NZ631355B2 - Self-lubricating surfaces for food packaging and food processing equipment - Google Patents

Abstract

article having a liquid-impregnated surface. The surface includes a matrix of solid features (124) (e.g., non-toxic and/or edible features) spaced sufficiently close to stably contain a liquid (126) therebetween or therewithin, wherein the liquid is non-toxic and/or edible. The article may contain, for example, a food or other consumer product, such as ketchup, mustard, or mayonnaise. The resulting article is water repellent, providing less viscous drag. n, for example, a food or other consumer product, such as ketchup, mustard, or mayonnaise. The resulting article is water repellent, providing less viscous drag.

Description

SELF-LUBRICATING SURFACES FOR FOOD PACKAGING AND FOOD PROCESSING EQUIPMENT Cross-Reference to Related ation This application claims priority to and the benefit of, and incorporates herein by nce in its entirety, US. Provisional Patent ation No. 61/614,941, filed March 23, 2012, and US. Provisional Patent ation No. 61/651,545, filed May 24, 2012.

Technical Field This invention relates generally to non-wetting and self-lubricating surfaces for food and other consumer product packaging and processing equipment.

Background The advent of micro/nano-engineered surfaces in the last decade has opened up new techniques for enhancing a wide variety of physical ena in thermofiuids sciences. For e, the use of micro/nano surface textures has provided nonwetting surfaces capable of achieVing less Viscous drag, reduced adhesion to ice and other materials, self-cleaning, and water repellency. These improvements result generally from diminished contact (i.e., less wetting) between the solid surfaces and adjacent liquids.

There is a need for improved non-wetting and self-lubricating surfaces. A particular need exists for ed non-wetting and self-lubricating surfaces for food packaging and food processing equipment.

Summafl of the Invention In general, the invention relates to -impregnated surfaces for use in food packaging and food processing equipment. In some embodiments, the surfaces are used in containers or bottles for food products, such as ketchup, d, aise, and other products that are poured, squeezed, or otherwise extracted from the containers or bottles. The surfaces allow the food products to flow easily out of the containers or bottles. The surfaces described herein may also prevent leaching of als from the walls of a food ner or food sing equipment into the food, y enhancing the health and safety of consumers.

In one embodiment, the surfaces provide barriers to diffusion of water or oxygen, and/or protect the contained material (e.g., a food product) from ultraviolet radiation. Cost-efficient methods for fabricating these surfaces are described herein.

Containers having liquid encapsulated coatings bed herein demonstrate surprisingly effective food-emptying ties. The embodiments described herein are ularly useful for use with containers or processing equipment for foods or other consumer products that notoriously stick to the containers or processing equipment (e. g., containers and equipment that come into contact with such consumer products). For example, it has been found that the embodiments described herein are useful for use with consumer products that are non- Newtonian fluids, particularly Bingham plastics and thixotropic fluids. Other fluids for which embodiments described herein work well include high viscosity fluids, high zero shear rate viscosity fluids (shear-thinning fluids), thickening fluids, and fluids with high surface tension. Here, fluid can mean a solid or liquid (a substance that flows).

Bingham plastics (e.g., yield stress fluids) are fluids that require a finite yield stress before beginning to flow. These are more difficult to squeeze or pour out of a bottle or other 5306498v1 container. Examples of Bingham plastics e mayonnaise, mustard, chocolate, tomato paste, and toothpaste. Typically, Bingham plastics will not flow out of containers, even if held upside down (e.g., toothpaste will not flow out of the tube, even if held upside down). It has been found that embodiments described herein work well for use with Bingham plastics.

Thixotropic fluids are fluids with ities that depend on the time history of shear (and whose Viscosities decrease as shear is ually applied). In other words, ropic fluids must be agitated over time to begin to thin. Ketchup is an example of a thixotropic fluid, as is yogurt. ments described herein are found to work well with ropic fluids.

Embodiments described herein also work well with high Viscosity fluids (e.g., fluids with greater than 100 cP, greater than 5000P, greater than lOOOcP, greater than 3000 CR or greater than 5000 cP, for example). Embodiments also work well with high zero shear rate Viscosity materials (e.g., shear-thinning fluids) above 100 CR Embodiments also work well with high surface tension substances, which are relevant where substances are ned in very small bottles or tubes.

In one aspect, the invention is directed to an article including a liquid-impregnated surface, said surface including a matrix of solid features spaced sufficiently close to stably contain a liquid therebetween and/or therewithin, wherein the features and liquid are non-toxic and/or edible. In certain embodiments, the liquid is stably contained within the matrix regardless of ation of the article and/or under normal ng and/or handling conditions. In certain embodiments, the e is a container of a consumer product. In certain embodiments, the solid features include particles. In certain embodiments, the particles have an average teristic dimension in a range, for example, of about 5 microns to about 500 microns, or about 5 microns to about 200 microns, or about 10 microns to about 50 microns. In certain embodiments, the 5306498V1 characteristic dimension is a diameter (e.g., for roughly spherical particles), a length (e.g., for roughly aped particles), a thickness, a depth, or a height. In certain ments, the particles include insoluble fibers, purified wood cellulose, micro-crystalline cellulose, oat bran fiber, kaolinite (clay l), Japan wax (obtained from berries), pulp (spongy part of plant stems), ferric oxide, iron oxide, sodium formate, sodium oleate, sodium palmitate, sodium sulfate, wax, carnauba wax, beeswax, candelilla wax, zein (from corn), dextrin, cellulose ether, Hydroxyethyl ose, Hydroxypropyl cellulose (HPC), Hydroxyethyl methyl cellulose, Hydroxypropyl methyl cellulose (HPMC), and/or Ethyl hydroxyethyl ose. In certain embodiments, the particles e a wax. In certain embodiments, the particles are randomly spaced. In certain embodiments, the particles are arranged with average spacing of about 1 micron to about 500 s, or from about 5 microns to about 200 microns, or from about 10 microns to about 30 s between adjacent les or rs of particles. In certain embodiments, the particles are spray-deposited (e.g., deposited by aerosol or other spray ism). In certain embodiments, the consumer product comprises at least one member selected from the group consisting of ketchup, catsup, mustard, mayonnaise, syrup, honey, jelly, peanut butter, , chocolate syrup, shortening, butter, margarine, oleo, grease, dip, yogurt, sour cream, cosmetics, shampoo, lotion, hair gel, and toothpaste. In certain embodiments, a food product is sticky food (e.g., candy, chocolate syrup, mash, yeast mash, beer mash, taffy), food oil, fish oil, marshmallow, dough, batter, baked goods, chewing gum, bubble gum, butter, cheese, cream, cream cheese, mustard, yogurt, sour cream, curry, sauce, ajvar, currywurst sauce, salsa lizano, chutney, pebre, fish sauce, tzatziki, sriracha sauce, vegemite, chimichurri, HP brown sauce, harissa, kochujang, hoisan sauce, kim chi, cholula hot sauce, tartar sauce, tahini, hummus, shichimi, ketchup, Pasta sauce, Alfredo sauce, Spaghetti sauce, icing, dessert 5306498V1 toppings, or whipped cream. In certain embodiments, the container of the consumer product is shelf-stable when filled with the consumer product. In certain embodiments, the consumer product has a viscosity of at least about 100 cP at room temperature. In certain embodiments, the consumer product has a viscosity of at least about 1000 cP at room temperature. In certain embodiments, the consumer product is a non-Newtonian material. In certain embodiments, the er product comprises a Bingham plastic, a thixotropic fluid, and/or a shear-thickening substance. In certain ments, the liquid includes a food ve (e.g., ethyl oleate), fatty acids, ns, and/or a ble oil (e.g.,olive oil, light olive oil, corn oil, n oil, rapeseed oil, linseed oil, grapeseed oil, flaxseed oil, canola oil, peanut oil, safflower oil, sunflower oil). In certain ments, the article is a component of consumer product processing equipment. In certain ments, the article is a component of food processing equipment that comes into contact with food. In certain embodiments, the liquid-impregnated surface has solid-to-liquid ratio less than about 50 percent, or less than about 25 percent, or less than about 15 percent.

In another aspect, the invention is directed to a method of manufacturing a container of a consumer product, the method including the steps of: providing a substrate; applying a texture to the substrate, the texture comprising a matrix of solid features spaced ently close to stably contain a liquid therebetween and/or therewithin (e. g., for example, stably contained when the container is in any orientation, or undergoing normal shipping and/or handling conditions throughout the useful lifetime of the container); and impregnating the matrix of solid features with the , wherein the solid es and the liquid are non—toxic and/or edible. In n embodiments, the solid features are particles. In certain embodiments, the applying step includes spraying a mixture of a solid and a solvent onto the textured substrate. In certain embodiments, 5306498vl the solid insoluble fibers, purified wood cellulose, micro-crystalline cellulose, oat bran fiber, kaolinite (clay mineral), Japan wax (obtained from s), pulp (spongy part of plant stems), ferric oxide, iron oxide, sodium formate, sodium oleate, sodium palmitate, sodium sulfate, wax, ba wax, beeswax, illa wax, zein (from corn), dextrin, cellulose ether, Hydroxyethyl cellulose, Hydroxypropyl cellulose (HPC), Hydroxyethyl methyl cellulose, Hydroxypropyl methyl cellulose (HPMC), and/or Ethyl hydroxyethyl cellulose.. In certain embodiments, the method es the step of allowing the solvent to evaporate following the spraying of the mixture onto the textured substrate and before the impregnating step. In certain embodiments, the method es the step of contacting the impregnated matrix of features with a consumer product. In n embodiments, the consumer product is ketchup, catsup, d, mayonnaise, syrup, honey, jelly, peanut , butter, chocolate syrup, shortening, butter, margarine, oleo, grease, dip, yogurt, sour cream, cosmetics, shampoo, lotion, hair gel, or toothpaste. In certain embodiments, In certain embodiments, the consumer product is a sticky food (e.g., candy, chocolate syrup, mash, yeast mash, beer mash, taffy), food oil, fish oil, marshmallow, dough, batter, baked goods, chewing gum, bubble gum, butter, cheese, cream, cream cheese, mustard, yogurt, sour cream, curry, sauce, ajvar, currywurst sauce, salsa lizano, chutney, pebre, fish sauce, tzatziki, sriracha sauce, te, chimichurri, HP sauce/brown sauce, harissa, kochujang, hoisan sauce, kim chi, cholula hot sauce, tartar sauce, tahini, hummus, shichimi, p, Pasta sauce, Alfredo sauce, Spaghetti sauce, icing, dessert toppings, or whipped cream. In certain embodiments, the liquid includes a food additive ethyl ), fatty acids, proteins, and/or vegetable oil olive oil, light olive oil, corn oil, soybean oil, rapeseed oil, linseed oil, grapeseed oil, fiaxseed oil, canola oil, peanut oil, safflower oil, and/or sunflower oil). In certain embodiments, the step of applying the texture to the substrate includes: 5306498vl exposing the substrate to a solvent (e.g., solvent-induced crystallization), extruding or blow- molding a mixture of materials, roughening the substrate with mechanical action (e. g., tumbling with an abrasive), spray-coating, polymer ng, depositing particles from solution (e.g., layer-by-layer deposition and/or ating away liquid from a liquid and particle sion), extruding or blow-molding a foam or foam-forming al (e.g., a polyurethane foam), depositing a polymer from a on, extruding or blow-molding a material that expands upon cooling to leave a wrinkled or textured surface, applying a layer of material onto a surface that is under tension or compression, performing non-solvent induced phase separation of a polymer to obtain a porous structure, performing micro-contact printing, performing laser rastering, performing nucleation of the solid e out of vapor (e.g., desublimation), performing anodization, milling, machining, knurling, e-beam milling, performing thermal or chemical oxidation, and/or performing chemical vapor tion. In certain embodiments, applying the texture to the substrate includes spraying a mixture of edible particles onto the substrate. In certain embodiments, impregnating the matrix of features with the liquid includes: spraying the encapsulating liquid onto the matrix of features, brushing the liquid onto the matrix of features, ging the matrix of features in the liquid, spinning the matrix of features, condensing the liquid onto the matrix of features, depositing a solution comprising the liquid and one or more le liquids, and/or spreading the liquid over the surface with a second immiscible liquid. In certain embodiments, the liquid is mixed with a solvent and then sprayed, because the solvent will reduce the liquid viscosity, ng it to spray more easily and more uniformly. Then, the solvent will dry out of the coating. In certain embodiments, the method r includes chemically ing the substrate prior to applying the texture to the substrate and/or chemically modifying the solid features of the texture. For example, the method may include 5306498v1 chemically modifying with a material having contact angle with water of r than 70 degrees (e.g., hobic material). The modification may be conducted, for example, after the texture is applied, or may be applied to particles prior to their application to the substrate. In certain embodiments, impregnating the matrix of features includes removing excess liquid from the matrix of features. In certain embodiments, removing the excess liquid includes: using a second immiscible liquid to carry away the excess liquid, using mechanical action to remove the excess liquid, absorbing the excess liquid using a porous al, and/or draining the excess liquid off of the matrix of features using gravity or centrifugal forces.

Elements of embodiments described with respect to a given aspect of the invention may be used in various embodiments of another aspect of the invention. For example, it is contemplated that features of dependent claims depending from one independent claim can be used in apparatus and/or s of any of the other independent claims.

Brief Description of the Drawings The objects and features of the invention can be better understood with reference to the drawings described below, and the claims.

FIG. la is a schematic cross-sectional View of a liquid ting a non-wetting surface, in accordance with certain embodiments of the invention.

FIG. lb is a schematic sectional View of a liquid that has impaled a non-wetting surface, in accordance with certain ments ofthe invention. is a schematic cross-sectional View of a liquid in contact with a liquid- nated e, in accordance with certain embodiments of the invention. 5306498V1 2012/042326 is an SEM (Scanning Electron Microscope) image of a typical rough surface obtained by spraying an emulsion of ethanol and carnauba wax onto an um substrate.

After drying, the particles display characteristic sizes of 10 um - 50 um and arrange into sparse clusters with characteristic spacings of 20 um - 50 um between adjacent particles. These particles constitute the first length scale of the hierarchical texture. is an SEM (Scanning on Microscope) image of exemplary detail of a particle of carnauba wax ed from a boiled ethanol-wax emulsion and sprayed onto an aluminum substrate. After drying, the wax particle exhibits porous sub-micron roughness features with characteristic pore widths of 100 nm — l um and pore lengths of 200 nm — 2 um.

These porous roughness es constitute the second length scale of the hierarchical texture. is an SEM (Scanning Electron cope) image of a l rough surface obtained by spraying an mixture of l and ba wax particles onto an aluminum substrate. After drying, the particles display characteristic sizes of 10 um - 50 um and arrange into dense clusters with characteristic spacings of 10 um - 30 mm between adjacent particles.

These particles constitute the first length scale of the hierarchical texture. is an SEM (Scanning Electron cope) image of exemplary detail of a particle of carnauba wax obtained from a wax particle-ethanol mixture sprayed onto an aluminum substrate. After drying, the wax particle exhibits low aspect ratio sub-micron roughness features with heights of 100 nm. These porous roughness features constitute the second length scale of the hierarchical texture. is an SEM (Scanning Electron Microscope) image of a typical rough surface obtained by spraying an emulsion of a t solution and carnauba wax onto an um substrate. After drying, the particles display characteristic sizes of 10 um - 10 um with and 5306498V1 average characteristic size of 30 um. They are sparsely spaces with characteristic spacings of 50 um - 100 um between adjacent particles. These particles tute the first length scale of the hierarchical texture. is an SEM (Scanning Electron Microscope) image of exemplary detail of a particle of carnauba wax obtained from a solvent-wax emulsion and sprayed onto an um substrate. After drying, the wax particle exhibits cron roughness features with characteristic widths of pore widths of 200 nm and pore s of 200 nm — 2 um. These porous roughness features constitute the second length scale of the hierarchical texture.

FIGS. 8 through 13 include a sequence of images of a spot of ketchup on a liquid- impregnated surface, in accordance with an illustrative embodiment of the invention. includes a sequence of images of ketchup flowing out of a plastic , in accordance with an illustrative embodiment of the invention. es a sequence of images of ketchup flowing out of a glass bottle, in accordance with an illustrative embodiment of the invention. includes a sequence of images of mustard flowing out of a bottle, in accordance with an illustrative ment of the invention. includes a sequence of images of mayonnaise flowing out of a bottle, in accordance with an illustrative embodiment of the invention. includes a sequence of images ofjelly flowing out of a bottle, in accordance with an rative embodiment of the invention. includes a sequence of images of sour cream and onion dip flowing out of a bottle, in accordance with an illustrative embodiment of the invention. 5306498v1 includes a sequence of images of yogurt flowing out of a bottle, in accordance with an illustrative embodiment of the invention. es a sequence of images of toothpaste flowing out of a bottle, in accordance with an illustrative embodiment of the invention. includes a sequence of images of hair gel flowing out of a bottle, in accordance with an rative embodiment of the invention.

It is contemplated that es, apparatus, s, and processes of the claimed invention encompass variations and adaptations developed using information from the embodiments described herein. tion and/or modification of the articles, apparatus, methods, and processes described herein may be performed by those of ordinary skill in the relevant art.

Throughout the description, where es and tus are described as having, including, or comprising specific components, or where processes and methods are described as having, including, or comprising specific steps, it is contemplated that, additionally, there are articles and apparatus of the t ion that consist essentially of, or consist of, the recited components, and that there are processes and methods according to the present invention that consist essentially of, or consist of, the recited processing steps.

It should be understood that the order of steps or order for performing certain actions is immaterial so long as the invention remains operable. Moreover, two or more steps or actions may be conducted simultaneously. 5306498vl 2012/042326 The mention herein of any publication, for example, in the Background section, is not an admission that the publication serves as prior art with respect to any of the claims presented herein. The Background section is presented for purposes of clarity and is not meant as a description of prior art with respect to any claim.

Liquid-impregnated surfaces are described in US. Patent Application No. ,356, titled “Liquid-Impregnated es, Methods of Making, and Devices Incorporating the Same,” filed November 22, 2011, the disclosure of which is hereby incorporated by reference herein in its ty. is a schematic cross-sectional view of a liquid 102 in contact with a traditional or previous non-wetting surface 104 (i.e., a gas nating surface), in accordance with some embodiments of the invention. The surface 104 includes a solid 106 having a surface texture defined by es 108. In some embodiments, a solid 106 is defined by es 108. The s between the features 108 are occupied by a gas 110, such as air. As depicted, while the liquid 102 is able to contact the tops of the features 108, a gas-liquid interface 112 prevents the liquid 102 from wetting the entire surface 104.

Referring to FIG. lb, in certain instances, the liquid 102 may ce the impregnating gas and become impaled within the features 108 of the solid 106. Impalement may occur, for example, when a liquid droplet impinges the surface 104 at high velocity. When impalement occurs, the gas occupying the regions between the features 108 is replaced with the liquid 102, either partially or completely, and the surface 104 may lose its nonwetting capabilities.

Referring to , in n embodiments, a non-wetting, liquid-impregnated surface 120 is provided that includes a solid 122 having textures (e.g., features 124) that are impregnated 5306498V1 2012/042326 with an impregnating liquid 126, rather than a gas. In s embodiments, a g on the surface 104 es the solid 106 and the impregnating liquid 126.

In the depicted embodiment, a contacting liquid 128 in contact with the surface, rests on the features 124 (or other texture) ofthe surface 120. In the regions between the features 124, the contacting liquid 128 is supported by the impregnating liquid 126. In certain embodiments, the contacting liquid 128 is immiscible with the impregnating liquid 126. For example, the contacting liquid 128 may be water and the impregnating liquid 126 may be oil.

In some embodiments, micro-scale features are used. In some embodiments, a micro- scale feature is a particle. Particles can be randomly or uniformly dispersed on a surface.

Characteristic spacing between particles can be about 200 um, about 100 um, about 90 um, about 80 um, about 70 um, about 60 um, about 50 um, about 40 um, about 30 um, about 20 um, about um, about 5 um or 1 um. In some embodiments, characteristic spacing between particles is in a range of 100 um - 1 um, 50 um - 20 um, or 40 um -30 mm. In some embodiments, teristic spacing between particles is in a range of 100 um - 80 um, 80 um - 50 um, 50 um - um or 30 um -10 um. In some ments, characteristic spacing between particles is in a range of any two values above.

Particles can have an average dimension of about 200 um, about 100 um, about 90 um, about 80, about 70 um, about 60 um, about 50 um, about 40 um, about 30 um, about 20 um, about 10 um, about 5 um or 1 um. In some embodiments, an average dimension of particles is in a range of 100 um - 1 um, 50 um - 10 um, or 30 um -20 um. In some embodiments, an average ion ofparticles is in a range of 100 um - 80 um, 80 um - 50 um, 50 um — 30 um or 30 um - 10 um. In some embodiments, an average dimension of particles is in a range of any two values above. 5306498v1 In some embodiments, particles are porous. Characteristic pore size (e.g., pore widths or lengths) of particles can be about 5000 nm, about 3000 nm, about 2000 nm, about 1000 nm, about 500 nm, about 400 nm, about 300 nm, about 200 nm, about 100 nm, about 80 nm, about 50, about nm. In some embodiments, characteristic pore size is in a range of 200 nm - 2 um or 100 nm - l um. In some ments, teristic pore size is in a range of any two values above.

The articles and methods described herein relate to liquid-impregnated es that are particularly valuable as interior bottle coatings, and le to food processing equipment. The articles and methods have applications across a wide-range of food packaging and process equipment. For example, the articles may be used as bottle coatings to improve the flow of the material out of the bottle, or flow over or through food processing ent. In certain embodiments, the surfaces or coatings described herein prevent leaching of chemicals from the walls of a bottle or food processing equipment into the food, thereby enhancing the health and safety of consumers. These surfaces and coatings may also provide barriers to diffusion of water or oxygen, and/or t the contained material (e.g., a food product) from ultraviolet radiation.

In certain embodiments, the surfaces or coatings described herein can be used with food bins/totes/bags and/or conduits/channels in industrial transportation setting as well as other food processing equipments.

In certain ments, the articles described here are used to contain a er product. For example, handling of sticky foods, such as chocolate syrup, in coated containers leaves significant amount of food left stuck to container walls. Coating container walls with liquid encapsulated texture can not only reduce food wastage but also lead to easy handling.

In certain embodiments, the articles described here are used to contain a food product.

The food t may be, for e, p, mustard, mayonnaise, butter, peanut butter, 5306498V1 jelly, jam, ice cream, dough, gum, chocolate syrup, yogurt, , sour cream, sauce, icing, curry, food oil or any other food product that is provided or stored in a container. A food product can also be dog food or cat food. The articles may also be used to contain household products and care products, such as cosmetics, lotion, toothpaste, shampoo, hair gel, medical fluids (e. g., antibacterial ointments or creams), and other related ts or chemicals.

In some embodiments, a consumer product in contact with an article has a ity of at least 100 cP (e.g., at room ature). In some embodiments, a consumer product has a viscosity of at least 500 CF, 1000 cP, 2000 CF, 3000 cP or 5000 CF. In some embodiments, a consumer product has a viscosity in a range of 100-500 cP, 500-1000 cP, or 1000-2000 cP. In some embodiments, a consumer t has a Viscosity in a range of any two values above.

In various ments, a liquid-impregnated surface includes a textured, porous, or roughened substrate that is encapsulated or nated by a non-toxic and/or an edible liquid.

The edible liquid may be, for example, a food additive (e.g., ethyl oleate), fatty acids, proteins, and/or or a ble oil (e.g.,olive oil, light olive oil, corn oil, soybean oil, rapeseed oil, linseed oil, grapeseed oil, flaxseed oil, canola oil, peanut oil, safflower oil, sunflower oil). In one embodiment, the edible liquid is any liquid approved for consumption by the US. Food and Drug Administration (FDA). The substrate is preferably listed in the FDA’s list of approved food contact substances, available at www.accessdata.fda.gov.

In certain embodiments, a textured material on the inside of an article (e.g., a bottle or other food ner) is integral to the bottle itself. For example, the textures of a polycarbonate bottle may be made of polycarbonate.

In various embodiments, the solid 122 comprises a matrix of solid features. The solid 122 or a matrix of solid features can include a non-toxic and/or edible material. In some 5306498V1 embodiments, es textures of a liquid-encapsulated include solid, edible materials. For example, the surfaces textures may be formed from a collection or coating of edible solid particles. Examples of solid, xic and/or edible als include insoluble fibers (e.g., purified wood cellulose, micro-crystalline cellulose, and/or oat bran fiber), wax (e.g., carnauba wax), and cellulose ethers (e.g., Hydroxyethyl cellulose, Hydroxypropyl cellulose (HPC), Hydroxyethyl methyl cellulose, Hydroxypropyl methyl ose (HPMC), and/or Ethyl hydroxyethyl cellulose).

In various embodiments, a method is provided for imparting a surface texture (e.g., roughness and/or porosity) to the solid substrate. In one ment, the texture is imparted by exposing the ate (e.g., polycarbonate) to a t (e.g., acetone). For example, the solvent may impart texture by inducing crystallization (e. g., polycarbonate may tallize when d to acetone).

In various embodiments, the texture is imparted through extrusion or blow-molding of a mixture of als (e. g., a continuous polymer blend, or mixture of a polymer and particles).

One of the materials may be subsequently dissolved, etched, melted, or evaporated away, leaving a textured, porous, and/or rough surface behind. In one embodiment, one of the materials is in the form of particles that are larger than an average thickness of the coating. Advantageously, packaging for food products (e.g., ketchup bottles) is currently produced using ion or blow-molding. Methods described herein may therefore be performed using existing equipment, with little added expense.

In certain embodiments, the texture is imparted by mechanical roughening (e.g.,tumbling with an abrasive), spray-coating or polymer spinning, deposition of particles from solution (e.g.,layer-by-layer deposition, evaporating away liquid from a liquid + particle 5306498v1 suspension), and/or extrusion or blow-molding of a foam, or foam-forming material (for example a polyurethane foam). Other possible methods for imparting the e include: deposition of a polymer from a on (e.g., the polymer forms a rough, porous, or textured surface behind); extrusion or blow-molding of a material that expands upon g, leaving a wrinkled e; and application of a layer of a material onto a surface that is under n or compression, and subsequently relaxing the tension or compression of surface beneath, resulting in a textured surface.

In one embodiment, the texture is imparted h non-solvent induced phase separation of a polymer, resulting in a sponge-like porous structure. For example, a solution of polysulfone, poly(vinylpyrrolidone), and DMAc may be cast onto a substrate and then immersed in a bath of water. Upon immersion in water, the solvent and non-solvent exchange and the polysulfone precipitates and hardens.

In some embodiments, a liquid-impregnated surface includes the impregnating liquid and portions of the solid al that extend or poke through the nating liquid (e.g., to contact an adjacent air phase). To achieve optimal non-wetting and self-lubricating performance, it is lly desirable to minimize the amount of solid material that s through (i.e., is not covered by) the impregnating liquid. For example, a ratio of the solid material to the impregnating liquid at the surface is preferably less than about 15 percent, or more preferably less than about 5 percent. In some embodiments, a ratio of the solid material to the impregnating liquid is less than 50 t, 45 percent, 40 percent, 35 percent, 30 t, 25 percent, 20 percent, 15 percent, 10 percent, 5 percent, or 2 percent. In some embodiments, a ratio of the solid material to the impregnating liquid is in a range of 50-5 percent, 30-10 percent, 20-15 percent or any two values above. In certain embodiments, a low ratio is achieved using surface 5306498V1 textures that are pointy or round. By contrast, surface textures that are flat may result in higher ratios, with too much solid material exposed at the surface.

In various embodiments, a method is provided for impregnating the surface texture with an impregnating . For example, the impregnating liquid may be sprayed or brushed onto the texture (e.g., a texture on an inner surface of a bottle). In one embodiment, the impregnating liquid is applied to the textured surface by filling or lly g a container that includes the textured surface. The excess impregnating liquid is then removed from the container. In various embodiments, the excess impregnating liquid is removed by adding a wash liquid (e.g., water) to the container to t or extract the excess liquid from the ner. onal methods for adding the impregnating liquid include spinning the container or surface in contact With the liquid (e.g., a spin coating process), and condensing the impregnating liquid onto the container or surface. In s embodiments, the impregnating liquid is applied by depositing a on with the impregnating liquid and one or more volatile s (e.g., via any of the previously described methods) and evaporating away the one or more volatile liquids.

In certain embodiments, the impregnating liquid is applied using a spreading liquid that spreads 0r pushes the impregnating liquid along the surface. For example, the impregnating liquid (e.g., ethyl oleate) and spreading liquid (e.g., water) may be combined in a container and agitated or stirred. The fluid flow Within the container may distribute the impregnating liquid around the container as it impregnates the e textures.

With any of these methods, the excess impregnating liquid may be mechanically removed (e.g., pushed off the e With a solid object or fluid), absorbed off of the surface using another porous material, or removed via gravity or centrifugal forces. The processing materials are ably FDA approved for consumption in small quantities. 5306498v1 Experimental Examples Creating matrix of solid features on interior bottle surfaces: In these ments, ZOO-proof pure ethanol (KOPTEC), powdered carnauba wax (McMaster-Carr) and aerosol carnauba wax spray (PPE, #CW-l65), which contains trichloroethylene, propane and carnauba wax, were used. The sonicator was from Branson, Model 2510. The advanced hot plate stirrer was from VWR, Model 97042-642. The airbrush was from Badger Air-Brush Co., Model Badger 150.

A first surface with a matrix of solid features was prepared by procedure 1 described here. A e was made by g 40 ml ethanol to 85 °C, slowly adding 0.4g carnauba wax powder, boiling the mixture of ethanol and was for 5 min, followed by allowing the e to cool while being ted from 5 min. The resulting mixture was sprayed onto a ate with an airbrush at 50 psi, and then allowing the ate to dry at ambient temperature and humidity for 1 min. SEM images are shown in FIGS 2 and 3.

A second surface was prepared by procedure 2 described here. A mixture was made by adding 4g powdered carnauba wax to 40 m1 ethanol and vigorously stirring. The resulting mixture was sprayed onto a substrate with an airbrush at 50 psi for 2 sec at a distance of 4 inches from the surface, and then allowing the substrate to dry at ambient temperature and humidity for 1 min. SEM images are shown in FIGS 4 and 5.

A third surface was prepared by procedure 3 described here. An aerosol wax was sprayed onto a substrate at a ce of 10 inches for 3 sec. We moved the spray nozzle such that spray residence time was no longer than 0.5 sec/unit area, and then allowed the substrate to dry at t temperature and humidity for l min. SEM images are shown in FIGS 6 and 7. 5306498v1 Impregnating a wax coating: A quantity of 5 to 10 mL of ethyl oleate (sigma h) or vegetable oil was swirled around in the bottles until the entire wax-covered surface prepared by procedure 3 described above became arent. Such a coating time is chosen so that cloudy (not patchy) coating forms over the whole surface. In some embodiments, a formed coating has a thickness in a range of 10-50 microns.

The excess oil was d by 2 different methods in the experiments. They were either drained by placing them upside down for about 5 minutes, or drained by adding about 50 mL ofwater to the bottle and shaking it for 5-10 seconds to entrain most of the excess oil into the water. The water/oil emulsion was then dumped out. In general, after ng, the coating appears clear. When it is over-drained it usually appears cloudy.

FIGS. 8 through 13 include a sequence of images of a spot of ketchup on a liquid- impregnated surface, in accordance with an illustrative ment of the invention. As depicted, the spot of ketchup was able to slide along the liquid-impregnated surface due to a slight tilting (e.g., 5 to 10 degrees) of the surface. The ketchup moved along the surface as a substantially rigid body, without leaving any ketchup residue along its path. The elapsed time from to was about 1 second. -emptying experiments: Unless otherwise ed, bottle-emptying experiments were conducted within about minutes after draining excess oil. Coated and uncoated bottles of the same type with an equal amount of the same condiment type. They were then flipped upside down. Plastic/glass bottles 5306498v1 were then repeatedly squeezed/pumped until more than 90% of the materials were removed, and then shaken until only small drops of the material were coming out of the uncoated bottles. The coated and uncoated bottles were then weighed, then rinsed, then weighed again, to determine the amount of food left in the bottles after the experiment.

Ketchu To prepare the liquid-impregnated surface for these images shown in FIGS 14 and 15, an inner surface of a plastic ic Heinz bottles made from polyethylene terephthalate (PETE) or glass container was sprayed for a few seconds with a mixture containing particles of carnauba wax and a solvent. After the solvent evaporated, the carnauba wax that remained on the surface provided surface texture or roughness. The surface texture was then impregnated with ethyl oleate by ng the ethyl oleate to the surface and removing the excess ethyl oleate.

FIGS. 14 and 15 include two sequence of images of ketchup flowing out of a bottle, in accordance with an illustrative embodiment of the invention. The bottle on the left in each image is a standard ketchup . The bottle on the right is a liquid-impregnated bottle.

Specifically, the inner es of the bottle on the right were liquid-impregnated prior to filling the bottle with ketchup. Aside from the different inner surfaces, the two bottles were identical.

The sequence of images show p flowing from the two s due to gravity. At time equal to zero, the lly full s were overturned to allow the ketchup to pour or drip from the bottles. As depicted, the ketchup d considerably faster from the bottle having the liquid-impregnated surfaces. After 200 seconds, the amount of ketchup remaining in the standard bottle was 85.9 grams. By comparison, the amount of ketchup remaining in the liquid- impregnated bottle at this time was 4.2 grams. 5306498v1 The amount of carnauba wax on the surface of the bottle was about 9.9 x 10'5 g/cm2.

The amount of ethyl oleate in the liquid-impregnated surface was about 6.9 x 10'4 g/cm2. The estimated coating thickness was from about 10 to about 30 micrometers.

Mustard To prepare the liquid-impregnated surface for these images shown in FIG 16, an inner surface of a container was sprayed for a few seconds with a mixture ning particles of carnauba wax and a solvent. After the solvent evaporated, the carnauba wax that remained on the surface provided surface texture or roughness. The surface texture was then impregnated with ethyl oleate by applying the ethyl oleate to the surface and removing the excess ethyl .

FIG 16 es a sequence of images of mustard flowing out of a bottle, in ance with an rative embodiment of the invention. The bottle on the left in each image is a standard mustard bottle (Grey Poupon mustard bottle). The bottle on the right is a liquid- nated bottle. Specifically, the inner surfaces of the bottle on the right were - impregnated prior to filling the bottle with mustard. Aside from the different inner surfaces, the two bottles were identical. The sequence of images show mustard flowing from the two bottles due to gravity. At time equal to zero, the initially full bottles were overturned to allow the mustard to pour or drip from the bottles. As depicted, the mustard drained considerably faster from the bottle having the liquid-impregnated surfaces. aise To prepare the liquid-impregnated surface for these images shown in FIG 17, an inner e of a container was sprayed for a few seconds with a mixture containing particles of 5306498v1 2012/042326 carnauba wax and a solvent. After the solvent evaporated, the carnauba wax that remained on the surface provided surface texture or roughness. The surface texture was then impregnated with ethyl oleate by applying the ethyl oleate to the surface and removing the excess ethyl oleate.

FIG 17 includes a sequence of images of mayonnaise flowing out of a bottle, in accordance with an illustrative embodiment of the invention. The bottle on the left in each image is a standard mayonnaise bottle (The Hellman’s Mayonnaise bottle). The bottle on the right is a liquid-impregnated bottle. Specifically, the inner surfaces of the bottle on the right were liquid-impregnated prior to filling the bottle with aise. Aside from the ent inner surfaces, the two bottles were identical. The sequence of images show mayonnaise flowing from the two s due to gravity. At time equal to zero, the initially full bottles were overturned to allow the mayonnaise to pour or drip from the bottles. As depicted, the mayonnaise drained erably faster from the bottle having the liquid-impregnated surfaces.

Two days later, the experiment was repeated and the coated bottle of mayonnaise still emptied substantially tely.

Jelly To prepare the liquid-impregnated surface for these images shown in FIG 18, an inner surface of a container was sprayed for a few seconds with a mixture containing particles of carnauba wax and a solvent. After the solvent ated, the carnauba wax that remained on the e ed surface texture or roughness. The surface texture was then impregnated with ethyl oleate by applying the ethyl oleate to the surface and removing the excess ethyl oleate.

FIG 18 includes a sequence of images ofj elly flowing out of a bottle, in accordance with an illustrative embodiment of the invention. The bottle on the left in each image is a 5306498V1 standard jelly bottle. The bottle on the right is a liquid-impregnated bottle. cally, the inner surfaces of the bottle on the right were liquid-impregnated prior to filling the bottle with jelly. Aside from the different inner surfaces, the two bottles were cal. The ce of images show jelly flowing from the two bottles due to gravity. At time equal to zero, the initially full bottles were overturned to allow the jelly to pour or drip from the bottles. As depicted, the jelly drained considerably faster from the bottle having the liquid-impregnated surfaces.

In addition, experiments were tested at 55 0C in a liquid-impregnated bottle with jelly.

The liquid-impregnated surface was stable and showed similar conveying effect.

Sour Cream and Onion Dip To prepare the liquid-impregnated surface for these images shown in FIG 19, an inner surface of a ner was d for a few seconds with a mixture containing particles of carnauba wax and a solvent. After the solvent ated, the carnauba wax that remained on the surface provided surface texture or roughness. The surface texture was then impregnated with canola oil by applying the canola oil to the surface and removing the excess canola oil.

FIG 19 includes a sequence of images of cream flowing out of a bottle, in accordance with an illustrative ment of the invention. The bottle on the left in each image is a standard bottle. The bottle on the right is a liquid-impregnated bottle. Specifically, the inner surfaces of the bottle on the right were liquid-impregnated prior to filling the bottle with cream.

Aside from the different inner surfaces, the two bottles were cal. The sequence of images show cream flowing from the two s due to gravity. At time equal to zero, the initially full bottles were overturned to allow the cream to pour or drip from the bottles. As depicted, the cream drained considerably faster from the bottle having the liquid-impregnated surfaces. 5306498V1 Yogurt To prepare the liquid—impregnated surface for these images shown in FIG 20, an inner surface of a ner was sprayed for a few seconds with a e containing particles of carnauba wax and a t. After the solvent evaporated, the carnauba wax that remained on the surface provided surface texture or roughness. The e texture was then impregnated with ethyl oleate by applying the ethyl oleate to the surface and removing the excess ethyl oleate.

FIG 20 includes a sequence of images of yogurt flowing out of a bottle, in accordance with an illustrative ment of the invention. The bottle on the left in each image is a standard bottle. The bottle on the right is a liquid-impregnated bottle. Specifically, the inner surfaces of the bottle on the right were liquid-impregnated prior to filling the bottle with yogurt.

Aside from the different inner surfaces, the two s were identical. The sequence of images show yogurt flowing from the two bottles due to gravity. At time equal to zero, the initially full bottles were overturned to allow the yogurt to pour or drip from the bottles. As depicted, the yogurt drained considerably faster from the bottle having the liquid-impregnated surfaces.

Toothpaste To prepare the liquid-impregnated surface for these images shown in FIG 21, an inner e of a container was sprayed for a few seconds with a e containing particles of carnauba wax and a solvent. After the t evaporated, the carnauba wax that remained on the surface provided surface texture or roughness. The surface texture was then impregnated with ethyl oleate by applying the ethyl oleate to the surface and removing the excess ethyl oleate. 5306498v1 FIG 21 includes a sequence of images of toothpaste flowing out of a bottle, in accordance with an illustrative ment of the invention. The bottle on the left in each image is a standard bottle. The bottle on the right is a liquid—impregnated bottle. Specifically, the inner surfaces of the bottle on the right were -impregnated prior to filling the bottle with toothpaste. Aside from the different inner surfaces, the two bottles were cal. The sequence of images show toothpaste flowing from the two bottles due to gravity. At time equal to zero, the initially full bottles were overturned to allow the toothpaste to pour or drip from the bottles. As depicted, the toothpaste d considerably faster from the bottle having the liquid- impregnated surfaces.

Hair Gel To prepare the liquid-impregnated surface for these images shown in FIG 22, an inner surface of a container was sprayed for a few seconds with a mixture ning particles of carnauba wax and a solvent. After the solvent evaporated, the carnauba wax that remained on the surface provided surface texture or roughness. The surface texture was then impregnated with ethyl oleate by applying the ethyl oleate to the surface and removing the excess ethyl oleate.

FIG 22 includes a sequence of images of hair gel flowing out of a bottle, in accordance with an illustrative embodiment of the invention. The bottle on the left in each image is a rd bottle. The bottle on the right is a -impregnated bottle. Specifically, the inner es of the bottle on the right were liquid-impregnated prior to filling the bottle with hair gel.

Aside from the different inner surfaces, the two bottles were identical. The sequence of images show hair gel flowing from the two bottles due to gravity. At time equal to zero, the initially full 5306498Vl 2012/042326 bottles were overturned to allow the hair gel to pour or drip from the bottles. As depicted, the hair gel drained considerably faster from the bottle having the liquid-impregnated surfaces.

Data from bottle empfling experiments The weight of food remaining in both the coated and uncoated bottles used in the above-described experiments was ed and is presented in Table 1 below. As is clear, the weight of t remaining in the bottles with liquid encapsulated interior surfaces (“coated bottles”) after emptying is significantly less than the weight of product remaining in the bottles without the liquid encapsulated surfaces.

Table 1 Weight of food remaining for coated and uncoated bottles Weight remaining in Weight remaining in Time of shaking coated bottle uncoated bottle Heinz ketchup 86 g 200 seconds (plastic) — 36 oz Heinz ketchup 41 g 29 seconds (glass) - 14 oz Welch’s Jelly 48 g 30 seconds (plastic) — 22 oz Grey Poupon 45 g 36 seconds Mustard (plastic) — oz Honey (plastic) _ 35 g 125 seconds Hellmann’s 85 g 46 seconds Mayonnaise ic) — 22 oz Eguivalents 5306498V1 WO 41888 While the invention has been ularly shown and described With reference to specific preferred embodiments, it should be understood by those skilled in the art that various changes in form and detail may be made therein Without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (36)

What is claimed :

1. An article comprising a liquid-impregnated surface, n said surface comprises a matrix of solid features spaced sufficiently close to stably contain a liquid therebetween and/or therewithin regardless of orientation of the e, wherein the spacing between the solid features is less than about 200 microns, wherein the solid features and impregnating liquid are non-toxic, and wherein the article includes the impregnating liquid between and/or within the matrix of solid features, the article being configured to contain a nce different from the impregnating , wherein the solid features have an e dimension in a range of up to 200 microns.

2. The e of claim 1, wherein the article is a container of a er product.

3. The article of claim 1, wherein the solid features comprise particles.

4. The article of claim 3, wherein the particles have an average dimension in a range of 50 nanometers to 50 microns.

5. The article of claim 3, wherein the particles comprise one or more members selected from the group consisting of ble fibers, purified wood cellulose, micro-crystalline cellulose, oat bran fiber, kaolinite, Japan wax, pulp, ferric oxide, iron oxide, sodium formate, sodium oleate, sodium palmitate, sodium sulfate, wax, carnauba wax, beeswax, candelilla wax, zein, dextrin, cellulose ether, Hydroxyethyl cellulose, Hydroxypropyl cellulose (HPC), Hydroxyethyl methyl cellulose, Hydroxypropyl methyl cellulose (HPMC), and Ethyl hydroxyethyl ose.

6. The article of claim 5, wherein the particles comprise a wax.

7. The article of claim 3, wherein the particles are randomly spaced.

8. The article of claim 7, wherein the particles are arranged with average spacing of up to 200 microns between adjacent les or clusters of particles.

9. The article of claim 3, wherein the particles are spray-deposited.

10. The article of claim 2, wherein the consumer product comprises at least one member selected from the group consisting of ketchup, catsup, mustard, aise, syrup, honey, jelly, peanut butter, butter, chocolate syrup, shortening, butter, margarine, oleo, grease, dip, yogurt, sour cream, cosmetics, shampoo, lotion, hair gel, and toothpaste.

11. The article of claim 2, n the container of the consumer product is shelfstable when filled with the consumer product.

12. The article of claim 2, wherein the consumer product has a viscosity of at least 100 cP at room temperature.

13. The article of claim 2, wherein the consumer product is a wtonian material.

14. The article of claim 1, wherein the impregnating liquid comprises at least one member selected from the group consisting of a food additive, fatty acids, ns, and a vegetable oil.

15. The article of claim 1, wherein the article is a component of consumer product sing equipment.

16. The article of claim 1, wherein the article is a ent of food processing equipment that comes into contact with food.

17. The article of claim 1, wherein the liquid-impregnated surface has solid-to-liquid ratio less than about 50 percent.

18. The article of claim 1, wherein the impregnating liquid is edible.

19. The article of claim 1, wherein the solid features and impregnating liquid are edible.

20. The article of claim 14, wherein the impregnating liquid comprises ethyl oleate.

21. The article of claim 14, wherein the impregnating liquid ses at least one member selected from the group consisting of olive oil, light olive oil, corn oil, soybean oil, rapeseed oil, linseed oil, grapeseed oil, flaxseed oil, canola oil, peanut oil, safflower oil, and sunflower oil.

22. A method of manufacturing a container of a er product, the method sing: providing a substrate; applying a texture to the substrate, the texture comprising a matrix of solid features spaced sufficiently close to stably contain a liquid therebetween and/or therewithin, wherein the spacing between the solid features is less than about 200 microns; impregnating the matrix of solid features with the liquid such that the matrix of solid features stably contains the liquid therebetween and/or therewithin after manufacture of the container, wherein the container is configured to contain a nce different from the impregnating liquid during use of the container, wherein the solid features and the liquid are nontoxic and/or ; and contacting the impregnated matrix of solid features with a consumer product, wherein the consumer product comprises at least one member selected from the group consisting of ketchup, catsup, d, mayonnaise, syrup, honey, jelly, peanut butter, chocolate syrup, shortening, butter, margarine, oleo, dip, , sour cream, ics, shampoo, lotion, hair gel, and toothpaste.

23. The method of claim 22, wherein the solid features are particles.

24. The method of claim 23, wherein the applying step comprises spraying a mixture of a solid and a solvent onto the substrate.

25. The method of claim 24, wherein the solid comprises one or more members ed from the group consisting of insoluble fibers, purified wood cellulose, micro-crystalline cellulose, oat bran fiber, kaolinite, Japan wax, pulp, ferric oxide, iron oxide, sodium formate, sodium oleate, sodium ate, sodium sulfate, wax, carnauba wax, beeswax, candelilla wax, zein (from corn), dextrin, cellulose ether, Hydroxyethyl cellulose, Hydroxypropyl ose (HPC), Hydroxyethyl methyl cellulose, Hydroxypropyl methyl cellulose (HPMC), and Ethyl hydroxyethyl cellulose.

26. The method of claim 24, comprising ng the solvent to evaporate ing the spraying of the mixture onto the ate and before the impregnating step.

27. The method of claim 22, wherein the liquid comprises at least one member selected from the group consisting of a food additive, fatty acids, proteins, and a ble oil.

28. The method of claim 22, wherein applying the texture to the substrate comprises a procedure ed from the group consisting of exposing the substrate to a solvent, extruding or blow-molding a mixture of materials, roughening the substrate with mechanical action, spraycoating , polymer spinning, ting particles from solution, extruding or olding a foam or foam-forming al, depositing a polymer from a solution, extruding or blow-molding a material that expands upon cooling to leave a wrinkled or textured surface, applying a layer of material onto a surface that is under tension or compression, performing non-solvent induced phase separation of a r to obtain a porous structure, performing micro-contact printing, performing laser rastering, performing nucleation of the solid texture out of vapor, performing anodization, milling, machining, knurling, e-beam milling, performing thermal or chemical oxidation, and performing chemical vapor deposition.

29. The method of claim 22, wherein ng the texture to the substrate comprises spraying a mixture of edible particles onto the substrate.

30. The method of claim 22, further comprising chemically modifying the substrate prior to applying the texture to the substrate and/or ally modifying the solid features of the texture.

31. The method of claim 22, wherein impregnating the matrix of solid features comprises removing a portion of the liquid that is not impregnated between or within the matrix of solid features from the matrix of solid features.

32. The method of claim 31, wherein removing the portion of the liquid that is not impregnated between or within the matrix of solid features ses a procedure selected from the group consisting of using a second immiscible liquid to carry away the n of the liquid that is not impregnated between or within the matrix of solid es, using ical action to remove the portion of the liquid that is not impregnated between or within the matrix of solid features, absorbing the n of the liquid that is not impregnated between or within the matrix of solid features using a porous material, and draining the portion of the liquid that is not impregnated between or within the matrix of solid features off of the matrix of solid features using gravity or centrifugal forces.

33. The method of claim 22, wherein the solid features have an e dimension in a range of up to 200 microns.

34. The method of claim 22, wherein the solid features are randomly spaced.

35. The method of claim 22, wherein the solid features are arranged with average spacing of up to 200 microns between adjacent particles or clusters of particles.

36. The method of claim 22, wherein the liquid is stably contained between and/or within the matrix of solid features after manufacture of the container less of orientation of the container.