Microporous foam weather seal

Abstract

The weatherseal includes an elongated microcellular foam bulb and an elongated microcellular foam fin element attached to and extending along the length of the foam bulb. The fin element includes a protrusion having opposing flat surfaces and at least one microcellular foam barb extending outward and downward from each surface along the length of the protrusion at an angle. As an alternative to barbs, another option is to use a hollow circular, higher durometer foamed thermoplastic elastomer that is pressed into a retention pocket. A T-groove variation with a foam bulb and polypropylene substrate is another option.

Description

Technical Field

[0001] (Cross - Reference to Related Applications) This application is related to and claims priority from U.S. Application No. 16 / 570,815, filed on September 13, 2019, the entire disclosure of which is incorporated herein by reference.

[0002] The present disclosure generally relates to weather seals used in windows and doors.

Background Art

[0003] A weather seal or weatherstrip is generally attached to the edges of doors and windows to reduce or prevent air from passing between the inside and outside of the door or window. Weather seals are also used to seal between the moving parts of windows and doors. Most typically, weather seals are composed of thermoplastic elastomers, EPDM rubber, wrapped urethane foam, or other flexible thermosetting materials. These materials have flexibility, elasticity, durability, generally have a low coefficient of friction, and provide a stable low closing force. It is very important to minimize the loss of the functional height of the weather seal until the end of the life of the window or door.

[0004] More advanced weather seals include a plurality of bulbs and sealing flaps that extend the reach of the bulb seal. Some advanced or high-performance weather seals have a solid foam core made from urethane foam or TPE water-expanded foam. In some cases, a hollow foam can also be used to reduce the closing force. The materials and processing methods used to make the foam-filled seals are complex, expensive, and require multiple steps. Urethane seals are non-recyclable and require special handling because they utilize a two-component chemical process. The two advanced weather seals described above use at least three different materials and require three extruders. If a lubricant coating is added to reduce friction, a fourth extruder is required. As a result, it is an expensive process that requires a significant amount of space. These processes also require highly skilled operators due to the complexity of the processes used.

[0005] Therefore, there is a need in the art for a more cost-effective solution for manufacturing an elastic foam bulb seal with insertion barbs that is recyclable, has a low closing force, and very little loss of functional height over time. This cost-effective and environmentally friendly solution would involve using two or at most three conventional extruders in a single-step process if a lubricant coating is required. SUMMARY OF THE INVENTION

[0006] The present disclosure is directed to a micro-cellular foam weather seal and a method for manufacturing the weather seal.

[0007] According to one aspect, a weather seal for use in a weather permeable barrier that separates indoors and outdoors includes an elongated compressible microporous foam valve adapted for connection to the barrier, and an elongated compressible microporous foam element attached to the foam valve and extending along the length direction of the foam valve, the microporous foam element being spaced apart from the barrier.

[0008] According to one embodiment, the weather seal further includes a silicone lubricant incorporated therein.

[0009] According to one embodiment, the weather seal further includes a polypropylene member attached to the foam valve, extending along the length direction of the foam valve, and to which the foam element is attached.

[0010] According to one embodiment, the polypropylene member is attached to the lower part of the valve portion and includes an elongated protrusion having opposing surfaces, and the foam element includes at least one return extending from each surface of the protrusion.

[0011] According to one embodiment, the weather seal further includes a pair of seal flaps extending obliquely upward from the upper part of the valve on the opposite side of the protrusion.

[0012] According to one embodiment, the foam valve has a predetermined first diameter, the foam element has a spherical shape, and has a second diameter smaller than the first diameter.

[0013] According to one embodiment, the foam valve has a teardrop shape and / or a predetermined length, and the foam element has a spherical shape with a diameter smaller than the predetermined length.

[0014] According to one embodiment, the foam valve has a hardness in the range of 10 to 75 durometers on the Shore A scale, and the foam element has a hardness in the range of 10 to 75 durometers on the Shore A scale.

[0015] According to one aspect, a method of manufacturing a microcellular foam weather seal for use in a weather barrier separating indoors and outdoors, the microcellular foam weather seal comprising an elongate compressible microcellular foam valve adapted for connection to the barrier and an elongate compressible microcellular foam element attached to the foam valve and extending along the length of the foam valve, the microcellular foam element being spaced apart from the barrier, the method comprising supplying a microcellular foam material from a storage cell to a metering blender and then to a dryer; supplying the microcellular foam material from the dryer to a main extruder; supplying a polypropylene material from a storage cell to a first co-extruder; drawing the microcellular foam material and the polypropylene material into a mold through the main extruder and the first co-extruder, respectively; forming the weather seal in the mold; drawing the weather seal from the mold to a sizing plate; drawing the weather seal from the sizing plate to a cooling tank; blowing excess water from the weather seal after passing through the cooling tank; and winding the weather seal onto a reel.

[0016] According to one embodiment, the method further comprises providing a second co-extruder and supplying a lubricant material to the second co-extruder.

[0017] According to one embodiment, the method further comprises injecting the lubricant material from the second co-extruder into the mold such that the lubricant material coats the weather strip when the weather strip is removed from the mold.

[0018] According to one embodiment, the method further includes optically inspecting the weatherstrip when the weatherstrip is removed from the cooling tank.

[0019] According to one embodiment, the method further includes maintaining the water in the cooling tank at a predetermined temperature.

[0020] A method of manufacturing a microcellular foam weather seal for use in a weather barrier separating indoor and outdoor areas, the microcellular foam weather seal comprising an elongate compressible microcellular foam valve adapted for connection to the barrier and an elongate compressible microcellular foam element attached to the foam valve and extending along the length direction of the foam valve, the microcellular foam element being spaced apart from the barrier, the method comprising preparing a setup sheet comprising die tool parameters, heating settings of a main extruder, and a material formulation; verifying that a correct die assembly is installed; verifying that a correct material formulation is used; verifying that the heating settings of the extruder are correct; stringing up the weatherstrip by pulling it through an assembly line towards a take-up machine; providing a procedure for a microcellular foaming agent to follow during the manufacture of the weather seal; stabilizing the pressure in the extruder for a predetermined time; inspecting the quality of the weatherstrip taken out of the manufacturing line; and adjusting the pulling speed of the weatherstrip on the manufacturing line if the weather seal fails the quality inspection.

[0021] These and other aspects of the present invention will become apparent from the embodiments described below.

[0022] The present invention will be more fully understood by reading the following detailed description in conjunction with the accompanying drawings.

Brief Description of the Drawings

[0023]

Figure 1

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DETAILED DESCRIPTION OF THE INVENTION

[0024] In the present disclosure, a microcellular foam weather seal of a thermoplastic elastomer will be described. The material used for the weather seal may be any of a thermoplastic elastomer (TPE: Thermoplastic Elastomers), a thermoplastic vulcanizate (TPV: Thermoplastic Vulcanizates), or a thermoplastic olefin (TPO: Thermoplastic Olefins).

[0025] Referring to FIG. 1, in one embodiment, the microcellular foam weather seal 10 generally includes an elongated bulb-like body 12 and an elongated barb element 14 extending along the length direction of the body 12. The fin element 14 includes fins / spines 16 having opposing flat surfaces and a series of barbs 18 extending obliquely outward from each flat surface of the fins / spines 16 toward the body 12. The plurality of barbs 18 have a width shorter than the height of the fins / spines 16 and are arranged in parallel at lateral intervals with respect to each other along the height direction of the fins / spines 16.

[0026] The barbs 18 and the body 12 are composed of a thermoplastic elastomer having a chemical blowing agent (for manufacturing the microcellular foam), while the fins / spines 16 are composed of polypropylene. The thermoplastic elastomer has a Shore A hardness of 10 to 75 durometers, more preferably 25 to 65 durometers, and the chemical blowing agent reduces the density by 10% to 40%. The body 12 has a preferred thickness of 0.020 inches to 0.200 inches.

[0027] Since the weather seal 10 is composed of a microcellular foam composition, as shown in FIG. 2, it has flexibility and elasticity to wrap around corners and maintain a 90-degree angle flexibly. Further, due to this flexibility, for example, as shown in FIG. 2, a single weather strip 10 can be used for the lower end and side ends of a barrier between indoors and outdoors, such as a door or a window 20. Therefore, the joints between the weather seal strips, which would be required without the flexibility provided by the seal 10, can be eliminated.

[0028] In addition to the advantage of improved flexibility, the microcellular foam composition reduces the cost of the seal and decreases the weight. Further, the microcellular foam reduces the closing force that the user has to exert, thereby reducing the pressure on the door and window hardware (the closing force is typically less than 5 pounds per foot in the most common designs). This is particularly important for facilities that emphasize compliance with the Americans with Disabilities Act. Also, the compression set resistance is about 10% or less.

[0029] Also, the blowing agent used to form the seal 10 can accept a silicone lubricant 22 that reduces the coefficient of friction by at least 20%. This further improves the advantages of the seal in addition to its low closing force and lightweight. Also, a colorant can be added for aesthetics. The desired low coefficient of friction can be achieved by adding a lubricant to the polymer mixture. Also, the desired low coefficient of friction can also be achieved by selectively co-extruding a thin layer of lubricant material in the area where the surface of the weather seal contacts the mating surface.

[0030] To manufacture the seal 10, co-extrusion of two materials, both of which are foams, is used. Since the return 18 is foamed, the mold design is simplified, and as a result, two extruders are required. An extension mandrel is used to improve the melt strength of the material since foaming occurs when the material exits from the die face and reaches atmospheric pressure. The extension mandrel allows the material to be strengthened until it approaches the water cooling tank.

[0031] Referring to FIG. 4, a flowchart showing the manufacturing process used is provided. For the purpose of manufacturing the foam bulb (100), the parts are printed (102), and a setup sheet (104) is constructed that describes the mold tooling, the heating settings of the main extruder, and the material formulation. For a sample of the setup data sheet, refer to FIGS. 5A and 5B. This setup sheet (104) is used in step 106 to prepare the manufacturing line.

[0032] In step 108, the microcontroller determines whether the correct mold assembly is set on the production line. If the correct mold assembly is not set, in step 110, the setup sheet 104 is referred to so that the correct mold assembly is set.

[0033] When the correct mold assembly is set in step 110 or the correct mold assembly is confirmed in step 108, in step 112, the microcontroller verifies whether the material recipe is correctly programmed on the production line. If the material recipe is not correctly programmed, in step 114, the program recipe is referred to from the setup sheet 104.

[0034] When the recipe is verified, in step 116, the microcontroller verifies whether the heating setting of the extruder is correct. If the heating setting of the extruder is incorrect, in step 118, the heating setting of the extruder is referred to from the setup sheet 104 and corrected. When verified, in step 120, the production line starts the string up of the foam valve, and in step 122, the microcontroller instructs the execution of the foaming procedure according to the setup sheet 104.

[0035] Next, in step 124, the microcontroller operates the production line for 5 minutes to stabilize the pressure of the material. The counter 126 checks when the 5-minute stabilization period is executed. Once operated and the production of the foam valve is executed, in step 128, the quality of the parts is inspected via the optical inspection device. If the quality inspection fails, in step 130, the speed of the extruder is operated until the quality becomes acceptable. When the quality becomes acceptable, in step 132, the good-quality foam valves are taken out from the assembly line (and wound on a reel, cut to a predetermined length, and packaged).

[0036] Referring to FIG. 6, a block diagram of the manufacturing line is provided. This line includes a mixing and drying container 200 for the material TPV / CFA. The mixing and drying container 200 conveys the mixed and dried material to a material distribution container 202, and the material distribution container 202 will distribute the material to the main extruder 204 via a hopper 206. A polypropylene (PP) distribution container 208 is installed in parallel with container 202 and distributes the PP material to the first co-extruder 210. Also, a lubricant material container 212 is installed in parallel and distributes the lubricant material to the second co-extruder 214.

[0037] The main extruder 204, the first co-extruder 210 and the second co-extruder 214 are arranged to extrude materials into a three-piece extrusion profile die 300 that includes three material outlets (one for the foamed PV material, one for the PP material, and one for the low-friction lubricant material). After exiting the die 300, the extruded weatherstrip then enters a sizing plate 216 at the leading end of a cooling water tank 218 filled with water at 50°F. The water cooler 220 maintains the water at a cooled temperature. When the weatherstrip is pulled out of the water tank 218, it then passes through a blower 222 that blows off the excess water. Then, the weatherstrip is pulled through the entire line and passes through a take-up / cutter 224 that cuts it to the desired length, or the product passes through the cutter and is wound onto a reel by a winder 226.

[0038] FIG. 7 shows a more detailed view of some of the devices. The mixing and drying container 200 includes a TPE holding cell 228 and a PP holding cell 230. The TPE material is sent to a weigh scale blender 232 where the CFA and TPV materials are mixed and then passed to a dryer 234.

[0039] Figure 8 shows the details of the mold 300 used to form the weatherstrip. The mold 300 includes three plates: a back plate 302, a compression plate 304, and a front plate 306. The material enters the back plate 302 from the extruders 204, 210, and 214 and exits the mold 300 through the front plate 306. The back plate 302 includes a main extruder input 308 for introducing the microcellular foam material into the mold 300. A co-extrusion input is provided for introducing the PP material into the mold 300 (and a separate input may be provided for the lubricant inlet). The splitter separates the main extruder material into two sections, one for the valve and one for the return. The back of the back plate is aligned with the face of the adapter die of the extruder, which is the first face of the profile die assembly into which the material is introduced.

[0040] The mandrel 320 is inserted into the compression plate and supplies air into the mold 300, which is important in terms of tolerance and machining. The mandrel 320 extends approximately 0.5 inches from the front of the mold 300. This extra length helps to improve the melt strength when exiting the mold prior to cooling in the water bath.

[0041] After exiting the compression plate 304, the material hits the front of the front plate 306. When exiting the front of the front plate, the various separate flow paths obtained by the confluence of the two materials are joined into one at the final opening.

[0042] In addition to the returnable weatherstrip, the same manufacturing process can be used with different molds to form weatherstrips of different profiles, also composed of foamed material. For example, referring to FIG. 9, there is a weatherstrip 500 of a high pocket profile having a spherical portion 502 and a cylindrical / spherical portion 504 with a smaller diameter than the spherical portion.

[0043] Alternatively, referring to FIG. 10, there is provided a weatherstrip having an upper valve portion 602 of a 25 durometer teardrop shape (inclined to a triangle) and a lower portion 604 of a 30 durometer cylindrical shape, with the diameter of the lower portion 604 being smaller than the length of the valve portion 602.

[0044] As another option, referring to FIG. 11, there is provided a weather seal 700. The weather seal 700 has a microcellular foam valve 702, a polypropylene protrusion 704, and a return 706 of the microcellular foam, similar to the weather seal 10, but further includes a pair of seal flaps 708 (substantially the same dimensions as the return 706) extending obliquely upward from the upper portion of the valve 702. The seal flaps 708 expand the seal area when compressed against the mating surface. Further, all of the multiple hollow valve profiles as taught in the applicant's pending prior U.S. patent applications published as U.S. Patent Application Publication No. 2012 / 0260579 and International Patent Application No. 2012 / 033773 (International Publication No. 2012 / 142574) are hereby incorporated by reference, but can be manufactured using a microcellular foam manufacturing process. The microcellular foam composition, which is a seal member in various weatherstrips, provides the above-described usefulness and improvements to the art, and each can be manufactured in the manner described herein.

[0045] Although various embodiments are described and illustrated in this specification, those skilled in the art can readily envision various other means and / or structures for performing the functions described in this specification and / or obtaining the results and / or achieving one or more of the advantages described in this specification. Each such variation and / or modification is considered to be within the scope of the embodiments described in this specification. More generally, those skilled in the art will appreciate that all of the parameters, dimensions, materials, and configurations described in this specification are intended to be exemplary, and that the actual parameters, dimensions, materials, and / or configurations will depend on the particular application or applications for which the present teachings are used. Those skilled in the art will recognize many equivalents to the specific embodiments described herein or will be able to ascertain such equivalents using only routine experimentation. Accordingly, the foregoing embodiments are presented by way of example only, and it should be understood that the embodiments may be practiced otherwise than as specifically described and claimed within the scope of the appended claims and their equivalents. Embodiments of the present disclosure are directed to the individual features, systems, articles, materials, kits, and / or methods described herein. Furthermore, any combination of two or more such features, systems, articles, materials, kits, and / or methods is included within the scope of the present disclosure if such features, systems, articles, materials, kits, and / or methods are not mutually inconsistent.

Claims

1. A method for manufacturing a microcellular foam weather seal for use in a weather-resistant barrier separating indoors and outdoors, wherein the microcellular foam weather seal comprises an elongate and compressible microcellular foam valve adapted for connection to the barrier, and an elongate and compressible microcellular foam element attached to the foam valve and extending along the length of the foam valve, the microcellular foam element being spaced apart from the barrier. a) Supplying a microcellular foam material from a first storage cell to a metering blender and then to a dryer. b) Supplying the microcellular foam material from the dryer to a main extruder. c) Supplying a polypropylene material from a second storage cell to a first co-extruder. d) Supplying a lubricant material from a third storage cell to a second co-extruder. e) Drawing the microcellular foam material, the polypropylene material, and the lubricant material into a mold through the main extruder, the first co-extruder, and the second co-extruder, respectively. f) Forming the weather seal within the mold. g) Drawing the weather seal from the mold into a sizing plate. h) Drawing the weather seal from the sizing plate into a cooling tank. i) Blowing excess water off the weather seal after passing through the cooling tank. j) Winding the weather seal onto a reel. A method comprising the above steps.

2. The method according to claim 1, further comprising providing the second co-extruder and supplying the lubricant material to the second co-extruder.

3. The method according to claim 1, further comprising coating the weather strip with the lubricant material when the weather strip is removed from the mold by injecting the lubricant material from the second co-extruder into the mold.

4. The method according to claim 1, further comprising optically inspecting the weather strip when the weather strip is removed from the cooling tank.

5. The method according to claim 1, further comprising maintaining the water in the cooling tank at a predetermined temperature. A method for manufacturing a microcellular foam weather seal for use in a weather-resistant barrier separating indoors and outdoors, the microcellular foam weather seal comprising an elongate compressible microcellular foam valve adapted for connection to the barrier, and an elongate compressible microcellular foam element attached to the foam valve and extending along the length of the foam valve, the microcellular foam element being spaced apart from the barrier. Preparing a setup sheet consisting of die tool parameters, heating settings of a main extruder, and a material formulation. Verifying that the correct die assembly is set up. Verifying that the correct material formulation is being used. Verifying that the heating settings of the main extruder are correct. Pulling the weather strip through a puller on the assembly line and pulling the weather strip. Providing procedures for the microcellular foam material to be followed during the manufacture of the weather seal. Stabilizing the pressure of the main extruder for a predetermined time. Inspecting the quality of the weather strip emerging from the production line. If the weather seal fails the quality inspection, adjusting the speed at which the weather strip is withdrawn from the production line. A method including the above steps.

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