Patent Application
20180245389
The present invention relates to a sliding screen sliding system, the sliding system comprising a slide bar having a sliding surface with low friction. Further, the invention relates to a sliding screen arrangement comprising such a sliding system.
Wardrobes having sliding doors are well-known in the art (cf. e.g. DE 298 13 478). Typically, the doors are arranged with supportive ball bearings, e.g. wheels rolling over a rail, at the upper end of the door and steering means, e.g. pins, at the lower. Ball bearings are working well, but suffer from being somewhat dust sensitive. Further, the start-stop resistance is very low if the doors are to be easily moveable; an inherent feature of ball bearings. At the end-positions, this may be partly overcome by providing resting end-positions provided with e.g. heads or recesses, for the wheels. However, this would not overcome the low start-stop resistance at intermediate positions. This type of problem is even more pronounced in heavier doors, such as glass doors that are used for patio doors and patio windows of glazed-in patios, and glass doors and glass windows of glazed-in balconies.
Sliding kitchen doors, being less heavy than wardrobe sliding doors, are typically not provided with ball bearings, but are mounted standing in a sliding groove, i.e. a linear plain bearing. For lighter doors this may work well, though the sliding resistance may be fairly high; especially at start. However, for heavier doors, e.g. wardrobe sliding doors, linear plain bearings typically provide too high sliding resistance for practical use; especially at start. Further, such linear plain bearings are sensitive to dust contamination affecting the sliding resistance very negatively.
Curtains represent another type of sliding screens. Also in this application there is a need for low sliding resistance, especially a low start resistance.
Given its simplicity, it would be desired to provide a linear slide bar with very low sliding friction for use in sliding screen sliding systems.
Consequently, the present invention seeks to mitigate, alleviate, eliminate or circumvent one or more of the above identified deficiencies and disadvantages in the art singly or in any combination by providing a sliding screen sliding system, comprising a linear slide bar having a slide surface coated with a lacquer comprising a resin, the lacquer in turn is at least partly coated with a lipophilic composition coating to provide a slide layer with lowered friction, and at least one sliding member. This provides for a low friction slide bar with efficient function in sliding screen systems. The linear slide bar and the sliding member are arranged in contact and the interface between the slide layer of the slide bar and the sliding member forms a linear plain bearing to allow for linear movement of the sliding member along the longitudinal axis of the linear slide bar. The sliding member is provided with a fastening arrangement adapted for connection to a sliding screen to allow for linear movement of the sliding screen along the longitudinal axis of the linear slide bar.
According to an aspect of the invention, the part of said sliding member to slide over the slide layer is configured as a blade extending in the sliding direction. The slide layer may arranged at a track, e.g. a groove or a hill, extending along the longitudinal axis of the slide bar. Presence of a track improves the control of the lateral position of the sliding member in relation to the slide bar when the sliding member slides along the slide bar.
According to an aspect of the invention, the slide bar may be an aluminum or steel bar. The slide surface may be lacquered by electrocoating or autodeposition in a bath containing the lacquer, or by electrostatic coating with a powder lacquer or by wet spraying with a liquid lacquer. At least the part of the sliding member being in contact with the slide layer may be made of a plastic. The slide bar may be a linear, preferably anodized, aluminum profile, having a surface layer onto which the lacquer has been applied. The thickness of the anodized oxide surface layer may be at least 5 micrometers, preferably at least 10 micrometers. The surface layer may be electrophoretically, such as anaphoretically, coated with an acrylic resin and subsequently heat cured to form the lacquer.
According to a preferred aspect, the lipophilic composition coating comprises compounds comprising C6 to C40, such as C8 to C30, or even C10 to C24, non-aromatic hydrocarbyl groups, such as alkenyl groups and/or alkyl groups, e.g. alkyl groups.
According to another aspect of the invention there is provided a sliding screen arrangement comprising the sliding system and a sliding screen. The sliding member is arranged to support the sliding screen to allow for linear movement of the sliding screen along the longitudinal axis of the linear slide bar. The sliding screen may be a sliding door or a sliding curtain.
According to another aspect of the invention there is provided an alternative sliding screen sliding system comprising at least one sliding member having a slide surface coated with a lacquer comprising a resin, wherein said lacquer in turn is at least partly coated with a lipophilic composition coating to provide a slide layer with lowered friction, and a linear slide bar. The linear slide bar and the sliding member are arranged in contact, whereby the interface between sliding member and the linear slide bar forms a linear plain bearing to allow for linear movement of the sliding member along the longitudinal axis of the linear slide bar. The sliding member is provided with a fastening arrangement adapted for connection to a sliding screen to allow for linear movement of the sliding screen along the longitudinal axis of the linear slide bar.
Further advantageous features of the invention are elaborated in embodiments disclosed herein. In addition, advantageous features of the invention are defined in the dependent claims.
The above and other aspects, features and advantages of which the invention is capable of will be apparent and elucidated from the following description of the present invention, reference being made to the accompanying drawings, in which
The present inventors have surprisingly found that coating a surface lacquered with a resin, for example an acrylic resin, with a lipophilic composition, such as for example sebum (natural or artificial), coconut oil, liquid paraffin, etc., provides a slide layer with extremely low friction (sliding resistance). The application of the lipophilic composition reduces the dynamic friction with as much as 75%. Further, and even more surprisingly, the effect is not temporarily, but seemingly permanent or at least very long-lasting. The need to replenish the lubricant may hence be dispensed with.
In experiments employing aluminum profiles having been anaphoretically coated with an acrylic resin subsequently heat cured to form a lacquer (cf. the Honny process, initially disclosed in GB 1,126,855), wherein the lacquer of the aluminum profiles was coated with sebum, the friction remained nearly the same after more than 70,000 test cycles of a sliding door being reciprocated along the profile. So many cycles by far exceed the expected number on lifetime cycles. Further, washing the coated aluminum profile with water/detergent, ethanol, and/or iso-propanol didn't affect the friction. Without being bond to any theory, it seems that the sebum coating provides an irreversibly bound lubricant coating on top of the lacquer comprising the acrylic resin. Further, the lacquer seems to be important in providing low friction.
According to an embodiment there is provided a sliding screen sliding system comprising a linear slide bar 10; 110; 210; 310 having a slide surface 14 coated with a lacquer 16 comprising a resin and at least one sliding member 20; 120; 220; 320. As illustrated in
As used herein, the phrase “sliding screen” is intended to mean plate like objects that may slide in a horizontal direction to permit or restrict access to and/or permit or restrict viewing of a certain area. Hence, the phrase “sliding screen” include, for example, sliding doors of wardrobes, sliding doors for cupboards, sliding doors for kitchen cupboards, sliding doors for glazed-in patios or balconies, sliding windows for glazed-in patios and balconies, sliding doors, with or without glass, that separate rooms in an apartment, house or office space, sliding curtains that cover windows or doors, sliding curtains that separate rooms or parts of rooms in an apartment, house or office space, etc.
By arranging the interface between slide layer 19 of the slide bar 10; 110; 210; 310 and the sliding member 20; 120; 220; 320 in sliding contact a linear plain bearing is provided as shown in
Such a low amount of the lipophilic composition coating 18 is needed, that the lipophilic composition may be applied to a sliding member 20; 120; 220; 320 rather than to the slide bar 10; 110; 210; 310. In sliding over the slide bar 10; 110; 210; 310, the lipophilic composition will be transferred to the slide bar 10; 110; 210; 310 to provide a lipophilic composition coating 18. Hence, the lipophilic composition coating 18 could be applied to the slide bar 10; 110; 210; 310, to the sliding member 20; 120; 220; 320, or both.
While the slide bar according to one preferred embodiment is an aluminum profile, preferably with an aluminum oxide layer, also other materials coated with a lacquer comprising a resin may be considered. In order to allow for long term use and to carry loads, the slide bar 10; 110; 210; 310 is typically made from a hard material, such as metal or glass. Especially, the surface of the slide bar 10; 110; 210; 310 should preferably be hard. The Vickers hardness of the material from which the slide bar 10; 110; 210; 310 is made, may be at least 50 MPa, more preferably at least 100 MPa, even more preferably at least 150 MPa, and most preferably at least 300 MPa. According to an embodiment, the slide bar 10; 110; 210; 310 is a metal bar, such as an aluminum bar or a steel bar. While it is preferred if an aluminum bar has an oxide layer, also a raw, i.e. not oxidized, lacquered aluminum bar may be used. It is however preferred if the surface of the aluminum bar is oxidized to provide the aluminum bar with a hard oxide surface layer.
The slide bar 10; 110; 210; 310 may be an aluminum bar. Further, the surface of the aluminum bar coated with the lacquer 16 may be an aluminum oxide layer. The thickness of such oxide layer may be at least 5 micrometers, more preferably at least 10 micrometers. Further, the thickness of the oxide layer may be less than 250 micrometers, such as less than 100 micrometers or less than 50 micrometers. As known in the art, the durability and hardness of the surface of aluminum profiles may be improved by oxidation due to the properties of aluminum oxide. The oxide layer initially provided by anodically oxidation is porous. While the pores may be closed by steam treatment, sealing via anaphoretically coating with an acrylic resin subsequently heat cured to form the lacquer, is even more effective in sealing the porous aluminum oxide layer: This method, firstly disclosed by Honny Chemicals Co. Ltd. (cf. GB 1,126,855), is often referred to as the Honny process.
Further, compared to plastic slide bars, a hard, stiff bar, such as aluminum or steel bar, may accept far more heavy loads and still provide low friction.
In addition, it has been found that a relatively high contact pressure in the contact between the slide bar 10; 110; 210; 310 and the sliding member 20; 120; 220; 320 reduces the friction. For this reason as well it is beneficial to make the slide bar 10; 110; 210; 310 from a hard material, such as aluminum or steel, since such materials can accept higher contact pressures, thereby reducing friction.
According to an embodiment, the low friction slide bar 10; 110; 210; 310 is a linear aluminum profile. Preferably, the linear aluminum profile is oxidized (e.g. anodized) in order to increase the hardness of the surface. The profile is typically anaphoretically coated with an acrylic resin subsequently heat cured, thereby providing a linear slide bar 10; 110; 210; 310 having lacquered slide surface 14. The aluminum profile may be anodized to obtain an anodized layer thickness of at least 5 micrometers, more preferably at least 10 micrometers, prior to application of the resin of the lacquer. Further, thickness of the anodized layer may be less than 250 micrometers, such as less than 100 micrometers or less than 50 micrometers. Such profiles may be obtained via the Honny process (cf above) or one of its derivatives. Typically, the Honny process is used to provide white, glossy profiles. However, neither the Honny process nor the present embodiments are limited to white profiles. The preferable feature is that the lacquer 16 is suitable for being coated with the lipophilic composition coating 18.
As known in the art, various resins, e.g. thermosetting resins, may be used to lacquer aluminum bars and other bars, i.e. to form a lacquer on aluminum bars and other bars, e.g. steel bars. The lacquer 16 comprises a resin. As known to the skilled person, a lacquer is a hard, thin coating. The resin of the lacquer 16 may for this application preferably comprise polar groups, such as hydroxyl groups, carboxylic acid groups, amide groups, cyano groups (nitrile groups), halide groups, sulfide groups, carbamate group, aldehyd groups, and/or ketone groups. Further may the resin of the lacquer 16 be a thermosetting resin.
Examples of resins for lacquering metal comprise acrylic resins and polyurethane resins. According to an embodiment, the resin is an acrylic resin, such as an acrylate resin, an acrylamide resin, a methacrylate resin, or a methyl metachrylate resin, and mixtures thereof. According to another embodiment, the resin is a polyurethane resin. The acrylic resin may be a thermosetting resin.
According to another embodiment, the resin of the lacquer 16 is selected from the group consisting of: acrylic resins, acrylate resins, acrylamide resins, methacrylate resins, methyl metachrylate resins, acrylonitrile resins, styrene-acrylonitrile resins, acrylonitrile styrene acrylate resins, reaction products or a mechanical mixture of alkyd resin and water-soluble melamine resin, reaction products or a mechanical mixture of a vinyl-modified unsaturated alkyd resin and a water-soluble melamine resin, and polymers and mixtures of one or several of these resins.
Further, the thermosetting resin may include the reaction product or a mechanical mixture of an alkyd resin and water-soluble melamine resin, or of a vinyl-modified unsaturated alkyd resin and a water-soluble melamine resin, the water-soluble melamine resin being obtained from hexamethylol melamine hexaalkylether. Vinyl modified unsaturated alkyd resins may be made by polymerization of a vinyl monomer with an alkyd resin composed of an unsaturated oil or fatty acid. As known to the skilled person, the term “vinyl monomer” relates to a monomer having a vinyl group (—CH═CH2) in the molecule, such as an acrylic ester, for example methyl acrylate and ethyl acrylate, a methacrylic ester, for example methyl methacrylate and hydroxyethyl methacrylate, an unsaturated, organic acid, for example acrylic acid and methacrylic acid, and styrene.
Processes for obtaining thermosetting acrylic resins are well-known to the skilled person. As an example, they may be obtained by heating and stirring a mixture consisting of organic solvents, such as methanol, ethylene glycol, monobutyl ether, and/or cyclohexanone, unsaturated organic acids, such as acrylic acid, methacrylic acid, and/or maleic anhydride, a cross-linking vinyl monomer (as defined above), such as methylol-acrylamide and/or methylol methacrylamide, a polymerizable vinyl monomer, such as styrene and/or acrylic acid ester, polymerization catalysts, such as benzoyl peroxides and/or lauroyl peroxides, and polymerization regulators, such as dodecyl mercaptan and/or carbon tetrachloride, to carry out polymerization, thereafter neutralizing the product with, for example, an aqueous solution of ammonia and/or triethylamine to make the resin soluble in water. Further, as known to the skilled person, thermosetting resins composed of alkyd resins and water-soluble melamine resin may be obtained from hexamethylol melamine hexaalkyl ether, may be obtained by mixing a water-soluble melamine resin at a temperature of from room temperature to 100° C. with an alkyd resin modified with a fatty acid, the alkyd resin having an acid value of from 10 to 80 and being obtained by heating a mixture consisting of (1) a saturated or unsaturated aliphatic acid, (2) ethylene glycol, glycerol, polyethylene glycol, other polyhydric alcohol or an epoxide, (3) adipic acid, sebacic acid, maleic anhydride or other polybasic acid or anhydride, and (4) a small quantity of cyclohexanone, toluene or other organic solvent. Thermosetting resins may also be obtained by mixing a water-soluble melamine resin and an alkyd resin from the ester exchange process, the resin being obtained by esterifying a mixture of dehydrated castor oil, an above-mentioned polyhydric alcohol and a small amount of an ester exchanging catalyst such as caustic potash, and thereafter esterifying also an above-mentioned polybasic acid or anhydride. As further known to the skilled person, thermosetting resins consisting of a modified acrylic resin and a water-soluble melamine resin, obtained from hexamethylol melamine hexaalkyl ether, may be obtained by polymerising by heating and stirring a mixture consisting of organic solvents, such as methanol, ethylene glycol, monobutyl ether and/or cyclohexanone, unsaturated acids, such as acrylic acid and/or methacrylic acid, a vinyl monomer (as hereinabove defined), such as styrene and/or acrylic acid ester, a cross-linking vinyl monomer, if necessary, such as methylol, is normally used. Good results may be obtained by using a concentration of resin of from 5 to 20% by weight and by regulating the voltage and the initial current density within a safe and economical range.
As known to the skilled person further resins for use in lacquering metal surfaces are known in the art. As an example, the resin of the lacquer may be selected from the group consisting of cationic epoxy electrocoat, epoxy and polyester resins, and polyester resins. Still further, lacquers adapted for autodeposition coating, such as Autophoretic™ coatings (e.g. Aquence™ Autophoretic® 866™ and BONDERITE® M-PP 930™, the latter being an epoxy-acrylic urethane) available from Henkel AG, DE, may also be used, especially in lacquering surfaces comprising iron.
The slide surface 14 may be lacquered by electrocoating involving dipping the slide member 10; 110; 210; 310 into a bath containing the lacquer and applying an electric field to deposit lacquer onto the slide member 10; 110; 210; 310 acting as one of the electrodes. Further, the lacquer may be provided in powder form or in liquid form. Both powder and liquid lacquers may be sprayed onto the slide surface 14 to coat it. For powder lacquers, electro static coating may be used. For liquid lacquers a wet spray application or application in a bath may be used. Further, liquid lacquers in a bath may apart from electrocoating be applied by autodeposition.
In order to provide low friction, the thickness of the lacquer should be as even as possible. Thus it may be preferred to apply the lacquer by an electrocoating process, e.g. anaphoretic coating (cf. the Honny method) or cataphoretic coating, providing very even coatings. There are two types of electrocoating, i.e. anodic and cathodic electrocoating. Whereas the anodic process was the first to be developed commercially, the cathodic process is nowadays more widely used. In the anodic process, a negatively charged material is deposited on the positively charged component constituting the anode. In the cathodic process, positively charged material is deposited on the negatively charged component constituting the cathode. In the art, cathodic electrocoating is also known as cathodic dip painting (CDP), cathodic dip coating, cataphoretic coating, cataphoresis and cathodic electrodeposition. Further, the electrocoating process may also be referred to by the trade names of the bath material used. Examples include Cathoguard (BASF), CorMax (Du Pont), Powercron (PPG) and Freiotherm (PPG). Further, also electrostatically coating by powder lacquers or autodeposition coating in a bath provide even coatings and may thus be used.
In lacquering steel surfaces, autodeposition may be used. As recognized by the skilled person, one of the important steps in autodeposition is the coating bath itself, where water-based paint emulsion at low solids (usually around 4-8% by weight) is combined with two other products. A “starter” solution of acidified ferric (Fe3+) fluoride initiates the coating reaction and an oxidizing product stabilizes the metal ions in the solution. The coating emulsion is stable in the presence of ferric ions, but unstable in the presence of ferrous ions (Fe2+). Therefore, if ferrous ions are liberated from the metal substrate, localized paint deposition will occur on the surface. Immersion of a component made from ferrous metal (e.g. steel) into an autodeposition bath causes the acidic environment to liberate ferrous ions, thereby causing the coating emulsion to be deposited, forming a mono-layer of paint particles. Henkel Adhesive Technologies (US)//Henkel AG & Co. KGaA (Germany) provides coatings under the trademark BONDERITE® for use in autodeposition.
As the lacquer 16 coated on the slide bar 10; 110; 210; 310 typically is more compressible than the material of the slide bar 10; 110; 210; 310 itself, and as load carrying sliding member will apply pressure on the lacquer 16 in sliding over the slide bar 10; 110; 210; 310, the thickness of the lacquer 16 preferably is to be kept thin to reduce compression of it. Compressing the lacquer 16 may negatively affect the sliding resistance; especially at the start of the sliding sequence, i.e. when the sliding member starts to move along the slide bar 10; 110; 210; 310 from a previous state of being at rest. According to an embodiment, the thickness of the lacquer 16 coated on the slide bar 10; 110; 210; 310 is thus 100 μm or less, preferably 75 μm or less, more preferably 50 μm or less. Further, the thickness of lacquer 16 coated on the slide bar 10; 110; 210; 310 may be 5 to 75 μm, such as 10 to 50 μm, or 15 to 40 μm. Layers of these thicknesses have been found to provide for efficient sliding behavior, also at the instance when the sliding member starts to move along the slide bar 10; 110; 210; 310.
Not only the low dynamic friction provided by the present linear slide bar, but also the low difference between the static and dynamic friction provided by the present linear slide bar is beneficial in terms of the sliding behavior.
In order to reduce the friction of the slide bar 10; 110; 210; 310, the slide bar 10; 110; 210; 310 is, at least partly, coated with a lipophilic composition coating 18 to provide a slide layer 19. Further, while various components may be present in the lipophilic composition coating 18 present on the lacquer 16, the composition typically comprises components with long carbon chains, e.g. carbon chains having a carbon atom length of C6 or more, such as C8 or more, or C12 or more. Thus, the lipophilic composition coating 18 may comprise compounds comprising C6 to C40, such as C8 to C30 or even C10 to C24, non-aromatic hydrocarbyl groups. Typical examples of such non-aromatic hydrocarbyl groups are alkenyl groups and alkyl groups, e.g. alkyl groups. Examples of compounds comprising such non-aromatic hydrocarbyl groups are:
As known to the skilled person and as recognized in IUPAC's gold book (International Union of Pure and Applied Chemistry, Compendium of Chemical Terminology—Gold Book, Version 2.3.3 of Feb. 2, 2014):
According to an embodiment, the lipophilic composition coating 18 present on the lacquer 16 comprises at least 1 wt. % such as at least 5 wt. %, 10 wt. %, 25 wt. %, 50 wt. %, 60 wt. %, 70 wt. %, 75 wt. %, 80 wt. %, 85 wt. % or 90 wt. % of compounds comprising C6 to C40, such as C8 to C30, alkyl groups. Thus, the lipophilic composition coating 18 may comprise least 1 wt. % such as at least 5 wt. %, 10 wt. %, 25 wt. %, 50 wt. %, 60 wt. %, 70 wt. %, 75 wt. %, 80 wt. %, 85 wt. % or at least 90 wt. % C6 to C40, such as C8 to C30, alkenes and/or alkanes, e.g. alkanes. Further, the lipophilic composition coating 18 present on the lacquer 16 may comprise least 1 wt. % such as at least 5 wt. %, 10 wt. %, 25 wt. %, 50 wt. %, 60 wt. %, 70 wt. %, 75 wt. %, 80 wt. %, 85 wt. % or at least 90 wt. % triglycerides and/or fatty acids (or alkyl esters thereof).
Whereas fatty acids have been found to improve the lubricating effect of mixtures of alkanes, such as liquid paraffin, they are less effective if used on their own. It is thus preferred if the lipophilic composition coating 18 present on the lacquer 16 is not only composed of fatty acids. The lipophilic composition present on the lacquer 16 may thus comprise less than 99 wt. % fatty acids, such as less than 95 wt. % fatty acids. However, lipophilic compositions essentially only comprising triglycerides, such as coco nut oil, provide very low friction and do thus represent a preferred lipophilic composition present on the lacquer 16.
According to an embodiment, the lipophilic composition coating 18 present on the lacquer 16 comprises at least 1 wt. % such as at least 5 wt. %, 10 wt. %, 25 wt. %, 50 wt. %, 60 wt. %, 70 wt. %, 75 wt. %, 80 wt. %, 85 wt. % or at least 90 wt. % of alkenes and/or alkanes, e.g. alkanes and 0.1 to 50 wt. %, such as 1 to 40 wt. % or 5 to 30 wt. % triglycerides and/or fatty acids.
According to another embodiment, the lipophilic composition coating 18 present on the lacquer 16 comprises at least 1 wt. % such as at least 5 wt. %, 10 wt. %, 25 wt. %, 50 wt. %, 60 wt. %, 75 wt. %, 80 wt. % or 90 wt. % in total of triglycerides and/or fatty acids and 0.1 to 95 wt. %, such as 1 to 90 wt. % or 5 to 60 wt. % alkenes and/or alkanes, e.g. alkanes.
As already mentioned, typical examples of compounds comprising C6 to C40 non-aromatic hydrocarbyl groups are tri-glycerides and fatty acids. According to an embodiment, the lipophilic composition coating 18 present on the lacquer 16 comprises triglycerides and/or fatty acids. The lipophilic composition coating 18 may thus comprises more than 25 wt. %, e.g. more than 50 wt. %, such as 50 to 100 wt. %, or 75 to 95 wt. %, in total of triglycerides and fatty acids. The triglycerides and/or fatty acids may either be used as the major component in the lipophilic composition coating 18 or as additives.
If to be used as a major component, the lipophilic composition present on the lacquer 16 coating may comprise more than 50 wt. %, such as 50 to 100 wt. %, or 75 to 95 wt. %, triglycerides, e.g. triglycerides to at least 90 wt. % composed of a glycerol residue and 3 residues of caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, and/or arachidic acid, such as 3 residues of lauric acid, myristic acid, palmitic acid, and/or stearic acid. According to an embodiment, the lipophilic composition coating 18 present on the lacquer 16 comprises coconut oil, such as at least 25 wt. % such as at least 50 wt. %, 60 wt. %, 70 wt. %, 75 wt. %, 80 wt. %, 85 wt. %, or at least 90 wt. % coconut oil. Coconut oil comprises triglycerides composed of fatty acids that are to a high degree saturated fatty acids. The coconut oil may be hydrogenated to various degrees to further reduce the amount of unsaturated fatty acids residues. Further, the lipophilic composition coating 18 present on the lacquer 16 may comprise more than 50 wt. %, such as 50 to 100 wt. %, or 75 to 95 wt. % fatty acids, e.g. caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, and/or arachidic acid, such as lauric acid, myristic acid, palmitic acid, and/or stearic acid. Furthermore, the lipophilic composition coating 18 present on the lacquer 16 may comprise more than 50 wt. %, such as 50 to 100 wt. %, or 75 to 95 wt. % alkyl esters of fatty acids, e.g. methyl or ethyl esters. The esterfied fatty acids may be caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, and/or arachidic acid, such as lauric acid, myristic acid, palmitic acid, and/or stearic acid.
If to be used as a minor additive, the lipophilic composition coating 18 present on the lacquer 16 may comprise 0.1 to 50 wt. %, such as 1 to 30 wt. % or 5 to 15 wt. %, triglycerides, e.g. triglycerides to at least 90% composed of a glycerol residue and 3 residues of caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, and/or arachidic acid, such as 3 residues of to at least 90% myristic acid, palmitic acid, and/or stearic acid. A preferred example of composition to be used to provide a lipophilic composition coating 18 comprising triglycerides is coconut oil. According to an embodiment, the lipophilic composition coating 18 present on the lacquer 16 comprises coconut oil, such as 0.1 to 50 wt. %, such as 1 to 30 wt. % or 5 to 15 wt. %, coconut oil. According to an embodiment, the lipophilic composition coating 18 present on the lacquer comprises at least 50 wt. % coconut oil, such as at least 60 wt. %, 70 wt. %, 75 wt. %, 80 wt. %, 85 wt. %, or at least 90 wt. % coconut oil. Coconut oil comprises triglycerides composed of fatty acids that are to a high degree saturated fatty acids. The coconut oil may be hydrogenated to various degrees to further reduce the amount of unsaturated fatty acids residues. Further, the lipophilic composition present on the lacquer 16 may comprise 0.1 to 50 wt. %, such as 1 to 30 wt. % or 5 to 15 wt. %, of fatty acids, e.g. caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, and/or arachidic acid, such as to at least 90% myristic acid, palmitic acid, and/or stearic acid. Furthermore, the lipophilic composition coating 18 present on the lacquer 16 may comprise 0.1 to 50 wt. %, such as 1 to 30 wt. % or 5 to 15 wt. %, of alkyl esters of fatty acids, e.g. methyl or ethyl esters. The esterfied fatty acids may be caproic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, stearic acid, and/or arachidic acid, such as to at least 90% myristic acid, palmitic acid, and/or stearic acid.
Both saturated and un-saturated compounds comprising C6 to C40 non-aromatic hydrocarbyl groups are well-known in the art. While both types of compounds will be efficient in reducing the sliding resistance, saturated compounds comprising C6 to C40 non-aromatic hydrocarbyl groups are deemed to be less sensitive to oxidative degradation. Thus, it may be preferred to use compounds comprising C6 to C40 non-aromatic hydrocarbyl groups being triglycerides composed of saturated fatty acids residues and/or saturated fatty acids in the composition. It may however not be necessary to use a 100% saturated fatty acids and/or triglycerides. As example, coconut oil is envisaged to have sufficient long term stability, though saturated fatty acids and/or triglycerides are preferred in terms of their long term stability.
As mentioned, the lipophilic composition coating 18 present on the lacquer 16 may comprises at least 1 wt. % C6 to C40 alkanes. As an example, the lipophilic composition coating 18 present on the lacquer 16 may thus comprise mineral oil, such as at least 1 wt. %, such as at least 5 wt. %, 10 wt. %, 25 wt. %, 50 wt. %, 60 wt. %, 70 wt. %, 75 wt. %, 80 wt. %, 85 wt. % or at least 90 wt. % mineral oil. Mineral oil is a colorless, odorless, light mixture of higher alkanes from a non-vegetable (mineral) source. Further, the lipophilic composition present on the lacquer 16 coating may comprise liquid paraffin, such as at least 1 wt. %, such as at least 5 wt. %, 10 wt. %, 25 wt. %, 50 wt. %, 60 wt. %, 70 wt. %, 75 wt. %, 80 wt. %, 85 wt. % or at least 90 wt. % liquid paraffin. Liquid paraffin, also known as paraffinum liquidum, is a very highly refined mineral oil used in cosmetics and for medical purposes. A preferred form is the one having CAS number 8012-95-1. Furthermore, the lipophilic composition coating 18 present on the lacquer 16 may comprise petroleum jelly (also known as petrolatum, white petrolatum, soft paraffin or multi-hydrocarbon), such as at least 1 wt. %, such as at least 5 wt. %, 10 wt. %, 25 wt. %, 50 wt. %, 60 wt. %, 70 wt. %, 75 wt. %, 80 wt. %, 85 wt. % or at least 90 wt. % petroleum jelly. Petroleum jelly is a semi-solid mixture of hydrocarbons (with carbon numbers mainly higher than 25). A preferred form is the one having CAS number 8009-03-8.
According to an embodiment the sliding system 101; 201, 301 comprises at least two sliding members 120, 120′; 220, 320. The interface between the slide layer of the slide bar 110; 210; 310 and each of the sliding members 120, 120′; 220; 320 forms a linear plain bearing to allow for linear movement of the sliding members 120, 120′; 220; 320 along the longitudinal axis of the linear slide bar 110; 210; 310. The sliding members 120, 120′; 220; 320 may be arranged to support a sliding screen 130; 230, 330 connected to the sliding members 120, 120′; 220; 320 to allow for linear movement of the sliding screen 130; 230; 330 along the longitudinal axis of the linear slide bar 110; 210; 310.
The slide layer 19 may be arranged at a track, e.g. a groove 11, 12; 111, 112, or a hill 211, extending along the longitudinal axis of the slide bar 10; 110; 210 to define a slide direction. Presence of a track improves the control of the lateral position of the sliding member 20; 120; 220 in relation to the slide bar when the sliding member slides along the slide bar 10; 110; 210.
According to an embodiment, the slide bar 10; 110 is provided with a groove 11; 111, as illustrated in
According to an embodiment, the slide bar 210 is provided with a hill 211, as illustrated in
Further, the part of the sliding member 20; 120; 220; 320 arranged in contact with the slide layer 19 may be configured as a blade 21; 121; 221; 321 extending in the sliding direction, as illustrated in
It was surprisingly found that decreasing the contact area at the interface between the slide bar 10; 110; 210; 310 and the sliding member 20; 120; 220; 320 reduced the friction, such as by configuring the part of the sliding member 20; 120; 220; 320 arranged in contact with the slide layer 19 as a blade 21; 121; 221; 321. Normally the risk for the bearing seizing typically increases with reduced contact area. In order to provide the sliding system 1; 101; 201; 301, the sliding member 20; 120; 220; 320 comprises at least one contact point in contact with the slide bar 10; 110; 210; 310 at the interface between the slide bar 10; 110; 210; 310 and the sliding member 20; 120; 220; 320. According to an embodiment, the contact area of each individual contact point is less than 3 mm2, such as less than 1.5 mm2, or less than 0.75 mm2. The slide member may further be provided with more than one contact point, such as 2, 3, or 4 contact points. If the sliding member is configured as having one or more blade(s) 21, 22, 23; 121, 123; 221; 321, 322, 323 extending in the sliding direction, then the edge of the blade represents an individual contact point.
It has been found that the friction becomes lower when the contact pressure between the sliding member and the slide bar is relatively high. The contact pressure is calculated by dividing the load carried by each individual contact point by the contact area of the contact point. For example, if the sliding door has a total weight of 8.5 kg this represents a total load of 83.3 N. The sliding door may be carried by two sliding members 20. Each sliding member 20 of the design illustrated in
In order to provide low friction, at least the part of the sliding member 20; 120; 220; 320 in contact with the slide layer is preferably made of a plastic comprising a polymer, such as a polymer comprising polar groups. Examples of such polar groups include hydroxyl groups, carboxylic acid groups, amide groups, halide groups, sulfide groups, cyano groups (nitrile groups), carbamate groups, aldehyde groups, and/or ketone groups
The polymer may be selected from the group consisting of polyoxymethylenes (POM), polyesters (e.g. thermoplastic polyesters, such as polyethylene terephthalate (PET), polytrimethylene terephthalate (PTT), polybutylene terephthalate (PBT), and polylactic acid (PLA), as well as bio-based thermoplastic polyesters, such as polyhydroxyalkanoates (PHA), polyhydroxybutyrate (PHB), and polyethylene furanoate (PEF)), polyamides (PA), polyvinyl chloride (PVC), polyphenylene sulfide (PPS), polyaryletherketone (PAEK; e.g. Polyether ether ketone (PEEK)), and Polytetrafluoroethylene (PTFE). Further, not only the part of the sliding member 20; 120; 220; 320 in contact with the slide layer may be made of a polymer, but the entire sliding member 20; 120; 220; 320 may be made of a polymer. Thus, the sliding member may be made, in its entirety, from a plastic comprising a polymer. As recognized by the skilled person, the plastic may further comprise other additives, such as fillers, colorants, and/or plasticizers. Further, the sliding member 20; 120; 220; 320 may be made from a composite comprising a polymer, such as one of the above listed polymers, filled with particles and/or fibers. The particles and/or fibers will increase the hardness, the stiffness, the creep resistance and elongation (compression) at yield of the sliding member 20. While not affecting the friction, presence of particles and/or fibers may affect the wear. Thus, use of particles and/or fibers in the plastic is less preferred.
According to an embodiment the linear slide bar 10; 110; 210 has two parallel slide layers, as illustrated in
In order to prevent rotation along the sliding axis, the sliding member 20; 320 is according to an embodiment, as shown in
According to an embodiment, wherein the linear slide bar 110 has two slide layers extending along the longitudinal axis of the slide bar 110, the sliding system 101 may be arranged to support two sliding doors 130, 130′ (cf.
According to an embodiment, the sliding member 20; 120; 320 is provided with two parallel blades 21, 23; 121, 123; 321, 323 arranged along the same longitudinal axis (cf.
In case the sliding system 1; 101; 201; 301 is to be used to support a sliding screen, e.g. a sliding door 30; 130; 230, or a sliding curtain 330, connected to the sliding member 20; 120; 220; 320, the sliding member 20; 120; 220; 320 may be provided with fastening arrangement(s) 28; 128; 328, e.g. holes, pins, etc., for connecting the sliding member 20; 120; 220; 320 to the sliding screen 30; 130; 230; 330.
As illustrated in
Further, the sliding system 1; 301 may be provided with more than one sliding member 20, 20′; 320 to be connected to a sliding door 30 (cf.
A further embodiment of the invention relates to a sliding door arrangement 2, such as a sliding door arrangement for a wardrobe. A schematic sliding door arrangement 2 is illustrated in
According to an embodiment, the sliding door 30; 130 is to be arranged hanging from the linear slide bar 10; 110. Embodiments according to which the sliding door 30; 130 is to be arranged hanging are illustrated in
In embodiments in which the sliding door 30;130 is to be arranged hanging from the linear slide bar 10; 110, the sliding door arrangement 2 may comprise a linear guide bar 40, illustrated in
According to another embodiment, a sliding door 230 is mounted standing on the linear slide bar 210. An example of the latter is illustrated in
Further, the part of the sliding member 220 arranged in contact with the slide layer is configured as a central blade 221 extending in the sliding direction and sliding on top of the hill 211. At each side of the central blade 221 there is a side blade 223 extending in the sliding direction and sliding on the sides of the hill 221. The side blades 223 act as side supports keeping the sliding member 220 in the correct position on the hill 211.
In embodiments in which the sliding door 230 is to be arranged standing on the linear slide bar 210, as described in
Smaller doors, such as kitchen cabinet doors, are examples of doors which may be standing on the linear slide bar 210, although also heavier doors, such as wardrobe doors and patio doors, may be arranged standing on the linear slide bar 210. Further, sliding doors 230 mounted standing on the linear slide bar 210, may not necessarily extend in the vertical plane, but may be slightly tilted with respect to the vertical plane, as is well-known for kitchen cabinet doors.
A further embodiment of the invention relates to a sliding curtain arrangement 302. A sliding curtain arrangement 302 is illustrated in
According to an embodiment, the sliding member 320, as illustrated in
Throughout herein, the slide layer has been described as arranged on the linear slide bar. According to an alternative embodiment illustrated in
Further, in such an embodiment, the linear slide bar 410 may be a plastic profile, whereas the sliding member 420 may be lacquered metal member, e.g. an aluminum or steel member.
In such an embodiment, previous aspects described herein in relation to the lacquered linear slide bar 10; 110; 210; 310, such as aspect of the lacquer and the lipophilic composition coating, respectively, are equally applicable to a lacquered sliding member 420. Similarly, previous aspects described herein in relation to the sliding member 20; 120; 220; 320, such as suitable materials for providing sliding member 20; 120; 220; 320, are equally applicable to a linear slide bar 410, such as a plastic profile. According to such an embodiment, the linear slide bar 410 may be a plastic profile provided with at least one ridge 421 extending along the longitudinal axis of the profile. The plastic profile may be provided with a sliding channel for the slide member 420 to slide in. At least one interior surface of the channel may be provided with a ridge 421 extending along the longitudinal axis of the channel. The plastic profile may be fitted inside a support member 450, such as a metal bar or rod, to enhance the mechanical strength of the plastic profile. The sliding system 401 is arranged in a manner such that the slide layer of the sliding member 420 engages with the ridges(s) 421 in sliding along the linear slide bar 410. Part of the sliding member 420 may be arranged to fit into the sliding channel and to engage with the ridge(s) 421 in sliding within the channel. This part may have a cross-section corresponding to, in general shape, not size, the cross-section of the channel excluding the ridge(s) 421. The plastic profile and its ridge(s) 421 may then serve to guide the sliding part 420.
Without further elaboration, it is believed that one skilled in the art may, using the preceding description, utilize the present invention to its fullest extent. The preceding preferred specific embodiments are, therefore, to be construed as merely illustrative and not limitative of the disclosure in any way whatsoever.
Although the present invention has been described above with reference to specific embodiments, it is not intended to be limited to the specific form set forth herein. Rather, the invention is limited only by the accompanying claims and, other embodiments than those specifically described above are equally possible within the scope of these appended claims, e.g. different embodiments than those described above.
In the claims, the term “comprises/comprising” does not exclude the presence of other elements or steps. Additionally, although individual features may be included in different claims, these may possibly advantageously be combined, and the inclusion of features in different claims does not imply that a combination of those features is not feasible and/or advantageous.
In addition, singular references do not exclude a plurality. The terms “a an”, “first”, “second” etc. do not preclude a plurality.
The following examples are mere examples and should by no means be interpreted to limit the scope of the invention, as the invention is limited only by the accompanying claims.
General
All chemicals were obtained from Sigma-Aldrich. In providing mixtures, e.g. palmitic acid 10 mass % in liquid paraffin, the two compounds (e.g. 3 g palmitic acid and 27 g liquid paraffin) were mixed under heating to melt the mixture. Further, the mixtures were applied to the slide bar before solidifying.
The test procedure used was based on SS-EN 14882:205. In short, a sled with parallel plastic blades (four in total; two along each longitudinal slide axis) of POM was positioned on an anodized aluminum profile (cf.
By using the test procedure described above, the resulting friction from application of various lipophilic compositions to anodized, lacquered aluminum profiles was determined. The resulting dynamic friction, mean value from three test sequences, was registered and compared to the dynamic friction for anodized aluminum profiles provided with a lacquer but not coated with any lipophilic composition (=control). The results are provided in Table 1 and 2 below.
As can be seen from Table 1 and 2, the resulting dynamic friction was reduced by about 75% by applying a lipophilic compositions to the anodized aluminum profiles, though the initial dynamic friction of the un-coated anodized aluminum profiles was not that high. Furthermore, whereas the dynamic friction remained low and nearly the same for the coated profiles over repeated cycles, the dynamic friction for un-coated anodized aluminum profiles was significantly increased (seizing) already after less than 20 test cycles.
It can also be seen from the above tables 1 and 2 that the tests including fatty acids or triglycerides resulted in a somewhat lower friction compared to pure Liquid paraffin, in particular when the fatty acid is myristic acid or palmitic acid, and when the triglyceride is tripalmitate. Coconut oil, being a mixture of various triglycerides, in which lauric acid is the most common fatty acid residue, provided very low friction (cf. Table 3). Further, neither ageing nor washing (wiping by a wet cloth 6 times, followed by wiping 4 times with a dry cloth) had any significant effect on the dynamic friction.
By using the test procedure described above, the resulting friction at various loads (5, 10 and 20 N, respectively) using liquid paraffin as the lipophilic composition coating was determined. Increasing the load did not result in increased friction. On the contrary, the lowest load (5 N) displayed the highest friction (friction value 0.052 (at 5N) vs. friction value 0.045 (at 10 N)/0.046 (at 20 N)).
In an additional experiment, a corresponding aluminum bar, but without any lacquer, was used. Use of palmitic acid 10 mass % in liquid paraffin as lubricant on the non-lacquered bar resulted in a dynamic friction of 0.1132, i.e. more than 100% higher than corresponding dynamic friction obtained with the lacquered aluminum bar (cf. Table 1; 0.042 and 0.047, respectively).
In additional examples also steel profiles as well as other lacquers were evaluated.
Lacquers:
Teknotherm 4400 (Teknos)—wet spray lacquer, Standofleet® (Standox) wet spray lacquer, Powercron® 6200HE (PPG)—cationic epoxy electrocoat, Interpon AF (AkzoNobel)—powder coating, and Alesta® (Axalta)—powder coating.
Profiles:
Aluminium (Al), and steel (Fe)
As can be seen from Table 4, the aluminum profiles displayed lower friction than the steel profiles though also the steel profiles displayed a very low friction. Further, whereas some of the alternative lacquers displayed comparable or lower friction than the SAPA HM-white profiles (dynamic friction mean: 0.033), the wet lacquered profiles displayed slightly higher friction. Without being bond to any theory, this may be due to wet lacquered profiles inherently having somewhat thicker lacquer and/or varying thickness of the lacquer. Further, in comparing coconut oil and liquid paraffin (data not shown) it was seen that coconut oil generally provided somewhat lower friction.
Tests were also performed in a full-scale test rig using a wardrobe door with a weight of 8.5 kg and using two sliding members 20 and a slide bar 10 of the type described hereinabove with reference to
| Number | Date | Country | Kind |
|---|---|---|---|
| 1551138-9 | Sep 2015 | SE | national |
| 1651048-9 | Jul 2016 | SE | national |
| 1651049-7 | Jul 2016 | SE | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/EP2016/071059 | 9/7/2016 | WO | 00 |
