Coextrusion dispensing head for pressure sensitive adhesives and thermoplastic elastomers and methods of using the same

Abstract

Method of coextruding pressure sensitive adhesives and thermoplastic elastomers are disclosed. The method may include an adhesive transfer process, a thermoplastic elastomer transfer process, and a dispensing head. The dispensing head may further include a channel wherein the pressure sensitive adhesive and the thermoplastic elastomer are in contact. The molten pressure sensitive adhesive and thermoplastic elastomer coextrude through an outlet in a desired shape.

Description

[0001] PA101207W002

[0002] COEXTRUSION DISPENSING HEAD FOR PRESSURE SENSITIVE ADHESIVES AND THERMOPEASTIC EEASTOMERS

[0003] AND METHODS OF USING THE SAME

[0004] BACKGROUND

[0005] The process of manufacturing a seal or gasket adhered with an adhesive to a substrate to restrict air or liquid flow for applications such as refrigerators, windows, etc. Conventionally, the seal or gasket is manufactured independently from the adhesive and later applied together prior to being applied to the desired substrate.

[0006] Rubber seals around openings are useful, for example, in the automotive and building industries as described in WO 2018 / 161068 (Murree et al.), U.S. Pat. Appl. Pub. No. 2008 / 0182074 (Pasquale et al.), and FR2851193, published August 20, 2004. The seals can have multiple layers or otherwise include multiple materials bonded together.

[0007] In unrelated disclosures, adhesives coextruded with other materials are described in U.S. Pat. Nos. 4,497,926 (Toy), 7,491,434, (Khandpur et al.), and 9,486,982 (Emslander et al.), U.S. Pat. Pub. No. 2021 / 0324244 (Bieber et al.), and GB1553881, published October 10, 1979.

[0008] In further unrelated disclosures, adhesives provided as core-sheath filaments are described in U.S. Pat. Appl. Pub. Nos. 2023 / 0089703 (Kalish et al.), 2022 / 0290335 (Behling et al.), 2022 / 0290334 (Sahni et al.), 2022 / 0259465 (Kugel et al.), and 2022 / 0134652 (Napierala et al.) and Int. Pat. Appl. Pub. No. WO 2021 / 130620 (Sahni et al.). Filament adhesives include those that use a core / sheath configuration, including adhesives that are dispensed in hot melt form and then cooled to provide a pressure-sensitive adhesive. Using the provided dispensing devices, and optionally with the assistance of a computer, these adhesives can be precisely applied to pre-determined locations on a substrate. The ability to customize the size and shape of a pressure-sensitive adhesive provides improved versatility for manufacturers. A variety of filament adhesives are previously known in the art, for example, at least the following patent applications: PCT Published Patent Application No. US2019 / 017,162, titled “Core-Sheath Filaments and Methods of Printing an Adhesive;” PCT Published Patent Application No. US2020 / 003123, titled “Adhesive Compositions, Assemblies and Methods Thereof;” PCT Published Patent Application No. US2020 / 174,396, titled “Extrudable Pressure-Sensitive Adhesive;” and PCT Published Patent Application No. US2022 / 134,652, titled “Filament Adhesive Dispenser System.” One example of an on- demand Bonding System using 3M VHB Extrudable Tape GP is commercially available as 3M On Demand Bonding System, which is commercially available from Nordson Corporation based in Westlake, Ohio.

[0009] SUMMARY

[0010] In the first aspect of the invention, a coextrusion dispensing head for a pressure sensitive adhesive and a thermoplastic elastomer is provided. The coextrusion dispensing head for a pressure sensitive adhesive and a thermoplastic elastomer, comprises: a first inlet for receiving the pressure sensitive adhesive and a second inlet for receiving the thermoplastic elastomer; a first outlet for extruding the pressure sensitive adhesive and the thermoplastic elastomer together; a first channel for the pressure sensitive adhesive within the coextrusion dispensing head from the first inlet to the first outlet; and a second channel for the thermoplastic elastomer within the coextrusion dispensing head from the second inlet to the first outlet, wherein within the coextrusion dispensing head the first channel and second channel merge before the first outlet.

[0011] In a second aspect of the invention, a method of coextruding a pressure sensitive adhesive and a thermoplastic elastomer on a substrate is provided. The method comprises: providing a source of molten pressure sensitive adhesive; providing a source of molten thermoplastic elastomer; flowing the molten pressure sensitive adhesive down a first flow path; flowing the molten thermoplastic elastomer down a second flow path; merging the first flow path and the second flow path so as to contact the flows of molten pressure sensitive adhesive and molten thermoplastic elastomer to form a third flow path; and coextruding the merged molten pressure sensitive adhesive and molten thermoplastic elastomer together through an outlet in a desired shape.

[0012] The words “preferred” and “preferably” refer to embodiments of the invention that may afford certain benefits, under certain circumstances. Other embodiments may also be preferred, under the same or different circumstances. Description of one or more alternative embodiments do not imply that the embodiments are not useful and is not intended to exclude any embodiments from the scope of the invention.

[0013] As used herein “a,” “an,” “the,” “at least one,” and “one or more” are used interchangeably. Thus, for example, a heater may refer to one or more heaters unless otherwise indicated. The above summary is not intended to describe each embodiment or every implementation of the present invention. Rather, a more complete understanding of the carriers and methods described herein will become apparent and appreciated by reference to the following Description of Exemplary Embodiments and claims in view of the figures of the drawings.

[0014] BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The present invention will be further described with reference to the views of the drawing, wherein:

[0016] FIG. 1 is a perspective view of an exemplary embodiment of a filament adhesive;

[0017] FIG. 2 is a side cross-sectional view of an exemplary embodiment of a dispensing head for dispensing the filament adhesive of FIG. 1;

[0018] FIG. 3 is a side elevational view of a barrel component within the dispensing head of FIG. 2, revealing certain internal surfaces in dotted lines;

[0019] FIG. 4 is a side elevational view of a screw component within the dispensing head of FIG. 2;

[0020] FIG. 5 is a front cross-sectional view of the screw component of FIG. 4;

[0021] FIG. 6 is perspective view of a system that incorporates the filament adhesive of FIG. 1 and dispensing head of FIGS. 2-4, respectively;

[0022] FIG. 7 is a side, schematic view of an inventive system for coextruding the filament adhesive of FIG. 1 and a thermoplastic elastomer, which includes an exemplary embodiment of the coextrusion dispensing head of the present invention and includes the adhesive dispensing system of FIG. 6;

[0023] FIG. 8A is a perspective view of a first exemplary embodiment of the coextrusion dispensing head of the present invention;

[0024] FIG. 8B is a front view of the coextrusion dispensing head of FIG. 8A;

[0025] FIG. 8C is a side view of the coextrusion dispensing head of FIG. 8A;

[0026] FIG. 8D is a top view of the coextrusion dispensing head of FIG. 8A;

[0027] FIG. 8E is a side cross-sectional view of the coextrusion dispensing head of FIG. 8A taken along line a-a in Figure 8B;

[0028] FIG. 8F is a perspective view of the coextrusion dispensing head of FIG. 8E;

[0029] FIG. 9 is a perspective view of a D-shaped hollow coextruded thermoplastic and adhesive article that may be coextruded by the coextrusion dispensing head of Figures 8A-8F; FIG. 10A is a perspective view of a second exemplary embodiment of the coextrusion dispensing head of the present invention;

[0030] FIG. 1 OB is a front view of the coextrusion dispensing head of FIG. 10A;

[0031] FIG. IOC is a side view of the coextrusion dispensing head of FIG. 10A;

[0032] FIG. 10D is a top view of the coextrusion dispensing head of FIG. 10A;

[0033] FIG. 10E is a side cross-sectional view of the coextrusion dispensing head of FIG. 10A taken along line b-b in Figure 10B;

[0034] FIG. 10F is a perspective view of the coextrusion dispensing head of FIG. 10E;

[0035] FIG. 11 is a perspective view of stacked, intersecting circle-shaped and hollow coextruded thermoplastic and adhesive article that may be coextruded by the coextrusion dispensing head of Figures 10A-10F;

[0036] FIG. 12 is a perspective view of a third exemplary embodiment of the coextrusion dispensing head of the present invention;

[0037] FIG. 13 is a cross-sectional view of a flat-stock, ribbon-shaped coextruded thermoplastic elastomer and adhesive article that may be coextruded by the coextrusion dispensing head of Figure 12; and

[0038] FIG. 14 are front views of a plurality of shaped dispensing faces suitable for use in the coextrusion dispensing head of the present invention.

[0039] DEFINITIONS

[0040] As used herein, the following terms are defined as set below:

[0041] “Non-tacky” refers to a material that passes a “Self-Adhesion Test”, in which the force required to peel the material apart from itself is at or less than a predetermined maximum threshold amount, without fracturing the material. The Self-Adhesion Test is described below and is typically performed on a sample of the sheath material to determine whether or not the sheath is non-tacky.

[0042] “Pressure-sensitive adhesives” (PSA) refers to materials that are normally tacky at room temperature and can be adhered to a surface by application of light finger pressure and thus may be distinguished from other types of adhesives that are not pressure-sensitive. A general description of pressure-sensitive adhesives may be found in the Encyclopedia of Polymer Science and Engineering, Vol. 13, Wiley-Interscience Publishers (New York, 1988). Additional description of pressure-sensitive adhesives may be found in the Encyclopedia of Polymer Science and Technology, Vol. 1, Interscience Publishers (New York, 1964). “Pressure sensitive adhesive” or “PSA”, as used herein, refers to a viscoelastic material that possesses the following properties: (1) aggressive and permanent tack, (2) adherence to a substrate other than a fluorothermoplastic fdm with no more than finger pressure, and (3) sufficient cohesive strength to cleanly release from the substrate. A pressure-sensitive adhesive may also meet the Dahlquist criterion described in Handbook of Pressure-Sensitive Adhesive Technology, D. Satas, 2nded., page 172 (1989). This criterion defines a pressure-sensitive adhesive as one having a one-second creep compliance of greater than 1 x 10‘6cm2 / dyne at its use temperature (for example, at temperatures in a range of from 15°C to 35°C).

[0043] DETAILED DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

[0044] In the following detailed description of the exemplary embodiments, reference is made to the accompanying figures of the drawings for a coextrusion dispensing head and affiliated methods of manufacture which form a part hereof and are shown by illustration specific embodiments. It is to be understood that other embodiments may be utilized, and structural changes may be made without departing from the scope of the present invention.

[0045] Thermoplastic elastomers are known to make high performance gasket seals in many industries including for example appliance, electronics and automotive industries. Typically these types of gasket seals are made in one location in non-custom lengths and shapes, and then manually applied at a manufacturing assembly plant. The coextrusion dispensing head and system of the present invention and methods of the present invention provide for gaskets and seals with adhesive to be directly created and bonded to substrates in one step at one location on the manufacturing floor. Coextruding a pressure sensitive adhesive and a thermoplastic elastomer directly on a substrate may produce a more desirable adhesive bond between the thermoplastic elastomer and the adhesive. Another potential advantage of coextruding the pressure sensitive adhesive and a thermoplastic elastomer directly on a substrate is the thermoplastic article may be formed into an irregular shape (e.g., comer or sharp edge) naturally that would otherwise not be desirable to manufacture independently. In addition, customized lengths and shapes of such gasket seals may be created by the coextrusion dispensing head and system of the present invention, in particular gasket seals that include desirable radiuses or curves in a continuous length of gasket that is directly adhered to the work piece or substrate. The coextrusion process with PSA increases the flexibility associated with designing parts, because no additional means of mechanical attachment of the gasket are required. Mechanical attachment of gaskets typically requires manual installation, whereas the coextrusion process with PSA enables gasket installation to be more readily automated. This process also simplifies creation of curved or otherwise complex shaped gaskets on various substrates (e.g., flat or non-flat). Manual installation of gaskets on curves can create localized stresses at the curves that can lead to premature failure. The method of coextruding a pressure sensitive adhesive and a thermoplastic elastomer on a substrate may include a variety of features designed to improve efficiency in manufacturing and effectiveness of a gasket in unique applications.

[0046] Figure 1 illustrates an exemplary embodiment of a filament adhesive 100, in particular a core-sheathed filament adhesive 100. Figures 2-6 illustrate a useful adhesive dispensing system 228 that produces molten pressure sensitive adhesive from the core-sheath filament adhesive 100.

[0047] One example of a suitable filament adhesives 100 for use in the coextrusion dispensing head of the present invention, in the system of the present invention including such coextrusion dispensing head, and in the methods of the present invention is commercially available from 3M Company based in St. Paul Minnesota as 3M™ VHB™ Extrudable Tape GP, 3M ID 7100268065.

[0048] FIG. 1 through Figure 6 illustrate one exemplary embodiment of the adhesive dispensing system 228 that produces molten pressure sensitive adhesive for use in the coextrusion dispensing head of the present invention. Figures 7-8D and 10A-12 illustrate certain embodiments of the inventive systems and coextrusion dispensing heads of the present invention.

[0049] The provided systems and methods can use filament adhesives 100. Filament adhesives 100 are adhesives provided in a continuous thread-like configuration. The filament adhesive 100 preferably has a uniform cross-section. Advantageously, a filament adhesive 100 can be fed continuously from a spool 236 into an adhesive dispensing apparatus or system 228, such as a dispensing head 250.

[0050] Particularly useful filament adhesives have a core-sheath filament configuration, as described in co-pending U.S. Patent Publication No. 2021-0002793 (Nyaribo, et al.), titled “Core-Sheath Filaments and Methods of Printing an Adhesive,” (Attorney Case No. 79994US008) which is hereby incorporated by reference. Core-sheath filament materials have a configuration in which a first material (i.e., the core 102) is surrounded by a second material (i.e., the sheath 104). Preferably, the core 102 and the sheath 104 are concentric, sharing a common longitudinal axis. The ends of the core need not be surrounded by the sheath.

[0051] An exemplary filament adhesive 100 is shown in FIG. 1. The core-sheath filament adhesive 100 comprises an adhesive core 102 and a non-tacky sheath 104. The adhesive core 102 is a pressure-sensitive adhesive at ambient temperature. As shown, the core 102 has a cylindrical outer surface 106 and the sheath 104 extends around the outer surface 106 of the core 102. The core-sheath filament adhesive 100 has a cross-section that is generally circular as shown here, but it is to be understood that other cross-sectional shapes (e.g., square, hexagonal, or multi-lobed shapes) are also possible.

[0052] Advantageously, the non-tacky sheath 104 prevents the fdament adhesive 100 from sticking to itself, thereby enabling convenient storage and handling of the fdament adhesive 100 on a spool.

[0053] The diameter of the core-sheath fdament 100 is not particularly restricted. Factors that influence the choice of fdament diameter include the size constraints on the adhesive dispenser 250, desired adhesive throughput, and precision requirements for the adhesive application. The core-sheath fdament 100 can comprise an average diameter of 1 millimeter to 20 millimeters, 3 millimeters to 13 millimeters, 6 millimeters to 12 millimeters, or in some embodiments, less than, equal to, or greater than 1 millimeter, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, or 20 millimeters. The fdament adhesive 100 can be a stock item and provided in any length appropriate for the application.

[0054] The dispensing methods described herein offer many potential technical advantages, at least some of which are unexpected. These technical advantages include: retention of adhesive properties after dispensing, low volatile organic compound (VOC) characteristics, avoiding die cutting, design flexibility, achieving intricate non-planar bonding patterns, printing on thin and / or delicate substrates, and printing on irregular and / or complex topologies.

[0055] Core sheath filament adhesives 100 according to the present disclosure can be made using any known method. In an exemplary embodiment, these filament adhesives 100 are made by extruding molten polymers through a coaxial die. Technical details, options and advantages concerning the aforementioned core sheath filament adhesives are described in co-pending U.S. Patent Publication No. 2021-0002793 (Nyaribo, et al.), titled “Core-Sheath Filaments and Methods of Printing an Adhesive,” (Attorney Case No. 79994US008) which is hereby incorporated by reference.

[0056] FIG. 2 shows a dispensing head 150 having a configuration for receiving, melting, mixing, and dispensing the filament adhesive 100 of FIG. 1. The dispensing head 150 includes a barrel 152 and a rotatable screw 154 received therein. A gearbox 156 and motor 158 are operatively coupled to the screw 154, and an alignment wheel 160, which may be motorized, is affixed to a side of the barrel 152 through which filament is guided into the dispensing head 150. Further details concerning each of these components are below. The barrel 152 has the configuration of a barrel used in a single screw extruder. The barrel 152 has an inner surface 170 that is cylindrical and engages the screw 154 in an encircling relation. The inner surface 170 terminates in an outlet 172 at a distal end of the barrel 152. The outlet 172 is generally circular but could also be rectangular or have any other suitable shape. The barrel 152 includes one or more embedded heating elements (not visible) for heating the inner surface 170 and melting the filament adhesive during a dispensing operation. Optionally, the inner surface 170 of the barrel 152 can be grooved or otherwise textured to increase friction between the barrel 152 and the extruded adhesive.

[0057] Referring again to FIG. 2, an inlet 174 extends through the top side of the barrel for receiving the filament adhesive. As further shown, the inlet 174 includes a front sidewall 176 defining a beveled nip point where the front sidewall 176 converges with the outer surface of the screw 154. Advantageously, the beveled nip point prevents breakage of the filament adhesive as it is drawn into the barrel 152. The beveled nip point is part of a robust feeding mechanism enabling the filament adhesive to be continuously fed into the barrel 152 without need for operator attendance.

[0058] The drive mechanism for the dispensing head 150 is provided by the gearbox 156 and motor 158. In some embodiments, the dispensing head 150 includes controls allowing for adjustment of the speed and / or torque of the rotatable screw 154. In some embodiments, the motor 158 is a servo motor. Servo motors are advantageous because they can provide a high degree of torque over a wide range of rotational speed.

[0059] As shown, the inlet 174 generally has the shape of a reverse funnel, in which the transverse cross-sectional area of the inlet 174 increases with increasing proximity to the screw 154. The inlet 174 has one or more sidewalls, such as front sidewall 176 as shown. The front sidewall 176 can be planar or curved. As viewed from a transverse direction, at least a portion of the front sidewall 176 extends at an acute angle relative to a longitudinal axis of the screw 154. The acute angle, which facilitates feeding ofthe filament adhesive, can be from 10 degrees to 70 degrees, from 18 degrees to 43 degrees, from 23 degrees to 33 degrees, or in some embodiments, less than, equal to, or greater than 10 degrees, 13, 15, 17, 20, 22, 25, 27, 30, 32, 35, 37, 40, 42, 45, 47, 50, 53, 55, 57, 60, 65, or 70 degrees.

[0060] FIG. 3 shows a top view of the barrel 152, revealing further detail concerning the shape ofthe inlet 174. The inlet 174 includes outer entrance 175 and hidden surfaces extending from the outer entrance 175 and shown in dotted lines. As can be seen from FIG. 3, the front sidewall 176 is not planar, but has a complex compound curvature. Curved surfaces of the inlet 174, which include the front sidewall 176, collectively define a recess in the inner surface 170 of the barrel 152 to accommodate the filament adhesive as it is being fed. Overall, the inlet 174 can extend along from 10 percent to 40 percent, from 15 percent to 35 percent, 20 percent to 30 percent, or in some embodiment, less than, equal to, or greater than 10 percent, 12, 15, 17, 20, 22, 25, 27, 30, 32, 35, 37, or 40 percent of the nominal screw length.

[0061] The recess circumscribed by the inlet 174 can extend, as here, along both axial and circumferential directions relative to the screw 154. By providing space for the filament adhesive to move within the barrel 152, the recess reduces the likelihood that the flights of the rotatable screw 154 would sever the filament adhesive during operation of the dispensing head 150. This is inconvenient because filament breakage interrupts the dispensing process, and requires that an operator manually re-inserts the filament adhesive into the dispensing head 150 before re-starting the process.

[0062] FIGS. 4 and 5 show features of the screw 154 in more detail. The screw 154 includes a shank 180 at one end for coupling to a drive mechanism. The shank 180 is connected to a shaft 182 with a diameter that progressively increases along its length. Extending around the shaft 182 are helical flights 184 for conveying molten material in the forward direction as the screw 154 rotates within the barrel 152.

[0063] Proximate to where the filament adhesive 100 is fed into the dispensing head 150, notches 188 are provided in the helical flights 184 to provide gripping lugs 186, as also shown in the cross-sectional view of FIG. 5. The gripping lugs 186 provide additional edges that assist in catching and actively conveying a continuous filament adhesive through the inlet 174 and into the barrel 152. This is a significant benefit over feeding mechanisms that require adhesive to be pushed into the feed zone, which can induce buckling and kinking of the filament adhesive. The gripping lugs 186 can extend across from 1 percent to 30 percent, from 3 percent to 25 percent, from 5 percent to 20 percent, or in some embodiments, less than, equal to, or greater than 1 percent, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 22, 25, 27, or 30 percent of the nominal screw length.

[0064] Located on the opposite end of the screw 154 is a mixing section 190. The mixing section 190 includes a plurality of mixing elements — here, cylindrical posts 192. The mixing section 190 may be represented in other configurations not shown in FIG. 4, however. Other screw features that may be employed as mixing elements include fluted cylinders (as found in Maddock mixers), densely flighted screw sections with crosscuts (as found in Saxton mixers), or any of a variety of known post patterns, including those used for pineapple mixers. Optionally, posts or pins may be disposed on the interior sidewalls of the barrel 152 and aid in the mixing process; if so, crosscuts may be present in the flights of the screw 154 to avoid interference. Apertures may also be present, that serve to disperse or distribute the adhesive composition within the barrel, and these can also act as mixing elements.

[0065] The length of the mixing section 190 is not particularly restricted and can depend on various factors including the adhesive composition being extruded and the feed rate of the filament adhesive. The mixing section 190 can be from 5 percent to 30 percent, from 7 percent to 25 percent, from 8 percent to 20 percent, or in some embodiments, less than, equal to, or greater than 5 percent, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 22, 25, 27, 30, or 35 percent of the nominal screw length.

[0066] For effective melting, mixing, and dispensing of a filament adhesive within a relatively compact enclosure, the ratio of nominal screw length and screw diameter can be from 8: 1 to 20: 1, from 9: 1 to 17: 1, from 10: 1 to 14: 1, or in some embodiments, less than, equal to, or greater than 8: 1, 9: 1, 10: 1, 11: 1, 12: 1, 13: 1, 14: 1, 15: 1, 16: 1, 17: 1, 18: 1, 19: 1, or 20: 1.

[0067] The provided dispensing head 150 can display significant throughputs. In preferred embodiments, the dispensing head is capable of dispensing the adhesive composition at a throughput of at least 3 kg / hr, at least 4 kg / hr, at least 5 kg / hr, at least 6 kg / hr, at least 7 kg / hr, or at least 8 kg / hr.

[0068] FIG. 6 presents a schematic illustration of a dispensing system 228 that includes a dispensing head 250 outfitted with a mount for attachment to the end of a movable arm 230. The dispensing head 250 can have features analogous to that of the dispensing head 150 as previously described. The movable arm 230 is affixed to a table 232 and can have any number of joints to allow the dispensing head 250 to be translated and rotated in up to six degrees of freedom. The movable arm 230 allows the dispensing head 250 to dispense an adhesive composition with precision and reproducibility, and over a wide range of locations relative to the table 232.

[0069] The dispensing system 228 additionally includes a filament adhesive 100 for continuously feeding into the dispensing head 250 as shown in FIG. 6. The filament adhesive 100 can be continuously unwound from a spool 236 as shown. It is to be understood that the location of the spool 236 relative to other components of the dispensing system 228 is not critical and can mounted where convenient. The spool 236 can be fixtured to the table 232 or a structure thereon.

[0070] In various embodiments, the portion of the spool 236 that contacts the filament adhesive 100 can have structural features that assist in conveyance of the filament adhesive 100. For example, that portion of the spool 236 may include spiked region, a tacky surface, or any other feature that assists in unwinding the filament adhesive 100. Although not illustrated in FIG. 6, the filament adhesive 100 may also be guided along a channel or pipe extending between the spool 236 and the dispensing head 250. The channel or pipe can include low-friction (e.g., fluoropolymer) surfaces to facilitate travel and prevent kinking of the filament adhesive 100 therein.

[0071] The dispensing head 250 of FIG. 6 is being shown dispensing an adhesive composition 238 in hot melt form onto the bonding surface of a substrate 240. The substrate 240 need not be limited and can be, for example, an industrial part to be adhesively coupled to an assembly. As an option, the substrate 240 can be mounted onto the table 232, thereby providing a spatial point of reference for positioning of the dispensing head 250. This can be especially useful in an automatic process, where a controller is used to control the position and orientation of the dispensing head 250.

[0072] Figure 7 illustrates an exemplary embodiment of coextrusion system 500 potential including the adhesive dispensing head 250 and system described relative to Figures 2-6.

[0073] FIG. 7 depicts a front view of the coextrusion dispensing system 500 for applying a pressure sensitive adhesive (PSA) and a thermoplastic elastomer directly on substrates, which incorporates the filament adhesive 100 and thermoplastic elastomer 314 additions. The filament adhesive 100 is fed by the adhesive barrel 152 where it is converted to molten adhesive and ultimately applied by in the coextrusion dispensing head 150. The molten adhesive travels through an adhesive transfer tube 302 from the adhesive dispensing head 250 to the coextrusion dispensing head 150. The coextrusion dispensing head 150 is controlled by a moveable arm 230. The thermoplastic elastomer 314 is fed to the thermoplastic elastomer dispensing head 312 and into the coextrusion dispensing head 304. The coextrusion dispensing head 150 may contain various ports to assist in processing such as a heating cartridge 316, air inlet 308, or a thermocouple channel 310. The coextrusion dispensing head 150 may contain more additional ports or less, depending on the configuration of the head 150 and the shape of the gasket desired. The pressure sensitive adhesive and thermoplastic elastomer coextruded out of the dispensing head 150 to a substrate 240. The coextrusion dispensing head 150 includes a shaped dispensing face 292 for producing the desired shape gasket made from the molten thermoplastic adhesive and molten adhesive, as further described below. The air introduced to the system 500 is expelled out of through outlet 319. The coextrusion dispensing head 150 may move relative to a substrate 240, (e.g., the head moves but the substrate is static) or a substrate 240 may move relative to the dispensing head 150.

[0074] Examples of substrates 240 include, but are not limited to, irregular surfaces, complex geometries, and flexible media. In some embodiments, the thermoplastic elastomer 314 may be fed to the coextrusion dispensing head 150 through a similar dispensing head 250 illustrated in FIG. 2.

[0075] It may be preferable to include multiple inlet ports for the PSA and thermoplastic elastomer, depending on the desired article. The selected chosen configuration may depend on the orientation and design characteristics of the final product. Similarly, the coextrusion dispensing head 150 may include multiple heaters, air inlet, and temperature probes to increase the ability to process different types of PSA and thermoplastic elastomers that required different process conditions.

[0076] FIGS. 8A-8F illustrate one embodiment of a coextrusion dispensing head 150 of the present invention for producing a shaped thermoplastic article 400, such as a gasket with a layer of pressure sensitive adhesive, which is illustrated in Figure 9. Figures 8E and 8F are cross sectional views of the coextrusion dispensing head 150 taken along line a-a in Figure 8B.The coextrusion dispensing head 150 is configured to receive molten thermoplastic elastomer through the thermoplastic elastomer inlet 330 feds into the system 500 from the top of the head 150. The coextrusion dispensing head 150 is also configured to receive molten pressure sensitive adhesive through the adhesive inlet 352 fed into the system 500 from the side of the coextrusion head 150. The pressure sensitive adhesive and thermoplastic elastomer exit the dispensing face 292a through the shaped dispensing face 322a that gives the extruded thermoplastic article 400 its shape. In the illustrated embodiment, the shaped dispensing face 322 includes a lower extrusion lip 320 and a upper extrusion lip 324 to form a shape like the letter D and to extrude a hollow, D-shaped article 400 illustrated in Figure 9 on a substrate 240. The air introduced to the system 500 is expelled out of the air outlet 319. The lower dispensing lip 320 shapes the pressure sensitive adhesive portion, whereas the upper dispensing lip 324 shapes the top of the thermoplastic elastomer portion. Together both portions form the thermoplastic article or “gasket” 400 with a layer of pressure sensitive 404 that is applied to the substrate 240 in FIG. 9. The coextrusion dispensing head 150 may contain an air inlet 308, thermocouple channel 310 or a heating cartridge 316. The coextrusion dispensing face 326 may be at an angle normal to the bottom edge 290a of the coextrusion dispensing head 150 at an angle a no more than 90 degrees.

[0077] FIG. 8C shows a side view of the coextrusion dispensing head 150 where the thermocouple channel 310 and air inlet 308 are shown in detail. In some other embodiments, the coextrusion dispensing head 150 may contain more or less ports.

[0078] FIG. 8D is a top view of the coextrusion dispensing head 150 wherein the thermoplastic elastomer is fed to the system 500. The thermoplastic elastomer inlet 330 contains a thermoplastic elastomer (“TPE”) channel 340 that keeps the TPE separate from the pressure sensitive adhesive which is being fed through the coextrusion dispensing head 150 through another inlet.

[0079] FIGS. 8E and 8F depict a cross sectional view of the coextrusion dispensing head 150, which is convenient for discussing the flow of materials through the coextrusion dispensing head 150. The thermoplastic elastomer inlet 330 is isolated from the incoming pressure sensitive adhesive inlet 352 by a dedicated TPE channel 340, which in one embodiment is preferably at least 240 mm in length. The adhesive inlet 352 is similarly in fluid communication with an isolated adhesive channel 354. In another embodiment, the adhesive channel 354 is preferably at least 240 mm in length. The pressure sensitive adhesive channel 354 and TPE channel 340 are separated by a fluid barrier 356. In some embodiments, the fluid barrier 356 is at least 240 mm in length. The length, width, and angle of the fluid barrier 356 may vary between designs based on the desired coextrusion dispensing head 150 configuration. The pressure sensitive adhesive (“PSA”) and TPE merge in a third channel, the coextrusion channel 358, wherein the PSA and TPE may be in fluid communication for at least 4 mm in length. In some embodiments, the coextrusion channel 358 may keep the PSA and TPE in fluid communication for less than, equal to, or greater than 10 mm, 15 mm, and 17 mm. One advantage the coextrusion channel 358 provides is a strong bond between the PSA and TPE in the final gasket. The extruded article is formed when the coextrusion channel 358 feeds the PSA and TPE through the shaped dispensing face 322, the lower dispensing lip 320 and upper dispensing lip 324. The air introduced to the coextrusion dispensing head 150 is expelled out of the air outlet 319. In some embodiments, the shaped dispensing face 322 may include multiple shapes or configurations, in various sizes to form a desired article configuration.

[0080] In some preferred embodiments of the coextrusion dispensing head 150, the coextrusion channel 358 is configured to provide a desired amount of time the PSA and TPE are in contact with the coextrusion dispensing head 150 prior to extrusion. The time PSA and TPE are in contact may be directly proportional to the extrusion dispensing rate which is at least 20 mm / s and no greater than 60 mm / s. In some other embodiments, exemplary dispensing rates and related in fluid communication length and times are shown in Table 1 and Table 2 below.

[0081] Table 1

[0082] Exemplary embodiments for 20 mm / second coextrusion dispensing rate

[0083] Table 2

[0084] Exemplary embodiments for 60 mm / second coextrusion dispensing rate

[0085] FIG. 9 shows a perspective view of the pressure sensitive adhesive and thermoplastic elastomer that forms a thermoplastic elastomer article 440, in this case a gasket, with a layer of adhesive 404 after both molten materials are coextruded together onto a substrate 240 and then cooled. The outer surfaces 403 and inner surfaces 402 including the flat surfaces 410 formed by the configured shape of the shape faces 322a when the materials are coextruded onto the substrate 240. A layer of pressure sensitive adhesive 404 is bonded to the outer flat surface opposite the flat internal surface 410 of the TPE article 400 and adhered to the substrate 240. In at least some embodiments, the thermoplastic article 400 may take on various curves and lengths depending on the desired application or gasket.

[0086] FIGS. 10A-10F illustrate another embodiment of a coextrusion dispensing head 300 of the present invention for producing another shaped thermoplastic article 400, such as a gasket, with a layer of pressure sensitive of adhesive 404, which is illustrated in Figure 11. Figures 10E and 10F are cross sectional views of the coextrusion dispensing head 300 taken along line b-b in Figure 10B.

[0087] The coextrusion dispensing head 300 is configured to receive molten thermoplastic elastomer through the thermoplastic elastomer inlet 330 feds into the system 500 from the top of the coextrusion dispensing head 300. The coextrusion dispensing head 300 is also configured to receive molten pressure sensitive adhesive through the adhesive inlet 352 fed into the system 500 from the side of the coextrusion head 300. The pressure sensitive adhesive and thermoplastic elastomer exit the dispensing face 326 through the shaped dispensing faces 322b that gives the extruded article its shape. The lower dispensing lip 320 shapes the form of the pressure sensitive adhesive layer, whereas the upper dispensing lip 324 shapes the top portion of the thermoplastic elastomer article. Additionally, the middle dispensing lip 325 forms the middle portion of the thermoplastic elastomer article. In the illustrated embodiment, the shaped dispensing face 322 includes a lower extrusion lip 320 and a upper extrusion lip 324 to form shapes of intersecting circles and to extruded a hollow article 400 illustrated in Figure 11 on a substrate 240. The lower dispensing lip 320 shapes the pressure sensitive adhesive portion, whereas the upper dispensing lip portions3 25, 324 shape s the intersection circle portions of thermoplastic elastomer. Together, they form the thermoplastic article or “gasket” 400 that is applied to the substrate 240 in FIG. 11. The coextrusion dispensing head 300 may contain a thermocouple channel 310, air inlet 308, or aheating cartridge 316. The coextrusion dispensing face 326 may be at an angle P relative to the bottom edge 290b of the coextrusion dispensing head 300 at an angle of 90 degrees. The air introduced to the system is expelled out of the air out 319.

[0088] FIG. 10C shows a side view of the coextrusion dispensing head 300 where the thermocouple channel 310 and air inlet 308 are shown in detail. In some other embodiments, the coextrusion dispensing head 300 may contain more or fewer ports, for example, to accommodate additional material flow streams.

[0089] FIG. 10D is a top view of the coextrusion dispensing head 300 wherein the thermoplastic elastomer is fed to the system. The thermoplastic elastomer inlet 330 contains a TPE channel 340 that keeps the TPE separate from the pressure sensitive adhesive which is being fed through the coextrusion dispensing head 300 through another inlet.

[0090] FIGS. 10E and 10F depict a cross sectional view of the coextrusion dispensing head 300 which is convenient for discussing the flow of materials through the coextrusion dispensing head 150. The thermoplastic elastomer (“TPE”) 330 is isolated from the incoming pressure sensitive adhesive inlet 352 by a dedicated TPE channel 340 which in one embodiment is preferably at least 240 mm in length. The adhesive inlet 352 is similarly in fluid communication with an isolated adhesive channel 354. The adhesive channel 354 is preferably at least 240 mm in length. The pressure sensitive adhesive channel 354 and TPE channel 340 are separated by a fluid barrier 356 which may be at least 4 mm in length. In some embodiments, the coextrusion channel 358 may keep the PSA and TPE in fluid communication for less than, equal to, or greater than 10 mm, 15 mm, and 17 mm. The length, width, and angle of the fluid barrier 356 may vary between designs based on the desired coextrusion dispensing head configuration. The PSA and TPE merge in a third channel, the coextrusion channel 358, wherein the PSA and TPE may be in fluid communication for at One advantage the coextrusion channel 358 provides is a strong bond between the PSA and TPE in the final article. The extruded article is formed when the coextrusion channel 358 feeds the PSA and TPE through the shaped dispensing face 322, the lower dispensing lip 320, upper dispensing lip 324, and the middle dispensing lip 325. The air introduced to the system 500 is expelled out of the air out 319. In some embodiments, the shaped dispensing head 150 faces 322 may include multiple shapes, in various sizes to form a desired article configuration.

[0091] In some preferred embodiments of the coextrusion dispensing head 300 the coextrusion channel 358 configured to provide a desired amount of time the PSA and TPE are in contact with the coextrusion dispensing head 150 prior to extrusion from the head 300. The time PSA and TPE are in contact is directly proportional to the extrusion dispensing rate which is at least 20 mm / s and no greater than 60 mm / s. The time PSA and TPE are in contact is directly proportional to the extrusion dispensing rate which is at least 20 mm / s and no greater than 60 mm / s. In some other embodiments, exemplary dispensing rates and related in fluid communication length and times are shown in Table 1 and Table 2 above.

[0092] FIG. 11 shows a perspective view of the pressure sensitive adhesive and thermoplastic elastomer that forms an alternative thermoplastic elastomer article 400, in this case a gasket, with a layer of pressure sensitive adhesive 404, after both molten materials are coextruded together onto a substrate 240 and then cooled. The outer surfaces 403a, 403b, inner surfaces 402a, 402b and flat surface 410 formed by the configured shape of the shape faces 322a when the materials are coextruded onto the substrate 240. A layer of pressure sensitive adhesive 404 is bonded to the outer flat surface opposite the flat internal surface 410 of the TPE article 400 and adhered to the substrate 240. In at least some embodiments, the thermoplastic article 400 may take on various curves and lengths depending on the desired application or gasket.

[0093] The bond strength between the PSA 404 and the substrate 240 in the embodiments described herein may be at least 1 N / mm. The bond strength is measured by a ninety-degree peel test. The ninety degree peel test is described by a section of the gasket was manually gripped near the initial peel front, and were not re-gripped during the test. The strip was pulled perpendicularly (i.e., 90 degrees) to the substrate at approximately 25 millimeters per second. The strip was pulled until the peel front moved at least 40 millimeters (i.e., 40 millimeters of the strip de-bonded from the substrate). A passing value was obtained if both specimen strips cleanly de-bonded from substrate, without leaving residue on the substrate, and exhibited no signs of delamination (i.e. wrinkling, bubbles, or deformation associated with delamination) between PSA and TPE.

[0094] FIG. 12 shows a perspective view of yet another embodiment of the coextrusion dispensing head 380 of the present invention referred to generally as a “flat stock ribbon” coextrusion dispensing head. The coextrusion dispensing head 304 contains a dispensing face 322a and a first outlet 323 including face 292c having semicircle portions 426a wherein the flat-stock ribbon profile is coextruded to form the thermoplastic article 400 illustrated in Figure 13.

[0095] FIG. 13 shows a cross-sectional view of the flat-stock, ribbon thermoplastic article 400 with a layer of adhesive 404. The TPE 430 is coextruded with the PSA 432 onto the substrate 240. In some embodiments, the TPE 430 has ribbons 426 to increase the ability to create a seal.

[0096] FIG. 14 shows the various gasket shapes envisioned to formed by the coextrusion head outlet. The shallow-D hollow profile is depicted by 450. The Tall-D hollow profile is depicted by 452. The stacked intersecting circle shape is depicted by 454. The profile shape is depicted by 456. The hollow L shape is depicted by 458. The hollow with top ribbons shape is depicted by 460. The flat stock ribbon shape is depicted by 462.

[0097] The coextrusion method and related components may be manufactured of any suitable materials. In some instances, it may be beneficial if the materials have selected physical characteristics, such as, e.g. electrical conductivity, thermal conductivity, and magnetic.

[0098] The thermoplastic elastomer (TPE) 314 composition useful in the dispensing heads described above as well as the methods disclosed herein typically includes a copolymer, in some embodiments, a block copolymer. The thermoplastic elastomer composition can include a single block copolymer or a mixture of two or more block copolymers. While the present disclosure is not to be bound by theory, it is believed that at the service temperature of the TPE, the block copolymer microphase separates into ordered nanoscale domains that include rubbery block domains and glassy block domains. When microphase separated, these copolymers form elastic, dimensionally stable solids that display significant shear strength. Unlike chemically crosslinked rubbers, the block copolymers are capable of being reversibly melted and resolidified; thus, they are known as thermoplastic elastomers. Thus, the TPE composition is not chemically crosslinked and advantageously does not require energy intensive curing steps and can be reprocessed. The TPE 314 composition useful for the methods disclosed herein comprises a styrenic block copolymer, a thermoplastic vulcanizate, a polyolefin copolymer, a polyolefin block copolymer, a polyurethane block copolymer, a (meth)acrylic block copolymer, or a combination thereof.

[0099] In some embodiments, the TPE 314 includes a styrenic block copolymer. The TPE composition can include a single block copolymer or a mixture of two or more block copolymers. The styrenic block copolymer can be a diblock copolymer, a triblock copolymer, a star block copolymer, or a combination thereof. Styrene monomers useful for making the polystyrene blocks may be unsubstituted or substituted. Useful styrene monomers contain at least 8 carbon atoms and, in some embodiments, contain at least 10 carbon atoms or at least 12 carbon atoms and up to 18 carbon atoms, up to 16 carbon atoms, or up to 14 carbon atoms. Examples of suitable styrene monomers include styrene, vinyltoluene (e.g., 2, 3, or 4- vinyltoluene), alpha-methyl styrene, 2,4-dimethyl styrene, ethyl styrene, 2,4-diethyl styrene, 3,5-diethyl styrene, alpha-2-methyl styrene, 4-tert-butyl styrene, 4-isopropyl styrene, and combinations thereof. Each polystyrene block can be a homopolymer or a copolymer. In some embodiments, the polystyrene end blocks each comprise at least one of unsubstituted polystyrene, poly (vinyltoluene), poly(alpha-methylstyrene), poly(2,4-dimethylstyrene), poly(ethylstyrene), poly(2,4-diethylstyrene), poly(3, 5 -diethylstyrene), poly(4-tert- butylstyrene), or poly(4-isopropyl styrene). In some embodiments, the polystyrene blocks each comprise unsubstituted polystyrene. Polystyrene blocks including polystyrene end blocks can represent from 5 to 50 percent by weight of the block copolymer.

[0100] Each rubbery block in the styrenic block copolymer can be the polymerized product of a conjugated diene, a hydrogenated derivative of a polymerized conjugated diene, or a combination thereof. The conjugated diene often contains 4 to 12 carbon atoms. Examples of useful conjugated dienes include butadiene, isoprene, 2-ethylbutadiene, 1 -phenylbutadiene, 1,3-pentadiene, 1,3 -hexadiene, 2,3-dimethyl-l,3-butadiene, 3-ethyl-l,3-hexadiene and combinations thereof. Each rubbery block can be a homopolymer or copolymer. In some embodiments, the rubbery block comprises at least one of poly(butadiene), poly(isoprene), poly(2 -ethylbutadiene), poly(l -phenylbutadiene), poly( 1,3 -pentadiene), poly( 1,3 -hexadiene), poly(2,3-dimethyl-l,3-butadiene), poly(3 -ethyl- 1,3 -hexadiene), poly(ethyleneZpropylene), poly(ethyleneZbutylene), or poly(isoprene / butadiene). In some embodiments, the rubbery block comprises at least one of polybutadiene, polyisoprene, poly(isopreneZbutadiene), poly(ethyleneZbutylene), poly(ethyleneZpropylene), or polyisobutylene.

[0101] Suitable materials for use as the block copolymer alone or in combination are commercially available, for example, under the trade designation “KRATON” from Kraton Performance Polymers (Houston, TX, USA), under the trade designation “SOLPRENE” from Dynasol (Houston, TX, USA), under the trade designation “QUINTAC” from Zeon Chemicals (Louisville, KY, USA), under the trade designations “VECTOR” and “TAIPOE” from TSRC Corporation (New Orleans, EA, USA), under the trade designation “TUFTEC” from Asahi Kasei (Tokyo, Japan), under the trade designation “SOFPRENE” from Cleanese (Pasadena, TX, USA), and under the trade designation “THERMOLAST” from Kraiburg TPE GmbH, Waldkraiburg, Germany.

[0102] In some embodiments, the TPE includes a thermoplastic polyolefin elastomer. Compositions including a thermoplastic polyolefin matrix with an elastomer in the matrix are sometimes referred to as thermoplastic vulcanizates (TPVs). Examples include a polypropylene matrix, with an ethylene propylene diene monomer (EPDM) rubber in the matrix. Examples of the diene in the EPDM include dicyclopentiadiene, alkyldicyclopentadiene, 1,4-pentadiene, 1,4- hexadiene, 1,5 -hexadiene, 1,4-heptadiene, 2- methyl-1, 5 -hexadiene, cyclooctadiene, 1,4- octadiene, 1,7-octadiene, 5-ethylidene-2- norbomene, 5-n-propylidene-2-norbomene, and 5- butylidene-2-norbomene. In some embodiments, the polyolefin thermoplastic elastomer is an olefin copolymer, in some embodiments, a block copolymer. Hard segments of such copolymers may include polyethylene and polypropylene segments. Soft segments of such copolymers can include C4- C18, C5-C12, or C6-C8 poly(l -alkene) segments. Examples of useful soft segments include those prepared from 1 -butene, 1 -hexene, 1 -octene, 1-dedene, 4-methyl-l -pentene, and 1- octadecene. Polyolefin TPE copolymers are typically made by metallocene catalysis. Useful polyolefin TPE copolymers include those available from Dow Chemical (Midland, Michigan) under the trade designation “INFUSE” and “ENGAGE”. Useful thermoplastic vulcanizates include those available from Celenase Corporation (Irving, Texas) under the trade designation “SANTOPRENE”. A combination of two or more polyolefin thermoplastic elastomers may be useful in the TPE composition.

[0103] In some embodiments, the TPE includes a thermoplastic polyurethane elastomer (TPU). A variety of TPUs are useful for practicing the present disclosure. They can be prepared by known methods or can be obtained commercially. A TPU is a thermoplastic block copolymer composed of a soft segment and a hard segment alternately connected, wherein the hard segment is an isocyanate segment (e.g., including an aliphatic isocyanate segment, an aromatic isocyanate segment, or a combination thereof), and the soft segment is a polyether polyol segment or a polyester polyol segment. Soft segments in TPUs can include polyethers or aliphatic polyester (e.g., aliphatic polyester, polytetrahydrofuran ether, polyphenylene ether, polypropylene oxide, polyethylene oxide, and combinations thereof) having a relative molecular mass in a range from 600 to 6000 grams per mole, for example. In addition to the ratio of the hard segment and the soft segment, the types of the isocyanate, the polyether polyol, and the polyester polyol also affect the properties of TPU. TPU molecules are substantially linear, and TPUs have some physical crosslinking, usually through the interaction between urethane groups in the molecules. Useful TPUs include those obtained from BASF Company, Uudwigshafen, Germany, under the trade designation “EUASTOUUANE”, from Covestro Company under the trade designation “DESMOPAN”, from Lubrizol Corporation, Wickliffe, OH, under the trade designations “ESTANE”, and TPU films produced by Shibata Company.

[0104] In some embodiments, the TPE includes a (meth)acrylic block copolymer. Each hard block of the (meth)acrylic-based block copolymer is usually prepared from a monomer composition that includes an alkyl methacrylate. Suitable alkyl methacrylates for preparing the hard blocks often have an alkyl group with 1 to 10 carbon atoms, 1 to 8 carbon atoms, 1 to 6 carbon atoms, 1 to 5 carbon atoms, or 1 to 4 carbon atoms. If the alkyl group has 3 to 5 carbon atoms, it is typically branched. If the alkyl group has 6 to 10 carbon atoms, it is typically cyclic or bicyclic. In some instances, the hard blocks are homopolymers and each homopolymer is a poly(alkyl methacrylate). Examples of poly(alkyl methacrylates) include poly(methyl methacrylate), poly(ethyl methacrylate), poly(isopropyl methacrylate), poly(isobutyl methacrylate), poly(sec-butyl methacrylate), poly(tert-butyl methacrylate), poly(cyclohexyl methacrylate), poly(methylcyclohexyl methacrylate), poly (3, 3, 5 -trimethylcyclohexyl methacrylate), and poly(isobomyl methacrylate). These homopolymers each have a glass transition temperature equal to at least 50 °C. In addition to the alkyl methacrylate monomers, the first A block can be prepared from other optional monomers provided the resulting polymeric blocks have a glass transition temperature that is equal to at least 50 °C when measured using Dynamic Mechanical Analysis. Examples of such monomers include 2- methoxyethyl methacrylate, phenyl methacrylate, benzyl methacrylate, 2-phenoxyethyl methacrylate, cyclohexyl acrylate, isobomyl acrylate, styrene, styrene-type monomers (e.g., alpha-methyl styrene, 3 -methyl styrene, 4-methyl styrene, ethyl styrene, isopropyl styrene, tertbutyl styrene, dimethyl styrene, 2,4,6-trimethyl styrene, and 4-methoxy styrene), and vinyl acetate.

[0105] The soft block of the (meth)acrylic-based block copolymer is typically formed from monomers that will provide polymeric blocks having a glass transition temperature no greater than 20 °C as measured using Dynamic Mechanical Analysis. The soft block is often prepared from a monomer composition that includes an alkyl acrylate. Suitable alkyl acrylates for forming the soft block often have an alkyl group with 2 to 20, 2 to 18, 2 to 12, or 2 to 10 carbon atoms. The alkyl group can be linear, branched, cyclic, or a combination thereof (e.g., the alkyl can have a cyclic group plus a branched or linear group). In some instances, the soft block is a homopolymer. Examples of homopolymers include poly(ethyl acrylate), poly(n-propyl acrylate), poly(n-butyl acrylate), poly(isobutyl acrylate), poly(sec-butyl acrylate), poly(isoamyl acrylate), poly(n-hexyl acrylate), poly(2 -methylbutyl acrylate), poly(4-methyl-2- pentyl acrylate), poly(cyclohexyl acrylate), poly(2-methylhexyl acrylate), poly(n-octyl acrylate), poly(2-octyl acrylate), poly(isooctyl acrylate), poly(2-ethylhexyl acrylate), poly(isononyl acrylate), poly(n-decyl acrylate), poly(isodecyl acrylate), poly(lauryl acrylate), poly (isotridecyl acrylate), poly(isostearyl acrylate), and poly(octadecyl acrylate). In addition to the alkyl acrylate monomers, the soft block can further include other optional monomer units provided the resulting polymeric block has a glass transition temperature that is no greater than 20 °C when measured using Dynamic Mechanical Analysis. Examples of monomers providing such monomer units include 2-ethoxy ethyl (meth)acrylate, 2-methoxy ethyl acrylate, 2-(2- ethoxyethoxy)ethyl acrylate, 2-biphenylhexyl acrylate, benzyl acrylate, 2-phenoxy ethyl acrylate, n-decyl methacrylate, lauryl methacrylate, n-octyl methacrylate, isooctyl methacrylate, 2-ethylhexyl methacrylate, and n-hexyl methacrylate. In some embodiments, the soft block is poly(n-butyl acrylate), poly(n-octyl acrylate), poly(2-octyl acrylate), poly(isooctyl acrylate), poly(2-ethylhexyl acrylate), or poly(isononyl acrylate). In some embodiments, the soft block is poly(n-butyl acrylate).

[0106] In some embodiments of the (meth)acrylic block copolymer, each hard block comprises monomeric units derived from methyl methacrylate and the soft block comprises monomeric units derived from n-butyl (meth)acrylate, in some embodiments, n-butyl acrylate. Suitable commercially available (meth)acrylic-based triblock copolymers can be obtained under the trade designation “KURARITY” from Kuraray Co., Ltd. (Tokyo, Japan) and under the trade designation “NANOSTRENGTH” from Arkema (Colombes, France).

[0107] One particularly suitable thermoplastic elastomer for use in the coextrusion dispensing head, system and methods of the present invention is disclosed in U.S. Patent Application No.

[0108] , (Attorney Case No. PA101209US01) titled “Article including Thermoplastic Elastomer Composition and Related Process,” filed on the same day as the present application and co-owned by the same assignee as the present application, which is hereby incorporated by reference.

[0109] The PSA useful in the dispensing head system above and methods of the present disclosure can be made using a number of different chemistries including styrenic block copolymers, (meth)acrylics, (meth)acrylic block copolymers, natural rubber, styrene butadiene rubber, butyl rubber, polyisobutylene, ethylene vinyl acetate, amorphous poly(alpha-olefins), silicones, polyvinyl ether, polyisoprene, polybutadiene, butadiene-acrylonitrile rubber, polychoroprene, polyurethane, polyvinylpyrrolidone, or combinations thereof.

[0110] A method of coextruding a pressure sensitive adhesive and a thermoplastic elastomer is described herein. The method may include at least an adhesive transfer process, a thermoplastic elastomer transfer process, a coextrusion dispensing head, and a substrate.

[0111] Additionally, the coextrusion dispensing head internally may include a first channel for the pressure sensitive adhesive and a second channel for the thermoplastic elastomer. Further, the coextrusion dispensing head may include a third channel for the pressure sensitive adhesive and the thermoplastic elastomer to merge prior to the dispensing head outlet. The third channel may include a distance such that the pressure sensitive adhesive and thermoplastic elastomer merge for at least 4mm prior to the coextrusion head outlet.

[0112] In preferred embodiments, the third channel containing the pressure sensitive adhesive and thermoplastic elastomer merge for at least 4 mm before the first outlet and at least 0. 1 seconds before the first outlet.

[0113] In some embodiments, the third channel containing the pressure sensitive adhesive and thermoplastic elastomer merge for at least 10 mm before the first outlet. In other embodiments, the third channel containing the pressure sensitive adhesive and thermoplastic elastomer merge for at least 17 mm before the first outlet.

[0114] The coextrusion method may further include a moveable arm which controls at least the coextrusion dispensing head relative to the substrate to form a desired shape. Additionally, the shape extruded on the substrate may include a radius of curvature. Different configurations may provide improved gasket effectiveness. Further, allowing the extruded shape to be applied direct to the substrate may allow for a more stable TPE shape that naturally cures in a curved position, which is preferred compared to the conventional shape that is cured in a straight line and bended around a comer. In some embodiments, the moveable arm may control the substrate relative to the coextrusion dispensing head.

[0115] Exemplary embodiments of the coextrusion dispensing head, system including the coextrusion dispensing head, and affiliated methods and herein have been discussed and reference made to possible variations. There and other variations and modifications will be apparent to those skilled in the art without departing from the scope of the invention, and it should be understood that this invention is not limited to the illustrative embodiments set forth herein. Accordingly, the invention is to be limited only by the claims provided below and equivalents thereof. Select Embodiments of the Present Disclosure

[0116] Embodiment 1 is a coextrusion dispensing head for a pressure sensitive adhesive and a thermoplastic elastomer, comprising: a first inlet for receiving the pressure sensitive adhesive and a second inlet for receiving the thermoplastic elastomer; a first outlet for extruding the pressure sensitive adhesive and the thermoplastic elastomer together; a first channel for the pressure sensitive adhesive within the coextrusion dispensing head from the first inlet to the first outlet; and a second channel for the thermoplastic elastomer within the coextrusion dispensing head from the second inlet to the first outlet, wherein within the coextrusion dispensing head the first channel and second channel merge before the first outlet.

[0117] Embodiment 2 is the coextrusion dispensing head of Embodiment 1, wherein the first channel and second channel merge for at least 4 mm before the first outlet.

[0118] Embodiment 3 is the coextrusion dispensing head of Embodiment 1, wherein the first channel and second channel merge for at least 10 mm before the first outlet.

[0119] Embodiment 4 is the coextrusion dispensing head of Embodiment 3, wherein the first channel and second channel merge for at least 17 mm before the first outlet.

[0120] Embodiment 5 is the coextrusion dispensing head of Embodiment 1 which further includes a source of pressure sensitive adhesive and a source of thermoplastic elastomer, wherein the source of pressure sensitive adhesive is connected to the first inlet and the source of thermoplastic elastomer is connected to the second inlet.

[0121] Embodiment 6 is the coextrusion dispensing head of Embodiment 5 wherein, the pressure sensitive adhesive and thermoplastic elastomer are in contact at least 4 mm prior to the first outlet.

[0122] Embodiment 7 is the coextrusion dispensing head of Embodiment 5, wherein the pressure sensitive adhesive and thermoplastic elastomer are in contact at least 0.2 seconds prior to the first outlet at an extrusion rate of 20 mm / s.

[0123] Embodiment 8 is the coextrusion dispensing head of Embodiment 5, wherein the pressure sensitive adhesive and thermoplastic elastomer are in contact at least 0.1 seconds prior to the first outlet at an extrusion rate of 60 mm / s.

[0124] Embodiment 9 is the coextrusion dispensing head of Embodiment 5 wherein, the pressure sensitive adhesive and thermoplastic elastomer are in contact at least 10 mm prior to the first outlet. Embodiment 10 is the coextrusion dispensing head of Embodiment 9, wherein the pressure sensitive adhesive and thermoplastic elastomer are in contact at least 0.5 seconds prior to the first outlet at an extrusion rate of 20 mm / s.

[0125] Embodiment 11 is the coextrusion dispensing head of Embodiment 9, wherein the pressure sensitive adhesive and thermoplastic elastomer are in contact at least 0.2 seconds prior to the first outlet at an extrusion rate of 60 mm / s.

[0126] Embodiment 12 is the coextrusion dispensing head of Embodiment 5, wherein, the pressure sensitive adhesive and thermoplastic elastomer are in contact at least 15 mm prior to the first outlet.

[0127] Embodiment 13 is the coextrusion dispensing head of Embodiment 12, wherein the pressure sensitive adhesive and thermoplastic elastomer are in contact at least 0.8 seconds prior to the first outlet at an extrusion rate of 20 mm / s.

[0128] Embodiment 14 is the coextrusion dispensing head of Embodiment 12, wherein the pressure sensitive adhesive and thermoplastic elastomer are in contact at least 0.3 seconds prior to the first outlet at an extrusion rate of 60 mm / s.

[0129] Embodiment 15 is the coextrusion dispensing head of Embodiment 5, wherein, the pressure sensitive adhesive and thermoplastic elastomer are in contact at least 17 mm prior to the first outlet.

[0130] Embodiment 16 is the coextrusion dispensing head of Embodiment 15, wherein the pressure sensitive adhesive and thermoplastic elastomer are in contact at least 0.9 seconds prior to the first outlet at an extrusion rate of 20 mm / s.

[0131] Embodiment 17 is the coextrusion dispensing head of Embodiment 15, wherein the pressure sensitive adhesive and thermoplastic elastomer are in contact at least 0.3 seconds prior to the first outlet at an extrusion rate of 60 mm / s.

[0132] Embodiment 18 is the coextrusion dispensing head of Embodiment 5, wherein the pressure sensitive adhesive is molten pressure sensitive adhesive and wherein the thermoplastic elastomer is molten thermoplastic elastomer.

[0133] Embodiment 19 is the coextrusion dispensing head of Embodiment 18, wherein the temperature of the molten pressure sensitive adhesive and thermoplastic elastomer are both at least 160 Celsius.

[0134] Embodiment 20 is the coextrusion dispensing head of Embodiment 18, wherein the molten pressure sensitive adhesive and molten thermoplastic elastomer are extruded directly on the substrate. Embodiment 21 is the coextrusion dispensing head of Embodiment 1, wherein the molten pressure sensitive adhesive and molten thermoplastic elastomer are coextruded directly on the substrate in the shape of a curve.

[0135] Embodiment 22 is the coextrusion dispensing head of Embodiment 1 further including a dispensing face and a bottom edge, wherein the dispensing face is at an angle a measured normal to the bottom edge.

[0136] Embodiment 23 is the coextrusion dispensing head of Embodiment 22, wherein the angle a is at least 56 degrees.

[0137] Embodiment 24 is the coextrusion dispensing head of Embodiment 22, wherein the coextrusion head dispensing face angle a is less than 90 degrees.

[0138] Embodiment 25 is the coextrusion dispensing head of Embodiment 1 further including a dispensing face and a bottom edge, wherein the dispensing face is at an angle P normal to the bottom edge.

[0139] Embodiment 26 is the coextrusion dispensing head of Embodiment 25, wherein the angle is 90 degrees.

[0140] Embodiment 27 is the coextrusion dispensing head of Embodiment 5, wherein the pressure sensitive adhesive is a filament adhesive and the thermoplastic elastomer is a filament thermoplastic elastomer.

[0141] Embodiment 28 is the coextrusion dispensing head of Embodiment 1 and Embodiment

[0142] 5, wherein the first outlet is shaped to provide at least a hollow shape of thermoplastic elastomer extruded with a layer of pressure sensitive adhesive.

[0143] Embodiment 29 is the coextrusion dispensing head of Embodiment 15, wherein the hollow shape of thermoplastic elastomer is a gasket.

[0144] Embodiment 30 is the coextrusion dispensing head of Embodiment 16, wherein the thermoplastic elastomer is in the shape of a flat-stock ribbon profde shape.

[0145] Embodiment 31 is the coextrusion dispensing head of Embodiment 16, wherein the thermoplastic elastomer is in the shape of D-shape hollow shape.

[0146] Embodiment 32 is the coextrusion dispensing head of Embodiment 16, wherein the thermoplastic elastomer is in the shape of a stacked intersecting circle shape.

[0147] Embodiment 33 is the coextrusion dispensing head of Embodiment 1 in combination with adhesive transfer head, wherein the adhesive transfer head comprises of a barrel including one or more heating elements; an inlet extending through a side of the barrel for receiving the filament adhesive, the inlet including a beveled nip point to prevent breakage of the filament adhesive as it is drawn into the barrel; an outlet at a distal end of the barrel for dispensing the filament adhesive in molten form; and a rotatable screw received in the barrel, the rotatable screw including at least one mixing element.

[0148] Embodiment 34 is the method of coextruding pressure sensitive adhesive and a thermoplastic elastomer, comprising: a source for of molten pressure sensitive adhesive; a source of molten thermoplastic elastomer; a first flow path for the molten pressure sensitive adhesive; a second flow path for the molten thermoplastic elastomer; a third flow path wherein the molten pressure sensitive adhesive in the first flow path and the thermoplastic elastomer in the second flow path are in fluid contact; coextruding the merged molten pressure sensitive adhesive and the molten thermoplastic elastomer together through an outlet in a desired shape.

[0149] Embodiment 35 is the method of Embodiment 34, wherein the first flow path and second flow path merge for at least 4 mm before the outlet.

[0150] Embodiment 36 is the method of Embodiment 34, wherein the first flow path and the second flow path merge for at least 10 mm.

[0151] Embodiment 37 is the method of Embodiment 34, wherein the first flow path and the second flow path merge for at least 17 mm.

[0152] Embodiment 38 is the method of Embodiment 34, wherein pressure sensitive adhesive and thermoplastic elastomer are in contact at least 0.2 seconds prior to the first outlet at an extrusion rate of 20 mm / s.

[0153] Embodiment 39 is the method of Embodiment 34, wherein the pressure sensitive adhesive and thermoplastic elastomer are in contact at least 0.1 seconds prior to the first outlet at an extrusion rate of 60 mm / s.

[0154] Embodiment 40 is the method of Embodiment 35, wherein the pressure sensitive adhesive and thermoplastic elastomer are in contact in the third flow path at least 0.2 seconds prior to the first outlet at an extrusion rate of 20 mm / s.

[0155] Embodiment 41 is the method of Embodiment 35, wherein the molten pressure sensitive adhesive and the molten thermoplastic elastomer are in contact in the third flow path for at least 0. 1 seconds prior to the first outlet at an extrusion rate of 60 mm / s.

[0156] Embodiment 42 is the method of Embodiment 34, wherein the first flow path of molten pressure sensitive adhesive and the second flow path of molten thermoplastic elastomer merge to form the third flow path at least 10 mm prior to the first outlet.

[0157] Embodiment 43 is the method of Embodiment 42, wherein the pressure sensitive adhesive and thermoplastic elastomer are in contact at least 0.5 seconds prior to the first outlet at an extrusion rate of 20 mm / s. Embodiment 44 is the method of Embodiment 42, wherein the pressure sensitive adhesive and thermoplastic elastomer are in contact at least 0.2 seconds prior to the first outlet at an extrusion rate of 60 mm / s.

[0158] Embodiment 45 is the method of Embodiment 34, wherein the first flow path of molten pressure sensitive adhesive and the second flow path of molten thermoplastic elastomer merge to form the third flow path at least 15 mm prior to the first outlet.

[0159] Embodiment 46 is the method of Embodiment 45, wherein the pressure sensitive adhesive and thermoplastic elastomer are in contact at least 0.8 seconds prior to the coextrusion step, and wherein the extrusion rate is 20 mm / s.

[0160] Embodiment 47 is the method of Embodiment 45, wherein the pressure sensitive adhesive and thermoplastic elastomer are in contact at least 0.3 seconds prior to the coextrusion step, and wherein the extrusion rate is 60 mm / s.

[0161] Embodiment 48 is the method of Embodiment 34, further comprising a substrate directly coextruding the merged molten pressure sensitive adhesive and molten thermoplastic elastomer together onto the substrate in the desired shape.

[0162] Embodiment 49 is the method of Embodiment 48, wherein the coextruding step includes coextruding through the outlet in a coextrusion dispensing head, and wherein the outlet is in the desired shape to form a gasket of the thermoplastic elastomer adhered to the substrate by the pressure sensitive adhesive.

[0163] Embodiment 50 is the method of Embodiment 49 further comprising moving the coextrusion dispensing head relative to the substrate to form a length of the gasket of thermoplastic elastomer adhered to the substrate by the pressure sensitive adhesive.

[0164] Embodiment 51 is the method of Embodiment 49 further including moving the substrate relative to dispensing head to form a length of the gasket of thermoplastic elastomer adhered to the substrate by the pressure sensitive adhesive.

[0165] Embodiment 52 is the method of Embodiment 48, wherein the thermoplastic elastomer gasket is adhered to the substrate by the pressure sensitive adhesive with a bond strength of at least 1 N / mm.

[0166] Embodiment 53 is the method of Embodiment 52, wherein the bond strength is measured by a ninety-degree peel test.

[0167] Embodiment 54 is the method of Embodiment 48, wherein the thermoplastic elastomer adhered to the substrate by the pressure sensitive adhesive includes a radius of curvature. Embodiment 55 is the method of Embodiment 49, wherein the coextrusion dispensing head moves in a curve relative to the substrate.

[0168] Embodiment 56 is the method of Embodiment 49, wherein the substrate moves in a curve relative to the coextrusion dispensing head. Embodiment 57 is the method of Embodiment 50, wherein the substrate also moves relative to the coextrusion dispensing head.

Claims

What is claimed is:

1. A coextrusion dispensing head for a pressure sensitive adhesive and a thermoplastic elastomer, comprising: a first inlet for receiving the pressure sensitive adhesive and a second inlet for receiving the thermoplastic elastomer; a first outlet for extruding the pressure sensitive adhesive and the thermoplastic elastomer together; a first channel for the pressure sensitive adhesive within the coextrusion dispensing head from the first inlet to the first outlet; and a second channel for the thermoplastic elastomer within the coextrusion dispensing head from the second inlet to the first outlet, wherein within the coextrusion dispensing head the first channel and second channel merge before the first outlet.

2. The coextrusion dispensing head of claim 1, wherein the first channel and second channel merge for at least 4 mm before the first outlet.

3. The coextrusion dispensing head of claim 2, wherein the first channel and second channel merge for at least 10 mm before the first outlet.

4. The coextrusion dispensing head of claim 3, wherein the first channel and second channel merge for at least 17 mm before the first outlet.

5. The coextrusion dispensing head of claim 1, further including a source of pressure sensitive adhesive and a source of thermoplastic elastomer, wherein the source of pressure sensitive adhesive is connected to the first inlet and the source of thermoplastic elastomer is connected to the second inlet.

6. The coextrusion dispensing head of claim 5 wherein, the pressure sensitive adhesive and thermoplastic elastomer are in contact at least 4 mm prior to the first outlet.7 The coextrusion dispensing head of claim 5, wherein the pressure sensitive adhesive and thermoplastic elastomer are in contact at least 0.2 seconds prior to the first outlet at an extrusion rate of 20 mm / s.

8. The coextrusion dispensing head of claim 5, wherein the pressure sensitive adhesive and thermoplastic elastomer are in contact at least 0. 1 seconds prior to the first outlet at an extrusion rate of 60 mm / s.

9. The coextrusion dispensing head of claim 5 wherein, the pressure sensitive adhesive and thermoplastic elastomer are in contact at least 10 mm prior to the first outlet.

10. The coextrusion dispensing head of claim 9, wherein the pressure sensitive adhesive and thermoplastic elastomer are in contact at least 0.5 seconds prior to the first outlet at an extrusion rate of 20 mm / s.

11. The coextrusion dispensing head of claim 9, wherein the pressure sensitive adhesive and thermoplastic elastomer are in contact at least 0.2 seconds prior to the first outlet at an extrusion rate of 60 mm / s.

12. The coextrusion dispensing head of claim 5 wherein, the pressure sensitive adhesive and thermoplastic elastomer are in contact at least 15 mm prior to the first outlet.

13. The coextrusion dispensing head of claim 12, wherein the pressure sensitive adhesive and thermoplastic elastomer are in contact at least 0.8 seconds prior to the first outlet at an extrusion rate of 20 mm / s.

14. The coextrusion dispensing head of claim 12, wherein the pressure sensitive adhesive and thermoplastic elastomer are in contact at least 0.3 seconds prior to the first outlet at an extrusion rate of 60 mm / s.

15. The coextrusion dispensing head of claim 5, wherein the pressure sensitive adhesive and thermoplastic elastomer are in contact at least 17 mm prior to the first outlet.

16. The coextrusion dispensing head of claim 15, wherein the pressure sensitive adhesive and thermoplastic elastomer are in contact at least 0.9 seconds prior to the first outlet at an extrusion rate of 20 mm / s.

17. The coextrusion dispensing head of claim 15, wherein the pressure sensitive adhesive and thermoplastic elastomer are in contact at least 0.3 seconds prior to the first outlet at an extrusion rate of 60 mm / s.

18. The coextrusion dispensing head of claim 5, wherein the pressure sensitive adhesive is molten pressure sensitive adhesive and wherein the thermoplastic elastomer is molten thermoplastic elastomer.

19. The coextrusion dispensing head of claim 18, wherein the temperature of the molten pressure sensitive adhesive and thermoplastic elastomer are both at least 160 Celsius.

20. The coextrusion dispensing head of claim 18 in combination with a substrate, wherein the molten pressure sensitive adhesive and molten thermoplastic elastomer are extruded directly on the substrate.

21. The coextrusion dispensing head of claim 20 in combination with a substrate, wherein the wherein the molten pressure sensitive adhesive and molten thermoplastic elastomer are coextruded directly on the substrate in the shape of a curve.

22. The coextrusion dispensing head of claim 1 further including a dispensing face and a bottom edge, wherein the dispensing face is at an angle a measured normal to the bottom edge.

23. The coextrusion dispensing head of claim 22, wherein the angle a is at least 56 degrees.

24. The coextrusion dispensing head of claim 22, wherein the coextrusion head dispensing face angle a is less than 90 degrees.

25. The coextrusion dispensing head of claim 1 further including a dispensing face and a bottom edge, wherein the dispensing face is at an angle normal to the bottom edge.

26. The coextrusion dispensing head of claim 25 wherein the angle P is 90 degrees.

27. The coextrusion dispensing head of claim 5, wherein the pressure sensitive adhesive is a filament adhesive and the thermoplastic elastomer is a filament thermoplastic elastomer.

28. The coextrusion dispensing head of claim 1 and claim 5, wherein the first outlet is shaped to provide at least a hollow shape of thermoplastic elastomer extruded with a layer of pressure sensitive adhesive.

29. The coextrusion dispensing head of claim 15, wherein the hollow shape of thermoplastic elastomer is a gasket.

30. The coextrusion dispensing head of claim 16, wherein the thermoplastic elastomer is in the shape of a flat-stock ribbon profile shape.

31. The coextrusion dispensing head of claim 16, wherein the thermoplastic elastomer is in the shape of D -shape hollow shape.

32. The coextrusion dispensing head of claim 16, wherein the thermoplastic elastomer is in the shape of a stacked intersecting circle shape.

33. The coextrusion dispensing head of claim 1 in combination adhesive transfer head, wherein the adhesive transfer head comprises: a barrel including one or more heating elements; an inlet extending through a side of the barrel for receiving the filament adhesive, the inlet including a beveled nip point to prevent breakage of the filament adhesive as it is drawn into the barrel; an outlet at a distal end of the barrel for dispensing the filament adhesive in molten form; and a rotatable screw received in the barrel, the rotatable screw including at least one mixing element.

34. A method of coextruding a pressure sensitive adhesive and a thermoplastic elastomer on a substrate, comprising: providing a source of molten pressure sensitive adhesive; providing a source of molten thermoplastic elastomer; flowing the molten pressure sensitive adhesive down a first flow path; flowing the molten thermoplastic elastomer down a second flow path; merging the first flow path and the second flow path so as to contact the flows of molten pressure sensitive adhesive and molten thermoplastic elastomer to form a third flow path; and coextruding the merged molten pressure sensitive adhesive and molten thermoplastic elastomer together through an outlet in a desired shape.

35. The method of claim 34, wherein the first flow path and second flow path merge for at least 4 mm before the outlet.

36. The method of claim 34, wherein the first flow path and the second flow path merge for at least 10 mm.

37. The method of claim 34, wherein the first flow path and the second flow path merge for at least 17 mm.

38. The method of claim 34, wherein pressure sensitive adhesive and thermoplastic elastomer are in contact at least 0.2 seconds prior to the first outlet at an extrusion rate of 20 mm / s.

39. The method of claim 34, wherein the pressure sensitive adhesive and thermoplastic elastomer are in contact at least 0. 1 seconds prior to the first outlet at an extrusion rate of 60 mm / s.

40. The method of claim 35, wherein the pressure sensitive adhesive and thermoplastic elastomer are in contact in the third flow path at least 0.2 seconds prior to the first outlet at an extrusion rate of 20 mm / s.

41. The method of claim 35, wherein the molten pressure sensitive adhesive and the molten thermoplastic elastomer are in contact in the third flow path for at least 0.1 seconds prior to the first outlet at an extrusion rate of 60 mm / s.

42. The method of claim 34, wherein the first flow path of molten pressure sensitive adhesive and the second flow path of molten thermoplastic elastomer merge to form the third flow path at least 10 mm prior to the first outlet.

43. The method of claim 42, wherein the pressure sensitive adhesive and thermoplastic elastomer are in contact at least 0.5 seconds prior to the first outlet at an extrusion rate of 20 mm / s.

44. The method of claim 42, wherein the pressure sensitive adhesive and thermoplastic elastomer are in contact at least 0.2 seconds prior to the first outlet at an extrusion rate of 60 mm / s.

45. The method of claim 34, wherein the first flow path of molten pressure sensitive adhesive and the second flow path of molten thermoplastic elastomer merge to form the third flow path at least 15 mm prior to the first outlet.

46. The method of claim 45, wherein the pressure sensitive adhesive and thermoplastic elastomer are in contact at least 0.8 seconds prior to the coextrusion step, and wherein the extrusion rate is 20 mm / s.

47. The method of claim 45, wherein the pressure sensitive adhesive and thermoplastic elastomer are in contact at least 0.3 seconds prior to the coextrusion step, and wherein the extrusion rate is 60 mm / s.

48. The method of claim 34 further comprising: providing a substrate; and directly coextruding the merged molten pressure sensitive adhesive and molten thermoplastic elastomer together onto the substrate in the desired shape.

49. The method of claim 48, wherein the coextruding step includes coextruding through the outlet in a coextrusion dispensing head, and wherein the outlet is in the desired shape to forma gasket of the thermoplastic elastomer adhered to the substrate by the pressure sensitive adhesive.

50. The method of claim 49 further comprising moving the coextrusion dispensing head relative to the substrate to form a length of the gasket of thermoplastic elastomer adhered to the substrate by the pressure sensitive adhesive.

51. The method of claim 49 further including moving the substrate relative to dispensing head to form a length of the gasket of thermoplastic elastomer adhered to the substrate by the pressure sensitive adhesive.

52. The method of claim 48, wherein the thermoplastic elastomer gasket is adhered to the substrate by the pressure sensitive adhesive with a bond strength of at least 1 N / mm.

53. The method of claim 52, wherein the bond strength is measured by a ninety-degree peel test.

54. The method of claim 48, wherein the thermoplastic elastomer adhered to the substrate by the pressure sensitive adhesive includes a radius of curvature.

55. The method of claim 49, wherein the coextrusion dispensing head moves in a curve relative to the substrate.

56. The method of claim 49, wherein the substrate moves in a curve relative to the coextrusion dispensing head.

57. The method of claim 50, wherein the substrate also moves relative to the coextrusion dispensing head.

Images