EP4215661B1 - Method for the preparation of noble metal meshes on flat knitting machines - Google Patents
Method for the preparation of noble metal meshes on flat knitting machines Download PDFInfo
- Publication number
- EP4215661B1 EP4215661B1 EP22152845.8A EP22152845A EP4215661B1 EP 4215661 B1 EP4215661 B1 EP 4215661B1 EP 22152845 A EP22152845 A EP 22152845A EP 4215661 B1 EP4215661 B1 EP 4215661B1
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- EP
- European Patent Office
- Prior art keywords
- layer
- precious metal
- knitting
- layers
- abutting
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- 238000009940 knitting Methods 0.000 title claims description 128
- 238000000034 method Methods 0.000 title claims description 56
- 229910000510 noble metal Inorganic materials 0.000 title claims description 26
- KDLHZDBZIXYQEI-UHFFFAOYSA-N Palladium Chemical compound [Pd] KDLHZDBZIXYQEI-UHFFFAOYSA-N 0.000 claims description 40
- BASFCYQUMIYNBI-UHFFFAOYSA-N platinum Chemical compound [Pt] BASFCYQUMIYNBI-UHFFFAOYSA-N 0.000 claims description 33
- 229910052763 palladium Inorganic materials 0.000 claims description 19
- 229910052697 platinum Inorganic materials 0.000 claims description 16
- 238000004519 manufacturing process Methods 0.000 claims description 14
- 239000000203 mixture Substances 0.000 claims description 5
- 229910001252 Pd alloy Inorganic materials 0.000 claims description 2
- 229910001260 Pt alloy Inorganic materials 0.000 claims description 2
- 239000010410 layer Substances 0.000 description 172
- 239000010970 precious metal Substances 0.000 description 154
- 239000004744 fabric Substances 0.000 description 41
- 239000000463 material Substances 0.000 description 16
- 239000010948 rhodium Substances 0.000 description 13
- 239000002356 single layer Substances 0.000 description 12
- 229910052703 rhodium Inorganic materials 0.000 description 11
- MHOVAHRLVXNVSD-UHFFFAOYSA-N rhodium atom Chemical compound [Rh] MHOVAHRLVXNVSD-UHFFFAOYSA-N 0.000 description 11
- 239000003054 catalyst Substances 0.000 description 10
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 description 7
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 6
- 229910052751 metal Inorganic materials 0.000 description 6
- 239000002184 metal Substances 0.000 description 6
- 229910045601 alloy Inorganic materials 0.000 description 5
- 239000000956 alloy Substances 0.000 description 5
- 229920000742 Cotton Polymers 0.000 description 4
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 3
- KJTLSVCANCCWHF-UHFFFAOYSA-N Ruthenium Chemical compound [Ru] KJTLSVCANCCWHF-UHFFFAOYSA-N 0.000 description 3
- 229910021529 ammonia Inorganic materials 0.000 description 3
- 230000000052 comparative effect Effects 0.000 description 3
- 239000010949 copper Substances 0.000 description 3
- 229910052802 copper Inorganic materials 0.000 description 3
- LELOWRISYMNNSU-UHFFFAOYSA-N hydrogen cyanide Chemical compound N#C LELOWRISYMNNSU-UHFFFAOYSA-N 0.000 description 3
- 229910052741 iridium Inorganic materials 0.000 description 3
- GKOZUEZYRPOHIO-UHFFFAOYSA-N iridium atom Chemical compound [Ir] GKOZUEZYRPOHIO-UHFFFAOYSA-N 0.000 description 3
- 150000002739 metals Chemical class 0.000 description 3
- 229910052759 nickel Inorganic materials 0.000 description 3
- 238000012856 packing Methods 0.000 description 3
- 229910052707 ruthenium Inorganic materials 0.000 description 3
- BQCADISMDOOEFD-UHFFFAOYSA-N Silver Chemical compound [Ag] BQCADISMDOOEFD-UHFFFAOYSA-N 0.000 description 2
- 238000007084 catalytic combustion reaction Methods 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 2
- 239000007789 gas Substances 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- -1 platinum metals Chemical class 0.000 description 2
- 229910052709 silver Inorganic materials 0.000 description 2
- 239000004332 silver Substances 0.000 description 2
- 230000000087 stabilizing effect Effects 0.000 description 2
- 229910052715 tantalum Inorganic materials 0.000 description 2
- GUVRBAGPIYLISA-UHFFFAOYSA-N tantalum atom Chemical compound [Ta] GUVRBAGPIYLISA-UHFFFAOYSA-N 0.000 description 2
- 238000009941 weaving Methods 0.000 description 2
- FHVDTGUDJYJELY-UHFFFAOYSA-N 6-{[2-carboxy-4,5-dihydroxy-6-(phosphanyloxy)oxan-3-yl]oxy}-4,5-dihydroxy-3-phosphanyloxane-2-carboxylic acid Chemical compound O1C(C(O)=O)C(P)C(O)C(O)C1OC1C(C(O)=O)OC(OP)C(O)C1O FHVDTGUDJYJELY-UHFFFAOYSA-N 0.000 description 1
- 241001136792 Alle Species 0.000 description 1
- 238000006189 Andrussov oxidation reaction Methods 0.000 description 1
- 229920003043 Cellulose fiber Polymers 0.000 description 1
- GRYLNZFGIOXLOG-UHFFFAOYSA-N Nitric acid Chemical compound O[N+]([O-])=O GRYLNZFGIOXLOG-UHFFFAOYSA-N 0.000 description 1
- 239000004677 Nylon Substances 0.000 description 1
- 229910000978 Pb alloy Inorganic materials 0.000 description 1
- 239000004952 Polyamide Substances 0.000 description 1
- 229910000629 Rh alloy Inorganic materials 0.000 description 1
- 229910001128 Sn alloy Inorganic materials 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 206010053615 Thermal burn Diseases 0.000 description 1
- ATJFFYVFTNAWJD-UHFFFAOYSA-N Tin Chemical compound [Sn] ATJFFYVFTNAWJD-UHFFFAOYSA-N 0.000 description 1
- 230000002378 acidificating effect Effects 0.000 description 1
- 229940072056 alginate Drugs 0.000 description 1
- 235000010443 alginic acid Nutrition 0.000 description 1
- 229920000615 alginic acid Polymers 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 description 1
- 229910017052 cobalt Inorganic materials 0.000 description 1
- 239000010941 cobalt Substances 0.000 description 1
- GUTLYIVDDKVIGB-UHFFFAOYSA-N cobalt atom Chemical compound [Co] GUTLYIVDDKVIGB-UHFFFAOYSA-N 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 238000009826 distribution Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- PCHJSUWPFVWCPO-UHFFFAOYSA-N gold Chemical compound [Au] PCHJSUWPFVWCPO-UHFFFAOYSA-N 0.000 description 1
- 229910052737 gold Inorganic materials 0.000 description 1
- 239000010931 gold Substances 0.000 description 1
- 229910017604 nitric acid Inorganic materials 0.000 description 1
- 229920001778 nylon Polymers 0.000 description 1
- 229910052762 osmium Inorganic materials 0.000 description 1
- SYQBFIAQOQZEGI-UHFFFAOYSA-N osmium atom Chemical compound [Os] SYQBFIAQOQZEGI-UHFFFAOYSA-N 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- PXXKQOPKNFECSZ-UHFFFAOYSA-N platinum rhodium Chemical compound [Rh].[Pt] PXXKQOPKNFECSZ-UHFFFAOYSA-N 0.000 description 1
- 229920002647 polyamide Polymers 0.000 description 1
- 229920000728 polyester Polymers 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 229920002451 polyvinyl alcohol Polymers 0.000 description 1
- 230000008092 positive effect Effects 0.000 description 1
- 238000011084 recovery Methods 0.000 description 1
- 229910001220 stainless steel Inorganic materials 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 239000000126 substance Substances 0.000 description 1
- WFKWXMTUELFFGS-UHFFFAOYSA-N tungsten Chemical compound [W] WFKWXMTUELFFGS-UHFFFAOYSA-N 0.000 description 1
- 229910052721 tungsten Inorganic materials 0.000 description 1
- 239000010937 tungsten Substances 0.000 description 1
- 229920002554 vinyl polymer Polymers 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Images
Classifications
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- D—TEXTILES; PAPER
- D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
- D04B—KNITTING
- D04B1/00—Weft knitting processes for the production of fabrics or articles not dependent on the use of particular machines; Fabrics or articles defined by such processes
- D04B1/14—Other fabrics or articles characterised primarily by the use of particular thread materials
-
- D—TEXTILES; PAPER
- D02—YARNS; MECHANICAL FINISHING OF YARNS OR ROPES; WARPING OR BEAMING
- D02G—CRIMPING OR CURLING FIBRES, FILAMENTS, THREADS, OR YARNS; YARNS OR THREADS
- D02G3/00—Yarns or threads, e.g. fancy yarns; Processes or apparatus for the production thereof, not otherwise provided for
- D02G3/02—Yarns or threads characterised by the material or by the materials from which they are made
- D02G3/12—Threads containing metallic filaments or strips
-
- D—TEXTILES; PAPER
- D10—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
- D10B—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
- D10B2101/00—Inorganic fibres
- D10B2101/20—Metallic fibres
-
- D—TEXTILES; PAPER
- D10—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
- D10B—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
- D10B2403/00—Details of fabric structure established in the fabric forming process
- D10B2403/02—Cross-sectional features
- D10B2403/024—Fabric incorporating additional compounds
- D10B2403/0242—Fabric incorporating additional compounds enhancing chemical properties
-
- D—TEXTILES; PAPER
- D10—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
- D10B—INDEXING SCHEME ASSOCIATED WITH SUBLASSES OF SECTION D, RELATING TO TEXTILES
- D10B2403/00—Details of fabric structure established in the fabric forming process
- D10B2403/03—Shape features
- D10B2403/032—Flat fabric of variable width, e.g. including one or more fashioned panels
Definitions
- the present invention relates to a method for producing a two-layer precious metal net on a flat knitting machine that has a first and a second needle bed.
- the method comprises providing at least one wire containing precious metal and knitting the precious metal net.
- the first and second layers of the precious metal net are knitted simultaneously on the first and second needle beds and a supporting net is knitted using a supporting thread on the first and second needle beds.
- An abutting edge of the supporting net is connected to the two layers of the precious metal net via connecting knitting stitches and in the knitting rows containing the connection, knitting takes place over both needle beds.
- the heterogeneous noble metal-catalyzed oxidation of ammonia (NH 3 ) to nitric acid (HNO 3 , Ostwald process) or production of hydrogen cyanide (HCN, Andrussow process) is of great importance due to the central relevance of the products for the chemical industry.
- the catalyst systems used for this are usually installed in the form of gas-permeable surface structures in the reaction zone of a flow reactor in a plane perpendicular to the flow direction of the fresh gas. Collection or catchment systems for the recovery of vaporized catalytically active components are also often based on such net-like structures. It is usually advisable to arrange several nets one behind the other and combine them to form a catalyst net stack.
- the individual nets consist of fine precious metal wires that predominantly contain platinum (Pt), palladium (Pd), rhodium (Rh) or alloys of these metals.
- Catchment nets in particular can also contain other components such as nickel.
- a number of processes are known for producing such knitted fabrics, for example weaving, knitting and knitting. Weaving and knitting are particularly suitable for producing rectangular net webs with a homogeneous material distribution and structure. They offer little flexibility in terms of the shape design and material variability of the products to be manufactured. In an additional process step, the nets must be cut from the manufactured webs to a size and shape suitable for the reactors, which creates waste with precious metal components. In addition, the machines used require long set-up times and use a lot of material.
- knitting offers greater flexibility: the weight per unit area as well as the structure, stretchability and strength of the available knitted fabrics can be varied by using the knitting patterns, wires (both in terms of thickness and material), needles and tension of the wire. Another advantage is the significantly shorter set-up times for the machines. It is also possible to use different materials in one knitted fabric; in so-called intarsia knitting, for example, different areas are made from different yarns or wires.
- the length of a knitted fabric is not limited in principle, but in the case of flat knitting machines the maximum width is determined by the width of the needle beds.
- Flat knitting machines or circular knitting machines can be used for knitting.
- the needles are arranged in a circular needle bed and the thread or wire is fed in a circular motion.
- Such machines allow tubular knitted goods to be produced in particular.
- the shape and size of the knitted goods can be varied. The latter can also have more than one needle bed, between which the yarn or wire is guided back and forth during production using thread guides.
- a single-layered knitted fabric can be produced in two ways: Firstly, when only one needle bed is used, i.e. only stitches are formed on one of the needle beds and knitted together. Secondly, stitches produced on the first needle bed can be knitted with stitches produced on the second needle bed, i.e. the thread is guided back and forth between the two needle beds within a forward and/or backward row. A two-layered knitted fabric is produced when both needle beds are knitted in parallel and the stitches produced on the first row of needles are not or only selectively knitted with the stitches produced on the second needle bed via the edge stitches. With this production method, two single-layered knitted fabrics or layers can also be produced in parallel on the first and second needle beds.
- EP0364153A1 describes the use of an additional precious metal-free thread when knitting a precious metal net, which increases the process stability.
- the additional thread is knitted parallel to the precious metal and can be removed from the homogeneous knitted fabric, consisting of precious metal material and thread material, after the knitting process if necessary.
- This process was further developed so that the additional thread and the precious metal are not knitted in parallel, but simultaneously. In this way, precious metal-free areas can be obtained in the finished knitted fabric, which led to a reduction in the use of precious metals.
- the object of the present invention was therefore to provide a method with high process stability for the production of precious metal nets on flat knitting machines using precious metal-containing wires and precious metal-free threads.
- the method according to the invention relates to knitting on a flat knitting machine with a first and a second needle bed.
- Knitting is characterized by the row-by-row production of the resulting knitted fabrics, in which interlocking stitches are formed.
- a knitting row is first formed on at least one of the needle beds.
- the next knitting row is then formed in the knitting direction, whereby the part of the knitted fabric that contains the first knitting row is referred to as "bottom” in the following.
- the thread or wire is guided from one side of the needle bed or needle beds to the other side and back.
- a knitting row therefore comprises a forward and a reverse row, which results from the thread guidance.
- the thread guidance can take place in a knitting row over only one or both needle beds.
- the thread can first be guided on the first needle bed for a complete knitting row (forward row), then the thread is guided in the opposite direction on the same needle bed or the second needle bed (reverse row).
- the thread can also be guided alternately on both needle beds in a forward and/or backward row, whereby connections are created between stitches on the two needle beds within one knitting row.
- the thread guide can be controlled via the The entire width of the needle bed or beds can be used, but it is also possible to knit over just parts of the width of the needle bed.
- the width and shape of the knitted fabric can be determined depending on the width of the needle bed being knitted over.
- the method comprises providing at least one wire containing precious metal.
- a wire containing precious metals is understood to mean a wire that consists of at least one precious metal or contains a significant proportion (> 50% by weight) of precious metal.
- precious metals are understood to mean a metal selected from the group consisting of platinum metals, gold and silver.
- Platinum metals are understood to mean the metals of the so-called platinum group, i.e. platinum (Pt), palladium (Pd), iridium (Ir), rhodium (Rh), osmium (Os) and ruthenium (Ru).
- the at least one precious metal-containing wire consists of platinum, a platinum alloy, palladium or a palladium alloy.
- a platinum-based alloy contains more than 50% by weight of platinum, and other alloy components include palladium, rhodium and ruthenium.
- a palladium-based alloy contains more than 50% by weight of palladium.
- the at least one noble metal-containing wire consists of an alloy selected from the group consisting of platinum with 1 - 15 wt.% rhodium, platinum with 1 - 15 wt.% rhodium and 0.1 - 20 wt.% palladium, platinum with 1 - 15 wt.% rhodium, 0.1 - 20 wt.% palladium and 0.1 - 5 wt.% ruthenium, platinum with 1 - 15 wt.% rhodium, 0.1 - 40 wt.% palladium and 0.001 - 5 wt.% iridium, platinum with 1 - 15 wt.% rhodium, 0.1 - 20 wt.% palladium and 0.001 - 5 wt.% tantalum, platinum with 1 - 15 wt.% rhodium, 0.001 - 5 wt.% iridium and 0.001 - 5 wt.% tanta
- precious metal-containing wires with a diameter of 40 - 150 ⁇ m, preferably 50 - 130 ⁇ m, are used.
- the at least one wire containing precious metal can be designed as a round wire, i.e. with a round cross-section.
- the wire can be designed as a flattened round wire or as a wire with a different cross-section.
- the at least one wire containing precious metals can comprise several wires, in this case also referred to as filaments, which can preferably be twisted together.
- the filaments can all be made of the same material, i.e. all contain precious metals, or they can be made of different materials, which in turn do not all have to contain precious metals.
- the precious metal-containing wires can be guided together when forming a stitch.
- the precious metal-containing wires consist of the same material; in other embodiments, precious metal-containing wires consisting of at least two different materials can be used.
- the several wires can have the same or different diameters.
- the first layer of the two-layer precious metal net is knitted simultaneously on the first needle bed and the second layer of the precious metal net is knitted on the second needle bed.
- two parts of the precious metal net to be produced are knitted simultaneously on one needle bed each, so the two layers are not produced one after the other.
- two-layer precious metal nets are understood to mean those precious metal nets that have two layers, whereby the layers can be connected to one another via one or more of their respective abutting edges or can also not be connected at their abutting edges.
- the two layers lie on top of one another, i.e. they overlap at least partially in the area of their surface area.
- Precious metal nets that, as in the case of the present invention, are connected to one another on one side via the abutting edges of the two layers are also referred to as two-layer precious metal nets.
- the first and second layers of the two-layer precious metal mesh each have two butt edges, i.e. each layer has a butt edge on one side and another butt edge on the other side.
- the first layer has the butt edges S11 and S12 and the second layer has the butt edges S21 and S22.
- the sides of the precious metal layers are to be understood in relation to the position of the butt edges on the two needle beds perpendicular to the knitting direction.
- the butt edges of a layer may not intersect, as in the case of a rectangular layer, or they may intersect, as in the case of a semicircular layer, for example.
- Butt edges can be connected to one another, preferably by at least one connecting knitting stitch. Butt edges can also abut one another without being connected. The butt edges are formed during the knitting process in the knitting direction from bottom to top.
- the two precious metal layers can also have an upper and/or lower edge or butt edge; the presence of these edges depends on the shape of the respective layer.
- a rectangular layer for example, has a lower and an upper edge or butt edge in addition to the two side butt edges, while a semicircular layer has no further edges or butt edges.
- the lower edges are those edges that are formed first in the knitting direction, i.e. are located at the bottom of the fabric. Accordingly, the upper edges are those that are formed later in the knitting direction.
- a butt edge of the first layer of the precious metal net S11 abuts at least partially against a butt edge of the second layer of the precious metal net S21.
- the other butt edges of the first and second layers of the precious metal net i.e. the butt edge S12 and the butt edge S22, abut each other at least partially.
- "At least partially abutting" is to be understood here as meaning that the butt edges abut each other over parts of their length in the knitting direction, i.e. over parts of the knitting rows that form them. In other words, the butt edges can also be at least partially offset from each other.
- the first and second layers of the two-layer precious metal mesh can be connected at least partially at their abutting edges by connecting knitting stitches.
- the two layers are connected to one another at their edge meshes via meshes that are formed from the at least one wire containing precious metal.
- This connection of the first and second layers of the two-layer precious metal net can take place on just one side or on both sides.
- the connection or connections can take place over the entire length or over parts of the length of the abutting edges. It can be advantageous for the connection to take place on one side over the entire length of the abutting edges.
- connection on both sides of the first and second layers of the two-layer precious metal mesh can be made at least over parts of their respective abutting edges, whereby these partial connections can be made at the same height, i.e. in the same knitting row or rows, or at different heights.
- the partial connections can be made over the same length of the abutting edges on both sides, i.e. over the same number of knitting rows.
- the partial connections can also be made over a different length of the abutting edges on both sides.
- the partial connections are made at least partially over the same knitting rows.
- knitting is at least partially done in a circle or in a circular manner, in other words, a ring-like structure is created over these knitting rows. It has been shown that knitting such an at least partially ring-like structure can have a further positive effect on the stability of the knitting process.
- the reference for the height of the knitted fabric is the bottom knitting row of the knitted fabric. Even if knitting of a layer begins in different knitting rows, the height of the entire knitted fabric remains the same, in other words, the layers of the knitted fabric at different heights can comprise a different number of knitting rows.
- the first and second layers of the two-layer precious metal mesh can be knitted from a precious metal-containing wire or precious metal-containing wires of the same composition.
- the two layers can also be knitted from precious metal-containing wire or precious metal-containing wires of different compositions.
- Precious metal-containing wire with the same or different diameters can be used to knit the first and second layers of the two-layer precious metal net. It has proven advantageous for the first and second layers of the precious metal net to be knitted from precious metal-containing wire or precious metal-containing wires of the same diameter.
- the first and second layers of the two-layer precious metal net can be knitted in the same or different knitting patterns. Different knitting patterns can be created, for example, by different stitch lengths, floats or catches. In preferred embodiments, the first and second layers of the precious metal net are knitted in the same knitting pattern.
- the first and second layers of the two-layer precious metal net can have the same or different lengths in the knitting direction and/or the same or different widths perpendicular to the knitting direction.
- the first and second layers of the precious metal net have the same length and the same width.
- the first and second layers of the two-layer precious metal net can have the same shape or different shapes.
- the first and second layers of the two-layer precious metal net particularly preferably have the same shape. It can be advantageous for the first and second layers of the two-layer precious metal net to have the shape of a semicircle. It can be particularly advantageous for these two semicircles to have the same width and the same length.
- the first and second layers of the two-layer precious metal mesh are congruent, in other words, the two layers can have the same length, the same width and the same shape.
- the method comprises providing at least one precious metal-free support thread.
- Suitable non-precious metal support threads can be selected by routine testing and taking into account the final intended use of the two-layer precious metal mesh and any additional steps in the manufacturing process.
- Preferred non-precious metal support threads can be removed after the precious metal mesh has been manufactured, for example by dissolving in acidic or basic media, cutting, melting or flaming.
- Such support threads can be natural or synthetic, organic in nature or inorganic in nature. Examples of suitable materials are polyamides, polyesters, cellulose fibers, cotton, acrylic-styrene polymers, nylon, PVA and other vinyl polymers, alginate, copper, silver, aluminum, or even metals with a low melting point such as tin and lead alloys.
- the at least one precious metal-free supporting thread can consist of only one thread-like element; such individual thread-like elements are also referred to as filaments in the case of precious metal-free threads.
- the precious metal-free supporting thread can also consist of more than one filament, which can advantageously be twisted together. These multiple filaments can consist of the same or different materials.
- a support net is knitted on the first and second needle bed simultaneously with the first and second layers of the two-layer precious metal net using the at least one precious metal-free support thread.
- the support net is knitted simultaneously with the two layers of the precious metal net to be produced, so the two layers and the support net are not produced one after the other.
- supporting net refers to the areas of the knitted fabric that are at least partially knitted using the precious metal-free supporting thread.
- the supporting net can also include other threads or wires.
- the knitted fabric comprises all the rows of knitting that are formed during the process.
- the knitted fabric comprises at least the first and second layers of the two-layer precious metal mesh and the support mesh.
- the knitted fabric can also comprise other parts or areas.
- all rows of knitting of the knitted fabric are knitted over the same width of the needle beds, in other words, the knitted fabric is preferably rectangular.
- the support net has a butt edge SH and an opposite edge KH.
- the butt edge SH and the opposite edge KH may not intersect, as in the case of a rectangular support net, or may intersect, as in the case of a semicircular support net.
- the butt edge SH and the edge KH are formed during the knitting process in the knitting direction from bottom to top.
- the butt edge SH of the support net abuts against a butt edge S11 and S21 of the first and second layers of the two-layer precious metal net.
- the edge of the support net that abuts against the two layers of the two-layer precious metal net is referred to as the butt edge SH.
- the butt edge SH accordingly includes the knitting rows in which both the layers of the two-layer precious metal net and the support net are knitted.
- the opposite edge KH accordingly connects the butt edge SH opposite edge of the support net in the same knitting rows, ie the butt edge SH and the edge KH have the same length in the knitting direction.
- the edge KH does not abut one of the two layers of the two-layer precious metal net.
- the shape of the edge and abutting edge of the support net is not further restricted.
- the shape of the support net is designed such that the shape of the knitted fabric is rectangular overall.
- the support net complements the layers of the precious metal net such that the shape of the knitted fabric, comprising the precious metal layer or layers and the support net, is rectangular overall.
- the shape of the support net preferably correlates with the shape of the first and second layers of the precious metal net.
- the support net preferably has a concave shape if the first and second layers of the precious metal net have a convex shape.
- the abutting edge SH has the same length as the abutting edges S11 and S12.
- the abutting edge SH comprises the same knitting rows as the abutting edges S11 and S12, so the support net abuts the abutting edges of the layers of the two-layer precious metal net over the entire length of the layers of the precious metal net.
- the abutting edge SH of the support net and the respective abutting edges S11 and S21 of the first and second layers of the two-layer precious metal net are connected to one another via at least one knitting stitch.
- the support net is at least partially connected to the two layers of the two-layer precious metal net during the knitting process. This stabilizes the knitting process.
- the abutting edge SH of the support net is connected over its entire length to the respective abutting edges S11 and S21 of the first and second layers of the two-layer precious metal net.
- the connecting knitting stitch or the connecting knitting stitches can be formed from the at least one precious metal-containing wire or the precious metal-free supporting thread.
- the connecting knitting stitch or the connecting knitting stitches are formed from the precious metal-free supporting thread.
- the support net is knitted in the knitting row(s) in which the butt edge SH of the support net is connected to the respective butt edges of the two layers of the precious metal net S11 and S21, with connecting stitches from both needle beds.
- Connecting stitches are understood to mean those knitting stitches that are between the first and the second needle bed.
- the support net is at least partially knitted in one layer. It has been shown that the single-layer design of the support net in the area or areas that are connected to the layers of the precious metal net leads to an increase in process stability.
- the precious metal-free support thread can be knitted in parallel with the at least one precious metal-containing wire, i.e., during knitting, stitches can be formed that comprise precious metal-containing wire and support thread.
- the relevant part of the resulting knitted fabric contains both precious metal and the material of the support thread.
- the support thread can also be used for parts or areas of the knitted fabric that do not contain precious metal-containing wire, i.e., in these cases, the resulting knitted fabric contains areas with and areas without precious metal-containing wire.
- the support net can comprise several areas.
- the support net can also comprise knitting rows in which no wire containing precious metals is used, i.e. in which only the precious metal-free support thread is used for knitting.
- the knitted fabric can comprise areas that do not contain any wire containing precious metals.
- the support net can comprise other edges in addition to the butt edge SH and the edge KH. Such edges can be formed in knitting rows in which no stitches of the layers of the precious metal net are knitted.
- the knitted fabric can also have knitting rows that are only formed by areas of the support net.
- the support net is knitted in two layers in the areas with knitting rows that do not contain a wire containing precious metals. In other words, the support net cannot be knitted in these knitting rows with connecting stitches between the first and second needle beds. These two layers can be connected at the edge stitches via connecting knitting stitches, so it may be advantageous for the support net to have a tubular structure in these areas. It may also be preferred that the support net is knitted in one layer in the areas that do not contain a wire containing precious metals.
- the support mesh comprises single-layer knitted regions and double-layer knitted regions that do not comprise any noble metal-containing wire.
- the support net only abuts the two layers of the two-layer precious metal net at the abutting edges S11 and S21. It may also be preferred that the support net also abuts the two layers of the two-layer precious metal net at the other edges or abutting edges of the two layers of the two-layer precious metal net S12 and S22.
- the abutting edge of the support net SH and the two abutting edges of the two layers of the two-layer precious metal net S12 and S22 can be connected to one another via at least one knitting stitch of the support thread. However, such a connection does not have to be made; in such embodiments, these abutting edges are not connected to one another via knitting stitches.
- the support net also abuts the respective lower and/or upper edges of the two layers of the two-layer precious metal net.
- the support net can only abut the lower or upper edges of the two layers of the precious metal net or the lower and upper edges.
- the support net surrounds the two layers of the two-layer precious metal net on at least two sides.
- the support net can surround the two layers of the two-layer precious metal net on more than two sides.
- the support net surrounds the sides of the two layers of the two-layer precious metal net by at least 50%. This means that at least 50% of the circumference of the two layers of the two-layer precious metal net is surrounded by the support net, more preferably at least 60%, even more preferably at least 80%. It can be particularly preferred for the support net to completely surround the two layers of the two-layer precious metal net.
- all areas of the support net can be knitted from precious metal-free support threads of the same composition.
- different areas can also be knitted from precious metal-free support threads of different compositions.
- Different areas of the support net can be knitted in the same or different knitting patterns.
- the method according to the invention may comprise further steps.
- the method may comprise providing at least one additional wire or thread.
- Suitable additional wires or threads may be used depending on the intended use and/or function in the manufacturing process or for the subsequent application of the precious metal mesh.
- the additional wire can be a wire made of a non-noble metal that is suitable for stabilizing the precious metal mesh when used in the reactor, for example it can be a steel or stainless steel wire.
- the method comprises the simultaneous knitting of regions of the knitted fabric using the at least one additional wire or thread.
- the knitted fabric can comprise parts or regions that contain only the additional wire or thread, or parts or regions that contain both the additional wire or thread and the precious metal-containing wire, or parts or regions that contain both the additional wire or thread and the precious metal-free support thread, or parts or regions that contain both the additional wire or thread and the precious metal-containing wire and the precious metal-free support thread.
- the support net can be removed in a further step. Suitable methods are known in principle to the person skilled in the art and depend on the type of precious metal-free support thread used and the precious metal-containing wire.
- the support net can, for example, be decomposed, dissolved, melted, flamed or cut off.
- a connecting mesh or several connecting meshes between the first and second layers of the two-layer precious metal net can be removed on at least one side, in other words, a connection between the two layers via the edge meshes can be separated on at least one side.
- illustration 1 shows a schematic of a vertically positioned flow reactor 1 for the heterogeneous catalytic combustion of ammonia.
- the catalyst system 2 forms the actual reaction zone of the flow reactor 1. It comprises a catalyst packing 3 and downstream catchment nets 4.
- the catalyst packing 3 comprises several catalyst nets 6 arranged one behind the other in the flow direction 5 of the fresh gas.
- the catalyst nets 6 are knitted nets, which are produced, for example, by knitting wire with a diameter of 76 ⁇ m from various platinum-rhodium alloys.
- Catchment nets 4 can also be provided.
- Figure 2 shows schematically the thread guide in an exemplary forward row of a knitting row between two needle beds 10 and 11 of a flat knitting machine. Needles that are used during the knitting process are highlighted, the direction of the thread guide is indicated by arrows. Each circle symbolizes a needle.
- Figure 2 A the thread guide for a thread or wire 12 is illustrated for a forward row in which only stitches are knitted on the first needle bed. If in the back row and all further complete knitting rows only stitches are knitted on the first needle bed 10, a single-layered knitted fabric is obtained. If in the back rows only stitches are knitted on the second needle bed 11, a two-layered knitted fabric is obtained.
- the knitting pattern used also contains a float: stitches are only formed on every second needle of the needle bed.
- Figure 2 B shows the forward row for a single-layered knit, where 12 stitches are knitted with the thread or wire on the first and second needle beds 10 and 11.
- Figure 3 shows embodiments of two-layer precious metal nets that can be produced using the method according to the invention on flatbed knitting machines with two needle beds.
- Figure 3 A and B show a two-layer precious metal net 100 consisting of two rectangular layers 101 and 102, with the frontal view in Figure 3 A only the first layer 101 is visible.
- Figure 3B shows a view of the precious metal net 100 opened along the abutting edges 111 of the first layer 101 or the abutting edge 112 of the second layer 102 that abuts against it.
- the abutting edge 112 of the first layer is congruent with the abutting edge 113 of the second layer 102.
- the "opening" is to be understood virtually at this point and serves to better understand the Invention.
- the two layers 101 and 102 are connected along their abutting edges 112 and 113 to the abutting edge 120 of a support net 130 (in the illustration in Figure 3B the connection to the abutting edge 113 is no longer shown for better illustration).
- the support net 130 is knitted in a single layer from a support thread, preferably a cotton thread, from connecting stitches from both needle beds.
- the edge 121 of the support net 130 opposite the abutting edge 120 does not abut any other sides or edges of the precious metal net 20'.
- Figure 3C shows a two-layer precious metal net 200 that is surrounded on two sides by a support net. Only the frontal view of a first rectangular layer 201 is shown, which lies congruently over another layer. Both layers are connected to two support net areas 230 and 231 via their respective two abutting edges (only the abutting edges of the first layer 201 (210 and 211) are visible in the illustration). The first area of the support net 230 is made in one layer. The second area 231 can be made in one or two layers.
- Figure 3D shows a Fig. 3 C analogous view of a two-layer precious metal net 300, which is surrounded by a support net on two adjacent sides.
- a precious metal net of this embodiment for example, knitting of the lower region 331 of the support net can be started, after which the two layers of the precious metal net 300 and a further region 330 of the support net are manufactured simultaneously. In the corresponding knitting rows, stitches are thus formed from the support material and the wire containing precious metal.
- the two regions of the support net 330 and 331 can expediently be connected to one another.
- Figure 3 E shows a Fig. 3 C analogous view of a two-layer precious metal net 400, which is surrounded on all four sides by a support net.
- the support net is expediently divided into the areas 430, 431, 432 and 433, these areas are preferably connected to one another.
- a two-layer precious metal net 500 is also surrounded on four sides by support net areas (530, 531, 532, 533).
- One of the support net areas 532 does not abut the precious metal net 500, but is spaced from the precious metal net by a gap 534.
- all areas are manufactured simultaneously, i.e. during a single knitting process, in the knitting direction from bottom to top.
- Figure 3 G shows a Fig. 3 C analogous view of a two-layer precious metal net 600 made of two semicircular layers (only the first layer 601 is visible). The two layers are on one side along the respective abutting edge (610 in the case of the first layer 601) with the support net 630 via its abutting edge 620.
- Figure 3 H also shows a two-layer precious metal net 700 formed from two semicircular layers, in which the layers are surrounded at both abutting edges by two support net regions 730 and 731.
- a rectangular layer (100 cm wide, 200 cm long) was knitted on each needle bed on a flat knitting machine with two needle beds using a PtRh5 wire (76 ⁇ m diameter), with the two layers being connected to one another on one side.
- a cotton yarn was used as the support thread.
- a single-layer support net area was knitted with the cotton yarn on the unconnected side of both layers.
- a single-layer knitted fabric with two areas (precious metal layer and support net) was therefore knitted on each of the two needle beds.
- a single-layer support net knitted over both needle beds was knitted on the unconnected side of the two layers. The two precious metal layers were therefore only knitted with stitches on one needle bed each, while the support net was knitted with stitches on both needle beds.
- the knitted fabric of the example according to the invention had a more uniform structure than the knitted fabric of the comparative example.
- Such irregularities in the knitted fabric represent potential mechanical weak points that have a negative effect on the use of the mesh in the reactor.
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Description
Die vorliegende Erfindung betrifft ein Verfahren zur Herstellung eines zweilagigen Edelmetallnetzes auf einer Flachstrickmaschine, die ein erstes und ein zweites Nadelbett aufweist. Das Verfahren umfasst das Bereitstellen von mindestens einem edelmetallhaltigen Draht und das Stricken des Edelmetallnetzes. Auf dem ersten und zweiten Nadelbett werden simultan die erste und die zweite Lage des Edelmetallnetzes und unter Verwendung eines Stützfadens auf dem ersten und zweiten Nadelbett ein Stütznetz gestrickt. Eine Stoßkante des Stütznetzes wird dabei mit den beiden Lagen des Edelmetallnetzes über verbindende Strickmaschen verbunden und in den die Verbindung enthaltenden Strickreihen wird über beide Nadelbetten gestrickt.The present invention relates to a method for producing a two-layer precious metal net on a flat knitting machine that has a first and a second needle bed. The method comprises providing at least one wire containing precious metal and knitting the precious metal net. The first and second layers of the precious metal net are knitted simultaneously on the first and second needle beds and a supporting net is knitted using a supporting thread on the first and second needle beds. An abutting edge of the supporting net is connected to the two layers of the precious metal net via connecting knitting stitches and in the knitting rows containing the connection, knitting takes place over both needle beds.
Die heterogen edelmetallkatalysierte Oxidation von Ammoniak (NH3) zu Salpetersäure (HNO3, Ostwald-Verfahren) oder Herstellung von Cyanwasserstoff (HCN, Andrussow-Verfahren) ist aufgrund der zentralen Relevanz der Produkte für die chemische Industrie von großer Bedeutung. Die dafür eingesetzten Katalysatorsysteme werden meist in Form von gasdurchlässigen Flächengebilden in die Reaktionszone eines Strömungsreaktors in einer Ebene senkrecht zur Strömungsrichtung des Frischgases eingebaut. Auch Auffang- oder Catchment-Systeme zur Rückgewinnung von verdampften katalytisch aktiven Bestandteilen basieren häufig auf solchen netzförmigen Strukturen. Es werden zweckmäßigerweise meist mehrere Netze hintereinander angeordnet und zu einem Katalysatornetzstapel zusammengefasst. Die einzelnen Netze bestehen dabei aus feinen Edelmetalldrähten, die überwiegend Platin (Pt), Palladium (Pd), Rhodium (Rh) oder Legierungen dieser Metalle enthalten. Vor allem Catchment-Netze können auch weitere Bestandteile wie beispielsweise Nickel enthalten.The heterogeneous noble metal-catalyzed oxidation of ammonia (NH 3 ) to nitric acid (HNO 3 , Ostwald process) or production of hydrogen cyanide (HCN, Andrussow process) is of great importance due to the central relevance of the products for the chemical industry. The catalyst systems used for this are usually installed in the form of gas-permeable surface structures in the reaction zone of a flow reactor in a plane perpendicular to the flow direction of the fresh gas. Collection or catchment systems for the recovery of vaporized catalytically active components are also often based on such net-like structures. It is usually advisable to arrange several nets one behind the other and combine them to form a catalyst net stack. The individual nets consist of fine precious metal wires that predominantly contain platinum (Pt), palladium (Pd), rhodium (Rh) or alloys of these metals. Catchment nets in particular can also contain other components such as nickel.
Zur Herstellung solcher Maschenwaren sind eine Reihe von Verfahren bekannt, zum Beispiel das Weben, Wirken und Stricken. Weben und Wirken sind vor allem für die Herstellung rechteckiger Netzbahnen mit homogener Materialverteilung und Struktur geeignet. In Bezug auf die Formgestaltung und Materialvariabilität der zu fertigenden Produkte bieten sie wenig Flexibilität. Aus den gefertigten Bahnen müssen in einem zusätzlichen Verfahrensschritt die Netze auf für die Reaktoren geeignete Größe und Form zugeschnitten werden, wobei Verschnitt mit Edelmetallbestandteilen entsteht. Außerdem erfordern die eingesetzten Maschinen lange Rüstzeiten und einen hohen Materialeinsatz.A number of processes are known for producing such knitted fabrics, for example weaving, knitting and knitting. Weaving and knitting are particularly suitable for producing rectangular net webs with a homogeneous material distribution and structure. They offer little flexibility in terms of the shape design and material variability of the products to be manufactured. In an additional process step, the nets must be cut from the manufactured webs to a size and shape suitable for the reactors, which creates waste with precious metal components. In addition, the machines used require long set-up times and use a lot of material.
Das Stricken bietet im Vergleich eine höhere Flexibilität: über die verwendeten Strickmuster, Drähte (sowohl was Dicke und Material betrifft), Nadeln und Zugspannung des Drahtes kann sowohl das Flächengewicht als auch die Struktur, Dehnbarkeit und Festigkeit der erhältlichen Gestricke variiert werden. Ein weiterer Vorteil sind die deutlich kürzeren Rüstzeiten der Maschinen. Außerdem ist die Verwendung unterschiedlicher Materialien in einem Gestrick möglich, beim s.g. Intarsien-Stricken werden beispielsweise unterschiedliche Bereiche aus unterschiedlichen Garnen oder Drähten gefertigt. Die Länge eines Gestricks ist dabei prinzipiell nicht begrenzt, die maximale Breite ist jedoch im Fall von Flachstrickmaschinen durch die Breite der Nadelbetten vorgegeben.In comparison, knitting offers greater flexibility: the weight per unit area as well as the structure, stretchability and strength of the available knitted fabrics can be varied by using the knitting patterns, wires (both in terms of thickness and material), needles and tension of the wire. Another advantage is the significantly shorter set-up times for the machines. It is also possible to use different materials in one knitted fabric; in so-called intarsia knitting, for example, different areas are made from different yarns or wires. The length of a knitted fabric is not limited in principle, but in the case of flat knitting machines the maximum width is determined by the width of the needle beds.
Beim Stricken können Flachstrickmaschinen oder Rundstrickmaschinen zum Einsatz kommen. Bei Rundstrickmaschinen sind die Nadeln in einem kreisförmigen Nadelbett angeordnet und die Faden- bzw. Drahtzuführung erfolgt entsprechend in einer kreisförmigen Bewegung. Solche Maschinen erlauben vor allem die Herstellung von schlauchförmigen Strickwaren. Auf Flachstrickmaschinen dagegen können Form und Maß der Gestricke variiert werden. Letztere können auch über mehr als ein Nadelbett verfügen, zwischen denen bei der Fertigung das Garn bzw. der Draht mittels Fadenführern hin- und her geführt wird.Flat knitting machines or circular knitting machines can be used for knitting. In circular knitting machines, the needles are arranged in a circular needle bed and the thread or wire is fed in a circular motion. Such machines allow tubular knitted goods to be produced in particular. On flat knitting machines, on the other hand, the shape and size of the knitted goods can be varied. The latter can also have more than one needle bed, between which the yarn or wire is guided back and forth during production using thread guides.
Die Verwendung von zwei Nadelbetten erlaubt die Herstellung eines einlagigen oder zweilagigen Gestricks. Ein einlagiges Gestrick kann prinzipiell auf zwei Arten entstehen: Einerseits, wenn nur auf einem Nadelbett gearbeitet wird, d.h. nur Maschen auf einem der Nadelbetten gebildet und miteinander verstrickt werden. Andererseits können auf dem ersten Nadelbett erzeugte Maschen mit auf dem zweiten Nadelbett erzeugten Maschen verstrickt werden, d.h. der Faden wird innerhalb einer Hin- und/oder Rückreihe zwischen den beiden Nadelbetten hin- und her geführt. Ein zweilagiges Gestrick entsteht dementsprechend, wenn parallel auf beiden Nadelbetten gestrickt wird und die auf der ersten Nadelreihe erzeugten Maschen nicht oder nur punktuell mit den auf dem zweiten Nadelbett erzeugten Maschen über die Randmaschen verstrickt werden. Bei dieser Herstellungsweise können also auch zwei einlagige Gestricke bzw. Lagen parallel auf dem ersten und zweiten Nadelbett gefertigt werden.The use of two needle beds allows the production of a single-layer or double-layered knitted fabric. A single-layered knitted fabric can be produced in two ways: Firstly, when only one needle bed is used, i.e. only stitches are formed on one of the needle beds and knitted together. Secondly, stitches produced on the first needle bed can be knitted with stitches produced on the second needle bed, i.e. the thread is guided back and forth between the two needle beds within a forward and/or backward row. A two-layered knitted fabric is produced when both needle beds are knitted in parallel and the stitches produced on the first row of needles are not or only selectively knitted with the stitches produced on the second needle bed via the edge stitches. With this production method, two single-layered knitted fabrics or layers can also be produced in parallel on the first and second needle beds.
Das Stricken von Edelmetallnetzen ist in der
In der
Es hat sich allerdings gezeigt, dass das simultane Stricken von edelmetallhaltigen und edelmetallfreien Drähten bzw. Fäden besondere Herausforderungen an den Strickprozess stellt und es, mutmaßlich durch die verschiedenen Materialeigenschaften, zum Verziehen des Gestricks und dadurch zu Instabilitäten im Produktionsprozess kommen kann. Solche Instabilitäten können sich einerseits in Abrissen des Drahtes während des Strickprozesses und andererseits in Unregelmäßigkeiten in Bezug auf die Struktur und die mechanischen Eigenschaften äußern, was beides ein Produkt mit mangelnder Qualität zur Folge haben kann.However, it has been shown that the simultaneous knitting of wires or threads containing and without precious metals poses particular challenges for the knitting process and, presumably due to the different material properties, can lead to distortion of the knitted fabric and thus to instabilities in the production process. Such instabilities can manifest themselves in the wire breaking off during the knitting process and in irregularities in terms of structure and mechanical properties, both of which can result in a product of poor quality.
Aufgabe der vorliegenden Erfindung war daher die Bereitstellung eines Verfahrens mit hoher Prozessstabilität zur Herstellung von Edelmetallnetzen auf Flachstrickmaschinen unter Verwendung von edelmetallhaltigen Drähten und edelmetallfreien Fäden.The object of the present invention was therefore to provide a method with high process stability for the production of precious metal nets on flat knitting machines using precious metal-containing wires and precious metal-free threads.
Die Aufgabe wird gelöst durch ein Verfahren zur Herstellung eines zweilagigen Edelmetallnetzes auf einer Flachstrickmaschine, wobei die Flachstrickmaschine ein erstes und ein zweites Nadelbett aufweist, umfassend die Schritte
- Bereitstellen von mindestens einem edelmetallhaltigen Draht,
- Bereitstellen von mindestens einem edelmetallfreien Stützfaden,
- Stricken einer ersten Lage des Edelmetallnetzes auf dem ersten Nadelbett und einer zweiten Lage des Edelmetallnetzes auf dem zweiten Nadelbett,
wobei die erste Lage über die Stoßkanten S11 und S12 und die zweite Lage über die Stoßkanten S21 und S22 verfügt, wobei die Stoßkante S11 zumindest teilweise an die Stoßkante S21 und die Stoßkante S12 zumindest teilweise an die Stoßkante S22 stößt, - Stricken eines Stütznetzes auf dem ersten und zweiten Nadelbett unter Verwendung des mindestens einen edelmetallfreien Stützfadens, wobei das Stütznetz über eine Stoßkante SH und eine der Stoßkante gegenüberliegende Kante KH verfügt, wobei die Stoßkante SH an jeweils eine Stoßkante S11 und S21 der beiden Lagen des Edelmetallnetzes stößt,
- wobei alle Strickvorgänge simultan erfolgen,
- dadurch gekennzeichnet, dass die Stoßkante SH des Stütznetzes mit den jeweiligen Stoßkanten S11 und S21 der beiden Lagen des Edelmetallnetzes über mindestens eine Strickmasche verbunden wird und dass das Stütznetz in den Strickreihen, auf der die Stoßkante SH des Stütznetzes mit den jeweiligen Stoßkanten der beiden Lagen des Edelmetallnetzes S11 und S21 verbunden wird, mit verbindenden Maschen von beiden Nadelbetten gestrickt wird.
- Providing at least one precious metal-containing wire,
- Provision of at least one precious metal-free support thread,
- Knitting a first layer of the precious metal net on the first needle bed and a second layer of the precious metal net on the second needle bed,
wherein the first layer has the abutting edges S11 and S12 and the second layer has the abutting edges S21 and S22, wherein the abutting edge S11 at least partially abuts the abutting edge S21 and the abutting edge S12 at least partially abuts the abutting edge S22, - Knitting a support net on the first and second needle bed using the at least one precious metal-free support thread, wherein the support net has a butt edge SH and an edge KH opposite the butt edge, wherein the butt edge SH abuts against a butt edge S11 and S21 of the two layers of the precious metal net,
- where all knitting processes take place simultaneously,
- characterized in that the abutting edge SH of the support net is connected to the respective abutting edges S11 and S21 of the two layers of the precious metal net via at least one knitting stitch and that the support net is knitted with connecting stitches from both needle beds in the knitting rows on which the abutting edge SH of the support net is connected to the respective abutting edges of the two layers of the precious metal net S11 and S21.
Im Rahmen der Erfindung wurde als überraschend erkannt, dass das Stricken eines Stütznetzes über beide Nadelbetten im Bereich, in dem es mit den Lagen des Edelmetallnetzes verbunden wird, eine stabilisierende Wirkung auf den Strickprozess hat. Mit anderen Worten bewirkt das zumindest teilweise Einbetten des Edelmetallnetzes in eine einlagige Stützstruktur eine Verminderung von Prozessstörungen in Form von Abrissen des edelmetallhaltigen Drahtes oder Unregelmäßigkeiten im Edelmetallgestrick.Within the scope of the invention, it was surprisingly recognized that knitting a support net over both needle beds in the area in which it is connected to the layers of the precious metal net has a stabilizing effect on the knitting process. In other words, at least partially embedding the precious metal net in a single-layer support structure reduces process disruptions in the form of tearing of the precious metal-containing wire or irregularities in the precious metal knit.
Das erfindungsgemäße Verfahren betrifft das Stricken auf einer Flachstrickmaschine mit einem ersten und einem zweiten Nadelbett.The method according to the invention relates to knitting on a flat knitting machine with a first and a second needle bed.
Stricken ist charakterisiert durch die reihenweise Herstellung der entstehenden Gestricke, bei der ineinandergreifende Maschen gebildet werden. Während des Strickvorgangs auf einer Flachstrickmaschine mit zwei Nadelbetten wird zunächst eine Strickreihe auf mindestens einem der Nadelbetten gebildet. In Strickrichtung wird im Anschluss die nächste Strickreihe gebildet, wobei im Folgenden auf den Teil des Gestricks, der die erste Strickreihe enthält als "unten" Bezug genommen wird. Die Faden- bzw. Drahtführung erfolgt von einer Seite des Nadelbettes oder der Nadelbetten zur anderen Seite und zurück. Wenn im Folgenden Bezug auf einen "Faden" genommen wird soll die jeweilige Ausführung auch für einen entsprechenden "Draht" gelten. Eine Strickreihe umfasst daher eine Hin- und eine Rückreihe, was sich aus der Fadenführung ergibt. Die Fadenführung kann dabei in einer Strickreihe über nur eines oder beide Nadelbetten erfolgen. Typischerweise kann der Faden für eine vollständige Strickreihe zunächst auf dem ersten Nadelbett geführt werden (Hinreihe), anschließend wird der Faden in entgegengesetzte Richtung auf dem gleichen Nadelbett oder dem zweiten Nadelbett geführt (Rückreihe). Der Faden kann aber auch in einer Hin- und/oder Rückreihe abwechselnd auf beiden Nadelbetten geführt werden, wobei innerhalb einer Strickreihe Verbindungen zwischen Maschen auf den beiden Nadelbetten erzeugt werden. Die Fadenführung kann über die gesamte Breite des Nadelbetts bzw. der Nadelbetten erfolgen, es kann aber auch nur über Teile der Breite der Nadelbetten gestrickt werden. Je nachdem über welche Breite der Nadelbetten gestrickt wird kann die Breite und auch die Form des Gestricks bestimmt werden.Knitting is characterized by the row-by-row production of the resulting knitted fabrics, in which interlocking stitches are formed. During the knitting process on a flat knitting machine with two needle beds, a knitting row is first formed on at least one of the needle beds. The next knitting row is then formed in the knitting direction, whereby the part of the knitted fabric that contains the first knitting row is referred to as "bottom" in the following. The thread or wire is guided from one side of the needle bed or needle beds to the other side and back. When reference is made to a "thread" in the following, the respective design should also apply to a corresponding "wire". A knitting row therefore comprises a forward and a reverse row, which results from the thread guidance. The thread guidance can take place in a knitting row over only one or both needle beds. Typically, the thread can first be guided on the first needle bed for a complete knitting row (forward row), then the thread is guided in the opposite direction on the same needle bed or the second needle bed (reverse row). The thread can also be guided alternately on both needle beds in a forward and/or backward row, whereby connections are created between stitches on the two needle beds within one knitting row. The thread guide can be controlled via the The entire width of the needle bed or beds can be used, but it is also possible to knit over just parts of the width of the needle bed. The width and shape of the knitted fabric can be determined depending on the width of the needle bed being knitted over.
Beim erfindungsgemäßen Verfahren erfolgen alle Strickvorgänge simultan. Darunter ist zu verstehen, dass mehrere Teilbereiche des zu fertigenden Gestricks gleichzeitig auf den beiden Nadelbetten gestrickt werden, die Fertigung der Teilbereiche also nicht nacheinander in mehreren Strickschritten erfolgt.In the method according to the invention, all knitting processes take place simultaneously. This means that several sub-areas of the knitted fabric to be produced are knitted simultaneously on the two needle beds, so that the production of the sub-areas does not take place one after the other in several knitting steps.
Das Verfahren umfasst das Bereitstellen von mindestens einem edelmetallhaltigen Draht.The method comprises providing at least one wire containing precious metal.
Unter einem edelmetallhaltigen Draht wird ein Draht verstanden, der aus mindestens einem Edelmetall besteht oder einen nennenswerten Anteil (> 50 Gew.-%) an Edelmetall enthält. Unter Edelmetallen wird im Rahmen der vorliegenden Erfindung ein Metall ausgewählt aus der Gruppe bestehend aus Platinmetallen, Gold und Silber verstanden. Unter Platinmetallen sind die Metalle der sogenannten Platingruppe, also Platin (Pt), Palladium (Pd), Iridium (Ir), Rhodium (Rh), Osmium (Os) und Ruthenium (Ru), zu verstehen.A wire containing precious metals is understood to mean a wire that consists of at least one precious metal or contains a significant proportion (> 50% by weight) of precious metal. In the context of the present invention, precious metals are understood to mean a metal selected from the group consisting of platinum metals, gold and silver. Platinum metals are understood to mean the metals of the so-called platinum group, i.e. platinum (Pt), palladium (Pd), iridium (Ir), rhodium (Rh), osmium (Os) and ruthenium (Ru).
Bevorzugt besteht der mindestens eine edelmetallhaltige Draht aus Platin, einer Platinlegierung, Palladium oder einer Palladiumlegierung. Eine platinbasierte Legierung enthält mehr als 50 Gew.-% Platin, als weitere Legierungsbestandteile sind insbesondere Palladium, Rhodium und Ruthenium zu nennen. Eine palladiumbasierte Legierung enthält mehr als 50 Gew.-% Palladium.Preferably, the at least one precious metal-containing wire consists of platinum, a platinum alloy, palladium or a palladium alloy. A platinum-based alloy contains more than 50% by weight of platinum, and other alloy components include palladium, rhodium and ruthenium. A palladium-based alloy contains more than 50% by weight of palladium.
Bevorzugt besteht der mindestens eine edelmetallhaltige Draht aus einer Legierung ausgewählt aus der Gruppe bestehend aus Platin mit 1 - 15 Gew.-% Rhodium, Platin mit 1 - 15 Gew.-% Rhodium und 0,1 - 20 Gew.-% Palladium, Platin mit 1 - 15 Gew.-% Rhodium, 0,1 - 20 Gew.-% Palladium und 0,1 - 5 Gew.-% Ruthenium, Platin mit 1 - 15 Gew.-% Rhodium, 0,1 - 40 Gew.-% Palladium und 0,001 - 5 Gew.-% Iridium, Platin mit 1 - 15 Gew.-% Rhodium, 0,1 - 20 Gew.-% Palladium und 0,001 - 5 Gew.-% Tantal, Platin mit 1 - 15 Gew.-% Rhodium, 0,001 - 5 Gew% Iridium und 0,001 - 5 Gew.-% Tantal, Palladium mit 1 - 25 Gew.-% Platin, Palladium mit 1 - 20 Gew.-% Platin und 1 - 15 Gew.-% Rhodium, Palladium mit 1 - 25 Gew.-% Wolfram, Palladium mit 1 - 15 Gew.-% Nickel, Palladium mit 0,001 - 5 Gew.-% Rhodium, Palladium mit 1 - 15 Gew.-% Kupfer, Palladium mit 1 - 15 Gew.-% Kupfer und 1 - 15 Gew.-% Nickel und Palladium mit 1 - 30 Gew.-% Cobalt.Preferably, the at least one noble metal-containing wire consists of an alloy selected from the group consisting of platinum with 1 - 15 wt.% rhodium, platinum with 1 - 15 wt.% rhodium and 0.1 - 20 wt.% palladium, platinum with 1 - 15 wt.% rhodium, 0.1 - 20 wt.% palladium and 0.1 - 5 wt.% ruthenium, platinum with 1 - 15 wt.% rhodium, 0.1 - 40 wt.% palladium and 0.001 - 5 wt.% iridium, platinum with 1 - 15 wt.% rhodium, 0.1 - 20 wt.% palladium and 0.001 - 5 wt.% tantalum, platinum with 1 - 15 wt.% rhodium, 0.001 - 5 wt.% iridium and 0.001 - 5 wt.% tantalum, palladium with 1 - 25 wt.% platinum, palladium with 1 - 20 wt.% platinum and 1 - 15 wt.% rhodium, palladium with 1 - 25 wt.% tungsten, palladium with 1 - 15 wt.% nickel, palladium with 0.001 - 5 wt.% rhodium, palladium with 1 - 15 wt.% copper, palladium with 1 - 15 wt.% copper and 1 - 15 wt.% nickel and palladium with 1 - 30 wt.% cobalt.
Vorzugsweise werden edelmetallhaltige Drähte eingesetzt, die einen Durchmesser 40 - 150 µm aufweisen, bevorzugt 50 - 130 µm.Preferably, precious metal-containing wires with a diameter of 40 - 150 µm, preferably 50 - 130 µm, are used.
Der mindestens eine edelmetallhaltige Draht kann als Runddraht, das heißt mit einem runden Querschnitt, ausgebildet sein. In einer anderen Ausführung kann der Draht als abgeflachter Runddraht oder als Draht mit einem anderen Querschnitt ausgeführt werden.The at least one wire containing precious metal can be designed as a round wire, i.e. with a round cross-section. In another embodiment, the wire can be designed as a flattened round wire or as a wire with a different cross-section.
Der mindestens eine edelmetallhaltige Draht kann mehrere Drähte, in diesem Fall auch als Filamente bezeichnet, umfassen, die bevorzugt miteinander verdrillt sein können. Die Filamente können alle aus dem gleichen Material bestehen, d.h. alle edelmetallhaltig sein, oder aus unterschiedlichen Materialien bestehen, die wiederum nicht alle edelmetallhaltig sein müssen.The at least one wire containing precious metals can comprise several wires, in this case also referred to as filaments, which can preferably be twisted together. The filaments can all be made of the same material, i.e. all contain precious metals, or they can be made of different materials, which in turn do not all have to contain precious metals.
In vielen Fällen kann es vorteilhaft sein, zwei oder mehr edelmetallhaltige Drähte gemeinsam miteinander zu verstricken. Mit anderen Worten können bei der Bildung einer Masche mehrere edelmetallhaltige Drähte gemeinsam geführt werden. Beim Stricken mit mehreren Drähten bestehen in einer Ausführungsform die edelmetallhaltigen Drähte aus dem gleichen Material, in weiteren Ausführungsformen können edelmetallhaltige Drähte bestehend aus mindestens zwei unterschiedlichen Materialien verwendet werden. Die mehreren Drähte können den gleichen oder unterschiedliche Durchmesser aufweisen.In many cases, it can be advantageous to knit two or more precious metal-containing wires together. In other words, several precious metal-containing wires can be guided together when forming a stitch. When knitting with several wires, in one embodiment the precious metal-containing wires consist of the same material; in other embodiments, precious metal-containing wires consisting of at least two different materials can be used. The several wires can have the same or different diameters.
Im erfindungsgemäßen Verfahren werden simultan auf dem ersten Nadelbett die erste Lage des zweilagigen Edelmetallnetzes und auf dem zweiten Nadelbett die zweite Lage des Edelmetallnetzes gestrickt. Mit anderen Worten werden während des Strickvorgangs gleichzeitig zwei Teile des zu fertigenden Edelmetallnetzes auf jeweils einem Nadelbett gestrickt, die Fertigung der beiden Lagen erfolgt also nicht nacheinander.In the method according to the invention, the first layer of the two-layer precious metal net is knitted simultaneously on the first needle bed and the second layer of the precious metal net is knitted on the second needle bed. In other words, during the knitting process, two parts of the precious metal net to be produced are knitted simultaneously on one needle bed each, so the two layers are not produced one after the other.
Unter "zweilagigen Edelmetallnetzen" werden im Rahmen der vorliegenden Erfindung solche Edelmetallnetze verstanden, die über zwei Lagen verfügen, wobei die Lagen über eine oder mehrere ihrer jeweiligen Stoßkanten miteinander verbunden sein können oder auch nicht an ihren Stoßkanten verbunden sein können. Die beiden Lagen liegen dabei übereinander, das heißt sie überlappen zumindest teilweise im Bereich ihrer Flächenausdehnung. Auch Edelmetallnetze die, wie im Fall der vorliegenden Erfindung, an einer Seite über die Stoßkanten der zwei Lagen miteinander verbunden sind werden als zweilagige Edelmetallnetze bezeichnet.In the context of the present invention, "two-layer precious metal nets" are understood to mean those precious metal nets that have two layers, whereby the layers can be connected to one another via one or more of their respective abutting edges or can also not be connected at their abutting edges. The two layers lie on top of one another, i.e. they overlap at least partially in the area of their surface area. Precious metal nets that, as in the case of the present invention, are connected to one another on one side via the abutting edges of the two layers are also referred to as two-layer precious metal nets.
Bei einem Aufklappen entlang der gemeinsamen Stoßkante ist ein einlagiges Edelmetallnetz erhältlich.When opened along the common edge, a single-layer precious metal net is available.
Die erste und die zweite Lage des zweilagigen Edelmetallnetzes verfügen jeweils über zwei Stoßkanten, d.h. jede Lage verfügt auf der einen Seite über eine Stoßkante und auf ihrer anderen Seite über eine weitere Stoßkante. Die erste Lage verfügt über die Stoßkanten S11 und S12 und die zweite Lage über die Stoßkanten S21 und S22. Die Seiten der Edelmetalllagen sind hierbei in Bezug auf die Lage der Stoßkanten auf den beiden Nadelbetten senkrecht zur Strickrichtung zu verstehen. Je nach Form der jeweiligen Lage können sich die Stoßkanten einer Lage nicht schneiden, wie im Fall einer rechteckigen Lage, oder sich schneiden, wie beispielsweise im Fall einer halbkreisförmigen Lage.The first and second layers of the two-layer precious metal mesh each have two butt edges, i.e. each layer has a butt edge on one side and another butt edge on the other side. The first layer has the butt edges S11 and S12 and the second layer has the butt edges S21 and S22. The sides of the precious metal layers are to be understood in relation to the position of the butt edges on the two needle beds perpendicular to the knitting direction. Depending on the shape of the respective layer, the butt edges of a layer may not intersect, as in the case of a rectangular layer, or they may intersect, as in the case of a semicircular layer, for example.
Stoßkanten können miteinander verbunden sein, bevorzugt durch mindestens eine verbindende Strickmasche. Stoßkanten können aber auch aneinanderstoßen, ohne verbunden zu sein. Die Stoßkanten werden während des Strickvorgangs in Strickrichtung von unten nach oben gebildet. Die beiden Edelmetalllagen können auch über eine obere und/oder untere Kante oder Stoßkante verfügen, das Vorhandensein dieser Kanten hängt von der Form der jeweiligen Lage ab. Eine rechteckige Lage verfügt neben den beiden seitlichen Stoßkanten beispielsweise über eine untere und eine obere Kante oder Stoßkante, eine halbkreisförmige Lage verfügt dagegen über keine weiteren Kanten oder Stoßkanten.Butt edges can be connected to one another, preferably by at least one connecting knitting stitch. Butt edges can also abut one another without being connected. The butt edges are formed during the knitting process in the knitting direction from bottom to top. The two precious metal layers can also have an upper and/or lower edge or butt edge; the presence of these edges depends on the shape of the respective layer. A rectangular layer, for example, has a lower and an upper edge or butt edge in addition to the two side butt edges, while a semicircular layer has no further edges or butt edges.
Unter den unteren Kanten sind hierbei diejenigen Kanten zu verstehen, die in Strickrichtung zuerst gebildet werden, sich also unten im Gestrick befinden. Dementsprechend sind unter den oberen Kanten diejenigen zu verstehen, die in Strickrichtung später gebildet werden.The lower edges are those edges that are formed first in the knitting direction, i.e. are located at the bottom of the fabric. Accordingly, the upper edges are those that are formed later in the knitting direction.
Eine Stoßkante der ersten Lage des Edelmetallnetzes S11 stößt zumindest teilweise an eine Stoßkante der zweiten Lage des Edelmetallnetzes S21. Außerdem stoßen die jeweils anderen Stoßkanten der ersten und zweiten Lage des Edelmetallnetzes, also die Stoßkante S12 und die Stoßkante S22, zumindest teilweise aneinander. Unter einem "zumindest teilweisen Aneinanderstoßen" ist hierbei zu verstehen, dass die Stoßkanten über Teile ihrer Länge in Strickrichtung aneinanderstoßen, also über Teile der sie bildenden Strickreihen. Mit anderen Worten könne die Stoßkanten auch zumindest teilweise versetzt zueinander sein.A butt edge of the first layer of the precious metal net S11 abuts at least partially against a butt edge of the second layer of the precious metal net S21. In addition, the other butt edges of the first and second layers of the precious metal net, i.e. the butt edge S12 and the butt edge S22, abut each other at least partially. "At least partially abutting" is to be understood here as meaning that the butt edges abut each other over parts of their length in the knitting direction, i.e. over parts of the knitting rows that form them. In other words, the butt edges can also be at least partially offset from each other.
Die erste und die zweite Lage des zweilagigen Edelmetallnetzes können durch verbindende Strickmaschen zumindest teilweise an ihren Stoßkanten verbunden werden. Darunter ist zu verstehen, dass die beiden Lagen über Maschen, die aus dem mindestens einen edelmetallhaltigen Draht gebildet werden, an ihren Randmaschen miteinander verbunden werden. Diese Verbindung der ersten und zweiten Lage des zweilagigen Edelmetallnetzes kann auf nur einer Seite oder auf beiden Seiten erfolgen. Die Verbindung oder die Verbindungen können über die gesamte Länge oder über Teile der Länge der Stoßkanten erfolgen. Vorteilhaft kann sein, dass die Verbindung an einer Seite über die gesamte Länge der Stoßkanten erfolgt.The first and second layers of the two-layer precious metal mesh can be connected at least partially at their abutting edges by connecting knitting stitches. understand that the two layers are connected to one another at their edge meshes via meshes that are formed from the at least one wire containing precious metal. This connection of the first and second layers of the two-layer precious metal net can take place on just one side or on both sides. The connection or connections can take place over the entire length or over parts of the length of the abutting edges. It can be advantageous for the connection to take place on one side over the entire length of the abutting edges.
In weiteren Ausführungsformen kann die Verbindung auf beiden Seiten der ersten und zweiten Lage des zweilagigen Edelmetallnetzes zumindest über Teile ihrer jeweiligen Stoßkanten erfolgen, wobei diese teilweisen Verbindungen auf gleicher Höhe, also in der gleichen Strickreihe oder den gleichen Strickreihen oder auf unterschiedlichen Höhen erfolgen können. Die teilweisen Verbindungen können über die gleiche Länge der Stoßkanten auf beiden Seiten erfolgen, also über die gleiche Anzahl von Strickreihen. Die teilweisen Verbindungen können aber auch über eine unterschiedliche Länge der Stoßkanten auf beiden Seiten erfolgen. In einer bevorzugten Ausführungsform erfolgen die teilweisen Verbindungen zumindest teilweise über die gleichen Strickreihen. In einer solchen Ausführungsform wird also zumindest teilweise im Kreis gestrickt bzw. rundgestrickt, mit anderen Worten entsteht über diese Strickreihen eine ringartige Struktur. Es hat sich gezeigt, dass das Stricken einer solchen zumindest teilweise ringartigen Struktur die Stabilität des Strickprozesses weiter positiv beeinflussen kann.In further embodiments, the connection on both sides of the first and second layers of the two-layer precious metal mesh can be made at least over parts of their respective abutting edges, whereby these partial connections can be made at the same height, i.e. in the same knitting row or rows, or at different heights. The partial connections can be made over the same length of the abutting edges on both sides, i.e. over the same number of knitting rows. However, the partial connections can also be made over a different length of the abutting edges on both sides. In a preferred embodiment, the partial connections are made at least partially over the same knitting rows. In such an embodiment, knitting is at least partially done in a circle or in a circular manner, in other words, a ring-like structure is created over these knitting rows. It has been shown that knitting such an at least partially ring-like structure can have a further positive effect on the stability of the knitting process.
Der Bezug für die Höhe des Gestricks ist die untere Strickreihe des Gestricks. Auch für den Fall, dass in unterschiedlichen Strickreihen mit dem Stricken einer Lage begonnen wird bleibt die Höhe des Gesamtgestricks gleich, mit anderen Worten können die Lagen des Gestricks auf unterschiedlichen Höhen eine unterschiedliche Anzahl von Strickreihen umfassen.The reference for the height of the knitted fabric is the bottom knitting row of the knitted fabric. Even if knitting of a layer begins in different knitting rows, the height of the entire knitted fabric remains the same, in other words, the layers of the knitted fabric at different heights can comprise a different number of knitting rows.
Bevorzugt kann die erste und die zweite Lage des zweilagigen Edelmetallnetzes aus einem edelmetallhaltigen Draht oder edelmetallhaltigen Drähten gleicher Zusammensetzung gestrickt werden. Die beiden Lagen können aber auch aus edelmetallhaltigem Draht oder edelmetallhaltigen Drähten unterschiedlicher Zusammensetzung gestrickt werden.Preferably, the first and second layers of the two-layer precious metal mesh can be knitted from a precious metal-containing wire or precious metal-containing wires of the same composition. However, the two layers can also be knitted from precious metal-containing wire or precious metal-containing wires of different compositions.
Zum Stricken der ersten und zweiten Lage des zweilagigen Edelmetallnetzes kann edelmetallhaltiger Draht mit dem gleichen oder unterschiedlichen Durchmessern verwendet werden. Es hat sich als günstig erwiesen, dass die erste und die zweite Lage des Edelmetallnetzes aus edelmetallhaltigem Draht oder edelmetallhaltigen Drähten gleichen Durchmessers gestrickt werden.Precious metal-containing wire with the same or different diameters can be used to knit the first and second layers of the two-layer precious metal net. It has proven advantageous for the first and second layers of the precious metal net to be knitted from precious metal-containing wire or precious metal-containing wires of the same diameter.
Die erste und die zweite Lage des zweilagigen Edelmetallnetzes können in gleichen oder unterschiedlichen Strickmustern gestrickt werden. Unterschiedliche Strickmuster können beispielsweise durch unterschiedliche Maschenlängen, Flottungen oder Fänge entstehen. In bevorzugten Ausführungsformen werden die erste und die zweite Lage des Edelmetallnetzes im gleichen Strickmuster gestrickt.The first and second layers of the two-layer precious metal net can be knitted in the same or different knitting patterns. Different knitting patterns can be created, for example, by different stitch lengths, floats or catches. In preferred embodiments, the first and second layers of the precious metal net are knitted in the same knitting pattern.
Die erste und die zweite Lage des zweilagigen Edelmetallnetzes können die gleiche oder unterschiedliche Längen in Strickrichtung und/oder die gleiche oder unterschiedliche Breiten senkrecht zur Strickrichtung aufweisen. Bevorzugt haben die erste und die zweite Lage des Edelmetallnetzes die gleiche Länge und die gleiche Breite.The first and second layers of the two-layer precious metal net can have the same or different lengths in the knitting direction and/or the same or different widths perpendicular to the knitting direction. Preferably, the first and second layers of the precious metal net have the same length and the same width.
Die erste und die zweite Lage des zweilagigen Edelmetallnetzes können die gleiche Form oder unterschiedliche Formen haben. Besonders bevorzugt haben die erste und zweite Lage des zweilagigen Edelmetallnetzes die gleiche Form. Es kann vorteilhaft sein, dass die erste und die zweite Lage des zweilagigen Edelmetallnetzes die Form eines Halbkreises aufweisen. Besonders vorteilhaft kann sein, dass diese beiden Halbkreise die gleiche Breite und die gleiche Länge aufweisen.The first and second layers of the two-layer precious metal net can have the same shape or different shapes. The first and second layers of the two-layer precious metal net particularly preferably have the same shape. It can be advantageous for the first and second layers of the two-layer precious metal net to have the shape of a semicircle. It can be particularly advantageous for these two semicircles to have the same width and the same length.
In bevorzugten Ausführungsformen sind die erste und die zweite Lage des zweilagigen Edelmetallnetzes deckungsgleich, mit anderen Worten können die beiden Lagen die gleiche Länge, die gleiche Breite und die gleiche Form haben.In preferred embodiments, the first and second layers of the two-layer precious metal mesh are congruent, in other words, the two layers can have the same length, the same width and the same shape.
Das Verfahren umfasst das Bereitstellen von mindestens einem edelmetallfreien Stützfaden.The method comprises providing at least one precious metal-free support thread.
Geeignete edelmetallfreie Stützfäden können durch Routineversuche und unter Berücksichtigung des endgültigen Verwendungszwecks des zweilagigen Edelmetallnetzes und eventuellen zusätzlichen Schritten im Herstellverfahren ausgewählt werden. Bevorzugte edelmetallfreie Stützfäden lassen sich nach der Herstellung des Edelmetallnetzes entfernen, beispielsweise durch Auflösen in sauren oder basischen Medien, Abschneiden, Schmelzen oder Abflammen. Solche Stützfäden können natürlicher oder synthetischer organischer Natur oder anorganischer Natur sein. Beispiele für geeignete Materialien sind Polyamide, Polyester, Zellulosefasern, Baumwolle, Acryl-Styrol-Polymere, Nylon, PVA und andere Vinylpolymere, Alginat, Kupfer, Silber, Aluminium, oder auch Metalle mit niedrigem Schmelzpunkt wie Zinn- und Blei-Legierungen.Suitable non-precious metal support threads can be selected by routine testing and taking into account the final intended use of the two-layer precious metal mesh and any additional steps in the manufacturing process. Preferred non-precious metal support threads can be removed after the precious metal mesh has been manufactured, for example by dissolving in acidic or basic media, cutting, melting or flaming. Such support threads can be natural or synthetic, organic in nature or inorganic in nature. Examples of suitable materials are polyamides, polyesters, cellulose fibers, cotton, acrylic-styrene polymers, nylon, PVA and other vinyl polymers, alginate, copper, silver, aluminum, or even metals with a low melting point such as tin and lead alloys.
Der mindestens eine edelmetallfreie Stützfaden kann aus nur einem fadenförmigen Element bestehen, solche einzelnen fadenförmigen Elemente werden auch im Fall von edelmetallfreien Fäden als Filamente bezeichnet. Der edelmetallfreie Stützfaden kann auch aus mehr als einem Filament bestehen, die vorteilhafterweise miteinander verdrillt sein können. Diese mehreren Filamente können aus dem gleichen oder unterschiedlichen Materialien bestehen.The at least one precious metal-free supporting thread can consist of only one thread-like element; such individual thread-like elements are also referred to as filaments in the case of precious metal-free threads. The precious metal-free supporting thread can also consist of more than one filament, which can advantageously be twisted together. These multiple filaments can consist of the same or different materials.
Im erfindungsgemäßen Verfahren wird simultan zur ersten und zweiten Lage des zweilagigen Edelmetallnetzes unter Verwendung des mindestens einen edelmetallfreien Stützfadens ein Stütznetz auf dem ersten und zweiten Nadelbett gestrickt. Mit anderen Worten wird das Stütznetz gleichzeitig mit den beiden Lagen des zu fertigenden Edelmetallnetzes gestrickt, die Fertigung der beiden Lagen und des Stütznetzes erfolgt also nicht nacheinander.In the method according to the invention, a support net is knitted on the first and second needle bed simultaneously with the first and second layers of the two-layer precious metal net using the at least one precious metal-free support thread. In other words, the support net is knitted simultaneously with the two layers of the precious metal net to be produced, so the two layers and the support net are not produced one after the other.
Unter "Stütznetz" werden die Bereiche des Gestricks verstanden, die zumindest teilweise unter Verwendung des edelmetallfreien Stützfadens gestrickt werden. Das Stütznetz kann auch weitere Fäden oder Drähte umfassen.The term "supporting net" refers to the areas of the knitted fabric that are at least partially knitted using the precious metal-free supporting thread. The supporting net can also include other threads or wires.
Das Gestrick umfasst alle Strickreihen, die während des Verfahrens gebildet werden. Das Gestrick umfasst mindestens die erste und zweite Lage des zweilagigen Edelmetallnetzes und das Stütznetz. Das Gestrick kann aber auch weitere Teile oder Bereiche umfassen. Bevorzugt werden alle Strickreihen des Gestricks über die gleiche Breite der Nadelbetten gestrickt, mit anderen Worten ist das Gestrick bevorzugt rechteckig.The knitted fabric comprises all the rows of knitting that are formed during the process. The knitted fabric comprises at least the first and second layers of the two-layer precious metal mesh and the support mesh. However, the knitted fabric can also comprise other parts or areas. Preferably, all rows of knitting of the knitted fabric are knitted over the same width of the needle beds, in other words, the knitted fabric is preferably rectangular.
Das Stütznetz verfügt über eine Stoßkante SH und eine gegenüberliegende Kante KH. Je nach Form des Stütznetzes können sich die Stoßkante SH und die gegenüberliegende Kante KH nicht schneiden, wie im Fall eines rechteckigen Stütznetzes, oder sich schneiden, wie beispielsweise im Fall eines halbkreisförmigen Stütznetzes. Die Stoßkante SH und die Kante KH werden während des Strickvorgangs in Strickrichtung von unten nach oben gebildet.The support net has a butt edge SH and an opposite edge KH. Depending on the shape of the support net, the butt edge SH and the opposite edge KH may not intersect, as in the case of a rectangular support net, or may intersect, as in the case of a semicircular support net. The butt edge SH and the edge KH are formed during the knitting process in the knitting direction from bottom to top.
Die Stoßkante SH des Stütznetzes stößt an jeweils eine Stoßkante S11 und S21 der ersten und zweiten Lage des zweilagigen Edelmetallnetzes. Mit anderen Worten wird die Kante des Stütznetzes, die an die beiden Lagen des zweilagigen Edelmetallnetzes stößt, als Stoßkante SH bezeichnet. Die Stoßkante SH umfasst dementsprechend die Strickreihen, in denen sowohl die Lagen des zweilagigen Edelmetallnetzes als auch das Stütznetz gestrickt werden. Mit der gegenüberliegenden Kante KH wird dementsprechend die der Stoßkante SH gegenüberliegende Kante des Stütznetzes in den gleichen Strickreihen bezeichnet, d.h. die Stoßkante SH und die Kante KH haben in Strickrichtung die gleiche Länge. Die Kante KH stößt nicht an eine der beiden Lagen des zweilagigen Edelmetallnetzes.The butt edge SH of the support net abuts against a butt edge S11 and S21 of the first and second layers of the two-layer precious metal net. In other words, the edge of the support net that abuts against the two layers of the two-layer precious metal net is referred to as the butt edge SH. The butt edge SH accordingly includes the knitting rows in which both the layers of the two-layer precious metal net and the support net are knitted. The opposite edge KH accordingly connects the butt edge SH opposite edge of the support net in the same knitting rows, ie the butt edge SH and the edge KH have the same length in the knitting direction. The edge KH does not abut one of the two layers of the two-layer precious metal net.
Die Form der Kante und Stoßkante des Stütznetzes ist nicht weiter beschränkt. Es hat sich aber als vorteilhaft erwiesen, dass die Form des Stütznetzes so gestaltet ist, dass die Form des Gestrickes insgesamt rechteckig ist. Mit anderen Worten ergänzt das Stütznetz die Lagen des Edelmetallnetzes derart, dass die Form des Gestricks, umfassend Edelmetalllage oder Edelmetalllagen und Stütznetz, insgesamt rechteckig ist. Dementsprechend korreliert die Form des Stütznetzes bevorzugt mit der Form der ersten und zweiten Lage des Edelmetallnetzes. Beispielsweise weist das Stütznetz bevorzugt eine konkave Form auf, falls die der erste und zweite Lage des Edelmetallnetzes eine konvexe Form aufweisen.The shape of the edge and abutting edge of the support net is not further restricted. However, it has proven to be advantageous that the shape of the support net is designed such that the shape of the knitted fabric is rectangular overall. In other words, the support net complements the layers of the precious metal net such that the shape of the knitted fabric, comprising the precious metal layer or layers and the support net, is rectangular overall. Accordingly, the shape of the support net preferably correlates with the shape of the first and second layers of the precious metal net. For example, the support net preferably has a concave shape if the first and second layers of the precious metal net have a convex shape.
In bevorzugten Ausführungsformen hat die Stoßkante SH die gleiche Länge wie die Stoßkanten S11 und S12. Mit anderen Worten umfasst die Stoßkante SH die gleichen Strickreihen wie die Stoßkanten S11 und S12, das Stütznetz stößt also über die gesamte Länge der Lagen des Edelmetallnetzes an die Stoßkanten der Lagen des zweilagigen Edelmetallnetzes.In preferred embodiments, the abutting edge SH has the same length as the abutting edges S11 and S12. In other words, the abutting edge SH comprises the same knitting rows as the abutting edges S11 and S12, so the support net abuts the abutting edges of the layers of the two-layer precious metal net over the entire length of the layers of the precious metal net.
Die Stoßkante SH des Stütznetzes und die jeweiligen Stoßkanten S11 und S21 der ersten und zweiten Lage des zweilagigen Edelmetallnetzes werden über mindestens eine Strickmasche miteinander verbunden. Mit anderen Worten wird das Stütznetz während des Strickvorgangs zumindest teilweise mit den beiden Lagen des zweilagigen Edelmetallnetzes verbunden. Dadurch wird eine Stabilisierung des Strickprozesses erreicht. Es kann bevorzugt sein, dass die Stoßkante SH des Stütznetzes über ihre gesamte Länge mit den jeweiligen Stoßkanten S11 und S21 der ersten und zweiten Lage des zweilagigen Edelmetallnetzes verbunden wird.The abutting edge SH of the support net and the respective abutting edges S11 and S21 of the first and second layers of the two-layer precious metal net are connected to one another via at least one knitting stitch. In other words, the support net is at least partially connected to the two layers of the two-layer precious metal net during the knitting process. This stabilizes the knitting process. It may be preferred that the abutting edge SH of the support net is connected over its entire length to the respective abutting edges S11 and S21 of the first and second layers of the two-layer precious metal net.
Die verbindende Strickmasche oder die verbindenden Strickmaschen können aus dem mindestens einen edelmetallhaltigen Draht oder dem edelmetallfreien Stützfaden gebildet werden. Bevorzugt wird die verbindende Strickmasche oder die verbindenden Strickmaschen aus dem edelmetallfreien Stützfaden gebildet.The connecting knitting stitch or the connecting knitting stitches can be formed from the at least one precious metal-containing wire or the precious metal-free supporting thread. Preferably, the connecting knitting stitch or the connecting knitting stitches are formed from the precious metal-free supporting thread.
Das Stütznetz wird in der oder den Strickreihen, in denen die Stoßkante SH des Stütznetzes mit den jeweiligen Stoßkanten der beiden Lagen des Edelmetallnetzes S11 und S21 verbunden wird, mit verbindenden Maschen von beiden Nadelbetten gestrickt. Unter "verbindenden Maschen" sind hierbei solche Strickmaschen zu verstehen, die zwischen dem ersten und dem zweiten Nadelbett gebildet werden. Mit anderen Worten wird das Stütznetz zumindest teilweise einlagig gestrickt. Es hat sich gezeigt, dass die einlagige Ausführung des Stütznetzes im Bereich oder Bereichen, die mit den Lagen des Edelmetallnetzes verbunden sind, zu einer Erhöhung der Prozessstabilität führt.The support net is knitted in the knitting row(s) in which the butt edge SH of the support net is connected to the respective butt edges of the two layers of the precious metal net S11 and S21, with connecting stitches from both needle beds. "Connecting stitches" are understood to mean those knitting stitches that are between the first and the second needle bed. In other words, the support net is at least partially knitted in one layer. It has been shown that the single-layer design of the support net in the area or areas that are connected to the layers of the precious metal net leads to an increase in process stability.
Der edelmetallfreie Stützfaden kann parallel mit dem mindestens einen edelmetallhaltigen Draht verstrickt werden, d.h. es können beim Stricken Maschen gebildet werden, die edelmetallhaltigen Draht und Stützfaden umfassen. Der betreffende Teil des entstehenden Gestricks enthält in diesen Fällen sowohl Edelmetall als auch das Material des Stützfadens. In anderen Ausführungsformen kann der Stützfaden auch für Teile oder Bereiche des Gestricks eingesetzt werden, die keinen edelmetallhaltigen Draht enthalten, d.h. das entstehende Gestrick enthält in diesen Fällen Bereiche mit und Bereiche ohne edelmetallhaltigen Draht.The precious metal-free support thread can be knitted in parallel with the at least one precious metal-containing wire, i.e., during knitting, stitches can be formed that comprise precious metal-containing wire and support thread. In these cases, the relevant part of the resulting knitted fabric contains both precious metal and the material of the support thread. In other embodiments, the support thread can also be used for parts or areas of the knitted fabric that do not contain precious metal-containing wire, i.e., in these cases, the resulting knitted fabric contains areas with and areas without precious metal-containing wire.
Das Stütznetz kann mehrere Bereiche umfassen. Beispielsweise kann das Stütznetz auch Strickreihen umfassen, in denen kein edelmetallhaltiger Draht eingesetzt wird, in denen also nur mit dem edelmetallfreien Stützfaden gestrickt wird. Mit anderen Worten kann das Gestrick Bereiche umfassen, die keinen edelmetallhaltigen Draht enthalten. In diesem Fall kann das Stütznetz neben der Stoßkante SH und der Kante KH auch weitere Kanten umfassen. Solche Kanten können in Strickreihen gebildet werden, in denen keine Maschen der Lagen des Edelmetallnetzes gestrickt werden. Mit anderen Worten kann das Gestrick auch über Strickreihen verfügen, die nur von Bereichen des Stütznetzes gebildet werden.The support net can comprise several areas. For example, the support net can also comprise knitting rows in which no wire containing precious metals is used, i.e. in which only the precious metal-free support thread is used for knitting. In other words, the knitted fabric can comprise areas that do not contain any wire containing precious metals. In this case, the support net can comprise other edges in addition to the butt edge SH and the edge KH. Such edges can be formed in knitting rows in which no stitches of the layers of the precious metal net are knitted. In other words, the knitted fabric can also have knitting rows that are only formed by areas of the support net.
Es kann bevorzugt sein, dass das Stütznetz in den Bereichen mit Strickreihen, die keinen edelmetallhaltigen Draht enthalten, zweilagig gestrickt wird. Mit anderen Worten kann das Stütznetz in diesen Strickreihen nicht mit verbindenden Maschen zwischen dem ersten und zweiten Nadelbett gestrickt werden. Diese beiden Lagen können an den Randmaschen über verbindende Strickmaschen verbunden sein, es kann also vorteilhaft sein, dass das Stütznetz in diesen Bereichen eine schlauchartige Struktur hat. Bevorzugt kann auch sein, dass das Stütznetz in den Bereichen, die keinen edelmetallhaltigen Draht umfassen, einlagig gestrickt wird.It may be preferred that the support net is knitted in two layers in the areas with knitting rows that do not contain a wire containing precious metals. In other words, the support net cannot be knitted in these knitting rows with connecting stitches between the first and second needle beds. These two layers can be connected at the edge stitches via connecting knitting stitches, so it may be advantageous for the support net to have a tubular structure in these areas. It may also be preferred that the support net is knitted in one layer in the areas that do not contain a wire containing precious metals.
In bevorzugten Ausführungsformen umfasst das Stütznetz einlagig gestrickte Bereiche und zweilagig gestrickte Bereiche, die keinen edelmetallhaltigen Draht umfassen.In preferred embodiments, the support mesh comprises single-layer knitted regions and double-layer knitted regions that do not comprise any noble metal-containing wire.
In bevorzugten Ausführungsformen stößt das Stütznetz nur an den Stoßkanten S11 und S21 an die beiden Lagen des zweilagigen Edelmetallnetzes. Es kann auch bevorzugt sein, dass das Stütznetz auch an den jeweilig anderen Kanten oder Stoßkanten der beiden Lagen des zweilagigen Edelmetallnetzes S12 und S22 an die beiden Lagen des zweilagigen Edelmetallnetzes stößt. Die Stoßkante des Stütznetzes SH und die beiden Stoßkanten der beiden Lagen des zweilagigen Edelmetallnetzes S12 und S22 können über mindestens eine Strickmasche des Stützfadens miteinander verbunden werden. Eine solche Verbindung muss aber nicht erfolgen, in solchen Ausführungsformen sind diese Stoßkanten nicht über Strickmaschen miteinander verbunden.In preferred embodiments, the support net only abuts the two layers of the two-layer precious metal net at the abutting edges S11 and S21. It may also be preferred that the support net also abuts the two layers of the two-layer precious metal net at the other edges or abutting edges of the two layers of the two-layer precious metal net S12 and S22. The abutting edge of the support net SH and the two abutting edges of the two layers of the two-layer precious metal net S12 and S22 can be connected to one another via at least one knitting stitch of the support thread. However, such a connection does not have to be made; in such embodiments, these abutting edges are not connected to one another via knitting stitches.
Es kann bevorzugt sein, dass das Stütznetz auch an die jeweiligen unteren und/oder oberen Kanten der beiden Lagen des zweilagigen Edelmetallnetzes stößt. Das Stütznetz kann dabei nur an die unteren oder oberen Kanten der beiden Lagen des Edelmetallnetzes oder an die unteren und oberen Kanten stoßen. In solchen Ausführungsformen umgibt das Stütznetz die beiden Lagen des zweilagigen Edelmetallnetzes an mindestens zwei Seiten.It may be preferred that the support net also abuts the respective lower and/or upper edges of the two layers of the two-layer precious metal net. The support net can only abut the lower or upper edges of the two layers of the precious metal net or the lower and upper edges. In such embodiments, the support net surrounds the two layers of the two-layer precious metal net on at least two sides.
Es kann vorteilhaft sein, dass das Stütznetz die beiden Lagen des zweilagigen Edelmetallnetzes an mehr als zwei Seiten umgibt. In bevorzugten Ausführungsformen umgibt das Stütznetz die Seiten der beiden Lagen des zweilagigen Edelmetallnetzes zu mindestens 50 %. Darunter ist zu verstehen, dass mindestens 50 % des Umfangs der beiden Lagen des zweilagigen Edelmetallnetzes vom Stütznetz umgeben sind, bevorzugter mindestens 60 %, noch bevorzugter mindestens 80 %. Besonders bevorzugt kann sein, dass das Stütznetz die beiden Lagen des zweilagigen Edelmetallnetzes vollständig umgibt.It can be advantageous for the support net to surround the two layers of the two-layer precious metal net on more than two sides. In preferred embodiments, the support net surrounds the sides of the two layers of the two-layer precious metal net by at least 50%. This means that at least 50% of the circumference of the two layers of the two-layer precious metal net is surrounded by the support net, more preferably at least 60%, even more preferably at least 80%. It can be particularly preferred for the support net to completely surround the two layers of the two-layer precious metal net.
Bevorzugt können alle Bereiche des Stütznetzes aus edelmetallfreien Stützfäden der gleichen Zusammensetzung gestrickt werden. Unterschiedliche Bereiche können aber auch aus edelmetallfreien Stützfäden unterschiedlicher Zusammensetzung gestrickt werden. Unterschiedliche Bereiche des Stütznetzes können in gleichen oder unterschiedlichen Strickmustern gestrickt werden.Preferably, all areas of the support net can be knitted from precious metal-free support threads of the same composition. However, different areas can also be knitted from precious metal-free support threads of different compositions. Different areas of the support net can be knitted in the same or different knitting patterns.
Das erfindungsgemäße Verfahren kann weitere Schritte umfassen.The method according to the invention may comprise further steps.
Das Verfahren kann das Bereitstellen von mindestens einem weiteren Draht oder Faden umfassen. Geeignete weitere Drähte oder Fäden können je nach vorgesehener Verwendung und/oder Funktion im Herstellverfahren oder für die spätere Anwendung des Edelmetallnetzes ausgewählt werden. Beispielsweise kann es sich bei dem weiteren Draht um einen Draht aus einem Nicht-Edelmetall handeln, der geeignet ist, um das Edelmetallnetz beim Einsatz im Reaktor zu stabilisieren, zum Beispiel kann es sich dabei um einen Stahl- oder Edelstahldraht handeln. Das Verfahren umfasst in diesen Fällen das simultane Stricken von Bereichen des Gestricks unter Verwendung des mindestens einen weiteren Drahtes oder Fadens. Das Gestrick kann in diesem Fall Teile oder Bereiche umfassen, die nur den weiteren Draht oder Faden enthalten oder Teile oder Bereiche, die sowohl den weiteren Draht oder Faden als auch den edelmetallhaltigen Draht enthalten oder Teile oder Bereiche, die sowohl den weiteren Draht oder Faden als auch den edelmetallfreien Stützfaden enthalten oder Teile oder Bereiche, die sowohl den weiteren Draht oder Faden als auch den edelmetallhaltigen Draht, als auch den edelmetallfreien Stützfaden enthalten.The method may comprise providing at least one additional wire or thread. Suitable additional wires or threads may be used depending on the intended use and/or function in the manufacturing process or for the subsequent application of the precious metal mesh. selected. For example, the additional wire can be a wire made of a non-noble metal that is suitable for stabilizing the precious metal mesh when used in the reactor, for example it can be a steel or stainless steel wire. In these cases, the method comprises the simultaneous knitting of regions of the knitted fabric using the at least one additional wire or thread. In this case, the knitted fabric can comprise parts or regions that contain only the additional wire or thread, or parts or regions that contain both the additional wire or thread and the precious metal-containing wire, or parts or regions that contain both the additional wire or thread and the precious metal-free support thread, or parts or regions that contain both the additional wire or thread and the precious metal-containing wire and the precious metal-free support thread.
Bevorzugt kann das Stütznetz in einem weiteren Schritt entfernt werden. Geeignete Verfahren sind dem Fachmann prinzipiell bekannt und sind von der Art des eingesetzten edelmetallfreien Stützfadens und dem edelmetallhaltigen Draht abhängig. Das Stütznetz kann zum Beispiel zersetzt, aufgelöst, geschmolzen, abgeflammt oder abgeschnitten werden.Preferably, the support net can be removed in a further step. Suitable methods are known in principle to the person skilled in the art and depend on the type of precious metal-free support thread used and the precious metal-containing wire. The support net can, for example, be decomposed, dissolved, melted, flamed or cut off.
In einem weiteren Schritt können auch eine verbindende Masche oder mehrere verbindende Maschen zwischen der ersten und zweiten Lage des zweilagigen Edelmetallnetzes an mindestens einer Seite entfernt werden, mit anderen Worten kann eine über die Randmaschen erfolgte Verbindung der beiden Lagen an zumindest einer Seite getrennt werden. Dadurch kann ein einlagiges Edelmetallnetz hergestellt werden, das nur noch an einer Seite, d.h. über jeweils nur eine Stoßkante, der beiden Lagen zumindest teilweise verbunden ist. Mit anderen Worten kann so ein einlagiges Edelmetallnetz erhalten werden.In a further step, a connecting mesh or several connecting meshes between the first and second layers of the two-layer precious metal net can be removed on at least one side, in other words, a connection between the two layers via the edge meshes can be separated on at least one side. This makes it possible to produce a single-layer precious metal net that is only partially connected on one side, i.e. via only one abutting edge of the two layers. In other words, this makes it possible to obtain a single-layer precious metal net.
Nachfolgend wird die Erfindung anhand von Abbildungen und einem Beispiel näher erläutert. Sie ist jedoch nicht auf diese Ausführungsformen beschränkt.
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Abbildung 1 -
Abbildung 2 -
Abbildung 3
-
illustration 1 -
Figure 2 shows schematically the thread guide of an exemplary forward row between the two needle beds of a flat knitting machine. -
Figure 3 shows embodiments of two-layer precious metal nets that can be produced using the method according to the invention on flatbed knitting machines with two needle beds.
Im erfindungsgemäßen Beispiel und im Vergleichsbeispiel wurde auf einer Flachstrickmaschine mit zwei Nadelbetten auf jedem Nadelbett mit einem PtRh5 Draht (76 µm Durchmesser) jeweils eine rechteckige Lage (100 cm Breite, 200 cm Länge) gestrickt, wobei die beiden Lagen auf einer Seite miteinander verbunden wurden. Als Stützfaden wurde ein Baumwollgarn eingesetzt. Im Vergleichsbeispiel wurde an beiden Lagen auf der nicht verbundenen Seite jeweils mit dem Baumwollgarn ein einlagiger Stütznetz-Bereich mitgestrickt. Auf den beiden Nadelbetten wurde also jeweils ein einlagiges Gestrick mit zwei Bereichen (Edelmetalllage und Stütznetz) gestrickt. Im erfindungsgemäßen Beispiel wurde auf der nicht verbundenen Seite der beiden Lagen ein einlagiges, über beide Nadelbetten gestricktes Stütznetz gestrickt. Die beiden Edelmetall-Lagen wurden also nur mit Maschen auf jeweils einem Nadelbett gestrickt, während das Stütznetz mit Maschen auf beiden Nadelbetten gestrickt wurde.In the example according to the invention and in the comparative example, a rectangular layer (100 cm wide, 200 cm long) was knitted on each needle bed on a flat knitting machine with two needle beds using a PtRh5 wire (76 µm diameter), with the two layers being connected to one another on one side. A cotton yarn was used as the support thread. In the comparative example, a single-layer support net area was knitted with the cotton yarn on the unconnected side of both layers. A single-layer knitted fabric with two areas (precious metal layer and support net) was therefore knitted on each of the two needle beds. In the example according to the invention, a single-layer support net knitted over both needle beds was knitted on the unconnected side of the two layers. The two precious metal layers were therefore only knitted with stitches on one needle bed each, while the support net was knitted with stitches on both needle beds.
Das Gestrick des erfindungsgemäßen Beispiels wies im Vergleich zum Gestrick des Vergleichsbeispiels eine gleichmäßigere Struktur auf. Solche Ungleichmäßigkeiten im Gestrick stellen potenziell mechanische Schwachstellen dar, die sich in der Anwendung des Netzes im Reaktor negativ auswirken.The knitted fabric of the example according to the invention had a more uniform structure than the knitted fabric of the comparative example. Such irregularities in the knitted fabric represent potential mechanical weak points that have a negative effect on the use of the mesh in the reactor.
- 11
- StrömungsreaktorFlow reactor
- 22
- KatalysatorsystemCatalyst system
- 33
- KatalysatorpackungCatalyst packing
- 44
- Catchment-NetzeCatchment nets
- 55
- StrömungsrichtungFlow direction
- 66
- einlagige Katalysatornetzesingle-layer catalyst nets
- 1010
- Erstes NadelbettFirst needle bed
- 1111
- Zweites NadelbettSecond needle bed
- 1212
- Faden / DrahtThread / Wire
- 100, 200, 300, 400, 500, 600, 700100, 200, 300, 400, 500, 600, 700
- EdelmetallnetzPrecious metal network
- 101, 201, 301, 401, 501, 601, 701101, 201, 301, 401, 501, 601, 701
- Erste Lage des EdelmetallnetzesFirst layer of the precious metal net
- 102102
- Zweite Lage des EdelmetallnetzesSecond layer of the precious metal net
- 110, 210, 310, 410, 510, 610, 710110, 210, 310, 410, 510, 610, 710
- Stoßkanten der ersten Lage des EdelmetallnetzesEdges of the first layer of the precious metal mesh
- 111, 211, 311, 411, 511, 611, 711 112, 113111, 211, 311, 411, 511, 611, 711 112, 113
- Stoßkanten der zweiten Lage des EdelmetallnetzesEdges of the second layer of the precious metal mesh
- 130, 230, 330, 430, 530, 630, 730130, 230, 330, 430, 530, 630, 730
- StütznetzSupport net
- 120, 220, 320, 420, 520, 620, 720120, 220, 320, 420, 520, 620, 720
- Stoßkante des StütznetzesEdge of the support net
- 121, 221, 321, 421, 521, 621, 721121, 221, 321, 421, 521, 621, 721
- Kante des StütznetzesEdge of the support net
- 231, 331, 431, 531, 731231, 331, 431, 531, 731
- Zweiter StütznetzbereichSecond support net area
- 432, 532432, 532
- Dritter StütznetzbereichThird support network area
- 433, 533433, 533
- Vierter StütznetzbereichFourth support network area
- 534534
- Lücke zwischen Edelmetallnetz und StütznetzGap between precious metal net and support net
Claims (14)
- A method for producing a two-layer noble metal mesh on a flat-bed knitting machine, the flat-bed knitting machine comprising a first and a second needle bed (10, 11), the method comprising the steps of- providing at least one noble-metal-containing wire (12),- providing at least one noble-metal-free support thread,- knitting a first layer (101, 201, 301, 401, 501, 601, 701) of the noble metal mesh on the first needle bed (10) and a second layer (102) of the noble metal mesh on the second needle bed (11),the first layer (101, 201, 301, 401, 501, 601, 701) comprising the abutting edges S11 and S12 (110, 210, 310, 410, 510, 610, 710) and the second layer (102) comprising the abutting edges S21 and S22 (111, 211, 311, 411, 511, 611, 711 112, 113), the abutting edge S11 at least partially abutting the abutting edge S21 and the abutting edge S12 at least partially abutting the abutting edge S22,- knitting a support mesh (130, 230, 330, 430, 530, 630, 730) on the first and second needle bed (10, 11) using the at least one noble-metal-free support thread, the support mesh (130, 230, 330, 430, 530, 630, 730) comprising an abutting edge SH (120, 220, 320, 420, 520, 620, 720) and an edge KH (121, 221, 321, 421, 521, 621, 721) opposite the abutting edge, the abutting edge SH (120, 220, 320, 420, 520, 620, 720) abutting an abutting edge S11 and S21 of each of the two layers of the noble metal mesh,all of the knitting processes taking place simultaneously,characterized in thatthe abutting edge SH (120, 220, 320, 420, 520, 620, 720) of the support mesh is connected to the respective abutting edges S11 and S21 of the two layers of the noble metal mesh via at least one knit stitch, and in that the support mesh is knitted with connecting stitches from both needle beds (10, 11) in the knitting rows on which the abutting edge SH (120, 220, 320, 420, 520, 620, 720) of the support mesh is connected to the respective abutting edges of the two layers of the noble metal mesh S11 and S21.
- The method according to claim 1, wherein the at least one noble-metal-containing wire consists of platinum, a platinum alloy, palladium, or a palladium alloy.
- The method according to either of the preceding claims, wherein the first and the second layer of the two-layer noble metal mesh are knitted from a noble-metal-containing wire or noble-metal-containing wires of the same composition.
- The method according to any of the preceding claims, wherein the first and the second layer of the noble metal mesh are knitted from a noble-metal-containing wire or noble-metal-containing wires of the same diameter.
- The method according to any of the preceding claims, wherein the first and the second layer of the noble metal mesh are knitted in the same knitting pattern.
- The method according to any of the preceding claims, wherein the first layer (101, 201, 301, 401, 501, 601, 701) and second layer (102) of the noble metal mesh are congruent.
- The method according to any of the preceding claims, wherein the first layer (101, 201, 301, 401, 501, 601, 701) and the second layer (102) of the two-layer noble metal mesh are at least partially connected at their abutting edges by at least one connecting knit stitch.
- The method according to any of the preceding claims, wherein the abutting edge SH of the support mesh (120, 220, 320, 420, 520, 620, 720) has the same length as the abutting edges S11 and S12 (110, 210, 310, 410, 510, 610, 710, 111, 211, 311, 411, 511, 611, 711, 112, 113) of the first and second layers (101, 201, 301, 401, 501, 601, 701, 102) of the two-layer noble metal mesh.
- Method according to any of the preceding claims, wherein the shape of the support mesh correlates with the shape of the first and second layers of the two-layer noble metal mesh.
- The method according to any of the preceding claims, wherein the abutting edge SH of the support mesh (120, 220, 320, 420, 520, 620, 720) is connected over its entire length to the respective abutting edges S11 and S21 (110, 210, 310, 410, 510, 610, 710, 111, 211, 311, 411, 511, 611, 711, 112, 113) of the first and second layers (101, 201, 301, 401, 501, 601, 701, 102) of the two-layer noble metal mesh.
- The method according to any of the preceding claims, wherein the support mesh surrounds at least 50% of the sides of the first and second layers (101, 201, 301, 401, 501, 601, 701, 102) of the two-layer noble metal mesh.
- The method according to the preceding claim, wherein the support mesh comprises a plurality of regions.
- The method according to the preceding claim, wherein the method comprises a further step in which the support mesh is removed.
- The method according to any of the preceding claims, wherein the method comprises a further step in which a connecting stitch or connecting stitches between the first and second layers of the noble metal mesh are removed on one side.
Priority Applications (3)
Application Number | Priority Date | Filing Date | Title |
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EP22152845.8A EP4215661B1 (en) | 2022-01-24 | 2022-01-24 | Method for the preparation of noble metal meshes on flat knitting machines |
PL22152845.8T PL4215661T3 (en) | 2022-01-24 | 2022-01-24 | Method for the preparation of noble metal meshes on flat knitting machines |
PCT/EP2022/080425 WO2023138806A1 (en) | 2022-01-24 | 2022-11-01 | Method for producing noble metal meshes on flatbed knitting machines |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
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EP22152845.8A EP4215661B1 (en) | 2022-01-24 | 2022-01-24 | Method for the preparation of noble metal meshes on flat knitting machines |
Publications (2)
Publication Number | Publication Date |
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EP4215661A1 EP4215661A1 (en) | 2023-07-26 |
EP4215661B1 true EP4215661B1 (en) | 2024-06-05 |
Family
ID=80001434
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
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EP22152845.8A Active EP4215661B1 (en) | 2022-01-24 | 2022-01-24 | Method for the preparation of noble metal meshes on flat knitting machines |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP4215661B1 (en) |
PL (1) | PL4215661T3 (en) |
WO (1) | WO2023138806A1 (en) |
Family Cites Families (5)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE68900928D1 (en) | 1988-10-12 | 1992-04-09 | Johnson Matthey Plc | METAL FABRIC. |
GB9016787D0 (en) | 1990-07-31 | 1990-09-12 | Heywood Alan E | Improvements in or relating to catalysts and getter systems |
EP1358010B2 (en) * | 2001-02-08 | 2008-07-23 | Umicore AG & Co. KG | Three-dimensional catalyst gauzes knitted in two layers |
EP3779005A1 (en) | 2019-08-16 | 2021-02-17 | Umicore Ag & Co. Kg | Knitting of precious metal nets with common material at the periphery, net from precious metal obtained thereby and a process using the precious metal net |
EP3795728A1 (en) | 2019-09-17 | 2021-03-24 | Umicore Ag & Co. Kg | Knitting of precious metal networks and a method using same |
-
2022
- 2022-01-24 EP EP22152845.8A patent/EP4215661B1/en active Active
- 2022-01-24 PL PL22152845.8T patent/PL4215661T3/en unknown
- 2022-11-01 WO PCT/EP2022/080425 patent/WO2023138806A1/en unknown
Also Published As
Publication number | Publication date |
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EP4215661A1 (en) | 2023-07-26 |
PL4215661T3 (en) | 2024-08-12 |
WO2023138806A1 (en) | 2023-07-27 |
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