WO2021252231A1

WO2021252231A1 - Foaming formulation dispensation method

Info

Publication number: WO2021252231A1
Application number: PCT/US2021/035367
Authority: WO
Inventors: Juan Carlos Medina; Jason A. Reese; Manoj THOTA; Kaoru Aou; Abhishek SHETE; Liangkai MA
Original assignee: Dow Global Technologies Llc
Priority date: 2020-06-09
Filing date: 2021-06-02
Publication date: 2021-12-16
Also published as: MX2022014749A; JP2023529811A; EP4161977A1; CN115698116A; KR20230022955A

Abstract

A method for dispensing a foaming formulation to a tire, comprising a tire, the tire featuring at least one interior surface, at least one exterior sidewall portion, and at least one exterior tread portion; and a foaming formulation; wherein the foaming formulation is dispensed upon the at least one interior surface of the tire, the tire oriented such that the tire may rest on its exterior sidewall portion while the foam formulation is dispensed.

Description

FOAMING FORMULATION DISPENSATION METHOD

Embodiments relate to a method for dispensing foaming formulations. More specifically, the embodiments relate to a method for dispensing foaming formulations upon the interior surface of a tire.

INTRODUCTION

The noise emitted from tires (tyres) against pavement is a common nuisance and sound pollution negatively impacts both urban and rural areas. The noise generated is also harmful to the tire itself due to the noise generated resonating within the internal cavity of the tire which can reduce tire durability. Thus, a tire which generates less noise is extremely desirable. There have been many attempts to generate such as tire, however, there continues to be a need for a method of mass production of a silent, or reduced noise, tire that is both efficient and lower cost.

Several pieces of prior art suggest various means to achieve sound dampening, but likely the most promising is the use of a foam within the tire to help stifle sound production. It has been known since at least the 1970s that tire noise can be decreased through the use of polyurethane solid foam (e.g., conventional slab stock foam) that is cut into shape and placed inside a pneumatic tubeless rubber tire and held in place with adhesive (See U.S. Patent No. 4,392,522). Placing foam within the tires in this manner is cumbersome and not easily automated thus there is a need for a more efficient method for production of tires with polyurethane foam within them. The presence of this adhesive also prevents these tires from being easily shredded and recycled.

Various attempts have been made to improve this process. For example, the process disclosed by U.S. Patent No. 9,315,611 discloses use of a liquid polyurethane foam that can be sprayed within the internal cavity of a tire, and subsequently cured, to reduce generated noise when the tire is in use. The specific type of polyurethane foam (formed from a mixture of polyether and polyester diols, which are further mixed with diisocyanates) utilized by this patent can be undesirable for mass production of tires for several reasons, the most notable one being poor adhesion to the interior of a tire, which can lead to failure of adhesion (i.e. delamination) after prolonged use of the tire. Other pieces of existent prior art fail to disclose the use of a foam which can sufficiently adhere to the interior of a tire and which is also suitable for efficient mass production.

For all these reasons and more, there is a need for a method of dispensing foaming reactive mixtures upon the interior of a tire that has better adhesion to butyl rubber, which is often the lining inside the tire, on the cavity surface. SUMMARY

Embodiments relate to a method of dispensing foaming formulations upon the interior surface of a tire. A first embodiment of this method may feature a fast-reacting open-cell flexible cavity filling thermosetting foam formulation (e.g., foam generated from the mixture of isocyanate-reactive component and isocyanate component), a pneumatic tubeless tire and a spray-dispensing mix head.

In this embodiment, the tire is turned to rotate along its vertical axis (axis collinear to the direction of Earth’s gravity), resting on one of its exterior side walls, with the tire radial direction in the horizontal plane, plus or minus a certain range (e.g., 5, 10, 20, 30, 45, or 60 degrees, etc.) from the horizontal plane. The foaming formulation is sprayed onto the interior tire cavity upon the interior tread surface and/or both the side wall surfaces. The spraying can be done upon the interior surfaces separately or simultaneously via any number of sprayheads, nozzles, etc.

The foaming formulation may be sprayed onto the interior of the tire as a single coating over one pass around the tire’s circumference, or multiple coatings. The coating of foaming formulation may be sprayed in patterns, the patterns achieved through different spray nozzle design or through use of spray masks (commonly used for the spraying of traffic markings). The spray heads may be spray-dispensing mix heads, such as those produced by Graco and Probler. The spraying may be carried out by any functionally relevant means, including via automated robotic arm, stationary sprayer, or manually done for larger tires.

In another embodiment, the foaming formulation may be dispensed by automated or manual pouring and thus the formulation may be thixotropic via use of thixotropic agents, including fumed silica, other fillers, and rheology-modifying liquids so that there is no dripping down the interior tire side walls as the formulation is poured.

The dispensation via pouring or spraying (or both) may be done by rotating the sprayhead or pouring mechanism within a stationary tire or by turning the tire around a stationary sprayer, etc. The sprayhead or pouring mechanism and tire may also move or rotate simultaneously in opposite directions to improve formulation application time, etc. In yet another embodiment, the tire to be coated in formulation may be described as lying on its side wall (horizontal) with no limit on the size of tire covered by the presently disclosed method. Any functionally capable application means may be utilized by the method/process disclosed herein. For example, the tire may move along a conveyor belt with an automated sprayer positioned such that it can dispense the foaming formulation onto the interior surfaces of the tire, without the tire having to be rotated, and then repeated for subsequent tires. The amount of foaming formulation sprayed upon the inside of a tire may be varied depending on the performance needed and sprayed in various geometric (or even random) patterns upon the inside surfaces of a tire.

The tires covered by this method may include, but are not limited to, tires for: bicycles, motorcycles, consumer and commercial automobiles, aircrafts, mining equipment, and heavy industrial and farming equipment. Examples of tire suppliers include Bridgestone, Michelin, Pirelli, Kumho, Continental, Dunlop, Goodyear, Hankook Tire, Toyo Tires, Yokohama Tire, Cooper Tire and Rubber, BF Goodrich, etc.

Another embodiment may be described as a method for dispensing a foaming formulation upon a tire, the method comprising a tire, the tire comprising at least one interior surface, at least one exterior sidewall portion, and at least one exterior tread portion; and a foam formulation; wherein the foam formulation is dispensed upon the at least one interior surface of the tire, the tire oriented such that the tire may rest on at least one exterior sidewall portion while the foam formulation is dispensed. The foam formulation dispensed upon the at least one interior surface of the tire may form a polyurethane foam. The foaming formulation may comprise at least a polyamine or polyetheramine.

This embodiment may also include a sprayhead, wherein the foaming formulation is dispensed upon the at least one interior surface of the tire via the sprayhead. The sprayhead may rotate while the foaming formulation is dispensed upon the at least one interior surface of the tire. The tire may rotate along its own vertical axis while the foaming formulation is dispensed upon the at least one interior surface of the tire. The foaming formulation may be dispensed upon at least one interior side wall portion or at least one interior tread portion of the interior surface of the tire. The foaming formulation may also be dispensed upon the at least one interior surface of the tire in a pattern.

In this embodiment and others, the foaming formulation may be dispensed upon the at least one interior surface of the tire, the tire oriented along its vertical axis with the radial direction of the tire in the horizontal plane, wherein the radial direction of the tire in the horizontal plane is plus or minus 0 to 60 degrees from the horizontal plane.

One major benefit of producing tires with interiors coated with polyurethane foam in the manner described is a large reduction in the time required to produce a reduced noise tire. Additionally, the foaming formulation utilized in the disclosed subject matter has excellent adhesion with the inner surfaces of a tire. This means no adhesive (or much less) need be used with many embodiments. Such adhesives are gummy, tacky adhesives made from low molecular weight butyl rubber, or silicone sealant (as described in U.S. Patent Application 2019/0177486 Al). Thus, tires with the presently disclosed foaming formulation applied to the inner surface of a tire can be more easily shredded in commercial tire shredders for tire recycling due to the reduced presence or complete absence of tacky adhesives mentioned above.

BRIEF DESCRIPTION OF THE DRAWINGS

Various embodiments are disclosed in the following detailed description and accompanying drawings:

Fig. 1 is a diagram of a rotating tire and sprayhead.

DETAILED DESCRIPTION

Embodiments relate to a method for applying a foam forming reactive mixture used to form polyurethane (PUR).

The foaming formulation may rely on the presence of polyurethane/polyurea polymers, which are the reaction product of an isocyanate moiety provided from an isocyanate component with an isocyanate-reactive moiety provided from an isocyanate -reactive component. The isocyanate component includes at least one isocyanate (e.g., a polyisocyanate and/or an isocyanate-terminated prepolymer). The isocyanate-reactive component includes at least a polyol component that includes one or more polyols and at least one or more polyamine. The isocyanate-reactive component and/or the isocyanate component may each independently include one or more optional additive components (such as a blowing agent, a fire barrier material, a filler, a catalyst, a curative agent, a chain extender, a flame retardant, a viscosity modifier, a pigment, a stabilizer, a surfactant such as a silicone surfactant, a plasticizer, a zeolite, moisture scavenger, and/or other additives that modify properties of the resultant final polyurethane product).

Polyol

The polyol component includes at least one poly ether polyol and/or polyester polyol. Exemplary polyether polyols are the reaction product of alkylene oxides (such as at least one ethylene oxide, propylene oxide, and/or butylene oxide) with initiators containing from 2 to 8 active hydrogen atoms per molecule. Exemplary initiators include ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol, butane diol, glycerol, trimethylolpropane, triethanolamine, pentaerythritol, sorbitol, ethylene diamine, toluene diamine, diaminodiphenylmethane, polymethylene polyphenylene polyamines, ethanolamine, diethanolamine, and mixtures of such initiators. Exemplary polyols include VORANOL™ products, available from The Dow Chemical Company.

The polyol component may include polyols that are useable to form viscoelastic polyurethane foams. For example, the polyol component may include a polyoxyethylene- poly oxypropylene poly ether polyol that has an ethylene oxide content of at least 50 wt %, that has a nominal hydroxyl functionality from 2 to 6 (e.g., 2 to 4), and has a number average molecular weight from 500 g/mol to 5000 g/mol (e.g., 500 g/mol to 4000 g/mol, from 600 g/mol to 3000 g/mol, 600 g/mol to 2000 g/mol, 700 g/mol to 1500 g/mol, and/or 800 g/mol to 1200 g/mol). The polyoxyethylene-polyoxypropylene poly ether polyol that has an ethylene oxide content of at least 50 wt % may account for 5 wt % to 90 wt % (e.g., 10 wt % to 90 wt %, 35 wt % to 90 wt %, 40 wt % to 85 wt %, 50 wt % to 85 wt %, 50 wt % to 80 wt %, and/or 55 wt % to 70 wt %) of the isocyanate-reactive component. The polyoxyethylene-polyoxypropylene polyether polyol which has an ethylene oxide content of at least 50 wt % may be the majority component in the isocyanate-reactive component.

The polyol component may include a polyoxypropylene -polyoxyethylene polyether polyol that has an ethylene oxide content of less than 20 wt % that has a nominal hydroxyl functionality from 2 to 6 (e.g., 2 to 4) and has a number average molecular weight greater than 1000 g/mol (or greater than 1500 g/mol) and less than 6000 g/mol. For example, the molecular weight may be from 1500 g/mol to 5000 g/mol, 1600 g/mol to 5000 g/mol, 2000 g/mol to 4000 g/mol, and/or 2500 g/mol to 3500 g/mol. The polyoxypropylene-polyoxy ethylene poly ether polyol that has an ethylene oxide content of less than 20 wt % may account for 5 wt % to 90 wt % (e.g., 5 wt % to 70 wt %, 5 wt % to 50 wt %, 10 wt % to 40 wt %, and/or 10 wt % to 30 wt %) of the isocyanate reactive component. The polyoxypropylene-polyoxyethylene polyether polyol that has an ethylene oxide content of less than 20 wt % may be in a blend with the polyoxypropylene poly ether polyol that has an ethylene oxide content of at least 50 wt %, whereas the latter of which is included in a greater amount.

The polyol component may include a polyoxypropylene poly ether polyol that has a nominal hydroxyl functionality from 2 to 6 (e.g., 2 to 4) and has a number average molecular weight from 500 g/mol to 5000 g/mol (e.g., 500 g/mol to 4000 g/mol, from 600 g/mol to 3000 g/mol, 600 g/mol to 2000 g/mol, 700 g/mol to 1500 g/mol, and/or 800 g/mol to 1200 g/mol). The polyoxypropylene polyether polyol may account for 5 wt % to 90 wt % (e.g., 5 wt % to 70 wt %, 5 wt % to 50 wt %, 10 wt % to 40 wt %, and/or 10 wt % to 30 wt %) of the isocyanate reactive component. The polyoxypropylene polyether polyol may be in a blend with the polyoxypropylene poly ether polyol that has an ethylene oxide content of at least 50 wt %, whereas the latter of which is included in a greater amount.

In exemplary embodiments, the polyol component of the isocyanate-reactive component for forming the polyurethane foam may include one or more polyols. The polyol component may include molecules with an average hydroxyl number (OH#) range of 15 - 700 mg KOH/g (average mixture), as measured by ASTM D4274, Test Method D. The average OH# of the polyol component is preferably 20 - 80, more preferably 20 - 70, yet more preferably 25 - 60, most preferably 28 to 34.

Isocyanate

The corresponding isocyanate in this embodiment may have an %NCO or isocyanate range, as measured by ASTM D5155 of preferably 25 - 49%, more preferably 26 - 35%, and is used in an isocyanate component-to-polyol component ratio by mass of preferably 0.5:1 to 1.8:1.

The isocyanate component may include one or more isocyanate such as polyisocyanate and/or isocyanate-terminated prepolymer. The isocyanate may be isocyanate-containing reactants that are aliphatic, cycloaliphatic, alicyclic, arylaliphatic, and/or aromatic polyisocyanates or derivatives thereof. Exemplary derivatives include allophanate, biuret, and NCO (isocyanate moiety) terminated prepolymer. For example, the isocyanate component may include at least one aromatic isocyanate, e.g., at least one aromatic polyisocyanate or at least one isocyanate-terminated prepolymer derived from an aromatic polyisocyanate. The isocyanate component may include at least one isomer of toluene diisocyanate (TDI), crude TDI, at least one isomer of diphenyl methylene diisocyanate (MDI), crude MDI, and/or higher functional methylene polyphenyl polyisocyanate. Examples include TDI in the form of its 2,4 and 2,6- isomers and mixtures thereof and MDI in the form of its 2,4'-, 2,2'- and 4,4'-isomers and mixtures thereof. The mixtures of MDI and oligomers thereof may be cmde or polymeric MDI and/or a known variant of MDI comprising urethane, allophanate, urea, biuret, carbodiimide, uretonimine and/or isocyanurate groups. Exemplary isocyanates include PAPI™ 94, PAPI ™

27, VORANATE™ M 220 (a polymeric methylene diphenyl diisocyanate available from The Dow Chemical Company). Other exemplary polyisocyanate include tolylene diisocyanate (TDI), isophorone diisocyanate (IPDI) and xylene diisocyanates (XDI), naphthalene diisocyanate (NDI), ortho-, meta-, and para-phenyl diisocyanates (o-PDI, m-PDI, p-PDI), modifications thereof, and other common diisocyanates.

A certain combination of EO-PO ratio in the polyol combined with a catalyst package can result in improved adhesion of the foam to the tire with a reduced or eliminated need for external adhesive. Additional embodiments of the presently disclosed method may include a foam formulation containing fumed silica (including types that are surface-functionalized) to impart extra sag resistance in coating on a vertical wall.

Polvamine

The polyamine component of the isocyanate-reactive component for forming the polyurethane foam may include one or more polyamines. The polyamines may be ethylenediamine, 1,3 -diamino-propane, 1,4-diamino-butane, diethylene -triamine, tetraethylenepentamine, pentaethylene-hexamine, hexaethylenediamine, bis(3- aminopropyl)amine, bis(hexanethylene)triamine, tris(2-aminoethyl)amine, triethylene-tetramine, N,N^,-bis(3-aminopropyl)-l,3-propanediamine, l,2-bis(2-aminoethoxy)ethane, branched polyethylenimine, chitosan, nisin, gelatin, 1,3 -diamino-guanidine, 1,1-di-methylbiguanide, guanidine, arginine, lysine, ornithine, or a combination thereof. In some embodiments, compounds having one or more — OH groups and one or more — NH — or N¾ groups, e.g. ethanolamine, 2-propanolamine, or chitosan can be used. Branched polyethyleneimines useful as polyamine typically have a molecular weight of 200 to 2,000,000 g/mol (e.g., 800 to 2,000,000 g/mol, 2,000 to 1,000,000 g/mol, 10,000 to 2,000,000 g/mol, and 20,000 to 100,000 g/mol).

The polyamines may also be, for example, polyoxyalkylenes or polyoxyalkylated compounds containing termi al amino groups, such as commercially available for example under the trade name Jeffamine (from Huntsman), polyetheramines available (from BASF) or PC amines (of Nitroil) are, in particular those having an average molecular weight in the range of about 200 to 5000 g/mol, in particular the following: polyether diamines with 2-aminopropyl or 2-aminobutyl end groups, especially Jeffamine D-230, Jeffamine D-400, Jeffamine D-2000, Jeffamine D-4000, Jeffamine XTJ-582, Jeffamine XTJ -578, Jeffamine HK-511, Jeffamine ED-600, Jeffamine ED-900, Jeffamine ED- 2003, Jeffamine XTJ-568, Jeffamine XTJ-569, Jeffamine THF-100, Jeffamine THF 140, Jeffamine THF-230, Jeffamine XTJ-533 or Jeffamine XTJ-536 (all available from Huntsman). polyether glycols with 4-aminobutyl-terminated from the animation of poly (tetramethylene ether), especially Jeffamine THF- 170 (from Huntsman). polyether monoamines, particularly alcohol-launched types, such as Jeffamine M- 600, Jeffamine M-1000, Jeffamine M-2005, Jeffamine M-2070, Jeffamine XTJ-581, Jeffamine XTJ-249, Jeffamine XTJ-435 or alkyl phenol-initiated types like Jeffamine XTJ-436 (all available from Huntsman). polyether from the polyalkoxylation of diols, in particular pro- poxyliertes 1, 4- dimethylolcyclohexane as Jeffamine RED-270 (from Huntsman). polyethertriamines, especially Jeffamine T-403, Jeffamine T-3000, Jeffamine T- 5000 or Jeffamine XTJ-566 (all available from Huntsman). polyether with secondary amino groups, especially Jeffamine SD-231, Jeffamine SD-401, Jeffamine SD-2001 or Jeffamine ST-404 (all available from Huntsman). aminopropylated polyetheramines, as obtainable by reacting poly ether amines with acrylonitrile and subsequent hydrogenation. Of these, preferred are polyetheramines having primary amino groups. Of these, preference is furthermore given to polyetheramines having an average molecular weight in the range from about 220 to 2000 g/mol.

One type of preferred polyetheramine is a polyoxypropylenediamine which optionally has fractions of other oxyalkylene units such as, in particular, oxy ethylene or 1,2-oxybutylene units, or a poly (tetramethylene ether) diamine which optionally has 1, 2-oxypropylene units , or a polyether monoamine or diamine or triamine with predominantly 1, 2-oxypropylene units from the poly addition of 1, 2-propylene oxide to starter molecules selected from the group consisting of alcohols, fatty alcohols, alkylphenols, diols and triols.

Even more preferably, a polyetheramine may be a polyoxypropylenediamine having an average molecular weight in the range of about 220 to 2000 g/mol. Most preferably the poly ether is a polyoxypropylene diamine having an average molecular weight in the range of about 400 to 500 g/mol, especially Jeffamine D-400 or Jeffamine XTJ-582 (both available from Huntsman) or PC-amines DA 400 (of Nitroil ) or polyetheramine D 400 (from BASF).

Surfactant

A surfactant, if present, may be one or more of silicone surfactants, such as an organosilicone type such as those prepared by the sequential addition of propylene oxide and then ethylene oxide to propylene glycol, solid or liquid organosilicones, and polyethylene glycol ethers of long chain alcohols. The silicone surfactants prepared by the sequential addition of propylene oxide and then ethylene oxide to propylene glycol are preferred, as are the solid or liquid organosilicones. Examples of useful organosilicone surfactants include commercially available polysiloxane/polyether copolymers such as TEGOSTAB (trademark of Evonik AG) B8462, B8404, B8871, B1048, B8462, B8427, B8433, B8734 LF2 and B8404, and VORASURF DC-193, DC-198, DC-5000, DC-5043, DC-5098 and DC-5043 surfactants, available from The Dow Chemical Company, and NIAX L-627, NIAX L-620, Niax L-6900 and NIAX L-618 available from Momentive Performance Materials. The surfactant may constitute from 0.1 to 5 percent, preferably from 0.25 to 2.5 percent, of the total weight of the isocyanate component in one embodiment.

Optional Additives

Optional additive components may include one or more blowing agents (such as water, carbon dioxide, acetone, hydrocarbons such as pentane, hydrochlorofluorocarbons, and hydrofluoro-olefms), one or more fillers (such as fire barrier materials, oxides, ceramics, and other fillers known in the art), one or more catalysts, one or more curing agents, one or more chain extenders, one or more crosslinkers, one or more moisture scavengers, one or more dyes/pigments, one or more antioxidants, one or more UV stabilizers, one or more release agents, one or more adhesion promoters, one or more nucleating additives, and other additives known in the art. Optional additive components may be added via a dedicated stream or premixed in with one of the reactive components (e.g. the polyol). Water is a preferred blowing agent and is used at preferably 3 - 8% with respect to the total mass of the polyol component.

Reinforcing fibers are also an additional, optional (yet useful), additive component in the making of PUR and/or PIR foam. Reinforcing fibers such as glass fibers, basalt fibers, carbon fibers, nylon fibers, and the like are useful in enhancing the mechanical properties of a final formed foam.

The embodiments listed here are non- limiting and various ratios of polyol, polyamine, isocyanate, and other components may be mixed as needed to achieve optimal performance. A non-exhaustive list of such components may be found in Table 1.

Method of Preparation and Application

In one embodiment, the presently disclosed method may include tires which are new. These tire’s inner surface has not been surface coated, cleaned, or pre-conditioned. They are considered and used as received. Used tires (e.g., those with less than 5000 miles of use on them) have also been utilized for this application, with minimal dust and dirt removal before application required.

The new or used tire is rotated around a vertical axis (axis collinear to the direction of Earth’s gravity), with the tire radial direction in the horizontal plane. Tire is rotated at 30-120 RPM. A low-pressure or high-pressure thermoset dosing unit (typical suppliers: GRACO, Cannon) may be filled with polyol and isocyante formulations as described within. The material temperatures in the tanks and circulation can range from 75 °C to 135°C. Flow rates can be set in the range of 10-150 grams per second. System pressures can range from 10-2000 PSI.

A range of mix heads, mix chambers, spray guns, may be used in conjunction with low- pressure or high-pressure thermoset dosing equipment. Typical suppliers are GRACO and Cannon. Spray nozzles can be used to adjust spray pattern and flow direction to apply foam at varying angles and widths upon the inside of a given tire. Typical spray nozzle suppliers are GRACO, Cannon, and Nordson. Application spray openings can range from 0.035 inches to 0.125 inches. The spray tip may be placed in line with the circumference center line at a distance of 6 inches to 12 inches perpendicular (ranging from +/- 45° to the tire interior surface).

The spray sequence may be planned so that spraying is done as a single coating over 1 turn around the circumference of a tire, or multiple coatings over multiple turns around the circumference. Spray times may range from 1-8 seconds. Material gel times may range from 10- 40 seconds with tack free times ranging from 15-120 seconds. Tires are rotated at speed through gel time and slowed to zero between gel and tack free time.

Foam geometry after curing is mostly dependent on material volume, flow rate, nozzle geometry, distance of nozzle to tire interior surface, and angle of nozzle to tire interior surface.

In one embodiment, the foam geometry may have cross sections ranging from linch wide x 0.5inches thick to 10 inches wide x 3 inches thick. The foam, once formed, may be formed into a different thickness or shape as needed by physical or automated means. For example, the foam may be trimmed to a thinner thickness, etc.

In a preferred embodiment, the tires are new, and the tire inner surface has not been surface coated, cleaned, or pre-conditioned. The tires are used as received. The tire is rotated around a vertical axis (axis collinear to the direction of Earth’s gravity), with the tire radial direction in the horizontal plane. The tire is rotated at 45 RPM. A high-pressure Cannon CF thermoset dosing unit is filled with polyol and isocyanate formulations as described within. Material temperatures in tanks and circulation are set at 100°C. Material circulation temperatures are set at 105°C and flow rates are set at 85 grams per second. The system pressure is set at 1000 PSI.

A Cannon FPL mix head is attached to the Cannon CF machine. This mix head is capable of mixing polyol and isocyante as well as being flushed with solvent for cleaning post formulation application. A standard Cannon nozzle is attached to the FPL mix head to produce a fan pattern spray. The nozzle tip has a 0.075inch opening. The spray tip is placed in-line with the circumference center line of the tire at a distance of 9.5inches perpendicular to the tire interior surface. The spray sequence is set to apply the foaming formulation for 4.0 seconds which results in the material being applied over 2.99 rotations of the tire circumference.

The material in this preferred example would have a gel time approximately 15 seconds and tack free time of approximately 30 seconds. The foam geometry of this preferred embodiment has a cross section of 8inches wide by linch thick.

Figure 1 (Fig. 1) is a diagram showing a tire 10 rotating around a stationary sprayhead 20. As shown in Fig.1 , in this embodiment, the tire 10 may be laid upon its side while rotated around a stationary sprayhead 20. The tire 10 may consist of an exterior tread portion 11 and side wall portions 12. The tread portion 11 is what meets the road when the tire 10 is in use and the side walls 12 are the portions which are typically roughly perpendicular to the tread portion 11. The tire 10 also features an interior cavity where air is stored when the tire 10 is in use. This interior cavity has at least one interior tire surface including an interior tread portion 13 and

- to - interior side wall portions 14. These interior portions correspond to the exterior portions and are their other side.

The sprayhead 20 in the diagram is shown as an L-shaped arrow, with the point of the arrow representing the head as well as the direction of the foaming formulation spray, with the rest of the arrow corresponding to the mechanical components, tubing, etc. needed to spray pressurized foam into the interior portions of the tire.

Also shown in Fig. 1 is the rotation of the tire 10 relative to the sprayhead (direction of the tire’s rotation 30 shown as a curved arrow in this diagram). In this embodiment, the tire 10 is turned to rotate along its vertical axis (the axis collinear to the direction of Earth’s gravity), resting on one of the tire’s 10 exterior side walls 12, with the tire radial direction in the horizontal plane, plus or minus a certain range (e.g., 20, 30, 45, or 60 degrees, etc.) from the horizontal plane. The foaming formulation is sprayed onto the interior of the tire upon the interior tread surface 13 and/or both the side wall surfaces 14. The spraying can be done upon these interior surfaces separately or simultaneously via any number of spray nozzles.

Put another way, the tire 10 rests on one of its side wall portions 12 while it is rotated around a sprayhead 20 positioned so that the foaming formulation may spray upon the interior surface(s) of the tire 10. The tire 10 may be rotated by any functional means. To keep the coating consistent the spraying can be biased to coat more initially on the upper side of the (vertically positioned) interior tread wall 13 surface than the lower side, to allow for sagging. The process detailed above may be performed whilst the tire rests upon a conveyer belt allowing for efficient mass production.

A sprayhead 20, used for applying foaming formulation, may rotate around a stationary tire 10 in some embodiments. The tire 10 may be oriented similarly to the tire 10 shown in Fig.

1. In some embodiments however, the sprayhead 20 may be moved while the tire is not rotated. In this embodiment, the sprayhead 20 rotates within the tire 10 to spray the foaming formulation onto the tire’s 10 inner surfaces. Such sprayhead 20 rotation may be achieved by any functional means, including the use of a robotic arm whilst the tire 10 rests on its side on a conveyor belt.

It should be noted that the rotation (direction of the tire’s rotation 30 shown as a curved arrow in this diagram) of a tire 10 and sprayhead 20 may also be coupled together in an embodiment in which the rotation of the tire 10 and sprayhead 20 are opposite to one another to enable faster application of the foaming formulation.

A standard automobile tire 10 features an external tread portion 11 and two sidewalls 12. The tire also features an interior cavity, the surface of which is an inner liner. In some embodiments, the foaming formulation may be sprayed upon portions of this inner liner. The

- it - interior cavity and/or inner liner features an interior tread portion 13 and two interior sidewall portions 14 which correspond to the similarly named exterior portions of the tire 10. The foaming formulation may selectively be applied to the interior sidewall portions 14 or the interior tread portion 13 (or both portions).

The foaming formulation may also be applied in patterns or at random upon the inside of a tire 10 depending on the needs of a given consumer. For example, it is known that rolling of a tire 10 (when in use) generates relative air flow along the circumferential direction inside of the tire cavity. Such rolling induced air flow can be made to travel in and out of a specially designed geometric foam pattern. In such an arrangement the acoustic wave energy, typically dominated by the cavity resonance, is dissipated in form of heat when air flows in and out through pore walls and struts of foam.

One such pattern may be regularly spaced strips of foam sprayed along the interior tread surface 13 of a tire 10. This pattern maximizes the surface area available for dissipation of energy associated with air travelling in a circumferential direction. The strips of foam are spaced at normal intervals relative to the circumferential direction. Such a pattern provides sound absorption and is resistant to delamination as the tire 10 undergoes cyclical deformation under load of the vehicles as it rolls along the road surface.

The foaming formulation may not only be sprayed but also formed, carved, or otherwise physically manipulated into any pattern upon the inside of a tire 10. In some embodiments, the foam is formed into a crosshatched pattern. Different patterns of foam may be applied to the interior of a tire to provide better sound dampening performance, durability, etc. Different patterns and/or thicknesses of foam may also be applied to the same or separate portions of the interior of a tire (e.g., sidewall 14 or tread 13 portions) depending on a given application of the disclosed process.

In some embodiments, the tires 10 may be moved along a conveyor belt as they rest upon their sidewall 12. One exterior tire sidewall 12 may rest on the conveyor belt while the exterior tread portion 11 of the tire 10 is perpendicular to the belt (and other side wall 12 is parallel to the conveyor). As the tires 10 are moved along the conveyor belt, a spray head 20 may enter the tire from above and spray foaming formulation upon the interior surfaces of the tire 10. Other embodiments are fully envisioned in which the sprayhead 20 may enter the tire 10 from below (or from above and below in unison) to more quickly apply the foaming formulation.

As mentioned above, a sprayhead 20 which dispenses foaming formulation may be placed upon a robotic arm. This robotic arm can maneuver the sprayhead within a tire 10 and then rotate (or have the tire 10 rotated around the sprayhead 20) to apply foaming formulation. The sprayheads 20 which deliver polyurethane foaming formulations are typically kept the two components of a given formulation separate (e.g., an A-side and B-side) and then mix the formulation components as they are dispersed. One type of sprayhead 20 is a T-shaped linear mixing head which mixes the pressurized polyol and isocyanate components in a mixing chamber before they exit the outlet nozzle which dispenses the formulation onto a substrate. The substrate in this discerption is the interior surfaces of a tire 10.

It should be noted any functionally capable means of applying the foaming formulation may be utilized to coat the interior cavity of a tire. Such means may include other types of sprayheads 20 such as a L-shaped mixing head, V-shaped linear mixing head, or a four component mixing head. The sprayhead 20 used in one embodiment of the disclosed process is an airless type sprayhead produced by GRACO. By “airless” it is meant that no propelling gas is ejected through the sprayhead 20 as the foam formulation is sprayed on the interior surfaces of the tire. Gasses may be passed through the sprayhead 20 between shots for cleaning purposes, etc. The spray tip of the sprayhead 20 in one embodiment may be a flat cone or jet nozzle. A flat cone refers to the spatial distribution of the sprayed foam formulation, and when viewed from the side, the sprayed foaming formulation forms a fan like shape, A jet nozzle refers to the spatial distribution of the sprayed foam formulation, and when viewed from the side, sprayed foam formulation forms a cone like shape.

The rotation speed of the sprayhead 20 utilized with respect to a tire 10 may be 0.5 to 15 seconds per one rotation (4 to 120 rpm). Multiple passes may be made and if the tire 10 is rotating, then the rotation speed of the tire 10 may be constant from 5 to 30 rpm. The dispensing volumetric flow rate can be varied in order to vary the final thickness achieved for the foam coating on the tire 10. Automated or manual pouring of the foaming formulation may also be utilized in place of, or in unison with, the spraying of the formulation upon a tire’s inner surfaces.

The foam generated from the mixture of isocyanate-reactive component and isocyanate component has excellent adhesive properties. Such adhesion enables the foam to remain affixed to the interior of a tire 10 without the need for any (or much less) adhesive.

EXAMPLES AND RESULTS

Application Test

To test application of the foaming formulation upon tires, used tires (e.g., those with less than 5000 miles of use on them) were utilized for this experiment. Tire sections were cut from the used tires. These sections were approximately 2 inches wide by the width of the tire tread (6- 8 inches depending on the tire), with minimal dust and dirt removal before application performed as needed. For the samples shown below in Tables 2A, 2B, 3A, 3B, the polyols and isocyanates were blended in a small vessel and poured onto tire sections. Approximately 25-35 grams of polyol was blended with isocyanates at the corresponding ratios listed in the tables in a 600ml plastic container within a fume hood. The lab and fume hood were held at 23 °C. The material was immediately (within 3 seconds) blended with a shear blade mixer for 3-5 seconds, and immediately poured (within 1.5 seconds) onto the tire sample. The foaming formulation covered the tire sample, and excess formulation which ran off the edge of the tire sample was removed.

The tire sections may also be indexed under the foaming formulation flow from a high- pressure or low-pressure machine (as described above) to apply foam to the tire sections.

Alternatively, the polyols and isocyanates may be hand mixed and poured on to the tire sections.

Table 1 - Foaming Formulation Components

*Note: All molecular weight values listed above are in g/mol.

Table 2 A - Example and Comparative Example Formulations

*Note: the values show in Table 2A are parts by weight of the overall foaming formulation

Table 2B - Example and Comparative Example Formulations (continued)

*Note: the values show in Table 2B are parts by weight of the overall foaming formulation Table 3A - Application Results

*Note: C = Cohesive Failure and A= Adhesive failure.

Table 3B - Application Results (continued)

*Note: C = Cohesive Failure and A= Adhesive failure.

Regarding the type of adhesion failure: foamed material (From Table 2A and 2B) is pulled from the tire surface using hand force. If the foam is peeled from the tire surface without any residue on tire it is deemed as Adhesive Failure (marked as A in Table 3A and 3B). If the foam is torn and leaves residue on the tire surface it is considered as Cohesive Failure (marked as C in Table 3A and 3B)

Regarding the Gel Time and Tack-free Time: Pre-blended polyols from formulations in Table 2 A and 2B were mixed with isocyanate (using high pressure machine) and dispensed on tire surface. The stopwatch was begun as soon as the dispense was initiated and gel time is time at which the foam forms a string (checked with wooden tongue depressor). The Tack-free Time 18

5UB5TITUTE SHEET (RULE 26) is the time from resin dispense to the time at which the foam surface does not stick to the wooden tongue depressor when pressed against with force.

Sound Absorption Test ASTM E1050

ASTM E1050 is a standard test to measure the acoustic absorption performance (SAC) of cellular and porous materials. Theoretical range of SAC can vary between 0 and 1, where value of 1 indicates that the material absorbs 100% of the incident sound and 0 indicates that the sample doesn't absorb any sound.

For some polyurethane foams, a skin may typically form upon the foam once formed. This skin can prevent or stifle the foam from absorbing sound; thus, SAC measurements were made on experimental samples (of the foaming formulation comprising) with and without the skin. The test result data below in Table 4 shows that the with skin / without skin sample difference becomes very prevalent above 600 Hz for the sound absorption coefficient (a). The presence of skin upon the foams does not however significantly affect the acoustic absorption performance in the frequency range of interest, between 150-250 Hz, where the tire cavity resonance noise lies for passengers. The frequency range would be even lower that this range for trucks and busses which have larger diameter tires. This is because the tire cavity resonance frequency is inversely proportional to the average of the inner and outer diameters of the tire cavity. Thus, the presence of skin upon the formed foam lining the inside of a tire should have no noticeable impact on the foams sound dampening for most applications of the presently disclosed process.

Table 4 - Sound Absorption Test

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5UB5TITUTE SHEET (RULE 26)

Cavity Pressure in Tire/Rim Assembly Model

To understand the effect of acoustic foam on air cavity resonance a simple stationary vibro-acoustic model was developed using the VA-One software application. The model constitutes a wheel rim surrounded by air cavity. The air cavity is modeled as an annular rectangular toroid that is 12.5” tall X 3.75” wide X 29” outer diameter. The rim is modeled as a cup with 3 mm thick walls and made of aluminum. Finite element analysis was conducted by discretizing the air cavity using acoustic elements and discretizing the rim using structural elements. To emulate tire-road excitation, one of the elements of the air cavity is excited with random vibration. Finally, the road surface is modeled as a rigid surface that reflects 100% of the pressure waves that are incident upon it.

The effect of tire cavity noise is studied by measuring the cavity pressure inside the tire and radiated pressure off the rim surface at 0.8 m. A boundary element algorithm that uses the velocity information on the surface of the rim was then used to calculate the pressure on a surface at a distance away.

The results of this computerized modeling may be found below in Tables 5 A and 5B. They show a cavity resonance peak of cavity pressure spectra (around 180 Hz) shifted to lower frequencies as acoustic damping increases, and this is consistent with the single degree of freedom mechanic that resonance frequency will reduce by adding damping. Additionally, the resonance peak height drops as a increases. A similar trend of reduction in cavity resonance peak intensity is also true for the radiated pressure spectrum, with the cavity resonance peak almost completely suppressed.

These results suggest that the foam material tested (foaming formulation), which offers acoustic absorption of around 10%, can significantly reduce the intensity of radiated pressure and cavity pressure inside a tire. It also suggests that a wide range of acoustic foams (a as measured in impedance tube) can be used for the suppression of acoustic noise, as seen in the simulation results.

Table 5A - Cavity Pressure

Table 5B - Radiated Pressure

The effect of foam thickness was also tested by the computerized model and these results are shown in Tables 5C and 5D below. The cavity resonance peak in both radiated pressure and cavity pressure spectra decrease in intensity and decrease in peak frequency as foam thickness is increased. Further, the radiated pressure was suppressed to a greater degree than the cavity pressure. This means the thinnest foam tested (5 mm thick) can suppress some amount of noise, and that thicker foam means even better suppression, when the foam is applied to the interior surfaces of a tire. Table 5C - Cavity Pressure

Table 5D - Radiated Pressure

Impact of Foam on Tread Tnner Surface vs. Side wall Model

In the above simulations, the foam treatment was applied on all interior surfaces of the tire. Another simulation was conducted to understand if there was any advantage to adding foam only on the interior tread surface of a tire or only an interior side wall surface of tire. One model features an interior side wall only application of the foam while another model is an inner tread surface only model.

The volume of foam applied was kept constant in the two model scenarios. This was achieved by applying a different thicknesses of foam treatments to the side wall and tread inner surface (9.4mm vs. 5mm, respectively) to account for the lower surface area of the side wall in comparison to tread inner surface. The foam material parameters were defined exactly the same (the different thicknesses being the reason for the different alpha values). The results of radiated and cavity pressure spectra for both models are shown below in the tables 6 A and 6B. The results suggest that applying foam on the inner side wall surface provides better acoustic performance at the cavity resonance frequency than applying same amount of foam on the tread inner surface of the tire.

Table 6 A - Cavity Pressure

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5UB5TITUTE SHEET (RULE 26)

Table 6B - Radiated Pressure

Claims

1. A method for dispensing a foaming formulation upon a tire, comprising: a tire, the tire comprising at least one interior surface, at least one exterior sidewall portion, and at least one exterior tread portion; and a foam formulation; wherein the foam formulation is dispensed upon the at least one interior surface of the tire, the tire oriented such that the tire may rest on at least one exterior sidewall portion while the foam formulation is dispensed.

2. The method of claim 1, wherein the foam formulation dispensed upon the at least one interior surface of the tire forms a polyurethane foam.

3. The method of claim 1, wherein the foaming formulation comprises at least a polyamine or polyetheramine.

4. The method of claim 1, further comprising a sprayhead, wherein the foaming formulation is dispensed upon the at least one interior surface of the tire via the sprayhead.

5. The method of claim 4, wherein the sprayhead rotates while the foaming formulation is dispensed upon the at least one interior surface of the tire.

6. The method of claim 4, wherein the tire rotates along its own vertical axis while the foaming formulation is dispensed upon the at least one interior surface of the tire.

7. The method of claim 1, wherein the at least one interior surface of the tire comprises at least one interior side wall portion and at least one interior tread portion, and wherein the foaming formulation is dispensed upon at least one interior side wall portion or at least one interior tread portion of the interior surface of the tire.

8. The method of claim 1, wherein the foaming formulation is dispensed upon the at least one interior surface of the tire in a pattern.

9. The method of claim 1, wherein the foaming formulation is dispensed upon the at least one interior surface of the tire, the tire oriented along its vertical axis with the radial direction of the tire in the horizontal plane, wherein the radial direction of the tire in the horizontal plane is plus or minus 20, 30, 45, or 60 degrees from the horizontal plane.