to create predefined breakpoints that facilitate the separation of plastic products from each other. This is particularly advantageous when the plastic products are made of polypropylene, which is extremely viscous after cooling, which makes it difficult to manually separate the plastic products without any additional mechanical device, such as scissors.

The term “cutting” or “laser cutting”, as used here, should be understood as cutting through a laser beam through a plastic material, preferably polypropylene and similar polymers or polyethylene, also including perforation, that is, alternating sections with through cutting and uncut sections, as well as cutting partially through or with the formation of thinned sections, which means that the material at the cutting point is not completely cut through, but only with a reduction in thickness, that is, the binding of the material is still there it can be, but can be mechanically separated with less effort. Thus, the term “cutting” or “laser cutting” describes the complete cutting through of a plastic material along the entire cutting pattern, or only at specified points in the cutting pattern, as well as the perforation of plastic material along the entire cutting pattern or only at specified points in the cutting pattern, there are, completely cut through sections are interspersed with uncut sections. The term “cutting”, or “cut” or “laser cut” should preferably be understood as cutting made in one segment of a continuous tape. After cutting has been done in one segment, perform the next cutting in the subsequent segment. Thus, each cutting refers to one segment, and each segment begins a new cutting process, referred to as a “cut” or “laser cut”.

The term “cutting pattern” should be understood as the totality of all cut sections that are recognized by an optical device for collecting data in one detection stage / technological cycle. The cutting pattern can be positioned in the continuous tape segment of interconnected plastic products. Thus, the term “cutting pattern” refers to the totality of individual cut lines within a single segment. Thus, if it is intended to cut plastic products in a continuous tape or strip of interconnected plastic products, the optical data acquisition device will gradually recognize a portion (i.e., a segment) of a continuous strip or tape of interconnected plastic products, which is fed to the device of the invention and then cut according to cutting pattern. The cutting pattern includes plastic products recognized by the optical data acquisition device, which are usually three-dimensional and are located above and below the plane, and are defined by a continuous strip or continuous tape, which may include additional user-defined and thereby predefined information regarding the cutting mode. An optical data acquisition device can detect, for example, where cutting should be performed. The cutting mode (fully, partially, with perforation, etc.) can be predefined by the user. Alternatively or additionally, the optical data acquisition device can detect corresponding markings, which not only provide information on where the cuts should be made, but can also include a cutting mode as information. Naturally, a combination of the above characteristics is possible, that is, a combination of predefined patterns and automatic detection of the cutting mode and / or cutting pattern is possible. Instead of a continuous strip or continuous tape, it is also possible that the optical data acquisition device detects single blocks or only sections of continuous tape, only there are isolated segments.

The cutting pattern and, ultimately, the cutting mode, is again determined by the optical device for collecting data for each segment, thereby it is possible to implement a variety of cutting patterns and cutting modes in random order. This is a clear advantage over mechanical cutting and / or punching methods. The tool for mechanical cutting or mechanical cutting is designed for a given cutting pattern or a given cutting mode and cannot adapt to changes in alternating segments with different cutting patterns and cutting modes. A laser cutting device can realize up to ten different cutting schemes with different cutting modes, which cannot be achieved with a mechanical cutting or punching tool. Even if you use various tools for cutting or cutting, there is still only a limited number of patterns that can be implemented. The device does not depend on the exact cutting pattern, that is, it is not limited to a specific pattern, but can detect and implement any cutting pattern.

The cutting pattern is determined using suitable markings that are detected by the optical data acquisition device. These may include color tags, volumetric tags, as well as radioactive tags.

Color tags include, for example, colored tags in the visible, infrared or UV region, and can be inserted into or attached to the plastic. This also applies to other materials that can be inserted into or attached to the plastic and differ from the plastic material, such as thin threads, wires or microparticles. Volume marks, on the other hand, can be made as protrusions, dents or holes in the plastic material. Radioactive tags are radioactive substances introduced into or attached to a plastic material, moreover, a labeled substance or solution in a plastic product can serve as a tag.

The data processing device determines which sections of the cutting circuit should be completely cut by the laser, or only perforated, made thinner and / or should not be processed. Thus, the laser is able to cut through specific sections completely, perforate them, reduce the thickness of the material to a predetermined degree, and / or skip predetermined sections, all within the cutting circuit detected and / or predefined by an optical data acquisition device, depending on which mode cutting was predefined by the user or marked in the cutting pattern or segment, respectively. The laser is controlled by the data processing device and is guided according to the cutting pattern detected by the optical data acquisition device and a predetermined cutting mode.

The use of a laser beam for precise cutting of plastic products is determined by an optical device for data collection, which determines the positional parameters of interconnected plastic products placed in a continuous plastic tape. Positional parameters may include information about the shapes, sizes, shapes, geometric configurations, laser marks, shadow projection, color recognition, light / dark areas or reflections that are detected by the optical data acquisition device.

In a preferred embodiment, the optical data acquisition device includes a camera. In another preferred embodiment, a laser scanner is used together with the detector to determine positional parameters by measuring interconnected plastic products placed in a continuous plastic tape. The laser can be deflected by a system of mirrors to image the full surface profile of plastic products.

Positional parameters are transferred to a data processing device, for example, a programmable microprocessor, where they are further processed. The term “processed” should be understood in such a way that actually defined positional parameters are compared with the positional parameters stored in the data processing device. For each combination of positional parameters, a cutting circuit is stored in the data processing device, which is transmitted to the laser control system to direct the laser.

This has the advantage that exact adherence to the dimensions of the plastic products placed in the tape is not required, since the optical data acquisition device detects the corresponding actual state of the plastic products. In particular, high temperatures are usually used to make plastic products. The resulting temperature-dependent expansion and / or contraction of the plastic makes, for example, mechanical cutting possible only at fixed lower temperatures. The use of the inventive method eliminates this problem, and plastic products can be precisely cut at different temperatures. Moreover, it follows that when cutting a variety of different plastic products, complex reconfiguration of the device is not required, since only cutting patterns should be changed for positional parameters.

In another preferred embodiment, the positional parameters are not compared with the stored positional parameters, but the data processing device calculates the corresponding cutting pattern from the collected positional parameters and transfers the calculated cutting pattern to the laser control system for guiding the laser.

In a further preferred embodiment, positional parameters are stored in the memory, as well as cutting patterns, which are adjusted by the respective actual positioning parameters, resulting in an adapted cutting pattern that is transmitted to the laser control system to direct the laser.

The laser control system preferably consists of an adjustable focusing optical system, an adjustable deflecting device, and a beam-forming device. In this context, the term "adjustable" should be understood so that the focusing optical system and the deflecting device can be adjusted according to the cutting schemes calculated in the device for processing data, and additionally that the data is transmitted in a suitable format. The beam-forming device collimates the laser beam and reduces beam divergence for better focusing. In accordance with certain positional parameters, the focus position and the intensity at the focal point of at least one laser are controlled using an adjustable focusing optical system and an adjustable deflecting device. If more than one laser is used, then preferably each laser is controlled by another laser control system.

In one embodiment, the laser control system includes a beam-forming device that collimates the laser beam, a telescopic lens system that reduces beam divergence for better focusing, a deflecting mirror system that directs the laser beam in two or three dimensions around interconnected plastic products according to a predefined pattern a cutting, focusing optical system that focuses the laser beam so that the plastic material evaporates while moving the laser ray, and electronic device with program control, which converts the data for cutting a moving mirror circuit.

In a preferred embodiment, the adjustable deflecting device is a scanner with a galvanometric mirror, deflecting the direction of the laser beam using mirrors. In more preferred embodiments, the scanner with a galvanometric mirror deflects the laser beam through two or more mirrors. One or more adjustable deflecting devices may be used depending on the geometric characteristics of the plastic products. In one preferred embodiment, no movement occurs between the plastic product and the laser optics, that is, the laser optics are fixed and stationary, and the laser beam is controlled only by an adjustable deflecting device.

In yet another embodiment, the laser beam is not deflected by an adjustable deflecting device, but the laser optics or part of the laser optics is moved relative to the plastic product to perform the cutting process. The term "laser optics" includes all the components necessary for the formation, focusing, regulation or amplification of a laser beam. For example, with respect to a plastic product, only a lens and a system of mirrors can move, or only a lens, or only a system of mirrors, or the entire laser optics as a whole.

In a particularly preferred embodiment, the laser beam is controlled by a movable adjustable deflecting device. The term "movable" in this context means that the adjustable deflecting device can move along the x-, y- and z-axes. This ensures that the laser beam can also reach and cut through areas that are difficult to access.

An additional advantage is that an adjustable deflecting device can also be used for simultaneous marking of ampoules, thereby cutting and marking are performed in one technological stage.

The focusing optical system is preferably a lens or mirror, more preferably a collecting lens or a focusing concave mirror. A concave mirror provides an additional advantage in that each laser wavelength can be focused at the same point without the need for special optical materials.

In one embodiment, the device includes a transport device for interconnected plastic products placed in a continuous tape. This transport device preferably consists of a feeding device that extends interconnected plastic products placed in a continuous tape, under a laser and an optical data acquisition device. This allows you to achieve high productivity and fully automate the cutting of plastic products placed in a continuous tape. Moreover, incompletely or incorrectly cut segments of the continuous tape could be introduced into the laser cutting process again to complete the cutting. The newly introduced segments are further cooled or cooled to room temperature before being reintroduced into the cutting process. However, the method according to the invention is able to complete an incorrect or imperfect laser cut inside these segments even at significantly different temperatures compared to the temperatures where the initial incorrect or imperfect laser cut was made. Defective products are detected in a new way by an optical data acquisition device and a data processing device, and laser cutting is repeated without the need to reset the entire device to the new temperature of the rejected products, and without the need to heat the rejected products to temperatures where the initial laser cut was made.

In other embodiments, the transport device is a conveyor belt on which interconnected plastic products are transported.

One of the significant advantages of laser separation of plastic products, such as ampoules, bags or other containers, is to create a fused edge, as opposed to a sharp edge after mechanical separation. This is especially important when cutting plastic products for use in the medical field, since a sharp edge can cause damage to sterile gloves or even injure the hand of a doctor or hospital staff when using such ampoules. Mechanically cut plastic products always have sharp edges due to the fact that there will be a sharp edge on the side where the cutting blade leaves the cut line.

The conventional fixed-beam laser cutting method and focusing through a process gas nozzle can also lead to burrs at the edges. It is better to cut the ampoules with a moving beam, for example, using a galvanoscanner, since this method can be carried out more precisely by fine-tuning the parameters of the laser and beam-forming elements, such as telescopes and lenses, and moving the scanner so that the edges are melted at the joints. To achieve this, a sensor and a control system are required as provided by the present invention.

However, even with this type of separation, it may be that the cut plastic products, such as ampoules, do not separate at the fused edges. This is a situation where the ampoules are held together by a barely perceptible sharp edge. When the ampoules are then finally separated, sharp edges still remain. Such sharp edges may result from a slight fluctuation in laser power or a barely detectable variation in beam direction.

Since ampoules are placed inside an ampoule package with very narrow connections, the quality of a laser incision can usually only be assessed using a very sophisticated image recognition system and special cameras. Such a system slows down the entire technological process, is initially expensive and prone to failures, and cannot be easily integrated into existing systems.

In yet another embodiment, the laser cutting device may optionally include a quality control device with an integrated pressure sensor for extruding cut plastic products. The interconnected plastic products housed in a continuous plastic tape are preferably not completely separated by a laser from the residual material, i.e. the frame, so that the cut plastic products can be transported inside the surrounding material until a final separation occurs. During laser cutting, precisely defined narrow joints remain between the plastic products and the surrounding residual material. For the final separation stage, plastic products are transported under a quality control device with an integrated pressure sensor. A stamp with the shape of the ampoule package or a stamp with a certain number of pins that strike at predetermined positions on a separate plastic product or section of a continuous plastic tape, that is, an adapted stamp, extrudes plastic products and especially the material between the narrowed sections of the ampoules, that is, the material between the neck areas of adjacent ampoules, from the residual surrounding material. If the pressure or force required to push the ampoules from the surrounding material and / or material between the narrowed sections exceeds a predetermined first adjustable value, this is an indication that the plastic products are not sufficiently separated and are still connected to the surrounding material, that is, all still connected to the tape or between each other.

Instead of a stamp that actually hits plastic products, or blocks, or packs of plastic products to separate them, a gas jet, such as an air stream or multiple air flows generated by one or multiple nozzles, can be used to apply a specific pressure of the gas stream to plastic products, or blocks, or bundles of plastic products. To do this, create single gas jets with a certain pressure, which again shows the quality of laser cutting in the sense that it can be determined whether the gas jet or gas jets were sufficient to separate single plastic products, or blocks, or packs of plastic products. Instead of gas, a qualified person can also use a liquid such as water for the same purpose.

Thus, a quality control device with an integrated pressure sensor is designed to extrude laser-cut plastic products from the surrounding residual material of a continuous tape, thereby forming separate plastic products, or blocks of plastic products that are still attached to each other but are already perforated, preferably by the laser used in the cutting device, so that the separation can be done easily without the formation of sharp edges. This is usually done using an adapted mold in the form of an ampoule or package of ampoules. Additionally, narrow dies may be included that push the residual material between the narrowed portions, that is, the area between the neck portions of two adjacent ampoules. If the pre-set first adjustable value is exceeded, then the laser cutting was insufficient, and these plastic products are assembled separately. This has the advantage that insufficiently cut plastic products can be collected separately from correctly cut plastic products, and then subsequently processed again, and thus not be lost. Thus, in one embodiment, a quality control device with an integrated pressure sensor consists of a mold adapted to the shape of ampoules, which accurately extrudes plastic products from the surrounding residual material.

In addition, a quality control device with an integrated pressure sensor can monitor the quality of laser cutting, that is, the quality of the intended separation, by measuring the resistance and / or force that is needed to extrude plastic products from the surrounding residual material. The pressure / force required to push the ampoules out of the surrounding material and / or narrowed portions of the ampoules, i.e. the material between the portions of the necks of adjacent ampoules, provides direct information on whether the laser cutting has sufficiently melted the material at the edges so that no sharp burrs occur.

The applicant found that when laser cutting, for example, polypropylene ampoules, the following is true:

if the pressure sensor does not detect any resistance, the ampoules separate correctly and the edges are completely melted around the ampoules

if the pressure sensor detects resistance up to 0.5 N to push the ampoules out of the surrounding residual material, then only a negligible rib is formed, and the use of the ampoules is safe.

if the pressure sensor registers a resistance of more than 0.5 N to eject the ampoules from the surrounding residual material, a significant sharp edge has formed, and the ampoules may be harmless and will be sorted.

Thus, if the required pressure required to eject plastic products, such as bags, vials, cans, ampoules or other containers, from the surrounding residual material and / or narrowed sections of the ampoules, that is, the material between the neck portions of adjacent ampoules, exceeds the second threshold value, but still less than the first threshold value, this indicates that laser cutting is unsatisfactory, and there is a potential dangerous formation of sharp edges or burrs in the plastic product.

In yet another embodiment, quality control is performed on the material between the narrowed sections, that is, in the area between the sections of the necks of two adjacent ampoules.

Thus, the force required to eject the plastic products from the surrounding residual material provides information on whether the plastic product is correctly cut, that is, whether the plastic products can be ejected from the surrounding material or not. In addition, the required force indicates whether faces are safe or if any edges have formed that could be potentially hazardous.

It will be clear to a person skilled in the art who is familiar with the description of a quality control device according to the invention with an integrated pressure sensor that the exact first and second values or threshold values for pressure / force depend on factors such as the type of plastic being cut, the thickness of the material, the temperature at which the cutting is performed, the laser output, and / or the geometric shape or size of the plastic products, and the like. It is within the competence of a qualified person to determine, with minimal experimental work, which pressure or threshold force is indicative of plastic products in a continuous tape. Thus, it is completely uncomplicated and even non-patentable to find out the proper pressure range, which for a given plastic product shows flawless cutting or unacceptable cutting so that it is necessary to adjust the laser.

In yet another embodiment, a quality control device with an integrated pressure sensor determines the quality of laser cutting by applying reduced pressure to a plastic product, such as an ampoule, ampoule packaging and / or narrowed portion, that is, the material between portions of the neck of the ampoule. The principle of operation is similar to the embodiment described above, however, the force required to separate the ampoule, package the ampoules and / or narrowed portion from the surrounding residual material is not measured here. Instead, a quality control device with an integrated pressure sensor measures the force required to apply a certain reduced pressure, such as a specific vacuum.

While pressure or force is applied from above to the upper side of individual plastic products or a package or package of plastic products, a reduced pressure or vacuum is applied from below to individual plastic products or a package or package of plastic products to separate individual plastic products or a package or package of plastic products from continuous plastic tape and from other individual plastic products or other packages or packages of plastic products.

In a third embodiment of the invention, a quality control device with an integrated pressure sensor exerts a pulling force that can be determined to evaluate the quality of the laser cutting. Such a pulling force can be applied by means of a device that grips individual plastic products or a package or bag of plastic products and separates them from a continuous plastic tape and from other individual plastic products or other packages or packages of plastic products. The force required to separate individual plastic products or packaging or a package of plastic products can be measured and is also an indicator of the quality of laser cutting to evaluate whether laser cutting was flawless or insufficient.

Thus, it does not matter whether separate plastic products or individual packages or individual plastic product packages are separated by applying a pushing force, such as pressure, or pulling force or reduced pressure, such as vacuum.

In another embodiment, the device includes a system for compensating for the effects of long-term drift of the laser beam and an adjustable deflecting device. This may occur due to changes in temperature, humidity, vibration, mechanical stress and aging of the components, and may adversely affect the accuracy of the laser beam. The system for compensating for the effects of long-term laser beam drift ensures that laser accuracy is always optimal, reducing production losses to an absolute minimum by keeping the device in working condition.

In one embodiment, a thermal imaging camera is used to record selective heating on a surface of a material lying outside the cutting pattern, but still within the deflection range of the mirrors of the adjustable deflector. Selective heating takes place as a result of the short-term direction of the beam to this surface of the material for a specific period of time. This short-term heating can, for example, be performed while the feed device extends the following interconnected plastic products placed in a continuous tape, under the laser and the optical data acquisition device. The thermal imaging camera compares the position on the receiver with the previously programmed adjusted / design positions. The collected data is then transmitted to the laser control system to adjust and adjust the cutting pattern. This control mechanism can take place both in each cutting process and in front of it, or at certain predetermined intervals. A camera for recording thermal images can also simultaneously determine the surface temperature of a heated material and from these data draw a conclusion about the laser power used to cut plastic products. Then, according to this, the laser power can be adjusted.

In yet another embodiment, the tape lying outside the cutting pattern, but still within the deflection range of the mirror system of the adjustable deflecting device, is pulled together with the plastic tape inside or outside it, whereby the laser removes the amount of material in the tape in the form of a dot. The camera compares the position of this point with the programmed control point, and any deviations are transmitted as correction data to the laser control system, similar to the process described above.

The interconnected plastic products for medical use housed in a continuous plastic tape are preferably vials, bags or containers, and even more preferably ampoules. In addition, according to the invention, medical devices or parts of medical devices, such as syringes, tubes, hollow fibers for dialyzers, or parts of powder inhalers can be cut off.

Particularly preferred is the use of the method for cutting multilayer plastic products, such as products made by coextrusion blow molding. These multilayer plastic products combine the positive properties of various plastics and are usually characterized by a barrier layer that is placed between two carrier layers that are interconnected by a binder. These multilayer plastic products are preferably used in applications where improved gas barrier performance is needed. Mechanical cutting methods have particular problems at the junctions of multilayer plastic products. Naturally, at the joints, the barrier layer is not very effective, and there is an increased risk that the barrier layer is destroyed as a result of mechanical cutting in these areas. The method according to the invention has the advantage that individual layers in multilayer plastic products are welded together at the joints and along the edges during laser cutting. Thus, the barrier properties at the joints, at the edges or at the seams remain unharmed and even improve, compared with methods of mechanical cutting.

The method for separating plastic products placed in or surrounded by plastic can be applied and performed in principle in a similar manner using the described laser control system for other plastic products, such as consumer goods or industrial parts.

The method according to the invention is particularly advantageous for cutting plastic ampoules interconnected, connected to each other and / or coupled together. These ampoules, for example, can be filled during the BFS process (blow-fill-seal process), but empty ampoules can also be processed. When plastic ampoules are made in a BFS process (“blow-fill-seal” process), the ampoules exit the loading machine in the form of rows of interconnected, connected to each other and / or ampoules joined together in a continuous tape. In this continuous tape, one row of ampoules interconnected, connected to each other and / or joined together follows another row of ampoules, and all rows are embedded in a continuous tape and surrounded by residual plastic material. In order to obtain as many ampoules as possible inside a continuous plastic tape, the ampoules are placed very close to each other, and thus the separation of the ampoules is very difficult. This is especially true for the narrowed part at the neck of the ampoule. The narrowed part at the neck of the ampoule is a critical area during mechanical cutting, as there is only a very small area that needs to be cut precisely, and often only partial separation is achieved. Thus, when opening or separating a single ampoule, there is a constant danger that an adjacent ampoule will be accidentally opened due to incomplete separation between the narrowed sections of the ampoules. The method of the invention can separate these ampoule sections reliably without risk of damage when opening the ampoules.

Ampoules in the medical field are usually produced in the form of packages, that is, a certain number of interconnected ampoules are cut mechanically from a continuous tape. However, ampoules, especially those made of polypropylene, tend to form sharp edges during mechanical cutting, or when one ampoule is manually separated from the ampoule packaging.

Unlike mechanical cutting, cutting using the device according to the invention has the following advantages. Plastic ampoules do not need cooling and can be cut off at higher temperatures. Differences in the size of the ampoules, which are initially inherent or inevitable when the ampoules are made at high temperatures, and during the shrinkage of the ampoules, when they are cooled, are detected by the device, and the laser beam is adjusted accordingly. In addition, when cutting with a laser, sharp edges and / or burrs are avoided, and with a laser, the ampoules can be provided with perforations or break points between or in plastic products, thereby facilitating their separation from each other.

In a preferred embodiment, plastic products or packages of plastic products are cut at temperatures of plastic products or packages of plastic products from 30 ° C to 155 ° C.

In other embodiments, the method may further include one of the following steps e) -e ″), in which:

e) carry out a quality test with a quality control device with an integrated pressure sensor that measures the force required to eject cut plastic products or packages of cut plastic products.

e ') carry out a quality test using a quality control device with an integrated pressure sensor that measures the reduced pressure required to separate the cut plastic products or packages of cut plastic products.

e '') perform a quality test using a quality control device with an integrated pressure sensor that measures the pulling force required to separate the cut plastic products or packages of cut plastic products.

In this way, a built-in pressure sensor measures force, reduced pressure, pulling force, or any other force that is required to separate the plastic products from the surrounding residual material. Pressure, or force, or reduced pressure (such as vacuum), below a certain value (for example, value A) shows correct and flawless cutting without sharp edges, while pressure, or force, or reduced pressure is higher than a certain value (for example, value B ) shows incorrect or defective cutting, so that plastic products cannot be separated, or cannot be easily separated, or cannot be separated without sharp edges. The pressure, or force, or reduced pressure between the value A and the value B indicates insufficient cutting, where the plastic products can still be separated, but could have sharp edges. Depending on the plastic product, the type of plastic used, and the use of the plastic product in medicine, cut plastic products obtained within the range between the value A and the value B could be sold as the correct medical products, or could be rejected as an irreparable manufacturing defect. Moreover, depending on the plastic product, the type of plastic used and the use of the plastic product in medicine, the value of A can be identical or almost identical to the value of B.

In a preferred embodiment, when the force for separating the plastic products from the surrounding material reaches the first predetermined adjustable value, this indicates that the plastic products are still connected to the tape and have not been successfully separated, that is, the force was insufficient. This also implies that when this first threshold value or first value has been reached, no additional force is applied to separate the plastic products. This is important because, if the plastic products are still firmly connected to the surrounding residual material, the application of an unlimited amount of force could damage the tape and then the plastic products, for example, if the (hot) tape is too stretched.

In addition, you can pre-set the second value / threshold value, which is near or below the first value. If the force required to separate the plastic products from the surrounding residual material exceeds this second value, but still is less than the first value, the plastic products have been successfully separated, but this is an indication of unsatisfactory and potentially dangerous formation of sharp edges or burrs. If the required force remains below this second value / threshold, then the laser cutting quality is satisfactory and there is no danger of sharp edges and / or burrs.

As described above, it is clear to a person skilled in the art that the exact first and second values or thresholds for pressure / force depend on factors such as the grade of cut plastic, the thickness of the material, the temperature at which the cutting is performed, the output power of the lasers and / or the geometric shape or size of plastic products, and the like. It is within the competence of a qualified person to determine, with minimal experimental work, which pressure or threshold force is indicative of plastic products in a continuous tape. Thus, it is completely uncomplicated and even non-patentable to find out the proper pressure range, which for a given plastic product shows flawless cutting or unacceptable cutting so that it is necessary to adjust the laser.

In a preferred embodiment, the ampoule tape (1) is pulled and positioned using a feeding device (2) under at least one adjustable deflecting device (5) and an optical data acquisition device (5a). The optical device (5a) for data collection recognizes in the segment the positional parameters of at least one track (II) of ampoules, and the data processing device calculates by the positional parameters a cutting circuit for cutting ampoules (III) individually or in packages of several ampoules of at least from one track (II) of ampoules. The track (II) of ampoules can be designated as a segment of the tape (1) of ampoules. This segment or track (II) of ampoules has a temperature of 67.5 ° C. when fed to the cutting device. When laser cutting begins, the temperature of the segment or track (II) of the ampoules is 67.1 ° C. At least one focused laser beam (IV) is modified by the beam forming device (4) so that the laser beam is suitable for separating the ampoules (III) by vaporizing the material between and / or around the ampoules. An adjustable deflecting device (5) and an adjustable focusing optical system (5b) adjust at least one focused laser beam (IV) according to the cutting scheme calculated by the data processing device for cutting ampoules individually or in packages of several ampoules. After the cutting process, the tape (1) of the ampoules is pulled further by the feeding device (2), and the next track (II) of the ampoules is positioned under the adjustable deflecting device (5) and the optical device (5a) for data collection. The cut-off ampoules (III) are still located in the tape (1) of the ampoules and are now placed under the device (7) for quality control with an integrated pressure sensor and a knife (8) for separating the tracks. A quality control device (7) with an integrated pressure sensor and a knife (8) for separating the tracks are activated, and the separated material between the narrowed sections is collected in a separate container (14). Ampoules (III) are now completely separated from the tape (1) of ampoules and transported in an upright position on an inclined plane to the external conveyor (9) for further processing. A knife (8) separates the residual material (10) of the track from the tape and collects the residual material in a container (15). When the quality control device (7) with integrated pressure sensor is activated to extrude the ampoules (III) from the tape, it simultaneously measures the required pressure. If one or more ampoules do not separate as planned, then the pressure required to squeeze the ampoules (III) out of the tape exceeds a predetermined adjustable threshold value, as a result, the shutter (11) opens, and the residual material with filled ampoules (12) drops into container (16). If the laser cutting device completely fails, then two shutters (13) are activated, and the feeding device (2) transports the remaining tape (1) of ampoules uncut from the device for later cutting. If the quality control device (7) with the built-in pressure sensor detects an insufficient, or inaccurate, or defective laser section of an ampoule segment or track (II), this ampule segment or path (II) when they are separated from the tape (1) ampoules, which is a continuous tape, can be reintroduced into the laser cutting process and again fed into the cutting device. When re-feeding this separated segment or separated track (II) of ampoules, this segment or track (II) of ampoules during this time cooled to a temperature of 48 ° C and decreased in size. However, a change in the size and geometric shape of the newly supplied segment or track (II) of the ampoules does not affect the second laser section. The cutting pattern is newly detected by the optical device (5a) for collecting data, and again a laser cut is performed to ensure correctly and accurately cut the segment or track (II) of the ampoules. The correctly and accurately cut segment or track (II) of the ampoules is then processed, as usual, in a quality control device (7) with an integrated pressure sensor without detecting inaccurate or defective cuts.

In yet another embodiment, a device according to the invention separates the container products from the frame and / or from each other and consists of at least one laser with at least one laser control system and at least one optoelectronic system for image recognition and image processing, which determines the position of the container products in the frame and / or relative to each other and transmits this data to at least one laser control system, resulting in at least one laser and / whether the laser beam is directed so that the product container is separated from the frame and / or from each other. The other embodiments and examples described in accordance with the invention in this application are advantageously applicable also in this embodiment.

The following examples describe preferred embodiments of the present invention and should in no way be construed as limiting the invention. Any alternatives and / or embodiments of the present invention that are natural or obvious to those skilled in the art are considered to be defined by the present invention and are within the scope of the claims.

Examples

Example 1:

The method of cutting interconnected plastic ampoules placed in a continuous tape:

The camera recognizes the positional parameters of interconnected plastic ampoules placed in a continuous ribbon of plastic. The positional parameters are converted by the data processing device into a cutting circuit for the laser beam. The exact path for separating the ampoules with laser beams is obtained by converting CAD graphics (computer-aided design) of the ampoules, which are transmitted in the form of converted commands to the laser beam control system. A beam-forming system, consisting of a lens system (4) for improving the characteristics of the beam, modifies the laser beam (6) so that the beam is suitable for separating the ampoules by evaporation, and is also divided into several beams. In total, four CO ₂ lasers with an output power of 200 W each are used. To improve the focusing characteristics of laser beams, the diameter of the laser beams expands and is adjusted to subsequent mirror deflecting devices. Mirror deflecting devices are sized so that the beam can move freely inside the aperture of the focusing optical system after deflection within the required deviation interval. In this example, four mirror deflecting systems and focusing optics are stationary placed one after another. Laser beams cut out packages of ampoules from a tape of ampoules with twenty adjacent ampoules, each package consisting of five ampoules. Due to the geometric shapes of the ampoules, the laser beam cannot reach the bottom of the ampoules in the same technological stage. Therefore, the bottoms of the ampoules are separated in the previous technological stage. In this technological stage, the remaining sides of the ampoule packages are cut, and the bottoms of the following ampoules are cut. Ampoule packages are still connected by narrow connecting portions to the outer frame, however, individual ampoule packages are completely separated from adjacent ampoule packages. The material between the ampoules inside the package is perforated with a laser, which facilitates the manual separation of ampoules.

Example 2:

A device for cutting interconnected plastic ampoules for use in the medical field, placed in a continuous tape:

The tape (1) with the ampoule tracks, which leaves the filling machine, is pulled with the help of a feeding device (2) to the processing position under the mirror deflecting device (5). In this position, the digital camera captures the multiple reference marks and compares the position of these marks with the design position of previously saved reference marks. Thus, both the position and size of the ampoules are recorded, and deviations in size and shape due to temperature variations or variations in the cooling areas inside the ampoules or ampoule track (1) are corrected and transmitted to control the laser beam.

The exact path for separating the ampoules with laser beams is obtained by converting CAD-graphs of the ampoules, which are transmitted in the form of converted commands to the laser beam control system. A beam-forming system, consisting of a lens system (4) for improving the characteristics of the beam, modifies the laser beam (6) so that the beam is suitable for separating the ampoules by evaporation, and is also divided into several beams. In total, four CO ₂ lasers are used with an output of 200 W each. To improve the focusing characteristics of laser beams, the diameter of the laser beams expands and is adjusted to subsequent mirror deflecting devices. Mirror deflecting devices are sized so that the beam can move freely inside the aperture of the focusing optical system after deflection within the required deviation interval. In this example, four mirror deflecting systems and focusing optics are stationary placed one after another. Laser beams cut out packages of ampoules from a tape of ampoules with twenty adjacent ampoules, each package consisting of five ampoules. Due to the geometric shapes of the ampoules, the laser beam cannot reach the bottom of the ampoules in the same technological stage. Therefore, the bottoms of the ampoules are separated in the previous technological stage. In this technological stage, the remaining sides of the ampoule packages are cut, and the bottoms of the following ampoules are cut.

All the components necessary for beam formation are connected to closed (17) granite structures (3), ensuring that no vibrations or vibrations are transmitted to the highly sensitive beam direction system. A control program for deflecting movable mirrors directs focused laser beams along the ampoule contours so that the ampoules separate from the residual material, leaving a couple of narrow joints. After this process, the feeding device (2) stretches the next track of ampoules to the processing position. Fully or almost completely separated ampoules, as well as possibly the material available between the narrowed sections, are separated from the residual frame using a quality control device (7) with an integrated pressure sensor, and the ampoules are transported in an upright position on an inclined plane to an external conveyor (9 ) for further processing, and the residual material between the narrowed sections is collected in a container (14). A quality control device (7) with a built-in pressure sensor consists of two simultaneously working dies, with one stamp pushing out the ampoule package and the other stamp pushing out the residual material between the narrowed sections. The dies are driven pneumatically, the pressure being adjustable. If the required pressure exceeds the first threshold value, the sensor is activated, showing incomplete separation of the ampoules, and then the sensor transmits a signal to the sorting device, which removes the ampoules. If the required pressure exceeds the second threshold value, but is still smaller than the first threshold value, the sensor is activated, showing unsatisfactory and potentially dangerous formation of sharp ribs or burrs in the ampoules, then the sensor transmits a signal to a sorting device that removes the ampoules. The removed ampoules are not an unrecoverable manufacturing defect, but rather can be reintroduced into the laser cutting repetition apparatus of the invention. Since this re-introduction can be carried out automatically, the device according to the invention or the machine according to the invention creates only a few irreparable production defects and thereby saves costs and material, and reduces waste.

A knife (8) separates the residual material (10) of the track from the tape, and the residual material is collected in a container (15). If one or more ampoules do not separate as intended and are still connected to the residual material, for example, when a quality control device with an integrated pressure sensor transmits a signal to a sorting device, a shutter (11) opens and the residual material with filled ampoules (12 ) falls into the container (16). If the laser cutting device stops completely, then two shutters (13) are triggered, and the feeding device (2) conveys the uncut tape from the later cutting device.

List of conventions:

Figure 1

I Tape with ampoule tracks

II Ampoule tracks

III Ampoules

IV focused laser beam

V Material between ampoules

VI Residual material / frame

Figure 2

1 Tape of ampoules

2 Feeding device

3 Granite construction

4 beam forming device

5 Adjustable Deflector

5a Optical data acquisition device

5b Adjustable Focusing Optical System

6 Laser

7 Quality control device with integrated pressure sensor

8 Knife to separate the tracks

9 Outdoor conveyor

10 Inclined plane for residual material

11 Damper for non-separated ampoules

12 Ampoule Tracks

13 Damper for redirecting filled tape

14 Container for residual material between narrowed areas

15 Container for residual material

16 container for tracks with ampoules

17 Cover cap for laser beam system

Description of figures

Figure 1

View A:

Top view of a tape or continuous strip with interconnected plastic ampoules (only three ampoule tracks are shown)

View B:

Side view of “View A” (on the left side). Shown are the ampoule bottoms on the ampoule track. The dashed lines schematically show a snapshot of laser beams.

View C:

Side view of “View A” (front viewing direction). Three ampoule tracks in the tape are shown.

Each track contains twenty ampoules, each of which is mutually connected with the rest of the surrounding material, as well as with neighboring ampoules on the sides and in the narrowed section. The laser cuts four packs of ampoules with five ampoules in each of the ampoule tracks containing twenty ampoules. This means that the two outermost ampoules in the ampoule path are still connected to the surrounding material by several narrow joints; however, the connections between the ampoule packages, that is, after every fifth ampoule, are completely separated from each other. The connections between the ampoules inside the ampoule package are perforated, which facilitates the manual separation of ampoules from the ampoule package. The material between the narrowed sections of the ampoules is completely cut out, and the upper edge of the ampoules is separated from the rest of the material, with the exception of some narrow joints. At this stage, the ampoule bottoms of the next ampoule track are separated from the surrounding material, again with the exception of a few narrow joints. The reason for this is the geometric shape of the ampoules, since laser beams cannot reach the bottoms of the ampoules in the same technological stage. Thus, the bottoms of the ampoules are separated in the previous technological stage. In this technological stage, the remaining sides of the ampoule packages are cut, and the bottoms of the following ampoules are cut.

Figure 2

Schematic side view of an embodiment for cutting interconnected plastic ampoules.

Claims (12)

1. The method of laser cutting of plastic products for use in the medical field, placed in a continuous tape, comprising the following stages, in which:
a) provide interconnected plastic products embedded in a continuous tape of plastic,
b) determine the positional parameters of the interconnected plastic products embedded in the continuous plastic tape using an optical data acquisition device and calculate the cutting pattern in the data processing device,
c) adjust the laser using a laser control system consisting of an adjustable focusing optical system, an adjustable deflecting device and a beam-forming device, and depending on certain positional parameters, the position and intensity of the focal point of the specified at least one laser are adjusted,
d) cut interconnected plastic products placed in a continuous tape of plastic, according to the calculated cutting scheme,
while plastic products or packaging of plastic products are cut at temperatures of plastic products or packaging of plastic products from 60 ° C to 155 ° C. 2. The method according to p. 1, further comprising stage e), in which
e) carry out a quality test using a quality control device with an integrated pressure sensor that measures the force required to eject cut plastic products or packages of cut plastic products. 3. The method according to p. 1, further comprising a stage e ′), in which
e ′) perform a quality test using a quality control device with an integrated pressure sensor that measures the reduced pressure required to separate the cut plastic products or packages of cut plastic products. 4. The method according to p. 1, further comprising stage e ″), in which
e ″) perform a quality test with a quality control device with an integrated pressure sensor that measures the pulling force required to separate the cut plastic products or packages of cut plastic products. 5. The method of laser cutting of plastic products for use in the medical field, placed in a continuous ribbon of plastic, consisting of laser-cut segments, comprising the following stages, in which:
a) provide interconnected plastic products embedded in a continuous plastic tape consisting of segments cut by a laser, each segment being cooled during laser cutting, and when cutting it has any temperature within the range of 30 ° C and 155 ° C,
b) determine the positional parameters of interconnected plastic products embedded in a continuous plastic tape in one segment using an optical data acquisition device and calculate the cutting pattern in the data processing device,
c) adjust the laser using a laser control system consisting of an adjustable focusing optical system, an adjustable deflecting device and a beam-forming device, and depending on certain positional parameters, the position and intensity of the focal point of the specified at least one laser are adjusted,
d) carry out laser cutting of interconnected, cooling plastic products placed in a continuous plastic tape in one segment according to the calculated cutting pattern. 6. The method of claim 5, further comprising step e), wherein
e) carry out a quality test using a quality control device with an integrated pressure sensor that measures the force required to eject cut plastic products or packages of cut plastic products. 7. The method according to p. 5, further comprising stage e ′), in which
e ′) perform a quality test using a quality control device with an integrated pressure sensor that measures the reduced pressure required to separate the cut plastic products or packages of cut plastic products. 8. The method according to p. 5, further comprising stage e ″), in which
e ″) perform a quality test with a quality control device with an integrated pressure sensor that measures the pulling force required to separate the cut plastic products or packages of cut plastic products. 9. The method according to any one of paragraphs. 5-8, in which interconnected plastic products placed in a continuous tape are cooled at a rate of from 0.01 ° C to 5 ° C per minute. 10. The method according to any one of paragraphs. 5-8, in which at least one segment with interconnected plastic products has a varying temperature than interconnected plastic products in any of the preceding segments. 11. The method according to any one of paragraphs. 5-8, in which interconnected plastic products placed in a continuous tape, consist of polypropylene and / or polyethylene. 12. The method according to any one of paragraphs. 5-8, in which not completely or incorrectly cut segments are re-fed and then again cut at a lower temperature.

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