DE102011001744A1 - Method for producing a fitting, fitting, household appliance and furniture - Google Patents

Abstract

A method for producing a fitting (1), in particular for household appliances, which has at least two interconnected components (2-11) and comprises the following steps: v) providing the components (2-11); in particular by punching and bending metal sheets (step 101) vi) assembling the components (3-11) to form a fitting (1); (Step 104) vii) coating the fitting (1) at least in sections by applying at least one coating (step 107); and viii) drying (step 108) and / or baking the coating (step 109); wherein an abrasive treatment of the surface (step 102, 114) takes place to set a surface roughness and at least one step of cleaning (step 103, 105, 115) of the surface to be coated takes place, which takes place before, during or after the treatment of the surface (step 102 , 114) is carried out, as well as a fitting and a household appliance.

Description

The present application relates to a method for producing a fitting, a fitting, a household appliance and a piece of furniture.

The EP 1 607 685 B1 discloses a method of manufacturing a telescopic drawer system which at least partially comprises a PTFE coating. This method assumes that a separate coating of the individual parts of the telescopic extension takes place and these are then assembled to the telescopic extension guide. The fitting parts must be transferred after punching and bending of the manufacturing plant to a coating plant, which is usually separated spatially from the manufacturing plant. For transport of the individual components, however, additional transport and storage capacities must be created in this process.

The DE 10 2009 044 340 A1 discloses that a component is smoothed prior to coating an inorganic-organic hybrid polymer layer. Smoothing is made possible by polishing, for example. The surface roughness continues to decrease.

It is now an object of the present invention to provide an alternative method for producing a fitting, which operates procedurally.

The invention achieves this object by a method having the features of claim 1 and a fitting having the features of claim 17.

• i) Bereitstellen der Bauteile; insbesondere durch Stanzen und Biegen von Metallblechen;
• ii) Montieren der Bauteile zu einem Beschlag;
• iii) Zumindest abschnittsweises Beschichten des Beschlags durch Aufbringen zumindest einer Beschichtung; und
• iv) Trocknen und/oder Einbrennen der Beschichtung, wobei vor dem Beschichten des Beschlags eine Behandlung der Oberfläche zur Einstellung einer Oberflächenrauhigkeit erfolgt und zumindest ein Schritt der Reinigung der zu beschichtenden Oberfläche erfolgt, welcher vor, während oder nach der Behandlung der Oberfläche durchgeführt wird.

According to the invention, a method for producing a fitting, which is composed of at least two interconnected components, comprises the following steps:

• i) providing the components; in particular by punching and bending metal sheets;
• ii) mounting the components to a fitting;
• iii) at least partially coating the fitting by applying at least one coating; and
• iv) drying and / or baking the coating, wherein before the coating of the coating, a treatment of the surface to adjust a surface roughness and at least one step of cleaning the surface to be coated, which is carried out before, during or after the treatment of the surface.

An improvement in the adhesion of the coating on the surface of a preassembled fitting can be made by a targeted adjustment of the surface roughness and thus at the same time allow the life of the fitting by prolonged protection against environmental influences.

A damage to the coating, as is possible in a mechanical assembly of coated components, is also advantageously avoided. Mounted fittings take up less space during transport and intermediate storage when transferring from a production plant to a coating plant, as individual components of a fitting. In addition, a faster production rate of fittings can be achieved.

Preferred embodiments are subject of the dependent claims.

It is advantageous if the surface to be coated of the assembled fitting is brought to a surface roughness by abrasive treatment. Depending on the coating composition and coating thickness, the surface roughness may be more or less pronounced. The abrasive treatment may u. a. by grinding, but more preferably by abrasive blasting.

Alternatively or additionally, the individual components, prior to their assembly to a fitting, can be treated abrasive. Burrs and other coarser bumps can thus be advantageously removed prior to assembly.

As an alternative or in addition to abrasive, ie material-removing, processes, the surface roughness can also be adjusted by applying at least one porous base coating to the mounted fitting and / or the fitting parts. The porous base coating advantageously causes the enlargement of the surface, to which the coating can be applied in the subsequent step. The Base coat can be applied both before and after assembly of the components, but should most preferably be done after the fitting has been assembled to avoid possible damage to the porous base coat during automatic assembly.

In one embodiment variant, at least one hard material coating is applied to the surface of the fitting as a porous basecoat. This hard coating as a primer coating provides additional protection of the surface against corrosion and scratches in addition to the coating applied thereon.

Another method for abrasive treatment can be carried out in an abrasive blasting with an inorganic and / or organic blasting material, since in this case the surface roughness can be controlled by the impact velocity of the blasting medium on the surface. The use of sand in a sandblasting process has proven to be cost effective, the blasting medium can be recycled after appropriate processing.

It is particularly advantageous if in a cleaning step, the removal of the blasting material is done by suction or rinsing, so that the fogging is not limited in its operation of remaining blasting material and the coating has no defects due to the inclusion of sand grains.

Alternatively or additionally, a further cleaning step after the surface treatment may include an alkaline cleaning and / or an ultrasonic cleaning, with firmly adhering dirt residues, oils or residual blasting material being removed from the surface. An alkaline cleaning can be carried out in particular after an etching step to adjust the surface roughness.

As a coating, a polymer, polymer derivative or a polymer mixture with a fluoropolymer, but especially a perfluoroalkoxyalkane (PFA) and / or polytetrafluoroethene (PTFE) may be selected to improve the anti-adhesion properties of the coating.

If the fitting is not exposed to increased soiling conditions, the fitting can be coated with a polyether ketone, in particular a polyetheretherketone (PEEK), which has a lower non-adhesive effect compared to fluoropolymers, but has a higher scratch resistance.

Alternatively or additionally, an inorganic-organic hybrid polymer layer can be applied as a coating on the surface of the fitting. Particular preference is given to silicon-containing organic compounds which, owing to their inorganic Si components, have a higher adhesive strength on the surface, in particular of metallic fittings, than the aforementioned fluorinated and polyether ketone polymers.

Synergy effects can also be advantageously achieved by combining the various properties of the polymers mentioned in a polymer mixture. It is particularly advantageous if the fluoropolymers, the polyether ketones and / or the inorganic-organic hybrid polymers are represented with a larger mass fraction compared to other components, such as dyes and the like, in the composition of a coating.

It is advantageous if the method is used for coating a drawer slide, which has a rail on which at least one further rail is movably supported by rolling elements, wherein the rolling elements are guided along tracks on the rails and before the abrasive treatment for adjustment the surface roughness is a masking of a part of the surface of the pullout guide to protect this surface of material removal and roughening.

In one embodiment of the method, the masking for the running surfaces of the pullout guide by covering the running surfaces, so as not to adversely affect the sliding properties of the rolling elements in the treads. At the same time, the coating can be removed very easily at this point due to the high mechanical stress in the sections of the running surfaces. With uncontrolled damage to a coating in a section, the removal of the coating can be disadvantageously accelerated, which is prevented by the protection of the raceways.

After the step of coating after drying and / or baking of the inorganic-organic hybrid polymer, an additional tempering of the coated coating takes place whereby organic constituents are at least partially oxidized so that a conversion and an associated additional curing of the hybrid polymer layer takes place. The annealing may be done in an oxygen-rich or oxygen-poor atmosphere where an oxygen-rich atmosphere of greater than 15% by mass has oxygen in the atmosphere and has an oxygen lean atmosphere of less than 15% oxygen in the atmosphere.

Here, the annealing in an oxygen-poor atmosphere, preferably in a nitrogen-rich atmosphere is preferred, since in this case an incomplete oxidation of the organic components of the hybrid polymer takes place, so that the surface coating is only partially cured and thereby can absorb shocks and shocks. Furthermore, better non-stick properties are achieved.

Higher scratch resistance is achieved by annealing in an oxygen-rich atmosphere at least 500 ° C, preferably about 650-750 ° C, whereby the hybrid polymer layer cures completely. The fully cured hybrid polymer layer is particularly suitable for use in ovens with pyrolysis function.

According to the invention, a fitting has a coating which has been produced by one of the methods described above. This fitting is resistant to corrosion and abrasive influences for a long time. He is also suitable for mass production.

According to the invention, a household appliance or furniture on this fitting. The fitting can be used in all household appliances. This includes u. a. Refrigerators, washing machines and in particular ovens. For use in ovens, a fitting must additionally be resistant to temperatures up to at least 250 ° C and also to the requirements of the FDA (food and drug administration) regulations for the contact of plastics with foodstuffs and REGULATION (EC) No. 1935/2004 OF THE EUROPEAN PARLIAMENT AND OF THE COUNCIL of 27 October 2004 on materials and articles intended to come into contact with foodstuffs, in order to be suitable for use in the food sector.

The invention is explained in more detail by several embodiments with reference to drawings. They show:

1 to 3 several views of an embodiment of a pullout guide produced by the method according to the invention.

4 and 5 a schematic flowchart and a flow chart of a first embodiment of a method according to the invention;

6 and 7 a schematic flowchart and a flowchart of a second embodiment;

8th and 9 a schematic flowchart and a flowchart of a third embodiment and

10 - 19 five schematic flow charts and five flow charts of other embodiments.

A pullout guide 1 includes a guide rail 2 , which can be fixed to a side rail in an oven, a side wall of a baking oven or a furniture body. At the guide rail 2 is a middle rail 3 over rolling elements 6 movably mounted. The middle rail 3 serves for the storage of a running rail 4 , For storage of the rails 2 . 3 and 4 are on the guide rail 2 and the running track 4 in each case at least two, in the exemplary embodiment, three raceways 9 for rolling elements 6 educated. The rolling elements 6 are on a Wälzkörperkäfig 7 kept as a unit. Furthermore, at the middle rail 3 a total of at least four careers, in the embodiment eight careers 8th for rolling elements 6 formed, each having at least two raceways 8th the guide rail 2 and at least two careers 8th the track 4 assigned.

For fastening the pullout guide 1 on a side rail of a oven are two brackets 5 on the guide rail 2 established. Other fastening means or attachment points can on the guide rail 2 be provided.

The pullout guide 1 is on the externally accessible area, ie on the outside of the guide rail 2 and the running track 4 with z. B. a PTFE-containing coating provided (polytetrafluoroethylene). One on the track 4 fixed end stop 10 is at its externally accessible areas also z. B. coated with a PTFE-containing coating. Also a retaining bolt 11 is z. B. equipped with a PTFE-containing coating. Also the brackets 5 are z. B. equipped with a PTFE-containing coating. The inside of the track 4 and the guide rail 2 on which the raceways 9 for the rolling elements 6 are formed, has no coating. Also the middle rail 3 completely inside the drawer slide 1 is arranged when the running rail 4 is arranged in the retracted position, has at least in the region of the raceways 8th no coating. This allows the raceways 8th through the material of the rails 2 . 3 and 4 be formed, mostly the careers 8th and 9 made of a bent sheet steel. On the outside is through the z. B. PTFE-containing coating on the rails 2 and 4 allows easy cleaning. This allows the pullout guide 1 be used particularly well in an oven, with a long life a high running quality is achieved. In the 1 to 3 is an over extension with three rails, 2 . 3 , and 4 shown. A version with at least three rails as a full extension is also conceivable. It is also possible, the pullout guide as a partial extension with only two rails (without the middle rail 3 ) or with more than three rails.

In addition to the PTFE-containing coating, the drawer guide can also have a PEEK-containing coating, a PFA-containing coating and / or an inorganic-organic hybrid polymer-containing coating.

The in the 1 - 3 The pullout guide shown is first assembled into a unit according to a first method according to the invention. In this case, both the assembly process and the coating process can be completely automated.

The 4 and 5 show the sequence of a first method according to the invention for producing a pullout guide 1 in the form of a full statement.

This takes place in a first step 101 the shaping or provision of the components 2 - 11 , This happens, for example, by punching and bending a metal strip.

This is followed by a step 102 in which a treatment of the surface for adjusting a surface roughness by abrasive blasting is performed. This setting can be specified by specifying one or more fixed parameters. This may preferably be the pressure with which the jet medium leaves a corresponding jet nozzle and / or the distance of the jet nozzle from the surface to be treated. The blasting medium is not dry snow or ice.

An abrasive treatment, so u. a. an abrasive blasting leads, for example, as opposed to a smoothing, to increase the surface roughness, u. a. the average and the maximum roughness depths compared to an untreated surface, whereby an overall roughened surface texture is created and at the same time, however, particularly protruding corners and ridges are removed.

The roughening of the surface improves the adhesion of the subsequently applied coating. The coating can "claw" into the created surface structure. The result is an intimate bond between the surface and the coating, thus reducing the risk that components of the coating will be released from the surface. The coating is more resistant to mechanical attack, such. B. by scouring pads or sharp objects.

In step 103 Cleaning takes place by removing the blasting material from the surface, in particular the rails 2 - 4 , This is preferably done by suction or blowing off the blasting material. Alternatively or additionally, the drawer slide can also be rinsed with a cleaning fluid.

In step 104 is a mounting of the individual components 2 - 11 to the pullout guide 1 carried out. This will be the individual components 2 - 11 put together and then limited by introducing notches or embossing in the rails in their travel.

Following this, the surface is moved in a further cleaning step of production residues in step 105 freed. This can preferably be done by a cleaning fluid. The cleaning in this step is preferably done by non-abrasive cleaning methods, so as not to change the surface roughness after the step 102 to effect. The non-abrasive cleaning methods include non-abrasive blasting, ultrasonic cleaning, plasma cleaning, laser cleaning, steam cleaning and dry cleaning. For example, the step 105 be carried out in an alkaline cleaning medium under the action of ultrasound. Furthermore, one or more rinses with demineralized water may be added until a neutral pH has been established.

Optionally, it may refer to the cleaning of the surface in step 105 a drying of the pullout guide 1 in step 106 connect. It can be controlled by a first decision stage A depending on the cleaning method, whether drying is necessary or not.

Following the cleaning after step 105 or drying after step 106 takes place in step 107 at least in sections, the coating of the drawer slide 1 , Any high-temperature-resistant plastic comes into consideration, but preferably PFA, PEEK and / or PTFE-containing mixtures. These solutions can be dispersed, for example, in a fluid, preferably water, and subsequently by painting or spraying onto the surface of the pullout guide 1 be applied.

Alternatively or additionally, an inorganic-organic hybrid polymer in a sol-gel process, at least partially on the surface of the pullout guide 1 be applied.

Alternatively, other application methods, depending on the type of applied plastics can be used. Thus, PEEK and PFA-containing mixtures can preferably be applied in a spraying process, in particular by plastic flame spraying.

The coating is completed in step 108 drying of the applied coating in which the fluid evaporates and only the dispersed plastic particles on the surface of the pullout guide 1 remain.

Depending on the type of applied coating and the application process, a step 109 a burning of the coating material into the surface of the pullout guide done. The baking is carried out at 250-500 ° C. The burn-in time is a few minutes to several hours, depending on the temperature. During firing in particular residual moisture is removed and formed a homogeneous polymer layer.

Following the firing takes place in step 110 Lubricating or applying lubricant to the pullout guide, wherein the lubricant for the use of the pullout guide in the oven area as well as the applied coating composition should be resistant to high temperatures up to a temperature of at least 250 ° C. Furthermore, the lubricant must be approved for the food industry.

Alternatively, the step 110 ie the application of lubricant, immediately after drying in step 108 respectively.

Alternatively, following the drying in step 108 a tempering in step 111 respectively. The annealing is preferably carried out at a temperature above 200 ° C. A temper after step 111 is particularly preferred when an inorganic-organic hybrid polymer is present as a coating. Annealing could be done, for example, by slow heating to the target temperature over 3 to 7 hours. The target temperature of, for example, 500 ° C is maintained for 30 to 120 minutes. This is followed by slow cooling to ambient temperature.

The annealing can in a first tempering step 111 be performed in a nitrogen atmosphere, wherein the coating is additionally compressed. By the annealing step in an oxygen-poor, nitrogen-rich atmosphere, the non-stick effect of the coated surface can be advantageously improved. Such a surface is also more elastic and can cushion shocks on the pullout guide.

Alternatively or additionally, annealing in an air atmosphere, with a mass fraction of about 20-25% O ₂ in the air, in a second annealing step 111b take place, wherein the coating at least is partially oxidized, which, in particular in an inorganic-organic hybrid polymer coating to a greater hardness and scratch resistance.

This scratch resistance can alternatively or additionally be increased by a third annealing step 111c in oxygen-rich atmosphere and with an O ₂ mass fraction greater than 25% in the air, preferably about 650-750 ° C takes place.

The treatment of the coated component after drying in step 108 can be controlled. For this purpose, a second decision stage B can be provided, which regulates a direct sequence of steps after drying. So can the steps 109 . 110 and 111 -C directly to the step 108 connect.

Alternatively, the second decision stage B can be automated, after drying after step 108 at least on the basis of a measurement parameter it is decided whether a burn-in or an annealing step is necessary.

In this case, preferably the layer thickness, the hardness and / or an interfacial tension can be determined as actual values and compared with predetermined desired values. If the actual values agree with the nominal values, the coated drawer guide can be used directly in step 110 be lubricated and then packaged. Otherwise, in particular in the case of inorganic-organic hybrid polymers, a tempering by one or more annealing steps 111 -C or, in the case of PEEK, PFA and PTFE, preferably afterburning 109 ,

In this case, the step sequence can be set by a third and a fourth decision stage C and D such that the oxygen supply and / or the temperature is increased gradually or continuously, so that the annealing first in oxygen-poor, nitrogen-rich atmosphere at about 500 ° C for several hours takes place and then carried out in an oxygen-rich atmosphere and / or 700 ° C for 10-30 minutes.

Alternatively, the third and fourth decision stages C and D can also be automated and carried out by determining at least one actual value and matching to a nominal value, preferably the hardness, the layer thickness or the interfacial tension. This is followed by a regulation of the transition from at least one oxygen-poor, nitrogen-rich annealing step 111 to one of the at least two oxygen-rich tempering steps 111b . 111c or the step of lubricating the pullout guide 110 , In addition, the decision levels B-D can also regulate the time span of each tempering step.

Subsequently, in a further step 112 a quality control of the pullout management 1 , Alternatively, in the quality control, parameters can be determined which are used to control the tempering and baking steps, in particular the temperature, the time period and the oxygen content during the baking or tempering of the coating of the drawer guide 1 can be used.

Subsequently, the pullout guide 1 packed and delivered.

The 6 and 7 show a method sequence, which differs from the preceding embodiment substantially in that the treatment of the surface roughness adjustment surface after step 102 at the pullout guide 1 done in the assembled state.

After the step 101 , ie the provision or shaping of the components 2 - 11 , takes place in step 104 the assembly of the pullout guide 1 ,

Since the setting of the surface roughness is preferably carried out with sand irradiation, isolated surfaces of the pullout guide are first masked after assembly. When masking after step 113 is a protective layer against the abrasive treatment preferably on the raceways 8th and 9 the pullout guide 1 , applied. This protective layer may, for example, have a wax-like consistency which at least dampens the speed of the blasting material before it impinges on the raceways or completely prevents the impact, so that removal of material from the surface of the raceways is no longer possible.

This is followed by the step 102 , That is, the adjustment of the surface roughness, on, wherein a roughening of the surface by abrasive blasting with a blasting material takes place. step 103 , relates to the removal of the blasting material from the surface and can be advantageous with step 105 , another cleaning step for Abrasion of production residues are combined. This is followed by the optional step 106 , drying the drawer slide, on.

The pullout guide 1 will now be in step 107 provided with a coating and then analogous to that in the 4 and 5 process further described.

The 8th and 9 describe an alternative method according to the invention, in particular for the pretreatment of the surface of the drawer slide 1 before the coating step 107 ,

It is initially analogous to the 6 and 7 in the process sequence of the steps 101 . 104 and 105 the shape of the individual components 2 - 11 the pullout guide 1 , the assembly of the pullout guide 1 and finally cleaning the pullout guide 1 , This process sequence is already carried out fully automatically for uncoated drawer slides.

Following the cleaning can be an optional drying after step 106 the pullout guide 1 respectively.

After cleaning after step 105 or drying after step 106 takes place in one step 114 coating the drawer slide with a porous base coat. This base coat increases the surface roughness. While in the 4 - 7 Material Abrasive or abrasive methods have been described in this method is a material order in advance, before the step 107 , the coating.

The porous base coating acts as a kind of adhesion promoter between the actual coating, which is applied in the connection and the mostly metallic surface of the fitting. In the case of fluoropolymers in particular, such a porous basecoat has proved to be particularly advantageous and improves the adhesion, in particular of PTFE.

The base coat can advantageously be designed as a hard coat so that, in addition to increasing the surface roughness of the coat, it also increases the scratch resistance. As porous hard coatings are, for example, silicon carbide or silicon nitride. They form a suitable basecoat for an inorganic-organic hybrid polymer coating because the inorganic-organic hybrid polymer is based on a silicon-oxygen framework.

After applying the base coat after step 114 Optionally, a cleaning step 115 the surface of the pullout guide 1 , This can preferably be done by a cleaning fluid. If this is the case, so may at the cleaning step 115 optionally a step of drying the surface 116 connect.

One determines the cleaning step 115 downstream sixth decision stage F the residual moisture of the surface and guides the pullout guide 1 following either a drying plant to or directly another coating plant, which in step 107 apply the actual coating to the surface of the pullout guide.

Depending on your needs, the cleaning step 115 or directly the coating 107 where a fifth decision stage E regulates which of the two method steps after the application of the base coating, ie after step 114 , should be carried out.

To the coating of the pullout guide in step 107 close further process steps 108 - 112 which analogous to the embodiment in the 4 and 5 can be performed.

Alternatively to that in the 8th and 9 also described before applying a base coat in step 114 a surface roughness can be preset by abrasive treatment. This advantageously increases the adhesion of the base coat.

According to a further preferred embodiment, a measurement of the surface roughness is carried out after the surface treatment after step 102 and or 114 , If the surface roughness proves to be insufficient, the process step of the surface treatment, in particular the abrasive blasting, should be repeated.

This measurement of the surface roughness can be carried out particularly preferably in a continuous production process by means of a laser measurement.

The 10 and 11 show a method sequence, which differs from the preceding embodiment, explained with reference to FIG 4 , Essentially differs in that instead of roughening the surface by abrasive blasting, an editing of the surface by brushing 117 takes place, wherein larger unevenness of the surface are removed and a surface can be produced with a maximum surface roughness of preferably less than 7 microns.

The surface treatment by brushing requires the cleaning step during the treatment of the surface. Unlike sandblasting, there are no foreign substances or residues such. B. blasting agent on the surface back. An additional wet-chemical cleaning of the surface may preferably take place in addition to the brushing.

The surface treatment, in particular by brushing, improves the adhesion of the coating on the surface to an untreated surface of the same material.

The brushing 117 takes place preferably by machining by means of rotating brushes from three sides, preferably by metal brushes whose contact pressure on the surface is individually adjustable. The shape of the brushes is preferably concave in order to achieve, for example, corner regions of a rail profile. Continue in step 101 , The molding, but no punching, so that an endless profile is formed, which in a later processing step, not shown, before assembly 104 the components of the pullout guide is separated.

The brushing is carried out with a brushing machine, in which one or more brushing stations are arranged, wherein each brushing station preferably a total of three brushes are used.

The brushing is preferably carried out on the outer surfaces of the rails of a pullout guide, ie on the surfaces that are perceived by the viewer of the respective rail in a pullout guide in the retracted state.

In this case, an endless profile is guided in the feed direction by the brush station. In a brush arrangement of the brush station, two brushes face each other and allow the surface treatment of opposite lateral outer surfaces of the endless profile. For example, the brushes each carry out a first linear movement towards the endless profile. A third brush for processing an upper side of the endless profile performs a second linear movement, preferably perpendicular to the plane of the first linear movements and the feed direction.

The brushes are arranged on a common linear slide, which has a defined travel. The movement of the linear slide takes place for example via a servo motor, wherein the contact pressure of each brush is individually adjustable. It can also be arranged on a linear slide several Bürstanordnungen.

To form a uniform profile on all sides of the endless profile, the speed of the brushes via frequency converter is adjustable. The brushes are operated by a separate drive.

By brushing 117 becomes at least "matt gloss" according to DIN 67530 guaranteed on the surface.

During brushing, the profile is freed from longitudinal grooves, which may already be present in the starting material and are difficult to remove by means known from the prior art.

Alternatively, the surface is treated by ultrasound 118 cleaned, leaving a liquid medium on the surface of the component 2 - 11 is applied and then transmitted by an ultrasonic generator using a sonotrode ultrasonic waves to the liquid medium. These ultrasonic waves lead in the liquid medium to the formation and implosion of gas bubbles due to cavity effects, whereby adhering contaminants are removed from the surface of the component.

In a particularly preferred embodiment of a cleaning by brushing the feed rate of the profile or the component is twice as much as the feed rate of the brush.

By treating with ultrasound 118 can be achieved a high gloss without brushing and at least matt finish with brushes on the surface.

Treating with ultrasound 118 and the brushing 117 is made in a particularly preferred embodiment of an endless profile, wherein the separation of the continuous profile to components of a drawer guide - not shown here - following the treatment with ultrasound 118 he follows.

This embodiment variant is particularly advantageous because the guidance of an endless profile in a production plant in the production process is particularly easy.

The cleaning process in the ultrasound station can be controlled by determining the profile gloss level. This is done by controlling the feed rate of the profile and the vibration amplitudes.

The degree of soiling, another criterion for the quality of the cleaning process, can then be determined by a wipe test.

A white cloth is rubbed over the profile surface and the degree of contamination is determined visually. In this case, the cloth in the present case on no perceptible dirt.

A 96 hour salt spray test demonstrated improved corrosion resistance, in particular surface corrosion resistance, over untreated profiles. An assessment was carried out after 16 h, 24 h, 72 h and 96 h.

Since it is already pre-cleaned, preferably high-gloss components in the assembly of the components for the pullout guide, is an additional cleaning 105 , as in 12 and 13 shown, also only optional. According to decision stage G, as an alternative to cleaning 105 and for optional drying 106 also an immediate coating 107 take place, preferably if no chips or other contaminants on the surfaces of the components can be found during assembly or in the separation of the components, not shown.

In the case of a transparent coating, the metallic luster of the profile is advantageously retained.

In the 14 and 15 are shown different ways of processing components of a drawer slide. The rails go through a pullout guide, so the track 4 , Guide rail 2 and possibly a middle rail 2 , a surface treatment in the form of brushes and ultrasonic cleaning for the at least partial production of high-gloss surfaces.

In other components of the drawer guide, in particular a stop, a clamp and / or a rolling element takes place after molding 119 roughening the surface by abrasive blasting 120 with a blasting medium.

After mounting the pullout guide, impurities remaining on the surface and the tracks of the pullout guide are detected at decision stage G and, if present, cleaning 105 carried out, to which an optional drying 106 followed. If the surface and the tracks of the pullout guide are free of contamination, a coating step takes place 107 and a subsequent procedure analogous to 4 ,

16 and 17 show a process flow in which the surfaces of rails of a pullout guide after molding 101 either by brushing 117 or by abrasive blasting 102 to be edited.

In a decision step H, the surface roughness is measured in a further variant of the method and subsequently a method of surface treatment is determined as a function of the degree of the measured surface roughness. Following the brushing 117 or the abrasive irradiation 102 is through an ultrasonic cleaning 118 a high-gloss surface free of grease, oil or other deposits created.

In an alternative embodiment, the rails of the drawer slide directly after the shaping 101 isolated and together with other components by assembly 104 assembled to a pullout guide.

Other components of the pullout guide are analogous to 14 by abrasive blasting 120 surface treated and in step 104 mounted to a pullout guide. The subsequent procedure is analogous to 4 ,

This in 18 and 19 The method illustrated differs from the method in 16 and 17 essentially in that instead of treating the surface with ultrasound 118 , or cleaning by cavity effects, a cleaning by plasma irradiation 121 is provided.

As a result, the surface is also freed of impurities.

In a further preferred embodiment, the rails 2 - 4 the pullout guide 1 , in particular the guide rail 2 and the track 4 and optionally the middle rail 3 , at least in sections, a brushed surface before coating. The texture of the surface has a main orientation direction, in the longitudinal direction of the rails, and consists of a plurality of grooves with a low penetration depth of preferably less than 7 microns in the surface which have Einzelorientierungsrichtungen. The average of the individual orientation directions or the direction vectors of the grooves specifies the main orientation direction of the texture or the surface structure. The pullout guide is matt glossy. The dispersion of the average roughness of the metallic surface after brushing against a non-brushed surface is reduced. Preferably, the variation of the average surface roughness of the metallic surface is less than half that of a non-brushed surface. The scattering of the average roughness value is an indication of whether a surface with homogeneous roughness is present or whether a surface has unevennesses. An uneven surface may have, for example, grooves and stress cracks of a maximum roughness depth of greater than 7 μm. The brushed surface extends at least over the entire outer surface of the respective rail, ie the area which for the end user in a pullout guide 1 is visible in the installed state.

In addition to the measurement of the average roughness Ra, it is also possible to determine the average roughness depth Rz and the maximum roughness depth Rmax in order to obtain more information on the roughness of the surface. Hereinafter, stainless steel sheets subjected to an abrasive surface treatment for surface roughening treatment and an untreated stainless steel sheet are compared. The maximum roughness depth and the average roughness depth for the roughened metal sheet and the untreated metal sheet were determined.

In the present case, the abrasive treatment was carried out by a brushing process. The metallic surface of the fitting is guided past a brushing station. The brushing station has brushes, which are filled with special abrasive bristles. As grinding bristles abrasive bristles are referred to as a brushing material for brushes for finishing. The bristle material may consist of nylon, for example. The abrasive used is preferably silicon carbide, aluminum oxide, chromium oxide, diamond and / or zirconium. The abrasive effect results from the hard and sharp tips of the abrasive material trapped in the brush material (eg, nylon). In the machining of workpieces is always released by the wear of the brush material, a certain amount of the abrasive.

The parameters 80, 120, 240 and 2000 therefore correspond to the grain of the abrasive bristles, the respective Bürstenbesatzes with which the surface of a fitting was roughened by abrasive treatment. The term "series" indicates the surface roughness of an untreated fitting. The term "ultrasound" reproduces the measured maximum roughness and the average roughness as a parameter of the surface roughness of a surface of a fitting cleaned with ultrasound.

In the case of the 120 grit, the series and the ultrasound measurements, the measurements were carried out on three fittings each, a triple measurement being made on each of the three different fittings. For each measured value, a total of nine measurements were carried out.

In the case of the 80, 240 and 2000 grit, a total of six measurements were carried out on one and the same fitting. The measured values in the table below were determined using stainless steel of the alloy 1.4301 (WNr.1.4301 (X5CrNi18-10), AISI 304 (V2A) ). Stainless steel 1.4301 Rmax [μm] Rz [μm] 120 scattering 0.68 0.47 Average 4.03 3.26 2000 scattering 0.47 0.31 Average 3.99 3.08 240 scattering 0.44 0.28 Average 4.02 3.33 80 scattering 0.73 0.23 Average 5.12 3.93 series scattering 0.62 0.20 Average 2.54 1.60 Ultrasonic scattering 1.55 0.41 Average 3.21 1.42

The measurements in the following table were made using stainless steel alloy 1.4016 (WNr 1.4016 (X6Cr17), AISI 430 ). Stainless steel 1.4016 Rmax [μm] Rz [μm] series scattering 1.61 0.62 Average 8.72 7.22

Based on the measured values, it can be seen that roughening of the surface has taken place as a result of the abrasive treatment, here by brushing. The surface roughness was measured with a HOMMEL TESTER T1000.

In a preferred embodiment of the invention, the average roughness depth R _{z of} the fitting after the abrasive treatment of the surface is greater than 1.85 μm; preferably greater than 2.0 microns, more preferably greater than 2.7 microns.

The mean value of the average roughness depth Rz of the fitting from at least six measurements is preferably 3.0-4.0 μm.

The mean value of the maximum roughness depth Rmax of the fitting from at least six measurements is preferably greater than 3.3 μm, preferably greater than 3.5 μm. Particularly preferably, the average value of the maximum roughness depth Rmax from at least six measurements is 3.8-5.2 μm.

Despite the measured values of the average roughness depth and the maximum roughness depth, which are increased relative to the surface of an untreated fitting, the average roughness value is preferably between 0.43-0.49 μm. This makes it possible to close an evenly roughened surface with a simultaneous increase in surface roughness.

In a preferred embodiment of the invention, the surface after the abrasive treatment therefore has an average roughness Ra of less than 2 μm, preferably less than 0.8 μm, particularly preferably less than 0.5 μm.

In a second embodiment, the outer surfaces of the pullout guide 1 a high-gloss surface. This is done by treating with ultrasound 118 reached. The average degree of gloss of the metallic surface is over 150, preferably over 200 at a 60 ° geometry and is based on the DIN 67530 carried out with a measuring device REFO 60 from Hach-Lange.

The table below describes the improved by the cleaning of the coated surface of the fitting gloss behavior of the fitting, which causes an improvement in the appearance of the fitting and at the same time provides a larger surface for applying the coating. Stainless steel 1.4301 Measurement series 1 Measurement series 2 series Average 117.5 118.4 120 Average 117.6 109.7 Ultrasonic Average 214.2 231.2

The average reported in the table is the determined gloss level of the surfaces before and after ultrasonic cleaning.

The measurement of the degree of gloss was carried out with a REFO 60 portable 600 angle reflector meter, wherein the measured gloss units after DIN 67530 be specified.

In a preferred embodiment of the invention, a metallic surface after the step of cleaning the surface to be coated according to claim 1 has a degree of gloss of at least 120, preferably at least 140, more preferably at least 190.

Cleaning of the surface is preferably carried out in a non-thermal cleaning process.

Measurement methods and definitions

Roughness Ra

The surface roughness reported in connection with this invention refers to the average roughness Ra [μm] DIN 4768 , The average roughness Ra is the arithmetic mean of the absolute amounts of the distances y of the roughness profile from the middle line within a measurement path. The roughness measurement is carried out with electrical stylus devices DIN 4772 ,

For measuring the average roughness Ra, the measurement conditions are DIN 4768 T1 established. The measurement was made across the texture of the surface.

The single roughness depth Zi is the distance between two parallels to a middle line, which touch the measured actual profile at the highest and the lowest point within a single measuring section.

The average roughness Az [μm] is the arithmetic mean of the single roughness depths Zi of five equidistant adjoining individual measuring sections.

The maximum roughness Rmax [μm] is the largest value of five individual roughness depths Z ₁ to Z ₅ .

corrosion monitoring

To monitor the nucleation process and the corrosion behavior, the electrochemical noise is monitored by electrochemical measuring equipment. Stainless steels are surrounded by a protective passive layer with a thickness of only approx. 1-20 nm, which can also be damaged if damaged. T. can regenerate itself. This layer is usually thinner than the wavelength of the visible light, so that it is imperceptible with conventional optical microscopes. The formation, damage and regeneration of the passive layer depends on the corrosion medium, the metal and the design. The design is determined by the surface roughness, the type of joining, constructive columns and the overall construction. The influence of the corrosion medium is determined by the concentration z. B. on corrosion promoting agents, such as chloride ions, the temperature and the flow rate of the corrosive agent determined. In the case of deviations from parameters such as the local oxygen concentration, the extent of possible microbes on the surface and the achievement of a critical temperature range, corrosion on stainless steels can take place. As a result of the shaping, it may possibly lead to damage of the passive layer by stress cracks and to a corrosion of the surface.

Here, dissolution processes and layer formation processes are confronted with the passive layer. Consequently, the passive layer is not a constant-thickness top layer but is subject to dynamic equilibrium.

If a liquid medium then settles on a metal surface, metal ions go into solution. The remaining excess of electrons and the potential change is detectable. Corrosion always forms in energetically preferred areas, eg. For example, local impurities or defects in the coating (scratches or debris pressed in during processing). These localized areas are usually only available for a short time, so that the passive layer can reproduce. In some cases, however, crevice corrosion or progressive pitting corrosion occurs.

The germs and corrosion areas are perceived as a fluctuating signal sequence, the so-called electrochemical noise, due to the potential changes. The cause of the electrochemical noise on passive metals are the activation and repassivation processes of the passive layer or the fluctuations in the charge caused thereby at the phase interface metal (passive layer) / electrolyte. Depending on the experimental setup, these charge fluctuations can be measured as current or potential noise. However, this method is used in the present case for quality control of the surface texture after cleaning the drawer runner by brushing, treating with ultrasound and / or treatment with plasma to ensure the quality of cleaning and the presence of a germ-free passive layer. Damage to the surface, as is necessary with other control methods, does not have to be done in this case. In addition, the smallest, visually barely perceptible nucleation sites can be detected and the corresponding purification process can be optimized to reduce the number of these germinal sites. Also, the occurrence of an increased concentration of compounds having chloride ions on the surface, for example, salt water splashes and the like are detectable in this way.

gloss

A medium gloss level indicates to what extent light is reflected when hitting the fitting. The degree of gloss is divided in metallic surfaces in high gloss, medium gloss and matt gloss and is based on the DIN 67530 Are defined. The gloss level is measured for different geometries (20 °, 60 °, 85 ° geometry). The determination of the gloss level is according to DIN 67530 a standardized measuring method. The measurements were based on the DIN 67530 carried out.

LIST OF REFERENCE NUMBERS

1

pull-out guide

2

guide rail

3

middle rail

4

runner

5

clip

6

rolling elements

7

Rolling Element

8th

raceways

9

raceways

10

attack

11

retaining bolt

101

Shaping the components

102

Adjustment of surface roughness by abrasive blasting

103

Removing the blasting material

104

Assembly

105

Clean

106

dry

107

coating

108

dry

109

branding

110

Lubricate

111

temper

111

first tempering step

111b

second annealing step

111c

third annealing step

112

Quality Control / Packaging

113

Mask

114

Apply a primer coat

115

Clean

116

dry

117

to brush

118

sonication

119

shape

120

Irradiate

121

plasma treatment

A

first decision stage

B

second decision stage

C

third decision stage

D

fourth decision stage

e

fifth decision stage

F

sixth decision stage

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 1607685 B1 [0002]
• DE 102009044340 A1 [0003]

Cited non-patent literature

• DIN 67530 [0093]
• AISI 304 (V2A) [0120]
• AISI 430 [0121]
• DIN 67530 [0128]
• DIN 67530 [0131]
• DIN 4768 [0134]
• DIN 4772 [0134]
• DIN 4768 T1 [0135]
• DIN 67530 [0143]
• DIN 67530 [0143]
• DIN 67530 [0143]

Claims (20)

Method for producing a fitting ( 1 ), in particular for household appliances, which comprises at least two interconnected components ( 2 - 11 ), comprising the following steps: i) providing the components ( 2 - 11 ); in particular by punching and bending metal sheets (step 101 ) ii) mounting the components ( 3 - 11 ) to a fitting ( 1 ); (Step 104 ) (iii) at least partial coating of the hardware ( 1 ) by applying at least one coating (step 107 ); and iv) drying (step 108 ) and / or baking the coating (step 109 ); whereby before coating the fitting ( 1 ) (Step 107 ) an abrasive treatment of the surface (step 102 . 114 . 117 . 120 ) for adjusting a surface roughness, and at least one step of cleaning (step 103 . 105 . 115 . 118 . 121 ) of the surface to be coated, which before, during or after the abrasive treatment of the surface (step 102 . 114 . 117 . 120 ) is carried out. A method according to claim 1, characterized in that the treatment of the surface (step 102 . 114 ) by abrasive treatment (step 102 ) of the assembled fitting ( 1 ) and / or the individual components ( 2 - 11 ) and / or by applying at least one porous base coat (step 114 ) on the assembled fitting ( 1 ) he follows. A method according to claim 2, characterized in that the porous base coating comprises at least one hard material coating. Method according to one of the preceding claims, characterized in that the abrasive treatment (step 102 ) is carried out by abrasive blasting with a mineral and / or organic blasting material. A method according to claim 4, characterized in that the cleaning of the components at least one step for removing the blasting material ( 103 ) by suction or rinsing. Method according to one of the preceding claims, characterized in that the cleaning (step 103 . 105 . 115 ) comprises a step of alkaline cleaning and / or ultrasonic cleaning. Method according to one of the preceding claims, characterized in that the coating contains a polymer, polymer derivative or a polymer mixture selected from a group consisting of a. Fluoropolymers, in particular perfluoroalkoxyalkanes and / or polytetrafluoroethene; b. Polyether ketones, in particular polyether ether ketones; and or c. inorganic-organic hybrid polymers. A method according to claim 7, characterized in that the coating contains for the majority of mass fraction compared to the other components of the coating, a polymer or polymer derivative selected from a group consisting of a. Fluoropolymers, in particular perfluoroalkoxyalkanes and / or polytetrafluoroethene; b. Polyether ketones, in particular polyether ether ketones; and or c. inorganic-organic hybrid polymers. Method according to one of the preceding claims, characterized in that the fitting ( 1 ) is a drawer slide, which is a rail ( 2 ), at which over rolling elements ( 6 ) at least one further rail ( 3 . 4 ) is movably mounted, wherein the rolling elements ( 6 ) along raceways ( 8th . 9 ) on the rails ( 2 . 3 . 4 ) and before the abrasive treatment for adjusting the surface roughness (step 102 ) masking a portion of the surface (step 113 ) of the pullout guide. Method according to claim 9, characterized in that the masking on the running surfaces ( 8th . 9 ), by covering the running surfaces ( 8th . 9 ), preferably by applying a waxy substance. Method according to one of the preceding claims, characterized in that after drying (step 108 ) and / or burn in (step 109 ) of the inorganic-organic hybrid polymer, an additional annealing (step 111 ) of the coated hardware ( 1 ) he follows. A method according to claim 11, characterized in that the annealing (step 111 ) in an oxygen-lean atmosphere, preferably in a nitrogen-rich atmosphere (step 111 ), he follows. A method according to claim 11 or 12, characterized in that the annealing in an oxygen-rich atmosphere at least 500 ° C, preferably about 650-750 ° C (step 111c ), he follows. Method according to one of the preceding claims, characterized in that the cleaning by treatment with ultrasound ( 118 ) or plasma ( 120 ) he follows. Method according to one of the preceding claims, characterized in that a treatment of the surface by brushing ( 117 ) he follows. Method according to one of the preceding claims, characterized in that the brushing ( 117 ) takes place at least on the outer surfaces of the rails of a pullout guide. Method according to one of the preceding claims, characterized in that the average roughness depth R _{z of} the fitting after the abrasive treatment of the surface is greater than 1.85 μm, preferably greater than 2.0 μm. Fitting ( 1 ), in particular furniture fitting ( 1 ), characterized in that the fitting ( 1 ) has a coating and is produced by one of the preceding methods. Household appliance, in particular oven, characterized in that the household appliance a fitting ( 1 ) according to claim 17. Furniture, characterized in that the furniture is a fitting ( 1 ) according to claim 18.

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