REFRIGERATOR APPLIANCE AND A METHOD FOR MANUFACTURING THE SAME
The present subject matter provides a refrigerator appliance and a method for manufacturing the same. The method includes applying a polyurethane elastomer onto a surface of an inner liner of the refrigerator appliance and injecting a polyurethane foam into a cavity defined between an outer case of the refrigerator appliance and the inner liner. The polyurethane elastomer can limit or prevent leakage of the polyurethane foam from the cavity.
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The present subject matter relates generally to refrigerator appliances and methods for manufacturing the same.
BACKGROUND OF THE INVENTIONCertain refrigerator appliances include double wall cabinets with inner liners and outer cases. In such refrigerator appliances, the inner liner and the outer case are spaced apart and define a cavity therebetween. An expandable foam material, such as a polyurethane foam, can be injected into the cavity between the inner liner and the outer case of the double wall cabinet in order to provide insulation within the double wall cabinet.
During expansion of the foam material, the expandable foam material fills the cavity between the inner liner and the outer case of the double wall cabinet. However, the expandable foam material can also leak out of the cavity at a seam between the inner liner and the outer case or at holes or openings in the inner liner or outer case, and the leaked foam material can cure on the inner liner, the outer case or other components of the refrigerator appliance. Removing such leaked foam material can be difficult and time consuming. In extreme cases, a refrigerator appliance is scrapped if removing such leaked foam material is impracticable or infeasible.
To limit or prevent leaks of the foam material, certain refrigerator appliances include an Olefin based thermoplastic positioned at the seam between the inner liner and the outer case or at holes or openings in the inner liner or outer case. However, the Olefin material bonds poorly to the inner liner and the outer case. Further, the Olefin material is dispensed at relatively high temperatures and accurately dispensing the Olefin material can be difficult. In particular, the inner liner can melt if the Olefin material's dispenser contacts the inner liner or is positioned next to the inner liner for an extended period of time.
Accordingly, a refrigerator appliance with features for limiting or preventing leaking of insulating foam material from a cavity of the refrigerator appliance would be useful. Further, a method for manufacturing a refrigerator appliance that avoids leaking of insulating foam material from a cavity of the refrigerator appliance would be useful. In particular, a method for manufacturing a refrigerator appliance that avoids leaking of insulating foam material from a cavity of the refrigerator appliance while avoiding the problems discussed above would be useful.
BRIEF DESCRIPTION OF THE INVENTIONThe present subject matter provides a refrigerator appliance and a method for manufacturing the same. The method includes applying a polyurethane elastomer onto a surface of an inner liner of the refrigerator appliance and injecting a polyurethane foam into a cavity defined between an outer case of the refrigerator appliance and the inner liner. The polyurethane elastomer can limit or prevent leakage of the polyurethane foam from the cavity. Additional aspects and advantages of the invention will be set forth in part in the following description, or may be apparent from the description, or may be learned through practice of the invention.
In a first exemplary embodiment, a method for assembling a refrigerator appliance is provided. The method includes providing an outer case of the refrigerator appliance and an inner liner of the refrigerator appliance, mounting the inner liner to the outer case such that the inner liner and the outer case define a cavity therebetween, applying a polyurethane elastomer onto a surface of the inner liner, and injecting a polyurethane foam into the cavity between the outer case and the inner liner.
In a second exemplary embodiment, a refrigerator appliance is provided. The refrigerator appliance includes an outer case and an inner liner spaced apart from the outer case such that the inner liner and the outer case define a cavity therebetween. The inner liner defines an interior volume configured for receipt of food items for storage. A polyurethane elastomer is positioned on a surface of the inner liner. A polyurethane foam is disposed within the cavity between the outer case and the inner liner. The polyurethane foam contacts the polyurethane elastomer, the inner liner and the outer case within the cavity.
These and other features, aspects and advantages of the present invention will become better understood with reference to the following description and appended claims. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth in the specification, which makes reference to the appended figures.
Reference now will be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, not limitation of the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For instance, features illustrated or described as part of one embodiment can be used with another embodiment to yield a still further embodiment. Thus, it is intended that the present invention covers such modifications and variations as come within the scope of the appended claims and their equivalents.
Refrigerator appliance 100 includes a cabinet or housing 120 that extends between a top portion 101 and a bottom portion 102 along a vertical direction V. Housing 120 defines chilled chambers for receipt of food items for storage. In particular, housing 120 defines fresh food chamber 122 positioned at or adjacent top 101 of housing 120 and a freezer chamber 124 arranged at or adjacent bottom 102 of housing 120. As such, refrigerator appliance 100 is generally referred to as a bottom mount refrigerator. It is recognized, however, that the benefits of the present disclosure apply to other types and styles of refrigerator appliances such as, e.g., a top mount refrigerator appliance or a side-by-side style refrigerator appliance. Consequently, the description set forth herein is for illustrative purposes only and is not intended to be limiting in any aspect to any particular refrigerator chamber configuration.
Refrigerator doors 128 are rotatably hinged to an edge of housing 120 for selectively accessing fresh food chamber 122. In addition, a freezer door 130 is arranged below refrigerator doors 128 for selectively accessing freezer chamber 124. Freezer door 130 is coupled to a freezer drawer (not shown) slidably mounted within freezer chamber 124. As discussed above, refrigerator doors 128 and freezer door 130 are shown in the closed configuration in
Turning now to
Inner liner 160 is positioned within outer case 150 and defines the chilled chambers of housing 120. In particular, inner liner 160 defines fresh food chamber 122 and freezer chamber 124 of housing 120. Inner liner 160 can be formed from any suitable material, such as molded plastic. In certain exemplary embodiments, inner liner 160 is a single, integral component that defines both fresh food chamber 122 and freezer chamber 124. In alternative exemplary embodiments, inner liner 160 is constructed with multiple components (e.g., at least two components) that are connected or mounted to one another to define fresh food chamber 122 and freezer chamber 124 as discussed in greater detail below.
Inner liner 160 is mounted or secured to outer case 150. In particular, inner liner 160 may be mounted to outer case 150 such that inner liner 160 and outer case 150 are spaced apart from each other and inner liner 160 and outer case 150 define a cavity 170 therebetween. Inner liner 160 may be mounted to outer case 150 using any suitable mechanism. For example, fasteners can be extended through flanges of inner liner 160 and outer case 150 at a front portion 104 of refrigerator appliance 100. In alternative exemplary embodiments, heat staking, ultrasonic welding, snap fit, or any other suitable mechanism may be used to mount inner liner 160 to outer case 150.
As may be seen in
Inner liner 160 defines an interior volume 169 (
As may be seen in
Refrigerator appliance 100 also includes a machinery compartment 151. A sealed system (not shown) for cooling air within chilled chambers of housing 120 may be positioned within machinery compartment 151. The sealed system includes components for executing a known vapor compression cycle for cooling air. The components include a compressor, a condenser, an expansion device, and an evaporator connected in series as a loop and charged with a refrigerant. The evaporator is a type of heat exchanger which transfers heat from air passing over the evaporator to the refrigerant flowing through the evaporator, thereby causing the refrigerant to vaporize. The cooled air is used to refrigerate one or more of the chilled chambers via fans. The construction and operation of the sealed system are well known to those skilled in the art.
To insulate chilled chambers of housing 120, such as fresh food chamber 122 and freezer chamber 124, polyurethane foam 192 is disposed within cavity 170. A portion of rear panel 180 is removed in
As discussed above, inner liner 160 include seam 166 and openings 168. During curing of polyurethane foam 192, polyurethane foam 192 expands and can flow through seam 166 and/or openings 168 into interior volume 169 of inner liner 160. Removing excess polyurethane foam 192 from inner liner 160 within interior volume 169 can be difficult and/or time consuming. Thus, refrigerator appliance 100 includes features for limiting or preventing polyurethane foam 192 from leaking into unwanted areas, such as machinery compartment 151 or interior volume 169 of inner liner 160. In particular, refrigerator appliance 100 includes features for limiting or preventing polyurethane foam 192 from leaking through seam 166 and/or openings 168.
As may be seen in
It should be understood that both polyurethane elastomer 190 and polyurethane foam 192 can be thermoset resins. Thus, once cured, polyurethane elastomer 190 and polyurethane foam 192 may not be melted. However, polyurethane foam 192 can include a foaming agent, such as cyclopentane or another suitable material. The foaming agent can boil at a polymerization temperature of reactants used to create polyurethane foam 192, and the foaming agent can create leavening within polyurethane foam 192 such that polyurethane foam 192 includes gaseous phase material disposed therein. Conversely, polyurethane elastomer 190 may not contain a volatile component such that nothing boils at a polymerization temperature of reactants used to create polyurethane elastomer 190. Accordingly, polyurethane elastomer 190 can be significantly denser than polyurethane foam 192. Further, polyurethane elastomer 190 is an elastomer. Conversely, polyurethane foam 192 can be a rigid foam. Thus, a Young's modulus of polyurethane elastomer 190 can be significantly less than a Young's modulus of polyurethane foam 192, and polyurethane elastomer 190 can be significantly more flexible than polyurethane foam 192.
At step 710, outer case 150 of refrigerator appliance 100 and inner liner 160 of refrigerator appliance 100 are provided. As discussed above, inner liner 160 and outer case 150 are components of housing 120, and inner liner 160 and outer case 150 are assembled together to form housing 120. At step 720, inner liner 160 is mounted to outer case 150. In particular, inner liner 160 may be mounted to outer case 150 such that inner liner 160 and outer case 150 are spaced apart from each other and inner liner 160 and outer case 150 define cavity 170 therebetween.
At step 730, polyurethane elastomer 190 is applied onto surface 161 of inner liner 160. For example, as shown in
Polyurethane elastomer 190 can be applied onto surface 161 of inner liner 160 using any suitable method or mechanism at step 730. For example, polyurethane elastomer 190 may be applied onto surface 161 of inner liner 160 manually or with a manually operated spray gun, or polyurethane elastomer 190 may extruded onto surface 161 of inner liner 160. As another example, an automated spray assembly 200 (
Automated spray assembly 200 includes a wand 202 and a spray head 204. Spray head 204 is mounted at a distal end 206 of wand 202. Polyurethane elastomer 190 exits automated spray assembly 200 at spray head 204 during application of polyurethane elastomer 190 with automated spray assembly 200 at step 730. To assist with applying polyurethane elastomer 190, wand 202 is sized for extending into cavity 170. In particular, as shown in
During step 730, polyurethane elastomer 190 can have any suitable temperature. For example, polyurethane elastomer 190 may have a temperature less than a melting temperature of inner liner 160 during step 730. In such a manner, damage to inner liner 160 due to application of polyurethane elastomer 190 can be avoided or limited. In certain exemplary embodiments, polyurethane elastomer 190 has a temperature that is about equal to room temperature, e.g., between about sixty-five degrees Fahrenheit and about one-hundred degrees Fahrenheit, during step 730. Relatively low temperature application of polyurethane elastomer 190 also permits placement of spray head 204 adjacent inner liner 160 within cavity 170 during application of polyurethane elastomer 190 at step 730 because at such temperatures spray head 204 is unlikely to damage inner liner 160, e.g., by melting inner liner 160.
At step 740, rear panel 180 is attached to outer case 150. In such a manner, cavity 170 can be sealed or fully defined with rear panel 180. At step 750, outer case 150 and inner liner 160 (e.g., and rear panel 180) are heated. During step 750, polyurethane elastomer 190 is also heated. Such elements are heated at step 750 in order to prepare such elements for application or injection of polyurethane foam 192. In addition, heating of polyurethane elastomer 190 at step 750 can also assist with curing polyurethane elastomer 190 prior to subsequent steps of method 700.
At step 760, polyurethane foam 192 is injected into cavity 170 between outer case 150 and inner liner 160. At step 770, polyurethane foam 192 within cavity 170 is cured. During step 770, polyurethane foam 192 expands such that polyurethane foam 192 extends between and adheres to inner liner 160 and outer case 150 (e.g., and rear panel 180) within cavity 170. Polyurethane elastomer 190 can limit or prevent leakage of polyurethane foam 192 out of cavity 170 during step 770. For example, polyurethane elastomer 190 can block polyurethane foam 192 at seam 166 and/or openings 168 and limit or prevent leakage of polyurethane foam 192 into interior volume 169 of inner liner 160 through such elements during step 770. Similarly, polyurethane elastomer 190 can also limit or prevent leakage of polyurethane foam 192 into machinery compartment 151 at step 770.
During step 770, the polyurethane foam 192 can also adhere to polyurethane elastomer 190 within cavity 170. In turn, polyurethane elastomer 190 can adhere to inner liner 160, outer case 150 or other components of refrigerator appliance 100. In such a manner, polyurethane elastomer 190 and polyurethane foam 192 can enhance a structural rigidity of housing 120 during step 770. In particular, after step 770, polyurethane foam 192 can hinder racking or other movement of housing 120 by extending between and adhering to outer case 150, inner liner 160, rear panel 180 and polyurethane elastomer 190.
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they include structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.
Claims
1. A method for assembling a refrigerator appliance, comprising:
- providing an outer case of the refrigerator appliance and an inner liner of the refrigerator appliance;
- mounting the inner liner to the outer case such that the inner liner and the outer case define a cavity therebetween;
- applying a polyurethane elastomer onto a surface of the inner liner; and
- injecting a polyurethane foam into the cavity between the outer case and the inner liner.
2. The method of claim 1, further comprising heating the outer case, the inner liner and the polyurethane elastomer prior to said step of injecting.
3. The method of claim 1, wherein the inner liner comprises a first portion and a second portion, the first and second portions of the inner liner mounted to each other such that the first and second portions of the inner liner define a seam therebetween, wherein said step of applying comprises applying the polyurethane elastomer onto the inner liner at the seam of the inner liner.
4. The method of claim 1, wherein the inner liner defines an opening, wherein said step of applying comprises applying the polyurethane elastomer onto the inner liner at the opening of the inner liner.
5. The method of claim 1, further comprising attaching a rear panel to the outer case after said step of applying and prior to said step of injecting.
6. The method of claim 1, wherein the polyurethane elastomer has a temperature between about sixty-five degrees Fahrenheit and about one-hundred degrees Fahrenheit during said step of applying.
7. The method of claim 1, wherein the inner liner defines an interior volume of the refrigerator appliance, wherein said step of applying comprises applying the polyurethane elastomer onto the surface of the inner liner such that the polyurethane elastomer on the surface of the inner liner hinders the polyurethane foam from entering the interior volume of the inner liner during said step of injecting.
8. The method of claim 1, wherein said step of applying comprises applying the polyurethane elastomer onto the surface of the inner liner with a wand having a spray head, the wand having a length about equal to a depth of the cavity between the inner liner and the outer case.
9. The method of claim 1, wherein the polyurethane elastomer has a temperature less than a melting temperature of the inner liner during said step of applying.
10. The method of claim 1, further comprising curing the polyurethane foam within the cavity between the outer case and the inner liner such that the polyurethane foam extends between the inner liner and the outer case within the cavity after said step of curing.
11. A refrigerator appliance, comprising:
- an outer case;
- an inner liner spaced apart from the outer case such that the inner liner and the outer case define a cavity therebetween, the inner liner defining an interior volume configured for receipt of food items for storage;
- a polyurethane elastomer positioned on a surface of the inner liner; and
- a polyurethane foam disposed within the cavity between the outer case and the inner liner, the polyurethane foam contacting the polyurethane elastomer, the inner liner and the outer case within the cavity.
12. The appliance of claim 11, wherein the inner liner comprises a first portion and a second portion, the first and second portions of the inner liner mounted to each other, the first and second portions of the inner liner defining a seam therebetween, the polyurethane elastomer positioned on the inner liner at the seam between the first and second portions of the inner liner such that the polyurethane elastomer is disposed between the polyurethane foam and the seam between the first and second portions of the inner liner.
13. The appliance of claim 12, wherein the first and second potions of the inner liner define a fresh food chamber.
14. The appliance of claim 12, wherein the first portion of the inner liner defines a fresh food chamber and the second potion of the inner liner defines a freezer chamber.
15. The appliance of claim 11, wherein the inner liner defines an opening that extends between the interior volume of the inner liner and the polyurethane elastomer, the polyurethane elastomer positioned on the inner liner at the opening of the inner liner such that the polyurethane elastomer is disposed between the polyurethane foam and the opening of the inner liner.
16. The appliance of claim 11, further comprising a rear panel mounted to the outer case such that the rear panel and the inner liner are spaced apart from each other, the inner liner, the outer case and the rear panel defining the cavity therebetween.
17. The appliance of claim 16, wherein the polyurethane foam extends between the inner liner, the outer case and the rear panel within the cavity.
18. The appliance of claim 11, wherein the polyurethane foam is a rigid closed cell polyurethane foam.
Type: Application
Filed: Oct 15, 2013
Publication Date: Apr 16, 2015
Applicant: General Electric Company (Schenectady, NY)
Inventor: Todd Duncan Cook (Cecilia, KY)
Application Number: 14/053,680
International Classification: F25D 23/08 (20060101); F25D 23/06 (20060101);