Method for making molded polymer foams

Abstract

The present invention is a process for making molded polymer foams, particularly laminate panels that include a central foam layer and surface layers on one or both sides. A flexible film dispenser (10) is folded or rolled and introduced into a mold cavity (7) through a mold opening (6). The dispenser is unfolded or unfolded inside the film cavity, and foam precursor is forced through the dispenser and into the mold cavity. The dispenser has multiple outlets (16) through which the foam precursor enters the mold cavity. This allows for more uniform distribution of the foam precursor throughout the mold cavity, improving product quality while reducing defects.

Description

[Technical Field]

[0001] The present invention relates to a method for producing molded polymer foams. [Background technology]

[0002] Many polymer foams are prepared by introducing a precursor fluid into a mold, where it expands and hardens to produce the polymer.

[0003] Product quality often depends on achieving uniform distribution of the precursor fluid before it hardens and can no longer flow, as non-uniform distribution can result in defects, poor performance, and even rejected parts.

[0004] Distributing precursor fluids is often a difficult problem. This becomes especially acute when producing large, thin parts such as laminate panels. Laminate panels, which can be single-sided or double-sided, are materials that include a polymer foam layer and a facing layer bonded to one or both sides of the foam layer. These products are useful as insulation panels due to the insulating properties of the foam layer.

[0005] Laminate panels are often produced industrially using a continuous process. A typical continuous process is commonly known as double-band lamination. In this process, the problem of obtaining uniform distribution of precursor fluid is addressed through the use of a distribution system that dispenses the precursor fluid through multiple outlets, but this is often imperfect. The outlets are positioned across the width of the bottom layer and are currently generally fixed. The bottom layer moves horizontally below the outlets. This movement produces strips of foam formulation on the bottom layer from each outlet. The foam formulation then expands to produce the foam. Ideally, the individual strips come into contact and bond as they expand, forming a continuous layer before they harden to the point where they can no longer flow. If desired, a top layer can be applied after the precursor fluid has been dispensed but before it has hardened to form a double-sided laminate panel.

[0006] Distribution systems useful for continuous lamination processes are described, for example, in EP 2125323(A), EP 2234732(A), WO 2021 / 045888, WO 2021 / 046019, WO 2021 / 046020, WO 2021 / 046021, and WO 2012 / 046022. WO 2021 / 046019, WO 2021 / 046020, WO 2021 / 046021, and WO 2012 / 046022 all describe flexible distributors made by bonding polymer films together in such a way as to create ducts and multiple outlets.

[0007] Some laminate panels are instead made by a discontinuous process. Discontinuous processes are frequently used to produce products with non-standard sizes or geometries and other specialty items that cannot be easily manufactured by a continuous process. In a discontinuous process, a bottom layer and optionally a top layer are horizontally oriented and define opposite major sides of a mold. The facing layers are separated by frame members that define the sides of the mold. The facing layers and frame members together define an enclosed space that is filled with a precursor fluid. The precursor fluid is dispensed into the enclosed space and allowed to harden. The frame members are then separated from the resulting panel. The top and bottom layers remain adhered to the polymer foam layer.

[0008] Distribution systems, such as those used in continuous laminate panel manufacturing, have not been useful in discontinuous processes due to the difficulty of introducing the distributor into the mold and removing the mold after the precursor fluid has been dispensed into the mold cavity. Instead, the precursor fluid is typically introduced into the mold cavity through one or more openings in a frame member. This often leads to poor distribution of the precursor fluid because the precursor fluid must flow a significant distance across the mold, from the edge where it is injected to the opposing edge, and laterally. So-called "lance" and "withdrawal" methods attempt to alleviate this problem by inserting a hollow lance into the interior of the mold and introducing the precursor fluid through the lance. The lance can be gradually withdrawn as the mold cavity fills. These methods reduce the distance the precursor must flow in one dimension, but not laterally, and therefore are not completely satisfactory. Summary of the Invention

[0009] The present invention, in one aspect, provides a process for making a molded polymer foam, comprising: a) a folded or rolled multi-layer film fluid dispenser through a mold opening into a mold cavity, the multi-layer film fluid dispenser comprising: (i) at least one first flexible film substrate layer; (ii) at least one second flexible film substrate layer; a first flexible film substrate layer bonded to a second flexible film substrate layer to form a multilayer film member, the multilayer film fluid dispenser further comprising: (iii) introducing a multilayer film fluid dispenser including at least one duct in fluid communication with the at least one inlet and a plurality of outlets, the at least one duct being disposed between the first flexible film substrate layer and the second flexible film substrate layer and forming one or more paths for fluid to pass through the multilayer film member from the at least one inlet in the duct to the plurality of outlets in the duct; b) unfolding or unrolling the multi-layer film fluid dispenser in a mold; c) flowing a polymer foam precursor fluid into at least one inlet, through at least one duct of the deployed or unfolded multilayer film fluid dispenser, and out a plurality of outlets into the mold cavity; and then performing a curing step by curing the polymer foam precursor fluid introduced into the mold cavity through the multilayer film fluid dispenser to produce a molded polymer foam in the mold cavity. [Brief explanation of the drawings]

[0010] [Figure 1A] 1A-1D are partial cross-sectional top views collectively illustrating one embodiment of the process of the present invention. [Figure 1B] 1A-1D are partial cross-sectional top views collectively illustrating one embodiment of the process of the present invention. [Figure 1C] 1A-1D are partial cross-sectional top views collectively illustrating one embodiment of the process of the present invention. [Figure 1D] 1A-1D are partial cross-sectional top views collectively illustrating one embodiment of the process of the present invention. [Figure 1E] 1A-1D are partial cross-sectional top views collectively illustrating one embodiment of the process of the present invention. [Figure 1F] 1A-1D are partial cross-sectional top views collectively illustrating one embodiment of the process of the present invention. [Figure 2] 1 is a front cross-sectional view of a first multi-film fluid dispenser for use in the present invention. [Figure 3] FIG. 3 is a cross-sectional side view taken along line 3-3 of FIG. 2. [Figure 4] FIG. 4 is a cross-sectional side view taken along line 4-4 of FIG. 2. [Figure 5A] FIG. 10 is a cross-sectional front view showing the insertion of a second multilayer film fluid dispenser for use in the present invention into a mold cavity. [Figure 5B]FIG. 10 is a cross-sectional front view showing the second multilayer film fluid dispenser fully inserted into the mold cavity. [Figure 6A] FIG. 10 is a cross-sectional front view of a third multi-layer film fluid dispenser for use in the present invention. [Figure 6B] FIG. 10 is a cross-sectional front view of a third multilayer film fluid dispenser fully inserted into a mold cavity. [Figure 7A] FIG. 10 is a cross-sectional front view showing the insertion of a fourth multilayer film fluid dispenser into a mold cavity for use in the present invention. [Figure 7B] FIG. 10 is a cross-sectional front view showing a fourth multilayer film fluid dispenser fully inserted into a mold cavity. DETAILED DESCRIPTION OF THE INVENTION

[0011] Referring to Figure 1, mold 1 includes bottom mold surface 2, top mold surface 3, and mold sides 4, which together define mold cavity 7. Mold opening 6 is provided in one of mold sides 4. As shown in Figures 1A and 1B, a folded or rolled multilayer film fluid dispenser 10 is inserted into mold cavity 7 through mold opening 6. Multilayer film fluid dispenser 10 is in fluid communication with an upstream distribution system (not shown) via conduit 11, through which polymer foam precursor fluid is directed via inlet 15 into duct 14 (see Figure 2).

[0012] 1, as shown in Figures 1B and 1C, the multilayer film fluid dispenser 10 is deployed or unfolded after insertion into the mold cavity 7. In its fully deployed or unfolded state, the multilayer film fluid dispenser 10 preferably spans at least 50%, at least 75%, or at least 90% of the width W of the mold cavity 7. As described below, various methods are useful for deploying or unfolding the multilayer film fluid dispenser 10.

[0013] 1 and 2, multilayer film fluid dispenser 10 includes ducts 14 that define multiple fluid paths through multilayer film fluid dispenser 10 from inlet 15 to outlet 16. After inserting multilayer film fluid dispenser 10 into mold cavity 7 and deploying or unfolding it, polymer foam precursor fluid flows from an upstream distribution system (not shown) via conduit 11 into multilayer film fluid dispenser 10 via inlet 15, from there through duct 14 and out multiple outlets 16 of the deployed or unfolded multilayer film fluid dispenser 10 into mold cavity 7. This generates jets 20 of polymer foam precursor fluid.

[0014] Adjacent jets 20 of polymer foam precursor fluid may be parallel to one another or slightly (e.g., up to 20°) off-parallel. Individual jets 20 of polymer foam precursor fluid expand and combine with adjacent jets 20 to form a continuous mass 50 of polymer foam precursor fluid within the mold cavity 7.

[0015] In the particular embodiment shown in FIG. 2 , the duct 14 is a branched system that includes branch points where the duct divides to define multiple flow paths. Seven such branch points are optionally shown in the embodiment shown in FIG. 2 , at each of which the incoming stream of polymer foam precursor fluid splits into two streams. The branched duct system may include only one such branch point or any greater number, such as at least two, at least three, at least four, at least five, at least seven, at least 10, at least 15, or at least 31, and up to 100, 50, or 25 branch points, for example. For purposes of the present invention, a “branch point” is simply a point in the duct 14 where the polymer foam precursor fluid, or a portion thereof, splits into two or more streams (preferably exactly two) as it passes through the duct system.

[0016] 2 includes the preferred feature that all of the flow paths from inlet 15 to outlet 16 have the same length. This feature ensures that the residence time of the polymer foam precursor fluid is the same or nearly the same for each of the flow paths, and the polymer foam precursor fluid arrives at each of outlets 16 in the same or nearly the same cure state. Being in the same cure state, the polymer foam precursor fluid exiting each of outlets 16 has the same or nearly the same viscoelastic properties at any given time.

[0017] The number of flow paths into which the polymer foam precursor fluid is divided within the distribution system may be as few as two, or may be any larger number, such as at least two, at least three, at least four, at least five, at least seven, at least eight, at least 10, at least 16, or at least 32, for example, up to 100, up to 50, or up to 25. Similarly, the number of outlets 16 may be as few as two, or may be any larger number, such as at least two, at least three, at least four, at least five, at least seven, at least eight, at least 10, at least 16, or at least 32, for example, up to 100, up to 50, or up to 25. In Figure 5, the number of flow paths and outlets 16 is arbitrarily shown as eight.

[0018] The outlets 16 may be arranged in a straight line, a staggered configuration, or any other useful configuration.

[0019] The outlets 16 in some embodiments are uniformly spaced along the width of the multilayer film fluid dispenser 10. The center-to-center distance between adjacent outlets 16 may be, for example, 10 to 300 mm, with preferred distances being 10 to 200 mm, 30 to 200 mm, or 50 to 150 mm. The center-to-center distance between the two outermost outlets 16 may be, for example, 20 to 200 cm, 20 to 150 cm, or 20 to 120 cm. The center-to-center distance between the two outermost outlets 16 may be, for example, 80 to 98% of the width W of the mold cavity 7.

[0020] 1 includes the optional features of (1) extending the unfolded or unrolled multilayer film fluid dispenser 10 at least partially through the mold cavity 7 to the distal end 8 opposite the mold opening 6 (as in FIG. 1C ), and (2) then withdrawing the unfolded or unrolled multilayer film fluid dispenser 10 away from the distal end 8 toward the mold opening 6 as the polymer foam precursor fluid exits the outlet 16 and is dispensed into the mold cavity 7. These preferred features help to distribute the polymer foam precursor fluid more evenly throughout the length L of the mold cavity 7.

[0021] As shown in FIG. 1C , in this embodiment, the unfolded or unrolled multilayer film fluid dispenser 10 moves toward the distal end 8 of the mold cavity 7 before initiating the flow of polymeric foam precursor fluid. The unfolded or unrolled multilayer film fluid dispenser 10 may be inserted, for example, at least 50%, at least 75%, or at least 90% of the length L of the mold cavity 7 (i.e., at least 50%, at least 75%, or at least 90% of the distance from the mold opening 6 to the distal end 8) before initiating the flow of polymeric foam precursor fluid. The flow of polymeric foam precursor fluid is then initiated, generating a jet 20 of polymeric foam precursor fluid, which expands and coalesces to form a continuous mass 50. The unfolded or unrolled multilayer film fluid dispenser 10 is then gradually withdrawn in the direction indicated by arrow 22 toward the mold opening 6 (as shown in FIGS. 1D and 1E ) while continuously or intermittently dispensing polymeric foam precursor fluid out of outlet 16 and into the mold cavity 7. The unfolded or unrolled multilayer film fluid dispenser 10 may be withdrawn at the same rate as the mold cavity 7 is filled with polymer foam precursor fluid.

[0022] The withdrawal method shown in Figure 1 is optional. In an alternative embodiment, the multilayer film fluid dispenser 10 is maintained in a constant position within the mold cavity 7 throughout the time that the polymer foam precursor fluid is dispensed. Thus, for example, instead of positioning the multilayer film fluid dispenser 10 near the distal end 8 of the mold cavity 7 and gradually withdrawing it (as shown in Figures 1C, 1D, and 1E), the multilayer film fluid dispenser may be held in a fixed position within the mold cavity 7, such as adjacent the mold opening 6 as shown in Figure 1E, as the polymer foam precursor fluid is dispensed into the mold cavity 7 from multiple outlets 16.

[0023] After the polymer foam precursor fluid expands and hardens to produce a molded polymer foam, sufficient polymer foam precursor fluid is introduced into the mold cavity 7 through the unfolded or unrolled multilayer film fluid dispenser 10 to completely fill the mold cavity 7.

[0024] As shown in Figure 1F, the multilayer film fluid dispenser 10 is removed from the mold cavity 7 through the mold opening 6 after the required amount of polymer foam precursor fluid has been introduced into the mold cavity 7. In order to remove the multilayer film fluid dispenser 10 through the mold opening 6, it is typically necessary to refold or reroll the multilayer film fluid dispenser 10.

[0025] The space within the mold cavity 7 that was occupied by the multilayer film fluid dispenser 10 before it was removed is typically filled with polymer foam precursor fluid due to further expansion within the mold cavity 7 after the multilayer film fluid dispenser 10 is removed but before curing is complete. This further expansion reduces or eliminates defects in the molded polymer foam in the area that was occupied by the multilayer film fluid dispenser 10 before it was removed.

[0026] The polymer foam precursor fluid is allowed to harden within the mold cavity to produce a shaped polymer foam product.

[0027] Referring now to Figures 2-4, a multilayer film fluid dispenser 10 includes a first flexible film substrate 10A and a second flexible film substrate 10B. In the embodiment shown in Figures 2-4, each of the flexible film substrates 10A and 10B is a multilayer structure, which is an optional but preferred embodiment. Each of the film substrates 10A and 10B may have more constituent layers or only one constituent layer. As shown, the flexible film substrate 10A is composed of an inner layer 12A and an outer layer 11A, and the flexible film substrate 10B is composed of an inner layer 12B and an outer layer 11B. The flexible film substrates 10A and 10B are joined to each other via the inner layers 12A and 12B, with surfaces 13A and 13B of the outer layers 11A and 11B, respectively, facing outward.

[0028] Duct 14 is created by bonding (e.g., by a heat sealing process) portions of flexible film substrate 10A to second film substrate 10B at predetermined spaced locations through inner layers 12A and 12B to form bond lines such as bond line 13E. As a result of the bonding process, duct 14 is formed by non-bonded surface portions 13C and 13D of inner layers 12A and 12B. Duct 14, formed by the selective bonding process, is embedded between first flexible film substrate 10A and second flexible film substrate 10B.

[0029] Multi-layer flexible fluid dispensing liner members and methods for making them are further described in WO 2021 / 046019.

[0030] Duct 14 is in fluid communication with at least one inlet 15 for receiving polymer foam precursor fluid from an upstream device (not shown), such as a mixhead. Duct 14 is further in fluid communication with a plurality of outlets 16 for discharging the polymer foam precursor fluid into mold cavity 7. The plurality of outlets 16 and inlet 15 are in fluid communication through duct 14.

[0031] In the particular embodiment shown in FIG. 2 , blind duct 18 is provided as a means for unfolding or expanding multilayer film fluid dispenser 10. Blind duct 18 is characterized by being in fluid communication with duct 14 (as shown) or inlet 15 (which may be the same inlet as duct 14 or a separate inlet), and having no associated outlet. Blind duct 18 extends outward from a central portion of multilayer film fluid dispenser 10 toward its lateral edges 19 and 19A. Polymer foam precursor fluid entering blind duct 18 from duct 14 and / or inlet 15 is captured within blind duct 18. When folded or rolled multilayer film fluid dispenser 10 is inserted into mold cavity 7 and the flow of polymer foam precursor fluid into multilayer film fluid dispenser 10 is initiated, blind duct 18 becomes filled with polymer film precursor fluid. The polymeric foam precursor fluid trapped within the blind duct 18 mechanically deploys or unfolds the multilayer film fluid dispenser 10 within the mold cavity 7. In such embodiments, the multilayer film fluid dispenser is preferably removed from the mold cavity 7 within a short time after the mold cavity 7 is filled with the polymeric foam precursor fluid and before the polymeric foam precursor fluid hardens within the blind duct 18, which makes it difficult to refold or reroll the multilayer film fluid dispenser 10.

[0032] In a variation of the embodiment shown in FIG. 2, the blind duct 18, instead of being in fluid communication with the duct 14 and / or the inlet 15, is in fluid communication with a separate inlet port through which a separate inflation fluid, such as air, another gas, or liquid, is forced into the blind duct 18 to inflate the blind duct 18 and deploy or unfold the multilayer film fluid dispenser 10 within the mold cavity 7.

[0033] Alternatively, the blind duct 18 and other separate devices for unfolding or expanding the multilayer film fluid dispenser 10 may be omitted, in which case the polymer foam precursor fluid flowing through the duct 14 provides sufficient rigidity to unfold or expand the multilayer film fluid dispenser 10.

[0034] A mechanical device for deploying or unfolding the multilayer film fluid dispenser 10 may be provided instead of or in addition to the blind duct 18. Examples of such mechanical devices include various types of spring systems and other mechanical actuators. FIG. 5 illustrates one such alternative embodiment. An arm 36 is pivotally secured to or adjacent the lateral sides 19 and 19A of the multilayer film fluid dispenser 10 at a pivot point 40 and is pivotally mounted at a fixed location upstream from the multilayer film fluid dispenser 10. In the particular embodiment shown in FIG. 5, the arm 36 is pivotally mounted on the conduit 11 at a pivot point 37. Instead of being mounted directly on the conduit 11, the pivot point 37 may be fixedly mounted on another device, such as an outer housing, collar, sheath, or the like, which is at a fixed location upstream from the multilayer film fluid dispenser 10. A spring mechanism may be provided at the pivot point 40 and / or the pivot point 37. As shown in FIG. 5A, the arm 36 is retained within a collar 41 to maintain the multilayer film fluid dispenser 10 in a folded or rolled position. The collar 41 is slidably mounted around the conduit 11, the arm 36, and the multilayer film fluid dispenser 10. The multilayer film fluid dispenser 10 passes through the mold opening 6 into the mold cavity 7 in the direction indicated by arrow A (FIG. 5B). The collar 41 is larger than the mold opening 6 and engages with and is retained by the mold side 4, which remains outside the mold cavity 7, as shown in FIG. 5B. The arm 36, no longer restrained by the collar 41, extends laterally by the action of a spring mechanism, unfolding or unrolling the multilayer film fluid dispenser 10 within the mold cavity 7. After the mold filling step is complete, the conduit 11 and the multilayer film fluid dispenser 10 are withdrawn from the mold cavity 7 by moving them in the direction indicated by arrow B. The pivot point 37 and arm 36 are pulled past the collar 41 and through the mold opening 6, pushing the pivot point 40 inward and refolding or rerolling the multilayer film fluid dispenser 10 so that it can be removed through the mold opening 6.

[0035] In the embodiment shown in FIG. 6 , a spring 61 mechanically actuates the deployment or unfolding of the multi-layer film fluid dispenser 10. The spring 61 is fixedly mounted to or adjacent the lateral sides 19 and 19A of the multi-layer film fluid dispenser 10 at attachment point 63 and is attached at a fixed location upstream from the multi-layer film fluid dispenser 10. In the particular embodiment shown in FIG. 6 , the spring 61 is attached to the conduit 11 at attachment point 62. Instead of being attached directly to the conduit 11, the spring 61 may be pivotally mounted on another device, such as an outer housing, collar, sheath, or the like, which is at a fixed location upstream from the multi-layer film fluid dispenser 10. The spring 61 and the multi-layer film fluid dispenser 10 are retained within a sheath 64 to maintain the multi-layer film fluid dispenser 10 in a folded or rolled position prior to insertion. The sheath 64 is slidably mounted around the conduit 11, spring 61, and multi-layer film fluid dispenser 10. The multilayer film fluid dispenser 10 passes through the mold opening 6 and enters the mold cavity 7. The sheath 64 is larger than the mold opening 6 and engages with and is held by the mold side 4 that remains outside the mold cavity 7, as shown in FIG. 6B. The spring 61, no longer constrained by the sheath 64, expands laterally, unfolding or unrolling the multilayer film fluid dispenser 10 within the mold cavity 7. After the mold filling step is complete, the conduit 11 and the multilayer film fluid dispenser 10 are withdrawn from the mold cavity 7 by moving them in the direction indicated by arrow B. The spring 61 and the multilayer film fluid dispenser 10 are withdrawn back into the sheath 64, depressing the attachment point 63 inward and refolding or rerolling the multilayer film fluid dispenser 10 so that it can be removed through the mold opening 6.

[0036] Yet another embodiment is shown in FIG. 7 . In this embodiment, curved actuator arms 71 operate to unfold or unroll the multi-layer film fluid dispenser 10. The curved actuator arms 71 are fixedly attached to or adjacent the lateral sides 19 and 19A of the multi-layer film fluid dispenser 10 at attachment points 72. In this position, the curved actuator arms 71 each curve outward from the conduit 11. Prior to introduction into the mold cavity 7, the curved actuator arms 71 and the multi-layer film fluid dispenser 10 are held within a sheath 74 to maintain the multi-layer film fluid dispenser 10 in a folded or rolled position. The multi-layer film fluid dispenser 10 passes through the mold opening 6 into the mold cavity 7 in the direction indicated by arrow A. The sheath 74 is slidably mounted around the conduit 11, the curved actuator arms 71, and the multi-layer film fluid dispenser 10. Sheath 74 is larger than mold opening 6 and engages with and is held by mold side 4 remaining outside mold cavity 7, as shown in FIG. 7B . As curved actuator arms 71 pass through sheath 74 and mold opening 6, their curvature pushes attachment points 72 laterally outward in the direction indicated by arrow C, unfolding or spreading multilayer film fluid dispenser 10 within mold cavity 7. After the mold filling step is completed, conduit 11 and multilayer film fluid dispenser 10 are withdrawn from mold cavity 7 by moving them in the direction indicated by arrow B. As curved actuator arms 71 are withdrawn through sheath 74, attachment points 72 are pushed inward, refolding or rerolling multilayer film fluid dispenser 10 so that it can be removed through mold opening 6.

[0037] The material of construction of the multilayer film fluid dispenser 10 is preferably an organic polymer. Examples of such organic polymers include polyethylene homopolymers and copolymers, including, for example, low density polyethylene, linear low density polyethylene, high density polyethylene, ultra-high molecular weight polyethylene, metallocene polyethylene, and the like. Other useful organic polymers include polyester, polypropylene, ethylene-propylene copolymer, oriented polyamide, polytetrafluoroethylene, various nylons, and the like.

[0038] Flexible film substrates 10A and 10B may independently have a single-layer structure or a multi-layer structure. As shown in FIGS. 2-4, flexible film substrate 10A and flexible film substrate 10B each have a two-layer structure. In such a two-layer structure, inner layer 12A and inner layer 12B may be, for example, a heat-sealable organic polymer such as polyethylene. In such an embodiment, outer layer 11A and outer layer 11B may be, for example, another polyethylene or a polyester such as poly(ethylene terephthalate). Multilayer flexible film substrate 10A and multilayer flexible film substrate 10B may be produced, for example, by a film coextrusion process.

[0039] If desired, a separate layer of adhesive may be disposed between flexible film substrate 10A and flexible film substrate 10B to form a bond therebetween, as further described in Figure 10 (and accompanying text) of WO 2021 / 046019. Similarly, a bonding layer may be disposed between inner layer 12A and outer layer 11A and / or between inner layer 12B and outer layer 11B.

[0040] The multilayer film fluid dispenser can be manufactured from a flexible film substrate using a method such as that described in, for example, WO 2021 / 046019, U.S. Patent Nos. 7,147,597, 8,231,029, 8,348,509, U.S. Patent Application Publication Nos. 2017 / 0247156, 2015 / 0314928, and 2015 / 0314919. The flexible film substrate is preferably joined to manufacture the multilayer film fluid dispenser using a heat sealing method. Sealing conditions can include, for example, a sealing pressure of 0.1 to 10 bar gauge (0.01 to 1 MPa), a sealing temperature of 100 to 200°C, and a sealing time of 0.1 to 2 seconds. The sealing pressure is applied to the portion of the flexible film substrate corresponding to the space between the ducts. No sealing pressure is applied to the area where the ducts will be formed.

[0041] The multilayer film fluid dispenser preferably exhibits a flexural modulus of 100 to 3000 MPa, as measured according to ASTM D790-17.

[0042] The multilayer film fluid dispenser preferably exhibits a tensile strength (ASTM D1708-18) at maximum force of 0.1-4 kPa, 0.1-10 kPa, or 0.18-8 kPa, and an elongation at maximum force of 40% or less, preferably 30% or less.

[0043] A mold is any container into which a polymer foam precursor fluid is introduced and cured. The mold includes a mold cavity whose surfaces define the geometry (size and shape) of the polymeric shaped foam, and at least one mold opening. The mold can be held in a press that applies pressure to the mold surfaces during at least the curing step to keep the mold closed and / or to control the amount of expansion achieved during the curing step.

[0044] In some embodiments, the mold forms all or part of the exposed surface of the finished product. Thus, the mold can be, for example, all or part of the shell of an insulating structure such as a refrigerator or freezer box, door, or panel or cooler, a buoy, life preserver or other life jacket, an automotive part, or another hollow structure where a polymeric foam core is required.

[0045] In other embodiments, only a portion of the mold forms all or part of the exposed surface of the finished product. An important example of such an embodiment is laminate panel production, in which the top and / or bottom surfaces of the mold form part of the finished product and are laminated to one or both sides of a molded polymer foam. In such cases, the mold typically consists of top and bottom panels and mold sides that are separate and / or separable from at least one of the top and bottom panels, so that the mold sides can be removed from the finished product while leaving the top and / or bottom panels adhered to the molded polymer foam. In such embodiments, the mold opening is preferably located in one or more of the mold sides, and the top and bottom panels are held in the press as described above, at least during the curing step.

[0046] The multilayer film fluid dispenser is introduced into the mold cavity through a mold opening. Because the mold opening is generally smaller than the multilayer film fluid dispenser in at least one dimension (typically width), the multilayer film fluid dispenser is folded or rolled prior to insertion to fit through the mold opening. The manner of folding or rolling is not critical. The multilayer film fluid dispenser may be folded (or simply crumpled) in a regular pattern or any random pattern, and may or may not be scored as part of the folding process.

[0047] Once introduced into the mold, the multi-film fluid dispenser is unfolded or unrolled as previously described.

[0048] The polymer foam precursor fluid flows into the duct inlet, then flows through the duct of the deployed or unfolded multilayer film fluid dispenser, out the multiple outlets, and into the mold cavity. During this step, the duct expands with the polymer foam precursor fluid, allowing it to flow through the expanded duct to the multiple outlets. The multilayer film fluid dispenser can be retracted through the mold cavity during this mold filling step, as described above with respect to FIG. 1.

[0049] The polymeric foam precursor fluid is typically produced by introducing its various constituent components into a mixhead via one or more supply systems. The supply systems may include various conduits, pumps, metering devices, storage devices, heating and / or cooling devices, and operating systems (including computerized operating systems) that may be useful or desirable to deliver the respective components to the mixhead in precise ratios and under suitable temperature and / or pressure conditions. The resulting polymeric foam precursor fluid is then transported to a multilayer film fluid dispenser via a suitable fluid transport system, such as conduit 11 in FIG. 1.

[0050] Sufficient polymer foam precursor fluid is introduced in this manner so that the mold cavity is filled after the polymer foam precursor fluid expands during the curing step. If desired, an amount of polymer foam precursor fluid in excess of the amount required to just barely fill the mold cavity (after expansion) may be introduced during this step. If the mold cavity is overfilled in this manner, the overfill may be 1-30%, i.e., the amount of polymer foam precursor fluid introduced is 1-30% more than the amount required to minimally fill the mold after expansion.

[0051] After the mold cavity is filled, the multilayer film fluid dispenser is preferably removed from the mold cavity through the mold opening. This is done by refolding and / or rewinding the multilayer film fluid dispenser and withdrawing it from the mold opening. Refolding or rewinding can be done in a variety of ways.

[0052] In embodiments where the multilayer film fluid dispenser includes blind ducts, fluid within such blind ducts can be removed to create subatmospheric pressure that pulls the lateral edges of the multilayer film dispenser toward the center, causing the multilayer film dispenser to refold or reroll.

[0053] In embodiments such as that shown in Figure 5, the arm 36 can be pulled outwardly through the collar 41. As the arm 36 passes outwardly through the collar 41, the pivot point 40 is pulled laterally inward toward the mold opening 6, pulling the lateral edges 19 and 19A of the multilayer film fluid dispenser 10 inward, refolding or rerolling the multilayer film fluid dispenser 10. A similar refolding action is seen in the embodiments shown in Figures 6 and 7. In the embodiment of Figure 6, the spring 61 is pulled outwardly through the sheath 64, which then pulls the attachment point 62 and the lateral edges 19 and 19A of the multilayer film fluid dispenser 10 inward, refolding or rerolling the multilayer film fluid dispenser 10. In the embodiment of FIG. 7, the curved actuator arms are pulled outward through sheath 74, again pulling attachment points 72 and 72' and lateral sides 19 and 19A of multilayer film fluid dispenser 10 inward, re-folding or re-rolling multilayer film fluid dispenser 10.

[0054] In yet another embodiment, the conduit 11 with the attached multilayer film fluid dispenser 10 is simply pulled through the mold opening 6 with enough force to deform the multilayer film fluid dispenser 10, and fold or crumple the multilayer film fluid dispenser 10 sufficiently to remove it from the mold cavity. The multilayer film fluid dispenser does not need to be refolded or rerolled in the same manner as it was before being inserted through the mold cavity.

[0055] During the curing step, the polymeric foam precursor fluid introduced into the mold cavity through the multilayer film fluid dispenser expands to form a shaped polymeric foam that fills the mold cavity. The preferred isocyanate-based polymeric foam precursor fluids described below typically begin to react, expand, and harden spontaneously upon contact of the polyisocyanate component with other ingredients, and thus hardening may begin during the mold filling step. For this reason, operating flow rates and other conditions are generally selected so that the polymeric foam precursor fluid remains flowable until it is discharged into the mold cavity through the multiple outlets of the multilayer film fluid dispenser.

[0056] Curing is continued until a dimensionally stable molded polymer foam is obtained. A foam is considered to be dimensionally stable if it does not collapse upon demolding and subsequently expands by no more than 10%, preferably no more than 5%.

[0057] Curing conditions are selected with respect to the particular polymeric foam precursor fluid. Depending on the particular case, the curing step can be carried out at temperatures as low as 0°C, as low as 20°C, and up to 100°C. Preferred isocyanate-based polymeric foam precursor fluids, for example, can be cured with or without the application of heat; the fluids typically exhibit an exothermic temperature increase as they react and cure. Even in this case, it may be desirable to accelerate or drive the cure to completion by applying heat to the exterior surface of the mold. For example, the mold surface may be heated to 50°C to 150°C, if desired for that purpose.

[0058] The internal mold pressure prior to expansion of the polymer foam precursor fluid may be below atmospheric pressure to slightly above atmospheric pressure. A pressure increase may be felt as the polymer foam precursor fluid expands. Typically, mechanical pressure is applied to the main mold surface to control unwanted expansion and set product dimensions, particularly thickness. The mold cavity may be vented.

[0059] Demolding times can vary considerably, from 30 seconds to 10 minutes or more. The molded polymer foam may be demolded once the polymer foam precursor fluid has cured sufficiently so that the molded polymer foam is dimensionally stable. Demolding occurs by removing the molded polymer foam from some or all of the mold components, or, if some or all of the mold surfaces remain with the product, when mechanical pressure is released. When certain products, such as laminate panels, are produced, some of the mold surfaces may remain with the molded polymer foam. Thus, for example, mold side 4 (see again FIG. 1 ) may be separated from the molded polymer foam, leaving top mold surface 3 and / or bottom mold surface 2 adhered to the molded polymer foam, thereby producing a laminate structure.

[0060] When producing such a laminated structure, the top and / or bottom mold surfaces are the facing materials that remain with the molded polymer foam. The top and / or bottom surfaces may be, for example, metal (which may have a coating applied), kraft paper or other paper, fiber-reinforced paper, metal foil-paper composite layers, plastic sheets or films, etc. If the facing surfaces are flexible (e.g., in the case of paper, plastic sheets, and films, and metal foil), the laminate panel may be referred to as an "insulation board." The term "laminate panel" is used herein to encompass panels made with rigid surfaces (such as metal sheets) as well as "insulation boards." Each facing layer preferably has a thickness of at most 5 mm, preferably at most 2.5 mm, or at most 1 mm.

[0061] The process of the present invention may, and preferably does, include various additional steps (and associated equipment) required to produce a product for a particular application. When making a laminate panel, the facing layer may be cut to a specific size and shape before the process begins. The facing layer, particularly the metal layer, may be pretreated to promote good adhesion to the polymer foam or otherwise facilitate panel manufacturing. Examples of pretreatment steps include unwinding, corona discharge treatment, profiling, heating to the process temperature, and applying a layer of adhesion promoter.

[0062] Similarly, the process may, and preferably does, include one or more downstream steps such as trimming the product, cooling the foam or laminate panel from the cure temperature, stacking the foam or laminate panel, packaging the foam or laminate panel, or otherwise preparing them for shipment or storage.

[0063] A preferred polymer foam precursor fluid is an isocyanate-based formulation containing at least one polyisocyanate, at least one blowing agent, at least one catalyst for the reaction of the polyisocyanate with itself, chemical blowing, and / or alcohol groups, and optionally, but preferably, at least one polyol. The polymer foam precursor fluid is a liquid or liquid / gas mixture (sometimes referred to as an "emulsion"). Thus, at least one of its components is liquid under operating conditions. A nucleating gas, such as air, nitrogen, hydrogen, or argon, may be mixed into the polymer foam precursor fluid.

[0064] Organic polyisocyanates suitable for use in the present invention include aliphatic, cycloaliphatic, araliphatic, or aromatic polyisocyanates, or a combination of any two or more thereof. These include, for example, alkylene diisocyanates, in particular those having 4 to 12 carbon atoms in the alkylene moiety, such as 1,12-dodecane diisocyanate, 2-ethyltetramethylene 1,4-diisocyanate, 2-methyl-pentamethylene 1,5-diisocyanate, 2-ethyl-2-butylpentamethylene 1,5-diisocyanate, tetramethylene 1,4-diisocyanate, preferably hexamethylene 1,6-diisocyanate, alicyclic diisocyanates, such as cyclohexane 1,3- and 1,4-diisocyanate and any mixtures of these isomers, 1-isocyanato-3,3,5-trimethyl-5-isocyanato-methylcyclohexane (isophorone diisocyanate), 2,4- and 2,6-hexahydrotoluene diisocyanate and the corresponding isomer mixtures, 4,4'-, 2,2'-, and 2,4'-dicyclohexylmethane diisocyanate and the corresponding isomer mixtures, araliphatic diisocyanates such as 1,4-xylylene diisocyanate and xylylene diisocyanate isomer mixtures, preferably aromatic diisocyanates and polyisocyanates such as 2,4- and 2,6-toluene diisocyanate and the corresponding isomer mixtures, 4,4'-, 2,4'-, and 2,2'-diphenylmethane diisocyanate and the corresponding isomer mixtures, mixtures of 4,4'- and 2,4'-diphenylmethane diisocyanate, polyphenyl-polymethylene polyisocyanates, mixtures of 4,4'-, 2,4'-, and 2,2'-diphenylmethane diisocyanate and polyphenylpolymethylene polyisocyanates (crude MDI), and mixtures of crude MDI and toluene diisocyanate may be mentioned. Modified polyisocyanates, i.e. products obtained by chemical reaction of organic diisocyanates and / or polyisocyanates, may also be used.Specific examples are ester-, urea-, biuret-, allophanate-, uretonimine-, carbodiimide-, isocyanurate-, uretdione-, and / or urethane-containing diisocyanates and / or polyisocyanates containing 33.6 to 15 weight percent, preferably 31 to 21 weight percent, of isocyanate groups, based on the total weight of the modified polyisocyanate. The organic polyisocyanates can be used alone or in combination.

[0065] Preferred polymer foam precursor fluids typically contain at least one polyol, i.e., a compound with two or more hydroxyl groups. A wide variety of polyols can be used, depending in part on the desired properties of the polymer foam. Useful polyols therefore include polyether polyols, polyester polyols, hydroxyl-terminated polybutadiene rubber, polyacrylate polyols, and polycarbonate polyols, as well as other types. Useful polyols have a hydroxyl equivalent weight of about 30 to 3,000, although for laminate panel production, it is preferred to use at least one polyol having a hydroxyl equivalent weight of 30 to 1,000, especially 125 to 560. The polyol may have a hydroxyl functionality of 2 to 8 or more hydroxyl groups per molecule.

[0066] Useful polyether polyols include, for example, ethoxylates and / or propoxylates of one or more hydroxyl and / or amine groups containing starters having an equivalent weight of 30 to 59, including one or more of ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, tripropylene glycol, glycerin, trimethylolpropane, trimethylolethane, neopentyl glycol, 1,6-hexanediol, 1,4-cyclohexanediethanol, 1,2,6-hexanetriol, monoethanolamine, diethanolamine, triethanolamine, pentaerythritol, erythritol, sorbitol, sucrose, mannitol, N,N,N',N'-tetrakis(2-hydroxypropyl)-ethylenediamine, diethyltoluenediamine, dimethylthiotoluenediamine, and combinations thereof.

[0067] Useful polyester polyols can be, for example, reaction products of organic dicarboxylic acids (or the corresponding acid anhydrides or esters) having from about 2 to about 12 carbon atoms with polyhydric alcohols, preferably diols and / or triols having from 2 to 12 carbon atoms, preferably from 2 to 6 carbon atoms. Examples of suitable dicarboxylic acids are succinic acid, glutaric acid, adipic acid, suberic acid, azelaic acid, sebacic acid, decanedicarboxylic acid, maleic acid, fumaric acid, preferably orthophthalic acid, isophthalic acid, terephthalic acid, and isomeric naphthalenedicarboxylic acids. The dicarboxylic acids may be used either alone or in admixture with one another. Examples of dihydric and polyhydric alcohols used to make polyester polyols are ethanediol, diethylene glycol, 1,2- and 1,3-propanediol, dipropylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,10-decanediol, glycerol, and trimethylolpropane. Modified aromatic polyester polyols, such as those described in U.S. Patent No. 6,359,022, containing one or more pendant aliphatic hydrocarbyl groups having 6 or more carbon atoms in a linear or branched chain, are also useful.

[0068] Additionally, polyester-polyols made from lactones such as ε-caprolactone or hydroxycarboxylic acids such as ω-hydroxycaproic acid and hydrobenzoic acid can also be used. Hybrid polyether-polyester polyols, such as those described in WO 2011 / 137011, are also useful.

[0069] Other useful polyols include compounds having 2 to 8 hydroxyl groups, an equivalent weight of up to 125, and a molecular weight of up to 200, such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propanediol, 1,3-propanediol, dipropylene glycol, tripropylene glycol, glycerin, trimethylolpropane, trimethylolethane, neopentyl glycol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, 1,2,6-hexanetriol, mannitol, sucrose, and sorbitol.

[0070] The polymer foam precursor fluid contains at least one blowing agent, which may be of the physical (endothermic) or chemical (exothermic) type, or both. Physical blowing agents are one or more compounds having a boiling point (at 1 atmosphere) between 10°C and 80°C, preferably between 10°C and 50°C, lacking hydroxyl, primary and / or secondary amine, thiol, carboxyl, or other groups other than halogen groups that are reactive with isocyanate groups under the conditions of the curing reaction. Useful physical blowing agents include hydrocarbons, hydrofluorocarbons, hydrochlorocarbons, hydrofluorochlorocarbons, ethers, and the like, having the aforementioned boiling points. C4-C6 hydrocarbons, such as any isomer (or mixture of isomers) of butane, pentane, and hexane, are particularly useful. Hydrofluoroolefins and hydrofluorochloroolefins, such as those described in U.S. Patent Application Publication No. 2007 / 0100010, are also useful. Specific examples include trifluoropropene, 1,3,3,3-tetrafluoropropene (1234ze), 1,1,3,3-tetrafluoropropene, 2,2,3,3-tetrafluoropropene (1234yf), 1,2,3,3,3-pentafluoropropene (1225ye), 1,1,1-trifluoropropene, 1,1,1,3,3-pentafluoropropene (1225zc), 1,1,2,3,3-pentafluoropropene (1225yc), (Z)-1,1,1,2,3-pentafluoropropene (1225yez), 1-chloro-3,3,3-trifluoropropene (1233zd), and 1,1,1,4,4,4-hexafluorobut-2-ene (1336mzzm). Mixtures of any two or more physical blowing agents may also be used.

[0071] The physical blowing agent may be present in an amount of, for example, at least 12 parts by weight per 100 parts by weight of polyol. The amount of physical blowing agent may be, for example, at least 12, at least 14, or at least 15 parts by weight on that basis, and may also be, for example, up to 25 parts, up to 22 parts, up to 20 parts, or up to 18 parts on the same basis.

[0072] A particularly suitable chemical blowing agent is water, which, when present, reacts to produce carbon dioxide.

[0073] Suitable catalysts include urethane catalysts, i.e., catalysts for the reaction of alcohol groups and / or water with isocyanate groups, isocyanate trimerization catalysts, and carbodiimide catalysts. Suitable urethane catalysts include tin(II) and tin(IV) catalysts, catalysts containing other Group III to Group XV metals, tertiary amine compounds, amidines, tertiary phosphines, and the like. Useful isocyanate trimerization catalysts include strong bases such as alkali metal phenolates, alkali metal alkoxides, alkali metal carboxylates, and quaternary ammonium salts. Useful carbodiimide catalysts include phospholene oxides such as 3-methyl-1-phenyl-2-phospholene oxide (MPPO), 3-methyl-1-ethyl-2-phospholene oxide (MEPO), 3,4-dimethyl-1-phenyl-3-phospholene oxide, 3,4-dimethyl-1-ethyl-3-phospholene oxide, 1-phenyl-2-phospholene-1-oxide, 3-methyl-1-2-phospholene-1-oxide, 1-ethyl-2-phospholene-1-oxide, 3-methyl-1-phenyl-2-phospholene-1-oxide, and their 3-phospholene isomers.

[0074] The polymer foam precursor fluid may further contain various optional ingredients. A foam-stabilizing surfactant is a useful optional ingredient. Suitable such surfactants include, but are not limited to, silicones such as silicone oils and organic silicone-polyether copolymers, including polydimethylsiloxane and polydimethylsiloxane-polyoxyalkylene block copolymers. Other suitable surfactants include organic surfactants such as nonylphenol ethoxylate and ethylene oxide / butylene oxide block copolymers.

[0075] Another optional component is a flame retardant such as phosphorus-containing flame retardants, halogenated flame retardants, and melamine.

[0076] In addition to the aforementioned components, the polymer foam precursor fluid may contain one or more fillers and / or reinforcing agents such as glass fiber, carbon fiber, flaked glass, mica, talc, melamine, and calcium carbonate; one or more pigments and / or colorants such as titanium dioxide, iron oxide, chromium oxide, azo / diazo dyes, phthalocyanines, dioxazines, and carbon black; one or more biocides; one or more preservatives; one or more antioxidants; one or more flame retardants; and the like.

[0077] The foam layer of the laminate panel made according to the present invention may have a compressive strength of, for example, 20 to 120 kg / m, as measured according to ASTM 1622-88. 3 or 30 to 80 kg / m 3 The cells may be at least about 70 percent closed, at least about 80 percent closed, or at least about 85 percent closed.

[0078] Laminate panels made according to the present invention can be used in the same manner and for the same purposes as laminate panels made using conventional processes. The panels can be used as insulation for buildings, vehicles, pavement, and other constructions. The panels are useful as lightweight decorative panels for building facades, interior wall partitions, and other applications.

[0079] The laminated panels made according to the present invention are useful in both industrial and residential applications. Applications include, for example, cryogenic storage insulation, doors, windows, and sliding shutters. The laminated panels are also useful as architectural or decorative panels, even when thermal insulation properties are not required. The laminated panels are useful, for example, in constructing building facades.

Claims

1. 1. A process for making a molded polymer foam, comprising: a) a folded or rolled multi-layer film fluid dispenser through a mold opening into a mold cavity, said multi-layer film fluid dispenser comprising: (i) at least one first flexible film substrate layer; (ii) at least one second flexible film substrate layer; the first flexible film substrate layer is joined to the second flexible film substrate layer to form a multilayer film member, the multilayer film fluid dispenser further comprising: (iii) introducing a multilayer film fluid dispenser including at least one duct in fluid communication with at least one inlet and a plurality of outlets, the at least one duct being disposed between the first flexible film substrate layer and the second flexible film substrate layer and forming one or more paths for fluid to pass through the multilayer film member from the at least one inlet in the duct to the plurality of outlets in the duct; b) unfolding or unrolling the multi-layer film fluid dispenser within the mold; c) flowing a polymer foam precursor fluid into the at least one inlet, through the at least one duct of the deployed or unfolded multilayer film fluid dispenser, and out the plurality of outlets into the mold cavity; and then performing a curing step by curing the polymer foam precursor fluid introduced into the mold cavity through the multilayer film fluid dispenser to produce the shaped polymer foam in the mold cavity.

2. 10. The process of claim 1, further comprising the steps of: d) refolding or rerolling the multilayer flexible film substrate layer after step c) and before the curing step; and e) removing the refolded or rerolled multilayer flexible film substrate layer through the mold opening.

3. 3. The process of claim 1 or 2, further comprising a demolding step after the curing step.

4. 4. The process of claim 1, wherein the mold comprises a bottom surface member, an opposing top surface member, and one or more mold frame members that define sides of the mold, and the bottom surface member, top surface member, and one or more mold frame members define the cavity of the mold.

5. 5. The process of claim 4, wherein in the demolding step, the one or more frame members are separated from the molded polyurethane foam, and the bottom surface member and the top surface member remain adhered to opposite sides of the molded polyurethane foam to form a laminate.

6. 6. The process of claim 1, wherein the multilayer film fluid dispenser includes one or more blind ducts in fluid communication with an inlet and having no associated outlet, and wherein in step b) the multilayer film fluid dispenser is deployed or unfolded by pumping a polymer foam precursor fluid and / or a separate inflation fluid into the blind ducts to inflate the blind ducts.

7. The process of any one of claims 1 to 5, wherein arms are pivotally secured to opposite lateral sides of the multilayer film fluid dispenser and are further pivotally attached at attachment points at fixed locations upstream from the multilayer film fluid dispenser (10), and in step b), the arms extend laterally outward to unfold or unfold the multilayer film fluid dispenser.

8. The process of any one of claims 1 to 5, wherein springs are fixedly mounted to opposite lateral sides of the multilayer film fluid dispenser and at attachment points 62 at fixed locations upstream from the multilayer film fluid dispenser, and in step b), the springs extend laterally outward to unfold or spread the multilayer film fluid dispenser.

9. 9. The process of any one of claims 1 to 8, wherein the unfolded or unrolled multilayer film fluid dispenser 10 is inserted at least 50% into the length L of the mold cavity before initiating polymer foam precursor fluid flow in step c), and during step c), the unfolded or unrolled multilayer film fluid dispenser is gradually withdrawn toward the mold opening while continuously or intermittently dispensing polymer foam precursor fluid out of the multiple outlets into the mold cavity.

10. The process according to any one of claims 1 to 9, which is a discontinuous laminate panel process.

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