Method for molding materials and molded products

Abstract

The present invention relates to methods for molding materials having a plurality of interstices (such as a network of voids) and molded products formed thereby. In a preferred embodiment, the material is a foam, such as polyurethane foam. The molding method allows such materials to be molded using contouring fabrication methods, including computer numerically controlled (CNC) milling, which is provided by way of example only. In contrast to methods that produce molded materials (such as by polymerization of a solution or emulsion of monomers), in some aspects the present invention contemplates molding pre-existing (preformed) materials having a plurality of interstices, such as a network of voids.

Description

Detailed Description of the Invention

[0001] [Field of the Invention] The present invention relates to methods for molding materials having a plurality of interstices (such as a network of voids) and molded products formed thereby. In a preferred embodiment, the material is a foam, such as polyurethane foam. The molding method allows such materials to be molded using contouring machining methods, including computer numerically controlled (CNC) milling, which is provided by way of example only. In contrast to methods that produce molded materials (such as by polymerization of a solution or emulsion of monomers), in some aspects the present invention contemplates molding pre-existing (preformed) materials having a plurality of interstices, such as a network of voids.

[0002] [Background of the invention] Flexible foam fabrication is the process by which foam is shaped to a desired end result by molding a foam material or casting a resin system (excluding casting, which mass-produces foam material intended for fabrication). Forming methods include hand molding; and computer numerically controlled molding, examples of which include CNC mills, lathes, and turn mill and multi-axis mechanical arm molding.

[0003] Materials such as polyurethane foams are notoriously difficult to mold with precision. While it is relatively easy to cut such foams with blades, saws, and the like, attempts to contour such foams using traditional machining methods (such as computer numerical control (CNC) methods) result in imprecise contours and generally undesirable machining finishes. In particular, the inventors believe that the poor finish is caused by deformation of the foam by the machining tool during the molding process, causing the material to cut or even crack in imprecise places. Rather than producing a smooth surface, such machining produces a rough surface.

[0004] Despite this challenge, molded polyurethane foam is widely used for padding in seating, mounting, etc. Often, users desire precisely molded polyurethane products for applications such as wheelchair seating when a custom molded product is desired.

[0005] There have been few attempts to overcome the problems described herein. Broadly speaking, the methods used so far can be classified as follows: Cryogenic Method. This method of machining is relatively fast, accurate, and achieves the desired results at the expense of higher equipment costs (which must be able to withstand extreme temperatures), handling, storage, and excessive use of liquefied gas coolants, combined with exposure to fine foam dust and the dangers of liquefied gas; Liquid Freezing. This method involves saturating the foam with water and then freezing the water in situ. Freezing is a simplified version of the low-temperature method, allowing for lower and comparable costs for low-temperature dry machining by using frozen water to maintain a sufficiently low temperature. However, this method requires that the water remain frozen (which can be assisted by cooling the foam and water) during all stages of the molding process for optimal results. The expansion of the water causes micro-fractures of the foam as it solidifies. Furthermore, freezing of water actually leads to suboptimal machining quality and accuracy, as machining tolerances can be unpredictably disrupted by the expansion of water within the foam at reduced temperatures, coupled with the loss of melting ice around the molding surface when high-speed, frictional machining tools contact the surface. Another problem with this method is that water must be contained, and the machined components must be compatible with water to avoid corrosion, electrical failure, and leakage; and Dry Machining Method: This method refers to techniques other than the cryogenic and liquid freezing methods described above, which require long machining times, high-end equipment and tooling, expose technicians to harmful dust, and only provide limited geometry sizes.

[0006] Due to the limitations of these methods, particularly the health hazards of generating fine particulates, traditional hand molding methods remain widely used in foam assembly.

[0007] Aside from flexible foam formation, it is often desirable to shape porous metal materials, which are typically inflexible. Compared to flexible foams, such materials present various challenges. For example, machining porous metal materials produces burrs, which vary in size and shape, depending in part on the temperature and material used. At elevated temperatures, the contact point between the cutting tool and the metal becomes softer, creating a tendency to plastically dislocate, causing the metal to form smears or burrs. Such temperatures also accelerate the dulling of machining tools. To overcome these challenges, it is possible to apply coolants to lower the temperature of the material to harden the metal, producing cleaner cuts and preventing burrs, smears, and associated damage. Further teaching in the field of porous metal machining clarifies the problems resulting from ductile shear, and solutions to smearing primarily rely on achieving "brittle shear" using cryogenic methods.

[0008] As with all methods of machining, in the methods described thus far, it is necessary to ensure that the material being formed is held securely during the forming process. Traditionally, materials are clamped or otherwise attached, such as by the use of adhesives such as cyanoacrylate or similar "super glue" adhesives. Such techniques generally damage the material due to the direct mechanical action of the clamps or as a result of the excessive force required to break the adhesive bond.

[0009] It is an object of the present invention to address one or more of the above problems, or at least to provide the skilled reader with a useful choice.

[0010] [Summary of the Invention] In a first aspect, the present invention provides a method of molding an elastic or viscoelastic material having a plurality of voids, comprising the steps of: i. providing an elastic or viscoelastic material having a plurality of voids; ii. contacting the material with the additive such that at least a portion of the additive is incorporated within at least a portion of the plurality of interstices of the material; iii. subjecting the material to conditions such that at least a portion of the incorporated additives solidify, harden, and / or stiffen; iv. shaping the solidified, hardened, and / or rigidified additive-incorporating material to thereby form a shaped additive-incorporating material; and v. removing at least a portion of said incorporated additive from said molded material incorporating said additive. Including, the additive solidifies, hardens and / or stiffens at temperatures above 0°C; A method is provided.

[0011] In some embodiments, the multi-void elastic or viscoelastic material is a void network elastic or viscoelastic material.

[0012] Thus, in a second aspect, the present invention provides a method of molding an elastic or viscoelastic material having a network of voids, comprising the steps of: i. providing an elastic or viscoelastic material having a network of voids; ii. contacting the material with an additive such that at least a portion of the additive is incorporated into at least a portion of the network of voids in the material; iii. subjecting the material to conditions such that at least a portion of the incorporated additives solidify, harden, and / or stiffen; iv. shaping the solidified, hardened, and / or rigidified additive-incorporating material to thereby form a shaped additive-incorporating material; and v. removing at least a portion of said incorporated additive from said molded material incorporating said additive. Including, the additive solidifies, hardens and / or stiffens at temperatures above 0°C; A method is provided.

[0013] The method of the present invention allows for the production of shaped elastic or viscoelastic materials having desirable surface finishes. The method utilizes additives that solidify, harden, and / or stiffen at temperatures above the freezing point of water (0°C at standard atmospheric pressure, 101.325 kPa). The additives are incorporated into the material such that the material can be shaped while the additives solidify, harden, and / or stiffen, thereby preventing undesired deformation of the material as it is shaped.

[0014] By way of example only, in some embodiments, the additive is a wax and the elastic or viscoelastic material having a plurality of interstices (e.g., a network of voids) is a polyurethane foam. In those embodiments, the method may involve incorporating molten wax within a material that solidifies upon cooling to room temperature, and the foam may then be shaped by CNC milling. At least a portion of the wax is then removed from the shaped foam.

[0015] Without wishing to be bound by theory, it is believed that this method allows for the molding of materials without substantially changing the modulus of elasticity of the material itself. Furthermore, additives may be selected so that there is a limited difference between the temperatures at which the additive is liquid and solid, and so that shrinkage, if any, of the material is very limited. Still further, by carefully adjusting the amount of additive incorporated into the material, it is possible to avoid saturation of the material, thereby providing greater control over potential expansion or contraction.

[0016] Furthermore, whereas previously published approaches to cryogenic technology weaken and damage the structure of foam materials at a molecular level to achieve machining, the present invention is believed to provide a mechanical advantage to the benefit of machining tools by focusing the shear forces between the high inertia of immobilized additives (particularly waxes) compared to the high momentum of the tool's rotating cutting edges.

[0017] Thus, the present invention represents a significant advance over previously published methods because it allows for the molding of elastic or viscoelastic materials at room temperature and other temperature ranges above the freezing point of water. The advantages of the present invention are compounded by the self-healing properties of the additives used in some embodiments. For example, any additive (such as wax) temporarily melted by a machining tool subsequently hardens after the tool has moved past, thereby once again contributing to the rigidity of the material. The use of wax-based additives can also lubricate machines and cutting tools for increased service life, and reduce the risk of electrical failure that would otherwise be possible when using water in previously published liquid freezing methods.

[0018] In a third aspect, the present invention provides a shaped elastic or viscoelastic material having a plurality of interstices (such as a network of voids) prepared by the method of the first or second aspect.

[0019] In a fourth aspect, the present invention provides the use of an additive that solidifies, hardens and / or stiffens at temperatures above 0°C to form an elastic or viscoelastic material having a plurality of interstices (such as a network of voids) into which the additive is incorporated.

[0020] In a fifth aspect, the present invention provides a contoured elastic or viscoelastic material having a plurality of interstices (such as a network of voids), at least a portion of the material having an additive incorporated therein, the additive solidifying, hardening and / or rigidifying at a temperature above 0°C.

[0021] As used herein, the term "contoured" refers to the form of an article that has been exposed to contouring, contour machining, 3D machining or 3D contour machining techniques.

[0022] In a sixth aspect, the present invention provides a method of molding an elastic or viscoelastic material having a plurality of voids, the method comprising: i. providing an elastic or viscoelastic material having a plurality of voids; ii. contacting the material with the additive such that at least a portion of the additive is incorporated within at least a portion of the plurality of interstices of the material; iii. subjecting the material to conditions such that at least a portion of the incorporated additives solidify, harden, and / or stiffen; iv. shaping the solidified, hardened, and / or rigidified additive-incorporating material to thereby form a shaped additive-incorporating material; and v. removing at least a portion of said incorporated additive from said molded material incorporating said additive. Including, The method further provides a method in which the additive solidifies, hardens, and / or stiffens when exposed to a change in condition other than water and selected from thermal, magnetic, electrical, chemical, and / or electromagnetic conditions.

[0023] In a seventh aspect, the present invention provides a method for molding an elastic or viscoelastic material having a network of voids, comprising the steps of: i. providing an elastic or viscoelastic material having a network of voids; ii. contacting the material with an additive such that at least a portion of the additive is incorporated into at least a portion of the network of voids in the material; iii. subjecting the material to conditions such that at least a portion of the incorporated additives solidify, harden, and / or stiffen; iv. shaping the solidified, hardened, and / or rigidified additive-incorporated material to thereby form a shaped additive-incorporated material; and v. removing at least a portion of said incorporated additive from said molded material incorporating said additive. Including, The method further provides a method in which the additive solidifies, hardens, and / or stiffens when exposed to a change in condition other than water and selected from thermal, magnetic, electrical, chemical, and / or electromagnetic conditions.

[0024] In some embodiments, the multi-porous elastic or viscoelastic material is a void network elastic or viscoelastic material.

[0025] In an eighth aspect, the present invention provides a method for molding an elastic or viscoelastic material having a network of voids, comprising the steps of: i. providing an elastic or viscoelastic material having a network of voids; ii. contacting the material with an additive such that at least a portion of the additive is incorporated into at least a portion of the network of voids in the material; iii. subjecting the material to conditions such that at least a portion of the incorporated additives solidify, harden, and / or stiffen; iv. shaping the solidified, hardened, and / or rigidified additive-incorporating material to thereby form a shaped additive-incorporating material; and v. removing at least a portion of said incorporated additive from said molded material incorporating said additive. Including, The method further comprises the step of: providing a coating of the additive that solidifies, hardens, and / or stiffens when exposed to a change in condition selected from magnetic, electrical, chemical, and / or electromagnetic conditions;

[0026] In a ninth aspect, the present invention provides a shaped elastic or viscoelastic material having a plurality of interstices (such as a network of voids) prepared by the method of the fifth or sixth aspect.

[0027] In a tenth aspect, the present invention provides the use of an additive for molding an elastic or viscoelastic material having a plurality of interstices (such as a network of voids) incorporating the additive, wherein the additive solidifies, hardens and / or stiffens when exposed to a change in condition selected from magnetic, electrical, chemical and / or electromagnetic conditions.

[0028] In an eleventh aspect, the present invention provides a contoured elastic or viscoelastic material having a plurality of interstices (such as a network of voids), at least a portion of the material having an additive incorporated therein, wherein the additive solidifies, hardens and / or stiffens when exposed to a change in condition selected from magnetic, electrical, chemical and / or electromagnetic conditions.

[0029] In a twelfth aspect, the present invention provides a method of forming a shaped elastic or viscoelastic material having a plurality of voids, the method comprising: i. contacting an additive with a resin capable of being cured to form an elastic or viscoelastic material in a container to form a mixture; ii. degassing the mixture, such as by vacuum, and / or mixing the mixture to form a homogeneous blend; iii. curing the resin to thereby form an elastic or viscoelastic material incorporating at least a portion of the additive; iv. shaping the material incorporating the additive, thereby forming the shaped material incorporating the additive; and v. Optionally, removing at least a portion of said incorporated additive from said molded material incorporating said additive. Including, wherein the additive solidifies, hardens and / or stiffens when exposed to a change in condition other than water and selected from thermal, magnetic, electrical, chemical and / or electromagnetic conditions; A method is provided.

[0030] In a thirteenth aspect, the present invention provides a method of forming a shaped elastic or viscoelastic material having a network of voids, comprising the steps of: i. contacting an additive with a resin capable of being cured to form an elastic or viscoelastic material in a container to form a mixture; ii. degassing the mixture, such as by vacuum, and / or mixing the mixture to form a homogeneous blend; iii. curing the resin to thereby form an elastic or viscoelastic material incorporating at least a portion of the additive; iv. shaping the material incorporating the additive to thereby form a shaped material incorporating the additive; and v. Optionally, removing at least a portion of said incorporated additive from said molded material incorporating said additive. Including, wherein the additive solidifies, hardens and / or stiffens when exposed to a change in condition other than water and selected from thermal, magnetic, electrical, chemical and / or electromagnetic conditions; A method is provided.

[0031] Further aspects of the present invention, which should be considered in all its novel aspects, will become apparent to those skilled in the art upon reading the following description, which provides at least one example of a practical application of the invention.

[0032] One or more embodiments of the present invention are described below, by way of example only, and not by way of limitation, with reference to the following drawings: [Brief explanation of the drawings]

[0033] [Figure 1] FIG. 1 shows a schematic flow chart for a process for incorporating a wax additive into a foam material and securing the material to a machined surface. [Figure 2] FIG. 1 shows a schematic flow chart of a process for single or double sided machining of foam material incorporating wax. [Figure 3] FIG. 1 shows a schematic flow chart of a process for removing at least a portion of an incorporated wax additive from a foam material. [Figure 4] FIG. 1 shows a schematic flow chart of the method of the present invention as applied to a number of shaped materials. [Figure 5]FIG. 1 shows a schematic flow chart for a method of the present invention in which a solid additive is used to produce a molded article. [Figure 6] FIG. 1 shows a schematic flow chart of several embodiments of the method of the present invention that includes contacting a foam with an additive. [Figure 7] FIG. 1 shows a schematic flow chart for the use of a container as a mold. [Figure 8] 1 shows a schematic flow chart for a process using solid granules, powders, etc. and other additives, which can optionally be manipulated by solids or other external stimuli. [Figure 9] FIG. 1 shows a schematic flow chart for a process where the addition or removal of heat can be used to modify the properties of an additive. [Figure 10] FIG. 10 shows a schematic flow chart of the continuing process therefor shown in FIG. 9. [Figure 11] FIG. 1 shows a schematic flow chart of the additive removal process. [Figure 12] FIG. 10 shows a schematic flow chart of the process in which a mold is used to create an impression in foam prior to CNC machining. [Figure 13] 1 shows a schematic flow chart of the process in which a mold is used to create an impression in foam prior to CNC machining. The diagram does not necessarily indicate the order of operations or any relationship between the steps on the page.

[0034] Foam is used as an example and for illustrative purposes only.

[0035] The vacuum bag is intended only to demonstrate by example. The vacuum bag can be arranged in other suitable configurations, such as sealing a suitable sheet to a solid plate so that the sheets can come together when under vacuum, or as a flexible gusset fastened between two solid plates. The plates can have one or more inlets / outlets as separate openings or valves; or multiple openings or valves that can converge via a manifold.

[0036] The press may be mechanical or manual; or manually operated; or a combination of bag configurations as described above that are mechanically or manually compressed.

[0037] [Detailed Description of the Invention] As used herein, the expression "elastic or viscoelastic" material refers to a material that: i. Resilient (elastic); or ii. Refers to a class of materials that are substantially deformable and elastic (viscoelastic) such that some energy is dissipated in the process of deforming from a first position to a second position and then substantially returning to the first position.

[0038] The material of the present invention comprises a matrix of solid material having a plurality of interstices, such as a network of voids. Examples of interstices include cells with incomplete wall region(s); tunnels; channels; holes; void platelets; interstitial spaces, etc. The interstices may be fluidly connected so that additives can penetrate the material through the network of voids, etc. The interstices may be arranged in a series of interstices, such as in a honeycomb material. Such interstices may or may not be in fluid communication with one or more other interstices. Nevertheless, such interstices are capable of having additives added to and / or removed from them. Preferably, such interstices are capable of having additives added to and removed from them.

[0039] Thus, the material of the present invention: Materials that are incapable of having additives added to them, and / or Materials that are incapable of having additives removed from them, and / or It should be distinguished from materials that do not contain a network of fluidly communicating voids, and typically contain a significant number of individual bubbles of gas.

[0040] By way of example only, open-cell foam is an elastic or viscoelastic material having a network of voids that can be used in the methods of the present invention, and closed-cell foam is not an elastic or viscoelastic material having a network of voids that can be used in the methods of the present invention.

[0041] As used herein, "void" refers to a space within a material that may be filled with, for example, a gas, a liquid, or some other material other than an elastic or viscoelastic material. A void is generally a small space, but can nevertheless be filled with, for example, a gas, a liquid, or some other material other than an elastic or viscoelastic material. The voids may be regularly shaped or irregularly shaped. The voids may be of the same size or different sizes. For example, in a foam, the voids generally consist of a series of spaces of different sizes. The size of a given void may be measured in several ways, including by a minimum, maximum, or average linear dimension. It may be convenient to measure the size of the void across two or more axes, such as two orthogonal axes, by an average linear dimension. The minimum size limit is generally limited only by the ability of a gas, liquid, or some other material other than an elastic or viscoelastic material to penetrate at least a portion of the void(s). Although the maximum size limit is generally unlimited, gaps having an average linear dimension on the order of up to about 1000 mm, e.g., up to about 500 mm, e.g., up to about 300 mm, e.g., up to about 100 mm, e.g., up to about 50 mm, e.g., up to about 25 mm, e.g., up to about 10 mm, e.g., up to about 5 mm, e.g., up to about 2 mm, e.g., up to about 1 mm, are preferred. In some embodiments, the gaps are at least 0.001 mm in size, e.g., at least 0.01 mm in size, e.g., at least 0.1 mm in size. It will be appreciated that some techniques, such as polyurethane emulsion polymerization, may be used to form materials with multiple gaps. Such techniques generally produce materials with gaps having a distribution of sizes. Thus, in some embodiments, the dimensional limits described herein apply to at least 60% of the gaps, e.g., at least 70% of the gaps, e.g., at least 80% of the gaps, e.g., at least 90% of the gaps, e.g., at least 95% of the gaps. In some embodiments, the dimensional limits stated herein apply to 100% of the gap.

[0042] As used herein, plural means two or more. It is generally the case that the elastic or viscoelastic material has at least some (3) pores, such as many pores, as well as a plurality of pores. The elastic or viscoelastic material may have at least 5, such as at least 10, such as at least 20, such as at least 50, such as at least 100, such as at least 500, such as at least 1000 pores.

[0043] As used herein, "void" refers to a space within a material that may be filled with, for example, a gas, liquid, or some other material other than the elastic or viscoelastic material. Voids are generally small spaces, but may nevertheless be filled with, for example, a gas, liquid, or some other material other than the elastic or viscoelastic material. Voids may be regularly shaped or irregularly shaped. Voids may be the same size or different sizes. For example, in foams, voids generally consist of a series of spaces of different dimensions. The size of a given void may be measured in several ways, including by the minimum, maximum, or average linear dimension. It may be convenient to measure the size of the void(s) across two or more axes, such as two orthogonal axes, by the average linear dimension. The minimum size limit is generally limited only by the ability of a gas, liquid, or some other material other than the elastic or viscoelastic material to penetrate at least a portion of the void(s). Although the maximum size limit is generally unlimited, voids having an average linear dimension on the order of up to about 1000 mm, e.g., up to about 500 mm, e.g., up to about 300 mm, e.g., up to about 100 mm, e.g., up to about 50 mm, e.g., up to about 25 mm, e.g., up to about 10 mm, e.g., up to about 5 mm, e.g., up to about 2 mm, e.g., up to about 1 mm, are preferred. In some embodiments, the interstices are on the order of at least 0.001 mm in size, e.g., at least 0.01 mm in size, e.g., at least 0.1 mm in size. It will be appreciated that several techniques, such as polyurethane emulsion polymerization, may be used to form materials with a network of voids. Such techniques generally produce materials with voids having a distribution of sizes. Thus, in some embodiments, the dimensional limits set forth herein apply to at least 60% of the voids, e.g., at least 70% of the voids, e.g., at least 80% of the voids, e.g., at least 90% of the voids, e.g., at least 95% of the voids. In some embodiments, the dimensional limits set forth herein apply to 100% of the voids.

[0044] It will be understood that not all of the voids in the material of the present invention are necessarily in fluid communication with one another. For the purposes of the present invention, it is sufficient that a significant number (e.g., at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%) are in fluid communication with one another. Thus, the term "void network" as used herein refers to a significant number (e.g., at least 10%) of voids that are in fluid communication with one another. Typically, at least 50% (e.g., at least 60%, at least 70%, at least 80%, at least 90%) of the voids are in fluid communication with one another.

[0045] One example of a material with multiple voids, where each void is not necessarily an interconnected cell, but is otherwise functionally identical to the more extensively reticulated and voided material described immediately above, is a flexible, elongated honeycomb material that is open-celled, but where additives do not pass easily (or at all) from cell to cell. This is a common material and can be used as a substitute for regular flexible polyurethane foam. Another example may be gill-like, such that it contains many elongated members (such as plates, wings, or rods), or resemble a soft, flexible heat sink. In such an example, the material may have voids (between the elongated members) but no substantial interconnections between the voids.

[0046] Other such materials of the present invention having multiple interstices can be described as brush-like in appearance, with the material having parallel or linear filaments (and which may be anchored at one or both ends). For example, materials having the appearance of dense silicone brushes can be molded using the disclosed invention. The purpose may be for small-scale production of contoured brushes or for prototyping or creating various vibration damping and buffering systems.

[0047] It will be understood that the present invention is premised, in part, on the ability of the additive to penetrate the material through interstices such as voids. Thus, the interstices (such as voids) are limited only by the requirement that the dimensions and other properties (including the chemical and / or physical properties of the matrix surrounding the material) allow the additive to penetrate through the interstices to a sufficient extent to enable the method of the present invention to be carried out.

[0048] Materials with multiple interstices (e.g., a network of voids) can be formed in many ways, such as by incorporating an expanding agent, such as sodium bicarbonate, into the material in some embodiments, such that the agent will outgas when the material is exposed to certain conditions, such as heating. Examples of such materials with multiple interstices (e.g., a network of voids) include foams, felts, lattices, and the like. Scaffolds , Coiled material (coiled materials) , meshes and webs. Preferably, the material of the present invention is a foam, and while it is convenient (for purposes of illustration only) to describe the invention in terms of foams, it will be understood that the general principles described herein may apply to any elastic or viscoelastic material having a plurality of interstices (such as a network of voids). Foams may be formed at least partially, if not entirely, from polymers that are natural or synthetic.

[0049] It will be appreciated that there are many known materials that have multiple interstices (e.g., a network of voids) that are neither elastic nor viscoelastic. Such materials include ceramic foams; metal foams; rigid foams (e.g., expanded polystyrene (EPS) and extruded polystyrene (XPS)); and rigid grade foams (e.g., rigid polyurethane (PU), rigid melamine foam). Such materials are not contemplated by the present invention for reasons discussed below, including that the method of the present invention can advantageously utilize the elasticity or viscoelasticity of the material to incorporate additives. Without these properties, the incorporation and subsequent removal of additives is more difficult to achieve.

[0050] It will be appreciated that the material should preferably be selected so as to be substantially resistant to the physical and / or chemical conditions to which it will be exposed in the method of the present invention.

[0051] As used herein, the term "additive" refers to a component that is separate from the elastic or viscoelastic material and that can be incorporated into at least a portion of the interstices (such as the network of voids) of the material. Examples of additives include: Waxes or waxy compounds and mixtures thereof. The waxes may preferably be water-insoluble. The waxy compounds may be water-soluble, such as PEG, panthenol, waxy emulsifiers and mixtures thereof; Crystalline solids / supersaturated liquids (e.g., supersaturated solutions that are stable at room temperature (e.g., sodium acetate trihydrate or similar); supersaturated solutions that are not stable at room temperature but require less heating to remain liquid than, for example, pure molten sucrose; crystalline materials in the molten state (such as sucrose) that crystallize upon cooling (this example may also include one or more modifiers to lower the melting point)). Salts and sugar alcohols may be used. Eutectic mixtures of sugar alcohols with other mixtures may also be utilized; liquid crystalline compounds (e.g., electroactive liquids that self-assemble to form more rigid materials and provide some resistance, e.g., electroactive materials consisting of solutions containing amphiphilic mesogens that can gel or stiffen in response to an electrical stimulus and can be reversible if not water soluble to removal); Solidifying non-Newtonian compounds, including those that solidify upon machining (e.g., cornstarch and water, which stiffen in response to applied cutting forces - such examples may also benefit from applied sonic vibration; cornstarch and oil as electrorheological liquids, which stiffen upon application of an electrical stimulus. Advantages include control of airborne particulates and the apparent self-healing properties of some such materials, which can flow into previously cut gaps (such as voids); Granules / powders / other solids (e.g., ferrous powder or granules (e.g., iron powder) that can flow into some materials with multiple interstices (such as a network of voids) and then form a quasi-solid upon application of magnetic stimulation (i.e., the friction between the granule and the foam essentially locks it in place). Such powders / granules can be removed in liquids by gravity and / or sonic agitation, optionally in combination with and / or to enhance magnetic forces). In general, the advantage of using magnets to remove powders or granules is the ease with which the powder or granules can be separated from waste materials; Granules / powder / other solids that can flow into some materials with multiple interstices (such as a network of voids) without magnetic influence or other condition changes. For example, a foam may be fixed in a container with walls; additive powder is shaken into the multiple interstices (such as a network of voids) of the foam and any space between the foam and the wall of the container; a foam containing powder additives is placed in a packed and supported condition so that the foam and additives can be formed, and then the formed foam is shaken to remove the powder additive (such as after removal from the container). The nominal advantages of using granules / powder / other solids that can flow into some materials with multiple interstices (such as a network of voids) are: the powder can be shaken in, shaken out, or melted out if necessary, thereby reducing energy requirements with virtually no heating; shorter processing times because the additives do not require cooling; little or no change in size of filled and empty foams due to the lack of thermal expansion; Granules / powder / other solids that can undergo a change in condition, such as melting. In such an example, the granules / powder / other solids can flow into some materials with multiple interstices (such as a network of voids). For example, a foam may be fixed in a container with walls; additive powder is shaken into the multiple interstices (such as a network of voids) of the foam and any space between the foam and the container wall; the foam containing the powder additive is placed in a packed and supported condition so that the foam and additive can be molded; by applying heat to the packed and supported foam before shaking the molded foam to remove the powder additive (such as after removing it from the container), the granules / powder / other solids on the outer surface of the composite can melt, creating a partial or complete seal between the granules / powder / other solid and the foam composite. Similarly, the bottom surface can be melted and adhered to, for example, a work surface. The nominal advantages of using granules / powders / other solids that can flow into some materials with multiple interstices (such as a network of voids) are: reduced energy requirements with virtually no heating since the powder can be shaken in, shaken out, or melted out if necessary; shorter processing times since the additive does not require cooling; little or no change in size of filled and empty foams since there is no thermal expansion; Liquids that can be hardened or arranged and oriented to become more rigid by other means (e.g., ferrofluids; which harden in response to a stimulus and return to a liquid when it is removed; starch solutions that are left to dry or harden using heat; proteins such as gelatin / collagen that are provided in solution form and then undergo intermolecular gelation).

[0052] Preferably, the additive is a wax or waxy compound.

[0053] As used herein, the expression "wax or waxy compound" refers to a compound that solidifies, hardens, and / or rigidifies sufficiently above the freezing point of water (0°C at standard atmospheric pressure, 101.325 kPa) to facilitate the performance of the methods of the present invention to enable the production of desired shaped materials, but that melts or softens without decomposition at temperatures above about 60°C (e.g., above about 50°C, e.g., above about 40°C). More typically, "wax or waxy compound" refers to a compound that generally solidifies, hardens, and / or rigidifies above 15°C (such as above 20°C), but that melts or softens without decomposition at temperatures above about 60°C (or above about 50°C, or above about 40°C). By way of example only, such a wax or waxy compound can be considered a grease-like additive that flows above 25°C, becomes almost a gel just below 25°C, and is machinable (albeit of poor quality) at any temperature below this, but that improves machining results when cooled below 0°C. An example of such a grease-like additive is a partially hydrogenated oil that is paste-like or gel-like at 25°C, but above this point becomes flowable and can penetrate the foam. Such an additive can remain stable in the foam at 25°C, giving increasingly machinable results as the temperature decreases. Below 0°C, it can become as stiff as paraffin wax at 25°C. In contrast to water, such a grease-like additive is well-bound in the voids of the foam above the additive's freezing point, which includes the machinable temperature of 25°C.

[0054] Waxes are generally organic in nature (generally aliphatic hydrocarbons) and insoluble in water at room temperature. Waxes can also be wetted by water and can form creams, gels, and / or pastes in some solvents, such as non-polar organic solvents. Waxes can be dissolved in some non-polar organic solvents, usually with the addition of heat. Waxes can spontaneously emulsify in the presence of some liquids to form microemulsions and / or can form emulsions with some liquids in the presence of surfactant(s).

[0055] The wax may have a melting point ranging from about 40° C. to about 150° C. In this sense, melting may also occur below 40° C. to a sufficient extent to facilitate incorporation within the interstices (such as the network of voids) of the material. It will be understood that incorporation may be achieved even if only a portion of the wax is substantially liquid and the remaining portion is, for example, microcrystalline.

[0056] Waxes can also be defined by viscosity. Viscosity measures the internal resistance of a material to flow, where a material with a high viscosity is considered "thicker" and less fluid than a material with a low viscosity. The melt viscosity of waxes can range from low to high and generally depends on the wax's molecular weight, crystallinity, and whether the wax is oxidized or copolymerized. Increasing the wax's molecular weight and density increases the wax's melt viscosity, while increasing the wax's crystallinity decreases the melt viscosity. Wax friability, i.e., its affinity for particle size reduction by mechanical force, increases with increasing crystallinity and decreases with increasing wax density and molecular weight. The melt viscosity of waxes is generally low above the melting point.

[0057] Suitable waxes include natural and synthetic waxes. Suitable waxes may include: Animal waxes (such as beeswax, China wax, shellac wax, spermaceti and wool wax (lanolin)); Vegetable waxes and hydrogenated vegetable oils (e.g. white bayberry wax, carnauba wax, castor wax, esparto wax, Japan wax, jojoba wax, ouricle wax, rice bran wax, soybean wax and hydrogenated oils from vegetable waxes - especially those that are pastes / greases at room temperature); mineral waxes (such as ceresin wax, montan wax, ozocerite wax and peat wax); Petroleum waxes (e.g., paraffin wax and microcrystalline wax); and Synthetic waxes (e.g., polyolefin waxes, including polyethylene waxes and polypropylene waxes, wax-grade polytetrafluoroethylene waxes (waxy grades of PTFE), Fischer-Tropsch waxes, stearamide waxes (including ethylene bisstearamide waxes), polymerized alpha-olefin waxes, substituted amide waxes (e.g., esterified or saponified substituted amide waxes), polyethers (e.g., polyethylene glycol, e.g., PEG 2000), and other chemically modified waxes, such as PTFE-modified polyethylene waxes). and combinations of the above. Of these, preferred waxes include hydrogenated vegetable waxes (e.g., palm wax and soy wax) and polyethers (e.g., polyethylene glycol). Hydrogenated vegetable oils and the solid fractions of lanolin are particularly preferred for the environmentally sustainable benefits they offer to the process and products of the present invention. Otherwise, paraffin, microcrystalline, and various synthetic waxes are preferred.

[0058] It will also be appreciated that many other additives such as sugars, sugar alcohols, salts, iron powder, etc. may also be desirable from an environmental / sustainable / resource recyclability perspective.

[0059] Other examples of additives include dry ferrous iron powder or compositions (such as colloids) containing ferrous iron particles, the properties of which can be tuned by magnetic stimulation to orient the foam to stiffen upon incorporation. Further examples of additives include non-Newtonian materials that stiffen in response to a stimulus, such as a high-frequency mechanical wave; or liquid crystals that are configured into a stiffened state upon electrical stimulation. These examples allow for tuning of the additive's properties and can increase the ease of additive removal.

[0060] Specific examples of additives that have been tested in the processes described herein include the following, which are listed along with their observed benefits: PEG1000-3000 - Hardness, machinability, airborne particle reduction, melting point, water solubility PEG3000-20000 - Hardness, machinability, airborne particle reduction, melting point, water solubility Paraffin Wax - Hardness, machinability, airborne particle reduction, melting point Additives with additional qualities related to sustainability, renewable and environmental impact include: Xylitol, erythritol, sorbitol; eutectic mixtures of erythritol / xylitol and erythritol / sorbitol, sorbitol / xylitol - hardness, melting point, machinability, water solubility Behentrimonium methosulfate 25, Glyceryl monostearate, Stearic acid - Hardness, melting point, machinability, reduction of airborne particles Sodium Acetate Trihydrate - Hardness, Melting Point, Machinability, Water Solubility Soy, Palm, Castor Oil Waxes and Blends - Hardness, Melting Point, Machinability, Airborne Particulate Reduction Isosorbide and 1,6-Hexanediol - Hardness, melting point, machinability, airborne particulate reduction Starch / water mixture - water soluble, machinable, reduces airborne particles Iron powder - hardness, machinability If the intention is to swell a material with multiple interstices (such as a network of voids), such as a foam (such as polyurethane), then the following non-exhaustive list of additives for machining is preferred: Trimethyl citrate, pantolactone (racemic), diacetone acrylamide, methyl nicotinate - Hardness, melting point, machinability, water solubility Crotonic acid - hardness, melting point, machinability, water solubility and precipitation from cold solution.

[0061] As used herein, the term "contacting" in the phrase "contacting a material with an additive such that at least a portion of the additive is incorporated into at least a portion of the interstices (such as the network of voids) of the material" refers to any process that brings the material and the additive into intimate contact such that at least a portion of the additive is incorporated in such a manner. In this context, the term "partial" may refer to at least 5%, such as at least 10%, for example at least 15%, for example at least 20%, for example at least 25%, for example at least 30%, for example at least 35%, for example at least 40%, for example at least 45%, for example at least 50%, for example at least 55%, for example at least 60%, for example at least 65%, for example at least 70%, for example at least 75%, for example at least 80%, for example at least 85%, for example at least 90%, for example at least 95%. The material may or may not be fully saturated with the additive (100% incorporation of the additive into the interstices). The process may involve the use of any one or more of the following: pouring; immersion; shaking; vibration; the use of reduced pressure (such as by application of a vacuum); the use of increased pressure. Such methods may also utilize a combination of such techniques.

[0062] The use of reduced pressure may involve placing the material and additive in a fixed-volume vacuum chamber or a variable-volume vacuum chamber (such as a bag), and then at a later stage, the pressure in the chamber is reduced, thereby allowing gas incorporated in the material to expand, escape from the material, and be replaced with the additive. In one embodiment, the foam material is placed in a bag, the gaseous contents of the bag are removed by vacuum, the foam is compressed, and then the additive is introduced into the vacuum chamber while expanding the foam, and / or the foam is expanded to incorporate the additive. The additive can be introduced into the vacuum chamber through the same or a separate port in such a manner that the vacuum in the chamber is reduced and the material expands (such as by using a peristaltic pump). This vacuum method can be particularly useful when incorporating molten wax within the foam, although it is generally desirable to ensure incomplete saturation in such embodiments. In some embodiments, materials having multiple voids (such as a network of voids), such as foams and solid additives, are placed in a vacuum bag; a vacuum is applied to the bag through an opening, compressing the material and extracting all or some of the air; the outlet is then sealed, and the vacuum bag is heated (such as by placing it in a heated liquid) to melt the additive, thereby drawing the molten additive into the material as it melts, resulting in a material fully expanded with additive throughout when the contents of the bag are returned to atmospheric pressure. Some nominal advantages of this method include: simpler equipment requiring less space and less exposure to leaks and hazards; improved repeatability and consistency due to the measurement of the weight of additive required; and fewer pipes requiring heating, improving reliability and preventing premature curing and blockage.

[0063] In some embodiments, a molded vacuum bag may be used to act as a mold so that materials with voids (e.g., voids, e.g., foam) can cool and harden without being removed from the bag. The vacuum bag can be molded itself or consist of one or more solid members with a shape (e.g., two solid plates with a silicone gusset or skirt connecting the two; or one plate with a vacuum sheet sealed around the periphery). When vacuum is applied, it exerts planar pressure across the material, and when the vacuum is released, it provides a flat surface for the material to cool. In some cases, the bottom plate exists as the intended work surface and can be placed on the machine floor for shaping. Alternatively, one or more plates can be molded (such as a mold). Nominal advantages include: simpler equipment requiring less space and less exposure to leaks and hazards; and the material (e.g., foam) is consistently flat and square when hardened. When using a two plate device for thinner sheets, it can gently sandwich / limit distortion, reducing warpage; and / or reducing process time and energy requirements for specific requirements (when smaller pieces are required or preparation of large slabs of material is not possible).

[0064] In some embodiments, additives may be used to expand materials with multiple interstices (e.g., a network of voids). For example, a material (e.g., a foam) may be contacted with an additive, which swells the material; while the material is swollen, the additive hardens; the material is molded; and the additive is then removed, causing the material to return to its original size. The method offers nominal advantages: it can improve infiltration of very fine foams by increasing the overall size of the material, thus improving the flow of additives into the material; and molding at an enlarged size improves machining resolution.

[0065] Another variation on the use of reduced pressure is the application of a force to an elastic or viscoelastic material having a plurality of voids (such as a network of voids) such that the material compresses and expels at least a portion of the void contents from the material. When the force is relaxed in the presence of an additive, the material thereby expands, incorporating at least a portion of the additive in the material. For example, a foam can be submerged in a bath or bag of liquid wax, the foam can be compressed to expel some of the incorporated gas, and then expanded to incorporate some of the liquid wax from the bath. In some embodiments, it is desirable to saturate the material with the additive, while in other embodiments, it is desirable to only partially saturate the material with the additive. In this example, the amount of gas expelled can vary depending on the degree of compression of the material. The amount of gas present in the material can also be controlled by several techniques, including withdrawing the partially compressed material from the bath before fully expanding the material. Another technique involves only partially compressing the material so that the product material incorporates some of the additive and some of the gas. In a further technique, the material is preferentially impregnated unevenly, e.g., from one side of the material, such that the material incorporates the additive to a greater extent on one side than on other portions of the material. It has been found that such a method allows a user to produce a material incorporating a desired ratio of gas and wax. Similar method(s) can be applied to other materials and / or additives. It will be appreciated that the ability to compress an elastic or viscoelastic material having multiple voids (such as a network of voids) represents a significant departure from previous methods used with non-elastic or non-viscoelastic materials.

[0066] Advantageously, the method of the present invention allows for control of the amount of additive incorporated and also control of where the additive is incorporated within the material. For example, the additive can be focused in specific areas to enhance the process and / or product. For example, a certain amount of wax can be incorporated into the foam just enough to coat the surfaces of the voids and immobilize most of the foam. As another example, a certain amount of wax can be incorporated only into the upper, machined layer of the foam, thereby substantially stiffening the material and providing a higher quality surface finish. Controlling the amount of additive incorporated into the material may allow for a reduction in the amount of additive needed, thereby facilitating easier removal of the additive.

[0067] Although the process of contacting the material with the additive has been described mostly for foams and waxes, the use of non-flowable additives is also contemplated. For example, additives in granular, powder, or mixtures thereof, particularly those that are flowable, can be incorporated into the material by pouring, or even by the use of vacuum, particularly if the additive is capable of being airborne.

[0068] As used herein, the phrase "exposing a material to conditions such that at least a portion of the incorporated additives solidify, harden, and / or stiffen" refers to applying one or more external stimuli to modify the conditions experienced by the material and additives. Examples of such stimuli include magnetic, electrical, thermal, chemical, mechanical, and electromagnetic.

[0069] Typically, the stimulus is a thermal stimulus, e.g., a stimulus that causes a decrease in the temperature of the additive. For example, the stimulus may simply be a decrease in the temperature of the environment in which the additive (and the material incorporating the additive) resides, such that the additive's temperature decreases, causing the additive to solidify, harden, and / or stiffen, as would be expected if the wax were to change from a liquid state to a substantially solid state.

[0070] As indicated above, other examples of stimulation include magnetic stimulation; application of force (including shear), such as by application of high frequency mechanical waves; or application of electrical stimulation.

[0071] In some embodiments, it may be desirable to further manipulate the material before molding. Examples of manipulations may include pressing, embossing, molding, folding, joining, splicing, and / or inserting pieces of material before the additive is cured or incorporated. This may include preforming a shape (such as a mold), machining multiple connected / spliced pieces of material smoothly, or pressing / compressing a material to reduce the amount of additive required. For example, preforming or compressing a material containing additives can be used to simplify and speed up some operations. In such embodiments, for example, when replicating a shape, compression can generally occur using a positive mold (and mirror image). For example, to create a foam hemisphere, the mold is a positive hemisphere, and when pressed into the foam, the highest point of the hemisphere is the lowest / most compressed part of the foam, embossing a negative impression into the foam. Thus, the method includes the following steps: contacting a foam with an additive and then placing it in a mold that compresses and embosses a hemisphere in the center; allowing the foam and additive to harden in the mold; the hemispherical embossment is substantially lower than the rest of the foam, thus excluding it from the cutting operation; if the foam in this case is merely ground or flattened to the depth of the embossment, the resulting foam will have a positive hemispherical shape that protrudes higher than the rest of the foam when the additive is removed. In another embodiment, the method includes the following steps: stamping a sheet of foam with a liquid additive using a positive mold; hardening the additive and maintaining the compressed or embossed state; cutting the material to remove the uncompressed portion; heating the additive and removing it to reveal a positive replica of the mold. Such a process can be advantageous for quickly creating standard or general shapes of articles before proceeding with further molding, or for easily creating textures that would otherwise be time-consuming to form. This may be used as an alternative to a foam convoluter, but includes removing additives that can retain their shape until they are removed.Additional benefits are believed to be: more complex shapes can be formed; further machining can be performed on the compressed foam; it is not limited to roller compression; foam slab material with a compressed shape or texture ready for further shaping can be maintained at room temperature; and mass production of items using the original method is possible. A possible additional benefit is that the pre-compressed foam blank can contain, for example, the impression of a standard wheelchair seat. Thus, one cutting path can provide the basic shape, and subsequent paths can be calculated to customize the shape for a specific customer. This effectively reduces the required cutting depth, increasing speed and reducing additive volume. Furthermore, the compressed foam is not permanently formed until the foam material is removed by machining. For example, a foam sheet containing a convoluted embossment can be heated, and the foam will return to a normal square foam sheet. When cut flat across it, it produces a convoluted sheet. Once the compressed shape and dimensions are known, it is still possible to shape the foam beyond the impression shape by corrections, such as machining the compressed portion to remove selected peaks of convolution. or the convoluted trough can be eliminated by not machining the uncompressed portion. Overall, these processes allow the core method of the present invention to be scaled from custom fabrication to more advanced mass production, including the addition of flexibility and customization. In such embodiments, the compression process can be by, for example, compressing before cooling; partially saturating the foam, cooling, and then pressing and bonding the compressed cells; or using a cold press to quickly harden the foam portion. Alternatively, this can be done using variations of the additives described above (powders, waxes, dry powdered additives, etc.), each with their own advantages. Obviously, these processes can be coupled with the core method of the present invention by using compression / embossing on one side and performing more complex machining on the other side.

[0072] Before and / or during the material-shaping process, the material is typically held securely in place such that the shaping device, e.g., mobile, moves around the immobilized material. Advantageously, certain embodiments of the present invention allow the material to be securely fixed to a surface in a manner that also allows for relatively easy removal of the material from the surface upon completion of the shaping process. In particular, heated / cooled work surfaces can be used, such as those provided by hydronic heat transfer. If an additive, such as wax, solidifies, hardens, and / or stiffens as a result of a temperature reduction, a foam incorporating the additive can be placed on a surface at a given elevated temperature (generally above the wax's melting temperature) and secured to the surface by lowering the surface's temperature, e.g., below the wax's melting temperature. Materials subjected to these conditions have been found to remain secured to the surface sufficiently to allow the shaping process to occur. Upon completion of the shaping process, the surface's temperature can be increased, allowing the material to loosen, be removed, and / or be repositioned. Such techniques offer significant advantages over previously published processes that require the use of clamps, strong adhesives (e.g., super glue), which are understood to damage the material and limit the possible machining geometries.

[0073] As used herein, the phrase "shaping a material" refers to any process by which a material is modified from one shape to a different shape. Generally, the present invention includes hand shaping and machining. Removal Examples of machining processes include computer numerically controlled (CNC) machining (such as contour machining). Such machining can be performed on lathes, mills, turn This includes the use of mills, multi-axis machine arms, multi-axis water jets, lasers, hot wires, sonic knives, reciprocating blades / saws, knives, and ablative tools.

[0074] Preferably, the machining process is CNC machining Use , this is including the depth or edge of a definable tool See, remove Machining examples YesSuch processes with definable tool depths or edges are generally performed using spindles (mills and turn Mill) or spindle and non-rotating feed tool (lathe and turn Mill) combination of , ultrasonic tools (non-rotary cutting machines), reciprocating tools (reciprocating motion and Concentric cutting machines), concentric rotary tools, grinding / sanding / fileting / burring tools.

[0075] Such processes having a definable tool depth or edge generally exclude processes such as lasers, water jets, plasma cutters, and air jets as well as band saws, chainsaws, and wire cutters, which do not cut at a guide location or radius.

[0076] As used herein, the phrase "removing at least a portion" of an incorporated additive refers to a process such as: agitating the material incorporating the additive (e.g., shaking, vibrating, compressing (which may be slow or fast; any number of compression / expansion cycles), or using centrifugal force) so that at least a portion of the additive is broken down and becomes unincorporated, at a stage where the unincorporated additive can be isolated; The material incorporating the additive is placed in a bath of liquid, optionally followed by agitation (e.g., shaking, vibrating, compressing, or using centrifugal force). The liquid bath may be at a different temperature (e.g., a heating device) than the material before being placed in the bath. The liquid may be a liquid that is immiscible with the additive. In one embodiment, the additive (e.g., wax) melts, becomes unincorporated, and separates from the material. For example: The material incorporating the wax can be placed in a bath of warm water and agitated so that the wax melts, separates from the material, partitions from the warm water, and accumulates on the surface of the warm water; Materials incorporating wax may also optionally incorporate a surfactant in admixture with the wax: when placed in an (optionally warm) bath of water and agitated, the wax melts, the surfactant solvates, and an emulsion of wax and surfactant forms; The material incorporating the wax can be placed in a bath of water (optionally warm) incorporating a surfactant, so that the wax (optionally melted) separates from the material and emulsifies in the water; A material incorporating wax can be placed in an (optionally warm) bath of solvent (capable of solvating the wax), and the material can be agitated so that the wax (optionally molten) separates from the material and dissolves in the solvent.

[0077] Agitating the material (e.g., shaking, vibrating, compressing (which may be slow or fast; any number of compression / expansion cycles), or using centrifugal force) while the material is subjected to heating so that at least a portion of the incorporated additive melts and flows out of the material. For example: In one such embodiment, this process may be accomplished by applying heat to the material incorporating the additive such that at least a portion of the additive melts, and then compressing the material to expel most of the additive from the material; In another such embodiment, both heat and compression can be applied continuously until the desired level of additive is removed; In another such embodiment, the material may be placed in a bag, the contents of which are subjected to a reduced pressure via vacuum, after which heat is applied to the bag to melt the additive, which can then be removed from the bag under vacuum.

[0078] It will be appreciated that any of the foregoing methods can be used to effect partial or complete removal of the additive from the material. Typically, such methods effect partial removal of the additive from the material. In such embodiments, it may be desirable to use a secondary removal process to remove any remaining additive. Such a secondary process may include any one or more of the removal techniques described above. For example: Applying the solvent to the material, optionally in combination with agitation (eg, shaking, vibrating, compressing, or using centrifugal force), to incorporate the remaining additives.

[0079] The step of removing at least a portion of the incorporated additives may be preceded by a further step of recovering the surfactant, wax and water for reuse.

[0080] In twelfth and thirteenth aspects, the present invention provides a method of forming a shaped elastic or viscoelastic material having a plurality of interstices (such as a network of voids), comprising the steps of: i. contacting the additive with a resin that can be cured to form an elastic or viscoelastic material in a container to form a mixture; ii. degassing the mixture, such as by vacuum, and / or mixing the mixture to form a homogeneous blend; iii. curing the resin to thereby form an elastic or viscoelastic material incorporating at least a portion of the additive; iv. shaping the material incorporating the additive to thereby form a shaped material incorporating the additive; and v. Optionally, removing at least a portion of said incorporated additive from said molded material incorporating said additive. Including, wherein the additive solidifies, hardens and / or stiffens when subjected to a change other than water and selected from thermal, magnetic, electrical, chemical and / or electromagnetic conditions; A method is provided.

[0081] This embodiment differs in some respects from the other embodiments in that the elastic or viscoelastic material is formed from a resin that is already in contact with an additive. However, it shares some similarities. In particular, the molded elastic or viscoelastic material that the method forms may be indistinguishable from molded elastic or viscoelastic materials formed by the other methods disclosed herein. The resin method may have certain advantages / disadvantages over methods that contact an additive with the elastic or viscoelastic material.

[0082] The resin can be shrinkable (by heating, electromagnetic radiation, electricity, etc.), so that the foam can be molded at a larger size and then shrunk. Nominal benefits of this method include enabling the molding of microstructures that would otherwise be too small to machine; and / or improved tooling precision—for example, molding at twice the size effectively doubles the machining tolerance when the material is finally shrunk. This resin technique can be applied to implant development; soft robotics; and the replication of very small biological structures. In the case of soft robotics, the resin can be reversibly controlled, providing novel types of multi-cell pumps or muscle analogs. This technique can also be paired with 3D printing, whereby an additive is 3D printed to form the desired voids (such as a network of voids) and coated into the resin; and the additive and resin are 3D printed. As is apparent, this tenth aspect is fundamentally different from 3D printing of a shrinkable resin per se, as that method does not involve the use of the additives and subsequent machining steps defined herein.

[0083] In some embodiments, the additive may comprise a mixture that is aerated, has a sufficiently low vapor pressure, or can outgas prior to bead formation. In such cases, the method may include the following steps: combining the additive (such as beads) with the resin; curing the resin; placing the cured resin containing the additive in a vacuum chamber with a sealed skin around its exterior to produce the cured resin containing the additive in the form of a foam incorporating the additive as a spacer; increasing the temperature of the vacuum chamber and reducing the pressure (in the event that, in the case of an aerated additive, the trapped air expands, thus expanding the bubbles in the foam); cooling and hardening the additive to maintain the expanded state of the foam at normal atmospheric pressure; molding the expanded foam to break the sealed outer skin; and heating the material to remove the additive and allow the foam to return to its original size.

[0084] Many of the above-described processes for additive removal advantageously avoid the use of hazardous solvents (compared to previously published methods), thereby reducing the hazards, storage, and costs associated with solvents in previously published methods.

[0085] The present invention increases the variety of materials suitable for the method, as the additive and removal method do not damage the material if solvents can be avoided, but solvent compatibility is not consistent across all materials (especially foams).

[0086] An additional advantage is the ease of emulsification, especially when the additive is incorporated in admixture with a surfactant, whereby the use of agitation combined with the proximity of the surfactant to the additive eliminates the problem of solvent penetration when removing deeply embedded additives such as may be found in much larger articles.

[0087] The present invention offers numerous advantages over previously published methods. Previously published methods did not address the environmental impact of those methods or disclose any innovative solutions. In contrast, the present invention allows for the recovery of additives, thereby providing an advanced environmentally sustainable method. For example, the ease of extraction and additive recovery allows for the reuse of additives, materials, and solvents (including water) in a closed-loop system. It has been discovered that the use of additives derived from sustainable, renewable resources can provide improvements in environmental sustainability. A further advantage is that the present invention can be adapted to such methods that increase adoptability, quality, time, and costs associated with storage and equipment by contracting one or more of the process steps with a third party. One such method may be to license a third party to perform the steps of incorporating additives into the material to reduce costs, increase quality, and improve consistency. The prepared material can be delivered to a third party who intends to perform the molding and additive removal of the material as needed. The third party can then collect the additives, prepare new material, and efficiently recycle the foam waste material. If necessary, a third party can perform further processing or reformulation of the additive if required, allowing a smaller entity to adopt the method and allowing a larger entity or new group specializing in additive handling and formulation, as well as handling of any waste materials, to focus on additive handling.

[0088] Another adaptation to reduce material waste facilitated by the present invention may be the preparation of molded foam blanks for machining, such as foam seating orthosis blanks, which can be machined to specific requirements instead of mass machining from a square foam block to arrive at the same shape as the orthosis blank.

[0089] A further advantage of the present invention is the control of particulate material (such as dust) during machining, as the additive binds to the waste material during machining, thereby effectively trapping the particulate material and thus eliminating the need for extraction equipment as airborne particles are largely eliminated.

[0090] An advantage over other methods of producing molded materials (such as foam articles) is the reduced storage required to store molds, which requires either large storage areas or the re-creation of molds from CAD files.

[0091] A further advantage is the ability to prepare materials with incorporated additives and store the prepared materials for extended periods without the need for specific storage conditions (such as refrigeration, which is required for some previously published methods). In this way, stockpiles of prepared materials (e.g., foams) can be made in large slabs or predetermined sizes and shapes. Pieces can be obtained from slabs only as needed, reducing waste and increasing cutting economy. Furthermore, by allowing a third party to prepare the material and supply it to the entity intending to mold it, the costs of the required equipment and space can be further reduced.

[0092] The present invention may also utilize 3D model making. In a departure from traditional methods of mold making, the use of minimal or no-contact 3D measurement, mapping, and / or tracking can be utilized to generate data that can be manipulated using CAD / CAM methods and the resulting output in form for machining. 3D measurement, mapping, and tracking can consist of typical medical imaging; MRI, CT, X-ray, or ultrasound, or 3D scanning, motion tracking, and mapping techniques, or pressure mapping and indentation mapping.

[0093] [Example] The following examples of the present invention are not exhaustive and are provided for illustrative purposes only.

[0094] An open-cell flexible foam block (2) (an example of an elastic or viscoelastic material with a network of voids) is prepared and shaped by machining. In one embodiment, the block (2) can be saturated into a mold (4) for complete additive incorporation. The mold can have an open bottom (10) to allow the block to be secured to the machine bed, or it can have a closed bottom (12) that allows the block to be moved and separated from the machine bed after the additive is incorporated. In either case, the block can optionally undergo partial addition / removal of any additives using a plunger (16). The mold can then be removed from the molded product and either secured to the machine bed (20) or separated from the machine bed (22). Once the additive-incorporated material (22) is separated from the machine bed, it can subsequently be secured to the machine bed by a separate heating step to remelt a portion of the wax (26) and secure it to the machine bed. In another embodiment, the block (2) can be contacted with hot molten wax in a bath (6), e.g., at 50-80°C, and optionally subjected to agitation by compression (14) using a plunger. The foam material can then be removed from the bath, and excess additive (18) can be poured out if partial saturation is desired. An optional secondary saturation step of one side (face) of the foam material (24) can be provided. In either case, the foam material can be secured to the machining surface by a separate heating step that remelts a portion of the wax (26) and secures it to the machining bed. In another embodiment, the block (2) can be placed in a bag (8) that applies a vacuum to reduce the air in the foam, after which hot wax can be pumped in to fill the air spaces and uniformly saturate the foam. After the foam material is removed from the bag, the foam material can be secured to the machining surface by a separate heating step that remelts a portion of the wax (26) and secures it to the machining bed.

[0095] The clamped material (28) can then be machined using a series of processes. In one embodiment, the material can be machined by one-sided machining (30), and the product can be removed from the machining bed by the application of heat (34). In another embodiment, the material can be machined by two-sided machining (32), which is achieved by leaving a boundary to create a trough. The trough (36) can be filled with wax or even a wax / waste (44) slurry until the top surface is at the machining level. The piece (38) can then be subjected to heat, removed from the bed (40), and then spun onto the machined surface and re-annealed (42). The spun piece can then be machined (46) into a two-sided machined product (48) and removed from the machining bed (50).

[0096] In an optional embodiment, the material can be placed in a hot bath of wax (52) to remelt the additives. Application of stripping and agitation (compression) (54) can be accomplished to remove most of the wax. Alternatively, the material can be placed in a bag that applies vacuum and heat to remove the molten wax from the foam material. The finished piece (58) can be washed, or a wax residue can be left behind to provide some degree of water repellency, conditioning, and / or antibacterial properties. Cleaning can be performed using a warm detergent (surfactant) solution in a bath; an ultrasonic bath using detergent and heat; continuous hot water flow or detergent; or a warm detergent bath with agitation or compression. Alternatively, a solvent can be used to regenerate the remaining wax by any of the appropriate aforementioned methods.

[0097] FIG. 4 shows that the method of the present invention can be applied to a mass-formed blank (60) as seen in step 1A, or to a formed blank (62) that is customized or machined to tolerances; or to the rework of previously formed material as seen in step 1B.

[0098] FIG. 5 illustrates an embodiment of the method of the present invention. In particular, step 1C illustrates an alternative process where a solid additive (64) is used to form voids in the resulting material when the additive is removed. Step 1 involves placing the solid additive (64) in a receptacle (66). Step 2 involves adding a bulk elastic / viscoelastic material (68). Step 3 involves degassing or mixing the additive and the aforementioned bulk material, if desired, and retaining it in the original receptacle or transferring it to another receptacle(s), followed by curing, hardening, and setting the bulk material. Step 4 involves shaping the hardened bulk material / additive mix. Step 5 involves completing a molding or further forming operation to achieve the desired shape. Step 6 involves heating the additive (70), which can be accomplished in a number of ways, with or without a vacuum bag. Step 7 involves removing the additive by means of vacuum (72) and / or compression (74). Step 8 provides the finished article. Further cleaning or processing may be undertaken, if desired.

[0099] As a specific example of the method, molten paraffin wax is dripped into a cold water bath at a constant rate to rapidly cool and form roughly spherically shaped beads. The paraffin is dripped from a height sufficient to form individual droplets, but not so high as to produce irregularly shaped pieces (e.g., flat, splattered shapes). A bath with constant annular flow directs the paraffin beads away from the point of release, minimizing bead fusion and clumping. The paraffin beads are removed from the bath and allowed to dry. The beads are placed in a rectangular container, and a two-component additive cure silicone is prepared and added to the container. The container containing the uncured silicone and beads is placed in a vacuum chamber and a reduced pressure is applied to remove unwanted pockets of trapped air. The container is removed from the vacuum chamber, and the silicone is allowed to cure. Once cured, the silicone containing the paraffin beads can be removed from the container, resulting in a rectangular silicone block containing the incorporated paraffin beads. The rectangular block is clamped to the work bed of a CNC router and machined to the desired shape. The machining process breaks the silicone skin, allowing the paraffin additive to be removed. The molded pieces are heated to melt them and then compressed to remove the paraffin. A detergent wash may be used to remove any unwanted residue. The final product is a molded, open-cell, elastomeric silicone foam.

[0100] In some embodiments, the additive beads can be selected from a range of suitable materials including waxes, waxy polymers, salts, sugars, sugar alcohols, etc. The described silicone "resins" can be substituted from a range of polymers characterized by properties such as elastic / viscoelastic, resilient, soft, flexible, etc. "Curing" in the descriptive sense can describe a range of known methods depending on the base material, such as drying, cross-linking with electromagnetic radiation, heating, or compounding.

[0101] Additionally, the additives may have secondary properties or be manipulated in a way that alters the final product. For example, prior to producing the molded beads, the additives may be agitated to incorporate air into the mixture so that the solid molded beads contain a portion of air throughout. A process to harden the silicone around the beads is then carried out, followed by heating the hardened silicone to melt the paraffin bead(s). The heated silicone is then placed in a vacuum chamber. A vacuum is applied, and the air bubbles dispersed throughout the additive expand. A skin formed around the outside of the silicone prevents air from escaping from the block of silicone material, thus expanding in size. The silicone piece is then cooled to an expanded state to retain its shape. The piece is then machined, and the additive is once again heated and removed, allowing the silicone piece to return to its original size. This process preferably involves the following events: Blending or melting the additive in such a way that the air bubbles do not agglomerate and are prevented from remaining in an expanded state; Expanding the silicone uniformly or predictably without interference with the outer skin; The strength of the additive upon expansion is sufficient to keep the silicone expanded for machining.

[0102] FIG. 6 illustrates various embodiments of the method of the present invention that include contacting a foam with an additive.

[0103] Step 2A includes several substeps: Sub-step 1 involves placing the foam (76) from Figure 4 (step 1A or 1B) into a vacuum bag (78); Sub-step 2 involves removing some or all of the air to compress the foam; Substep 3 involves introducing the additive (80) into contact with the foam, which can be by negative pressure of foam inflation or injection by other means, such as by pump, syringe or other suitable means; Sub-step 4 results in a foam containing the additive.

[0104] Step 2B includes several sub-steps: Sub-step 1 involves a foam (82) positioned in a container containing an additive (84; e.g., the additive is heated to a liquid state) and a suitable press (86); Sub-step 2 involves compressing the foam to expel all or part of the air inside; Sub-step 3 involves releasing the press to draw the additive into the bubbles.

[0105] Step 2C includes several sub-steps: Substep 1 involves placing the foam (88) in a suitable vacuum bag (90) or similar container containing a solid state additive (92); Sub-step 2 involves applying a vacuum to remove air and compress the foam, resulting in a solid additive and compressed foam; Sub-step 3 involves heating the additive and foam by suitable means while still leaving air voids or partial air voids; Sub-step 4 involves drawing the additive (as it becomes liquid) into the compressed foam, resulting in an uncompressed foam containing the incorporated additive.

[0106] FIG. 7 shows a process similar to that shown in step 2B, where the container acts as a mold: Step 2D includes several sub-steps: Substep 1 involves placing foam (94) in a container (96) containing an additive (98; illustratively, the additive is heated to a liquid state) and a suitable press (100); Substep 2 involves compressing the foam to expel all or part of the air inside; Sub-step 3 involves releasing the press to draw the additive into the foam, followed by cooling the foam / additive in the container; Substep 4A shows that the container or the base of the container is a work floor or floor intended to be attached to a machine floor. Optionally, the sides (102) of said container can be removed.

[0107] Substep 4B involves removing the cured foam (104) from the container.

[0108] FIG. 8 illustrates a process in which solid granules, powders, etc. are additives and can be manipulated, optionally or if necessary, by solids or other external stimuli.

[0109] Step 2E includes several sub-steps: Substep 1 involves applying additive (106) as solid granules to foam (108) located in a container that is agitated to facilitate movement of the additive into the foam.

[0110] Substep 2 shows the additives in the foam.

[0111] Sub-step 3A essentially involves forming the foam and additives into a more solidified composite within the container.

[0112] Sub-step 3B shows the additive undergoing a magnetorheological change such that the individual granules are substantially more tightly held or confined from movement by a magnetic field applied in the vicinity of the container.

[0113] Sub-step 3C shows the additive undergoing a magnetorheological change such that the individual granules are substantially more firmly held or confined from movement on the work or machining floor by the magnetic field.

[0114] Substep 4 shows the shaped foam being agitated to remove the additives, further separating the waste material from the additives, and the application of a magnetic field can further assist in attracting and collecting the additives. This can be accomplished in the bath or elsewhere dry.

[0115] FIG. 9 shows how the addition or removal of heat can be used to modify the properties of the additive.

[0116] Step 3A includes several substeps: Substep 1 involves cooling the additive and foam (112) by orientation; by cooling substantially more additive in the area of interest; or concentrating the additive (110) in the desired area of the foam by reapplying it to the desired area of an already cured foam.

[0117] The additive can be concentrated in the areas that will be machined to improve forming in sub-step 2 (if additive requirements are reduced).

[0118] In step 3B, the excess additive (114) can be poured out or compressed to the desired amount.

[0119] In step 4A, the foam is allowed to harden and can be clamped to the work surface.

[0120] In step 4B, the foam can be allowed to harden in a vacuum bag or other suitable container (including that of step 3A), which may be molded into a form.

[0121] In step 4C, the foam can be cured by other means and then clamped to the work surface.

[0122] Step 5 includes the following substeps: Substep 1 involves fastening the hardened foam to the work surface by heating the work surface with or without a heated surface to adhere the foam or by applying a molten additive to the work surface.

[0123] Sub-step 2 involves cooling the work surface to clamp the foam, or allowing it to cool without additional cooling. Alternatively, the foam can be clamped by other means, such as standard workpiece clamping, such as a chuck, vice, clamp, vacuum clamp, etc.

[0124] FIG. 10 shows, by way of example, how the process of FIG. 9 can be continued.

[0125] Step 6A(1) involves forming the foam (116).

[0126] Step 6B describes a method for machining multiple sides, including the following substeps: Sub-step 1 involves applying an additive (118) to the surface or to a pre-formed, subsequently cured, shaped trough.

[0127] Sub-step 2 involves facing a flat or shaped (eg, stake, vice, or other attachment method such as a connecting member) top.

[0128] Substep 3 (for additive-fastened foam) involves heating the bed and repositioning the workpiece (120).

[0129] In substep 4 (if fastened by additive), the workpiece is positioned and the work bed is cooled.

[0130] Sub-step 5 involves shaping the repositioned workpiece.

[0131] Sub-step 7 involves removing the foam formed by the application of heat from the work surface.

[0132] FIG. 11 illustrates the removal of additives.

[0133] Step 8A includes the following substeps: Substep 1 involves heating the shaped foam (122) by any suitable means, such as by conduction in a container of water or liquid additive, or by radiant heat.

[0134] Sub-steps 2, 3 and 4 refer to pressing the heated, shaped foam by suitable means.

[0135] Step 8B includes the following substeps: Sub-step 1 shows the molded foam (124) placed in a suitable vacuum bag or configuration as described in the introduction to the description. The molded foam is heated by suitable means as described in step 8A. To improve this step, a vacuum may be applied before and during heating.

[0136] Substeps 2 and 3 show vacuum being applied to remove the additive and then released to expand the foam. Optionally, the bag can be compressed by some other means.

[0137] A further step of cleaning or residue removal may be desirable.

[0138] Figures 12 and 13 show how the addition or removal of heat can be used to modify the properties of the additive.

[0139] Step 2F includes several substeps: Substep 1 involves placing the foam (126) into a container (128) containing an additive (130; e.g., the additive is heated to a liquid state) and a suitable press (132); Sub-step 2 involves compressing the foam to expel all or part of the air inside; Sub-step 3 involves releasing the press to draw the additive into the bubbles; Sub-step 4 involves compressing the foam using a mold (134); Sub-step 5 involves cooling the foam / additive while compressing it with a mold within the container; Sub-step 6 shows the hardened foam containing the impression of the mold; Sub-steps 7 and 8 involve the removal of foam material using surface machining operations (molding); Sub-step 9 involves heating the shaped foam by any suitable means, for example by conduction in a container of water or liquid additive, or by radiant heat; sub-step 10 involves compressing the heated foam / additive; Substep 11 shows the resulting foam revealing the shape of the mold.

[0140] Unless the context clearly requires otherwise, throughout the description and claims, the words "comprise", "comprising", and the like are to be construed in an inclusive sense, i.e., in the sense of "including but not limited to", as opposed to an exclusive or exhaustive sense.

[0141] The entire disclosures of all applications, patents and publications, cited above and below, if any, are hereby incorporated by reference.

[0142] The reference herein to any prior art is not, and should not be, taken as an acknowledgment or any form of suggestion that that prior art forms part of the common general knowledge in that field of endeavor in any country in the world.

[0143] The invention may also be broadly stated to consist in the components, elements and features referred to or shown in the specification of this application, individually or collectively, in combination with any or all of two or more of said components, elements or features.

[0144] Where reference is made in the foregoing description to integers or components that have known equivalents thereof, those integers are incorporated herein as if individually set forth.

[0145] It should be noted that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the spirit and scope of the present invention and without diminishing its attendant advantages. Accordingly, such changes and modifications are intended to be included within the present invention. [1] A method for molding an elastic or viscoelastic material having a plurality of voids, comprising: i. providing an elastic or viscoelastic material having a plurality of voids; ii. contacting the material with the additive such that at least a portion of the additive is incorporated within at least a portion of the plurality of interstices of the material; iii. subjecting the material to conditions such that at least a portion of the incorporated additives solidify, harden, and / or stiffen; iv. shaping the solidified, hardened, and / or rigidified additive-incorporated material to thereby form a shaped additive-incorporated material; and v. removing at least a portion of the incorporated additive from the molded material incorporating the additive. Including, The method, wherein the additive solidifies, hardens and / or stiffens at temperatures above 0°C. [2] The method according to [1], wherein the plurality of gaps is a network of voids. [3] The method according to [1], wherein the elastic or viscoelastic material is selected from foams and / or sponges, felts, lattices, skeletal structures, coiled materials, meshes and / or webs. [4] The method according to [1], wherein the elastic or viscoelastic material is a foam. [5] The method according to any one of [1] to [4], wherein the additive is selected from waxes or waxy compounds and mixtures thereof; crystalline solids / supersaturated liquids; liquid crystalline compounds; non-Newtonian compounds that solidify; granules / powders / other solids that can be poured into elastic or viscoelastic materials; liquids and / or solids that can be hardened or arranged and oriented to become more rigid by other means. [6] The method according to any one of [1] to [5], wherein the additive is a wax or a wax-like compound. [7] A molded elastic or viscoelastic material having a plurality of voids, prepared by the method according to any one of [1] to [6]. [8] Use of an additive that solidifies, hardens, and / or stiffens at temperatures above 0°C to form an elastic or viscoelastic material having a plurality of voids into which the additive is incorporated. [9] A contoured elastic or viscoelastic material having a plurality of voids, at least a portion of the material having an additive incorporated therein, the additive solidifying, hardening, and / or rigidifying at a temperature above 0°C.

[10] A method for molding an elastic or viscoelastic material having a plurality of voids, comprising: i. providing an elastic or viscoelastic material having a plurality of voids; ii. contacting the material with the additive such that at least a portion of the additive is incorporated within at least a portion of the plurality of interstices of the material; iii. subjecting the material to conditions such that at least a portion of the incorporated additives solidify, harden, and / or stiffen; iv. shaping the solidified, hardened, and / or rigidified additive-incorporating material to thereby form a shaped additive-incorporating material; and v. removing at least a portion of said incorporated additive from said molded material incorporating said additive. Including, The method, wherein the additive solidifies, hardens, and / or stiffens when exposed to a change in condition other than water and selected from thermal, magnetic, electrical, chemical, and / or electromagnetic conditions.

[11] The method of

[10] , wherein the elastic or viscoelastic material is selected from foams, felts, lattices, skeletal structures, coiled materials, meshes, and / or webs.

[12] The method according to

[11] , wherein the elastic or viscoelastic material is a foam.

[13] The method according to any one of

[10] to

[12] , wherein the additive is selected from waxes or waxy compounds and mixtures thereof; crystalline solids / supersaturated liquids; liquid crystalline compounds; non-Newtonian compounds that solidify; granules / powders / other solids that can be poured into elastic or viscoelastic materials; and liquids that can be hardened or arranged and oriented to become more rigid by other means.

[14] The method according to any one of

[10] to

[13] , wherein the additive is a wax or a wax-like compound.

[15] A method for molding an elastic or viscoelastic material having a plurality of voids, comprising: i. providing an elastic or viscoelastic material having a plurality of voids; ii. contacting the material with the additive such that at least a portion of the additive is incorporated within at least a portion of the plurality of interstices of the material; iii. subjecting the material to conditions such that at least a portion of the incorporated additives solidify, harden, and / or stiffen; iv. shaping the solidified, hardened, and / or rigidified additive-incorporating material to thereby form a shaped additive-incorporating material; and v. removing at least a portion of said incorporated additive from said molded material incorporating said additive. Including, The method, wherein the additive solidifies, hardens and / or stiffens when exposed to a change in condition selected from magnetic, electrical, chemical and / or electromagnetic conditions.

[16] The method according to

[15] , wherein the plurality of gaps is a network of voids.

[17] A molded elastic or viscoelastic material having a plurality of voids, prepared by the method according to any one of

[10] to

[16] .

[18] Use of an additive to mold an elastic or viscoelastic material having a plurality of voids incorporating the additive, wherein the additive solidifies, hardens, and / or stiffens when exposed to a change in condition selected from magnetic, electrical, chemical, and / or electromagnetic conditions.

[19] A contoured elastic or viscoelastic material having a plurality of gaps, at least a portion of the material having an additive incorporated therein, the additive solidifying, hardening, and / or stiffening when exposed to a change in condition selected from magnetic, electrical, chemical, and / or electromagnetic conditions.

[20] A method of forming a molded elastic or viscoelastic material having a plurality of voids, comprising: i. contacting an additive with a resin capable of being cured to form an elastic or viscoelastic material in a container to form a mixture; ii. degassing the mixture, such as by vacuum, and / or mixing the mixture to form a homogeneous blend; iii. curing the resin to thereby form an elastic or viscoelastic material incorporating at least a portion of the additive; iv. shaping the material incorporating the additive to thereby form a shaped material incorporating the additive; and v. Optionally, removing at least a portion of said incorporated additive from said molded material incorporating said additive. Including, The method, wherein the additive solidifies, hardens, and / or stiffens when exposed to a change in condition other than water and selected from thermal, magnetic, electrical, chemical, and / or electromagnetic conditions.

Claims

1. 1. A method of molding an elastic or viscoelastic material having a plurality of voids, comprising: i. providing an elastic or viscoelastic material having a plurality of pores; ii. contacting the material with the additive such that at least a portion of the additive is incorporated within at least a portion of the plurality of interstices of the material; iii. subjecting the material to conditions such that at least a portion of the incorporated additives solidify, harden, and / or stiffen; iv. shaping the solidified, hardened, and / or stiffened additive-incorporated material using a contouring machining process to result in forming a shaped additive-incorporated material, wherein the contouring machining process is performed using CNC machining; and v. Removing at least a portion of the incorporated additive from the molded material incorporating the additive. Including, The method, wherein the additive solidifies, hardens and / or stiffens at temperatures above 0°C.

2. The method of claim 1 , wherein the plurality of interstices is a network of voids.

3. 2. The method of claim 1, wherein the elastic or viscoelastic material is selected from foams and / or sponges, felts, lattices, skeletal structures, coiled materials, meshes and / or webs.

4. The method of claim 1 , wherein the elastic or viscoelastic material is a foam.

5. A method according to any one of claims 1 to 4, wherein the additive is selected from waxes or waxy compounds and mixtures thereof; crystalline solids / supersaturated liquids; liquid crystalline compounds; non-Newtonian compounds that solidify; granules / powders / other solids that can be poured into elastic or viscoelastic materials; liquids and / or solids that can be hardened or arranged and oriented to become more rigid by other means.

6. The method according to any one of claims 1 to 5, wherein the additive is a wax or a wax-like compound.

7. 1. Use of an additive that solidifies, hardens, and / or stiffens at temperatures above 0°C to mold an elastic or viscoelastic material having a plurality of voids into which the additive is incorporated, wherein the elastic or viscoelastic material is shaped by a contour machining process before removing at least a portion of the additive from the elastic or viscoelastic material, and wherein the contour machining process is performed using CNC machining.

8. 7. The method according to any one of claims 1 to 6, wherein the additive is selected from waxes or waxy compounds and mixtures thereof; crystalline solids / supersaturated liquids; liquid crystalline compounds; non-Newtonian compounds that solidify; granules / powders / other solids that can be poured into elastic or viscoelastic materials; liquids that can be hardened or arranged and oriented to become more rigid by other means.

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