Method and device for mechanically separating multi-layer conical interlayer

Abstract

Disclosed is a method for separating a first layer from the remainder of a tapered multi-layer sandwich sheet in which the tapered multi-layer sandwich sheet is heated and then the first layer and the remainder of the tapered multi-layer sandwich sheet are pulled in different directions in a defined orientation to separate the first layer from the remainder of the tapered multi-layer sandwich sheet. The first layer of the tapered multilayer interlayer sheet is separated from the remainder without corrugating or tearing the tapered multilayer interlayer sheet.

Description

Background Art

[0001] Multilayer sandwiches are increasing their share in the sandwich market, but have limited recyclability in the extrusion process because different layers may have different physical and chemical properties. When the multilayer sandwich material (which includes skin layers and core layers) is added back into the skin layer extrusion process, the core layer material that is immiscible with the skin layer material forms small but discrete core layer material areas, which can cause a certain level of haze. Due to the formation of haze, the amount of core layer material that can be added back into the skin layer must be limited. The inability to reprocess such multilayer materials indefinitely is a significant economic loss as well as an environmental burden.

[0002] Skin layers can be peeled off from multi-layer sheets manually to demonstrate the concept of mechanical separation. However, improved processes and machinery will help achieve a stable, consistent and cost-effective mechanical separation operation.

[0003] U.S. Patent No. 5,368,978 discloses a method for delaminating imaging materials, comprising providing an imaging material comprising a donor element and a receptor element, heating the imaging material, applying opposing forces to the donor element and the receptor element to separate the imaging material into a donor element and a receptor element, and accumulating the separated donor element. In a preferred method, one or both of the opposing forces is a vacuum, and accumulation is performed by winding after separation when the vacuum is released from the donor element. The apparatus for delaminating imaging materials includes means for applying heat and pressure to the imaging material, means for applying a separating force to at least one of the donor element and the receptor element forming the imaging material, and means for separating the donor element and the receptor element. In a preferred embodiment, the apparatus also includes means for winding the donor element and means for preheating the imaging material before applying the separating force.

[0004] U.S. Patent No. 5,934,577 discloses a method for separating the components of a multilayer material, the multilayer material comprising at least one layer of a base plastic (A) and a layer of plastic (B), which are separated by a layer of a bonding plastic (C), wherein: (1) the material is heated to a temperature T1 between the crystallization temperature (Tc) of plastic B and Tc-20°C, (2) then, at approximately the same temperature, the material is shredded by shearing so as to produce stratification, thereby converting the material into two types of small-sized particles, some (X) consisting essentially of the base plastic (A) and others (Y) consisting essentially of plastic B and bonding plastic (C), and (3) particles X and Y are subsequently separated by electrostatic separation.

[0005] U.S. Patent No. 10,513,102 discloses a peeling device, which includes: a conveying roller, which is configured to convey a laminate made by peelably laminating a first substrate and a second substrate having an opening; a peeling roller, which is arranged facing the conveying roller, sandwiching the laminate therebetween, and is configured to peel the second substrate from the first substrate; a winding roller, which is arranged away from the peeling roller and is configured to wind the second substrate peeled from the first substrate; and an auxiliary winding roller, which is arranged between the peeling roller and the winding roller and includes a step portion configured to maintain the width of the opening.

[0006] US2020 / 0147933 A1 discloses a method for recycling an intermediate film for laminated glass, which comprises the step of separating a layer containing layer A and a layer containing layer B of a laminated glass (1) containing at least layer A and layer B from the intermediate film.

[0007] WO2022 / 250944 discloses a method for separating a first layer from a remaining portion of a multilayer interlayer sheet, wherein the multilayer sheet is heated and then the first layer of the multilayer interlayer sheet is separated from the remaining portion by pulling the first layer and the remaining portion of the multilayer interlayer sheet in different directions and at a defined orientation.

[0008] There remains a need for methods and apparatus for separating the layers of a multi-layer interlayer, particularly a multi-layer tapered (or wedge-shaped) interlayer, to facilitate reprocessing of the material during the manufacturing process.

[0009] Conical (or wedge-shaped) interlayers are often referred to as head-up display ("HUD") interlayers or interlayers for HUD systems. These HUD interlayers are often used in laminated safety glass in vehicles equipped with HUD systems. HUD systems project an image of the instrument panel or other important information onto the windshield in a position directly visible to the vehicle operator. Such displays allow the driver to remain focused on the upcoming path of travel while visually accessing the instrument panel, navigation and / or safety information.

[0010] To reduce ghost images in a windshield, one approach is to orient the inner and outer glass panels at an angle to each other. This way, the location of the primary image reflected from the inner panel and the secondary image reflected from the outer panel are aligned to a single point, thereby producing a single image. Typically, this is accomplished by displacing the outer panel relative to the inner panel using a wedge-shaped or "tapered" interlayer that includes at least one area of ​​non-uniform thickness (i.e., a wedge shape, rather than a profile of constant or uniform thickness). With the development of tapered interlayers, a method or process is needed to facilitate the separation of the layers of the tapered interlayer for reprocessing or recycling during the manufacturing process. Summary of the invention

[0011] In one aspect, the present invention relates to a continuous method for separating a first layer of a tapered multilayer interlayer sheet having a thicker side and a thinner side from the remainder, the method comprising heating the tapered multilayer sheet to an elevated temperature; and then separating the first layer of the tapered multilayer interlayer sheet from the remainder by pulling the first layer and the remainder of the tapered multilayer interlayer sheet in different directions. According to this aspect, during the continuous method, a positioning roller (which is also a heating unit and is located before the separation point) is positioned so that it is tilted in the Z direction and / or the Y direction to prevent the thicker side of the tapered multilayer interlayer from shifting toward the middle of the roller. Between the face plates holding the rollers, the positioning rollers can be tilted in the Z direction up to about 1% of the roller length and in the Y direction up to about 0.5% of the roller length, as further described below.

[0012] In another aspect, the present invention relates to a continuous method for separating a first layer from a remaining portion of a tapered multilayer interlayer sheet, the method comprising: heating the tapered multilayer sheet to an elevated temperature; then separating the first layer from the remaining portion of the tapered multilayer interlayer sheet by pulling the first layer and the remaining portion of the tapered multilayer interlayer sheet in different directions and in a certain orientation, while during the continuous method, also tilting a positioning roller located between a separate heating unit and the separation point so that it is tilted in the Z direction and / or the Y direction to prevent the thicker side of the tapered multilayer interlayer from shifting toward the middle of the roller. Therefore, according to the present invention, the positioning roller can also be used as a heating unit, or a heating unit separate from the positioning roller can be provided. According to the present invention, the angle α is defined by the first layer and the tapered multilayer sheet at the separation point, the angle β is defined by the tapered multilayer sheet and the remaining portion of the tapered multilayer sheet at the separation point, and the angle γ is defined by the first layer and the remaining portion of the tapered multilayer sheet at the separation point, and the following formula is satisfied:

[0013] β / α≥1

[0014] 30°≤γ≤180°

[0015] α+β+γ=360°.

[0016] According to the present invention, the inclination of the positioning roller in the Z and / or Y direction and the orientation remain unchanged during the continuous method. The inclination of the positioning roller requires further clarification of the above-mentioned angles. The amount of inclination of the positioning roller can be changed according to the wedge angle of the tapered multilayer interlayer. Since the inclination of the positioning roller in the Z and / or Y direction is relatively small, the separation angles α and β only change slightly. When the positioning roller changes, the angle α at one end of the roller will be slightly different from the angle α at the other end of the roller due to the movement of the roller in the Z and / or Y direction. The same is true for angle β. Since the inclination of the positioning roller in the Z and / or Y direction is relatively small, as described below, the angle will only change slightly. Along the positioning roller, the angles α and / or β will change slightly from one end of the roller to the other end compared to when the positioning roller is not tilted (or stationary at the origin). For use in the above equations, angles α and β should be selected so that angle β is at its minimum (at the point on the registration roller where angle β is minimum and defined by the first layer and the tapered multilayer sheet at the separation point), and angle α is at its maximum level and defined by the tapered multilayer sheet and the remainder of the tapered multilayer sheet at the separation point. The above relative formulas for α, β, and γ will still be satisfied.

[0017] In one aspect, a continuous method for separating a first layer from a remainder of a tapered multi-layer interlayer sheet comprises:

[0018] a. heating the tapered multilayer interlayer sheet to a temperature of about 25 ℃ to about 70 ℃; and

[0019] b. then separating the first layer of the tapered multilayer interlayer sheet from the remaining portion by pulling the first layer and the remaining portion of the tapered multilayer interlayer sheet in different directions,

[0020] wherein during the continuous process, the angle α defined by the first layer and the tapered multilayer interlayer sheet at the separation point is less than or equal to the angle β defined by the tapered multilayer interlayer sheet and the remainder of the tapered multilayer interlayer sheet at the separation point, and

[0021] wherein the tapered multilayer interlayer sheet has a thicker side and a thinner side, and wherein during the continuous process, a positioning roller located between the heating unit and the separation point is positioned so that it is tilted in the Z direction by up to about 1% of the length of the positioning roller, or in the Y direction by up to about 0.5% of the length of the positioning roller, or in the Z direction by up to about 1% of the length of the positioning roller and in the Y direction by up to about 0.5% of the length of the positioning roller to prevent the thicker side of the tapered multilayer interlayer sheet from shifting toward the middle of the positioning roller.

[0022] In another aspect, a continuous method for separating a first layer from a remainder of a tapered poly(vinyl acetal) multilayer interlayer sheet comprises:

[0023] a. heating the tapered multilayer interlayer sheet to a temperature of about 25 ℃ to about 70 ℃; and

[0024] b. then separating the first layer of the tapered multilayer interlayer sheet from the remaining portion by pulling the first layer and the remaining portion of the tapered multilayer interlayer sheet in different directions,

[0025] wherein during the continuous process, the angle α defined by the first layer and the tapered multilayer interlayer sheet at the separation point is less than or equal to the angle β defined by the tapered multilayer interlayer sheet and the remainder of the tapered multilayer interlayer sheet at the separation point, and

[0026] wherein the tapered multilayer interlayer sheet has a thicker side and a thinner side, and wherein during the continuous process, a positioning roller located between the heating unit and the separation point is positioned so that it is tilted in the Z direction up to about 1% of the length of the positioning roller, or tilted in the Y direction up to about 0.5% of the length of the positioning roller, or tilted in the Z direction up to about 1% of the length of the positioning roller and tilted in the Y direction up to about 0.5% of the length of the positioning roller to prevent the thicker side of the tapered poly(vinyl acetal) multilayer interlayer sheet from shifting toward the middle of the positioning roller.

[0027] In another aspect, a continuous method for separating a first layer from a remainder of a tapered multi-layer interlayer sheet comprises:

[0028] a. heating the tapered multilayer interlayer sheet to a temperature of about 25 ℃ to about 70 ℃; and

[0029] b. then separating the first layer of the tapered multilayer interlayer sheet from the remaining portion by pulling the first layer and the remaining portion of the tapered multilayer interlayer sheet in different directions,

[0030] wherein during the continuous process, the angle α defined by the first layer and the tapered multilayer interlayer sheet at the separation point is less than or equal to the angle β defined by the tapered multilayer interlayer sheet and the remainder of the tapered multilayer interlayer sheet at the separation point, and

[0031] wherein the tapered multilayer interlayer sheet has a thicker side and a thinner side, and wherein during the continuous process, a heating unit also serving as a positioning roller is positioned before the separation point so that it is tilted in the Z direction by up to about 1% of the length of the positioning roller, or in the Y direction by up to about 0.5% of the length of the positioning roller, or in the Z direction by up to about 1% of the length of the positioning roller and in the Y direction by up to about 0.5% of the length of the positioning roller to prevent the thicker side of the tapered multilayer interlayer sheet from shifting toward the middle of the positioning roller.

[0032] In another aspect, a continuous method for separating a first layer from a remainder of a tapered poly(vinyl acetal) multilayer interlayer sheet comprises:

[0033] a. heating the tapered multilayer interlayer sheet to a temperature of about 25 ℃ to about 70 ℃; and

[0034] b. then separating the first layer of the tapered multilayer interlayer sheet from the remaining portion by pulling the first layer and the remaining portion of the tapered multilayer interlayer sheet in different directions,

[0035] wherein during the continuous process, the angle α defined by the first layer and the tapered multilayer interlayer sheet at the separation point is less than or equal to the angle β defined by the tapered multilayer interlayer sheet and the remainder of the tapered multilayer interlayer sheet at the separation point, and

[0036] wherein the tapered multilayer interlayer sheet has a thicker side and a thinner side, and wherein during a continuous process, a heating unit (also used as a positioning roller) positioned before the separation point is positioned so that it is tilted in the Z direction up to about 1% of the length of the positioning roller, or in the Y direction up to about 0.5% of the length of the positioning roller, or in the Z direction up to about 1% of the length of the positioning roller and in the Y direction up to about 0.5% of the length of the positioning roller to prevent the thicker side of the tapered poly(vinyl acetal) multilayer interlayer sheet from shifting toward the middle of the positioning roller.

[0037] In another aspect, the present invention relates to an interlayer comprising a first layer obtained in the process described herein. In another aspect, the present invention relates to a composition comprising a first layer obtained in the process described herein.

[0038] In another aspect, the invention relates to an apparatus for carrying out the method of the invention.

[0039] Further aspects of the invention are as disclosed and claimed herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 is a schematic diagram of a method for mechanically recycling a multilayer sandwich.

[0041] Figure 2 is a schematic diagram of an apparatus for mechanically separating a multilayer sandwich according to the present invention.

[0042] Figure 3 is a schematic diagram of the proper orientation of the membrane when being separated.

[0043] Figure 4 is a schematic diagram of the mechanical separation of a tapered multilayer sandwich, showing the tilting of the positioning rollers in the Z and / or Y direction.

[0044] 5( a ) and 5 ( b ) are diagrams showing the positions of the positioning rollers relative to the Cartesian axis.

[0045] Figure 6(a) to Figure 6(h) is a series of graphs showing the tilt of the registration rollers relative to Cartesian coordinates.

[0046] Figure 7(a) to Figure 7(d) 1 is a diagram showing an inclination angle q of the positioning roller in the Z direction when viewed from the XZ plane.

[0047] Figure 8(a) to Figure 8(d) This is a view of the positioning roller tilted at an angle -Y in the Y direction as viewed from the XY plane.

[0048] Fig. 9 is another schematic diagram of a device for mechanically separating a multilayer sandwich according to the present invention.

[0049] Fig.10 is another schematic diagram of the device for mechanically separating a multilayer sandwich according to the present invention

[0050] Fig.11 is a schematic diagram of the proper orientation of the membrane when being separated.

[0051] Fig.12 is a schematic diagram of the proper orientation of the membrane when being separated.

[0052] Fig.13 is a schematic diagram of the mechanical separation of a tapered multilayer sandwich, showing the tilting of the positioning rollers in the Z and / or Y direction. DETAILED DESCRIPTION

[0053] The following embodiments and combinations are included within the scope of the present invention: A continuous method for separating a first layer from a remainder of a tapered multilayer interlayer sheet comprises:

[0054] a. heating the tapered multilayer interlayer sheet to a temperature of about 25 ℃ to about 70 ℃; and

[0055] b. then separating the first layer of the tapered multilayer interlayer sheet from the remaining portion by pulling the first layer and the remaining portion of the tapered multilayer interlayer sheet in different directions,

[0056] wherein during the continuous process, the angle α defined by the first layer and the tapered multilayer interlayer sheet at the separation point is less than or equal to the angle β defined by the tapered multilayer interlayer sheet and the remainder of the tapered multilayer interlayer sheet at the separation point, and

[0057] wherein the tapered multilayer interlayer sheet has a thicker side and a thinner side, and wherein during the continuous process, a positioning roller located between the heating unit and the separation point is positioned such that it is tilted in the Z direction up to about 1% of the length of the positioning roller, or tilted in the Y direction up to about 0.5% of the length of the positioning roller, or tilted in the Z direction up to about 1% of the length of the positioning roller and tilted in the Y direction up to about 0.5% of the length of the positioning roller to prevent the thicker side of the tapered multilayer interlayer sheet from shifting toward the middle of the positioning roller. In some aspects, the tapered multilayer interlayer sheet is a poly(vinyl acetal) sheet.

[0058] In the method, in some aspects, the positioning roller is located between the heating unit and the separation point, and the positioning roller is positioned and tilted up to about 1% of the length of the positioning roller in the Z direction and up to about 0.5% of the length of the positioning roller in the Y direction. In other aspects, the heating unit itself can be used as the positioning roller, and a separate positioning roller is not required.

[0059] In some aspects, the first layer comprises a poly(vinyl butyral) polymer having a Tg of about 25° C. to about 40° C. In some aspects, the tapered multilayer interlayer sheet is heated to a temperature of 30° C. to 70° C. in step a). In some aspects, at least a portion of the remainder of the tapered multilayer interlayer sheet comprises a poly(vinyl butyral) polymer having a Tg at least 15° C. lower than the Tg of the first layer.

[0060] In some aspects of the method, during the separation step, the first layer is pulled by the first layer pulling roller and the remaining portion of the tapered multilayer interlayer sheet is pulled by the remaining portion pulling roller, and wherein when separation occurs, a distance between the first layer pulling roller and the remaining portion pulling roller is maintained that is less than about 50% of the width of the sheet.

[0061] In some aspects, the method further includes cooling one or more of the first layer and the remainder of the tapered multilayer interlayer sheet to a temperature below the Tg of the poly(vinyl butyral) of the first layer or the Tg of the poly(vinyl butyral) of the remainder of the tapered multilayer interlayer sheet, and in some aspects, the method further includes cooling the first layer to a temperature of about 15°C to about 30°C, or the method further includes cooling the remainder of the tapered multilayer interlayer sheet to a temperature of about -15°C to about 0°C.

[0062] In some aspects, the distance between the first layer of pulling rollers and the remaining portion of pulling rollers when separation occurs is less than about 15% of the width of the sheet, or the distance between the first layer of pulling rollers and the remaining portion of pulling rollers when separation occurs is less than about 5% of the width of the sheet.

[0063] In some aspects, the tapered multilayer sandwich sheet includes a core layer with skin layers on each side. In some aspects, the first layer includes a first skin layer, and wherein the first skin layer is thicker than another skin layer. In addition, in some aspects, the first layer includes a first skin layer, and wherein the first skin layer is thinner than another skin layer.

[0064] In some aspects, the tilt is at least 0.001 mrad. In some aspects, the wedge angle of the interlayer to be separated varies by about ±0.15 mrad.

[0065] In another aspect, a continuous method for separating a first layer from a remainder of a tapered multi-layer interlayer sheet comprises:

[0066] a. heating the tapered multilayer interlayer sheet to a temperature of about 25 ℃ to about 70 ℃; and

[0067] b. then separating the first layer of the tapered multilayer interlayer sheet from the remaining portion by pulling the first layer and the remaining portion of the tapered multilayer interlayer sheet in different directions,

[0068] wherein during the continuous process, the angle α defined by the first layer and the tapered multilayer interlayer sheet at the separation point is less than or equal to the angle β defined by the tapered multilayer interlayer sheet and the remainder of the tapered multilayer interlayer sheet at the separation point, and

[0069] wherein during the continuous process, the tapered multilayer interlayer sheet has a thicker side and a thinner side, and wherein a heating unit (also serving as a positioning roller) positioned before the separation point is positioned so that it is tilted in the Z direction by up to about 1% of the length of the positioning roller, or in the Y direction by up to about 0.5% of the length of the positioning roller, or in the Z direction by up to about 1% of the length of the positioning roller and in the Y direction by up to about 0.5% of the length of the positioning roller to prevent the thicker side of the tapered multilayer interlayer sheet from shifting toward the middle of the positioning roller.

[0070] In another aspect, a continuous method for separating a first layer from a remainder of a tapered poly(vinyl acetal) multilayer interlayer sheet comprises:

[0071] a. heating the tapered multilayer interlayer sheet to a temperature of about 25 ℃ to about 70 ℃; and

[0072] b. then separating the first layer of the tapered multilayer interlayer sheet from the remaining portion by pulling the first layer and the remaining portion of the tapered multilayer interlayer sheet in different directions,

[0073] wherein during the continuous process, the angle α defined by the first layer and the tapered multilayer interlayer sheet at the separation point is less than or equal to the angle β defined by the tapered multilayer interlayer sheet and the remainder of the tapered multilayer interlayer sheet at the separation point, and

[0074] wherein the tapered multilayer interlayer sheet has a thicker side and a thinner side, and wherein during a continuous process, a heating unit positioned before the separation point is positioned such that it is tilted in the Z direction up to about 1% of the length of the positioning roller, or in the Y direction up to about 0.5% of the length of the positioning roller, or in the Z direction up to about 1% of the length of the positioning roller and in the Y direction up to about 0.5% of the length of the positioning roller to prevent the thicker side of the tapered poly(vinyl acetal) multilayer interlayer sheet from shifting toward the middle of the positioning roller.

[0075] The method according to the present invention is described herein as a continuous method, but the word "continuous" is not intended to be particularly limited. It will be understood by those skilled in the art of industrial methods that continuous methods can be distinguished from batch methods, and the longer the method can be maintained continuously, the greater the advantage in terms of production volume. Therefore, the advantage of the method of the present invention is that, in a steady state, a multilayer sheet roll can be continuously separated for a considerable period of time, and according to the present disclosure, those skilled in the art can adjust the method to maintain the desired continuity when implementing them. Therefore, the present invention and claims are intended to cover any method that may be artificially interrupted or interfered with in an attempt to avoid the method from being carried out continuously. Other aspects are as disclosed and claimed herein.

[0076] Thus, in one aspect, the present invention relates to a method and apparatus for separating two layers of a tapered multilayer interlayer by: (i) unrolling the tapered interlayer from a roll; (ii) heating the tapered interlayer with one or more heated rolls and / or a separate IR heater; (iii) peeling off the first layer or skin layer under a separating force; and (iv) collecting the separated skin layer and the remainder of the tapered multilayer sheet for subsequent reuse as an interlayer assembly. In this regard, during the continuous process, a positioning roll located between the heating unit and the separation point or also serving as a heating unit is positioned so that it is tilted in the Z direction and / or the Y direction to prevent the thicker side of the tapered multilayer interlayer from shifting toward the middle of the roll. The positioning roller may be tilted in the Z direction by up to about 1% of the roller length, or up to about 0.9%, 0.8%, 0.7%, 0.6%, 0.5%, 0.4%, 0.3%, 0.2%, 0.1% or less, and in the Y direction between the panels that retain the roller, by up to about 0.5% of the roller length, or up to about 0.4%, 0.3%, 0.2%, 0.1% or less, as further described below.

[0077] In some aspects, the heating unit and / or positioning rollers are tilted in the Z direction by at least 0.01 millirads and less than 0.05 millirads.

[0078] In another aspect, the invention relates to a method and apparatus design in which the core and skin material of a conical acoustic multilayer sandwich reprocess material (sometimes referred to as a wedge or head-up display ("HUD") sandwich or sheet), e.g., roll widths up to about 1.4 m and roll weights of 500 kg (although longer and heavier rolls may be used), are separated by mechanically peeling off one skin layer of the conical multilayer sandwich sheet at a rate of 2 m / min to 20 m / min, e.g., which allows unrestricted use of recycled skin layers in extrusion. A general overview of the method is provided in Figure 1 As used herein, a tapered multilayer interlayer describes a tapered or wedge-shaped interlayer having a core layer and two skin layers (ie, a three-layer interlayer), but tapered multilayer interlayers having more layers may also be used with appropriate modifications.

[0079] Thus, the present invention relates to a method of combining a first layer or skin layer with a tapered (or wedge-shaped) multilayer interlayer sheet (e.g., Eastman's Saflex TM Method and apparatus for mechanical separation of acoustic HUD PVB sandwich). Thus, in this regard, the goal is to mechanically separate a skin layer from a core-skin bilayer of a tapered acoustic (wedge-shaped) three-layer sandwich, but the range of processable materials for the device disclosed in the present invention is not limited to three layers, but includes tapered multi-layer sandwiches, where the number of layers is greater than 2, or greater than 3, or greater than 5, or 5 or more, partially or entirely in the transverse direction of the sheet, and the sandwich is tapered or wedge-shaped. The separation typically occurs between the skin layer adjacent to the acoustic core layer and the rest of the sheet including the core layer itself.

[0080] like Figure 2 As shown, in one embodiment, the mechanical separation device for unfolding the tapered multilayer interlayer may include (1) an unfolding unit, (2) an optional edge trimming unit, (3) one or more tension rollers, (4) pre-positioning rollers, which have optional cooling, (5) a heating or annealing unit, (6) an additional or second positioning roller, which has optional cooling, (7) a first layer pulling roller for the first layer or skin layer, (8) a remaining portion pulling roller for the remaining portion of the sheet, which is typically a core-skin bilayer, (9) one or more tension rollers for the first layer or skin layer, (10) one or more tension rollers for the remaining portion of the sheet, which is typically a core-skin bilayer, (11) a skin layer collection unit, which can be a winder, a container with or without a roller gap system, or a granulator (or other collection device), and (12) a core-skin bilayer collection unit, which can be a winder, a container with or without a clamping system, or a granulator (or other collection device).

[0081] In order to unwind the tapered sandwich, there is a pre-positioning roller (4) for guiding or positioning the tapered sandwich when it is unwound from the unwinding unit (1). Figure 4 As shown, the second positioning roller (in Figure 2 The roller (6) indicated in the figure is located between the heating unit and the separation point, and the positioning roller can be precisely tilted in the Z direction, in the Y direction, or in both the Z direction and the Y direction to prevent the thicker side of the tapered multilayer interlayer from moving toward the middle of the roller or shifting its position and causing wrinkling of the thinner side of the sheet, which will eventually lead to process stoppage and / or sheet tearing.

[0082] like Fig. 9As shown, in one embodiment, the mechanical separation device for unrolling the tapered multilayer sandwich may include (1) an unrolling unit, (2) an optional edge trimming unit, (3) one or more tension rollers, (4) an optional pre-positioning roller, which has an optional cooling, (5) a heating or annealing unit, (6) a positioning roller, (7) a first layer pulling roller for the first layer or skin layer, (8) a remaining part pulling roller for the remaining part of the sheet, which is typically a core-skin bilayer, (9) one or more tension rollers for the first layer or skin layer, (10) one or more tension rollers for the remaining part of the sheet, which is typically a core-skin bilayer, (11) a skin layer collection unit, which may be a winder, a container with or without a clamping system, or a granulator (or other collection device), and (12) a core-skin bilayer collection unit, which may be a winder, a container with or without a clamping system, or a granulator (or other collection device). As already described herein, the positioning roller (6) is positioned by tilting to prevent creep.

[0083] like Fig.10 As shown, in one embodiment, the mechanical separation device for unfolding the tapered multilayer interlayer may include (1) an unfolding unit, (2) an optional edge trimming unit, (3) one or more tension rollers, (4) optional pre-positioning rollers, which have optional cooling, (5) a heating or annealing unit, which also serves as a positioning roller, (7) a first layer pulling roller for the first layer or skin layer, (8) a remaining portion pulling roller for the remaining portion of the sheet, which is typically a core-skin double layer, (9) one or more tension rollers for the first layer or skin layer, (10) one or more tension rollers for the remaining portion of the sheet, which is typically a core-skin double layer, (11) a skin layer collection unit, which can be a winder, a container with or without a clamping system, or a granulator (or other collection device), and (12) a core-skin double layer collection unit, which can be a winder, a container with or without a clamping system, or a granulator (or other collection device). As shown Fig.10 As shown, there is no optional second registration roll, and instead the sheet is sent directly from the heating or annealing unit (5) to a separation point where the sheet is divided and sent to a first layer pull roll (7) for the first layer or skin layer and a remainder pull roll (8) for the remainder of the sheet. The heating unit (also the registration roll) is tilted as described herein to prevent the sheet from creeping, i.e., from shifting or shifting its position toward the middle of the roll and causing wrinkling of the thinner side of the sheet.

[0084] For unwinding the tapered sandwich, in another embodiment, there is an optional pre-positioning roller (4) for guiding or positioning the tapered sandwich when it is unwound from the unwinding unit (1). Fig.11 As shown, the positioning roller (in Figure 2 and Fig. 9The roller (6) is located between the heating unit (5) and the separation point, and the positioning roller can be precisely tilted in the Z direction, in the Y direction, or in both the Z and Y directions to prevent the thicker side of the tapered multilayer interlayer from moving toward the middle of the roller or shifting its position and causing wrinkling of the thinner side of the sheet, which will eventually lead to process stoppage and / or sheet tearing. Fig.12 As shown, there is no optional second positioning roller (6). Instead, the heating unit (5) also acts as a positioning roller and can therefore be precisely tilted in the Z direction, in the Y direction, or in both the Z and Y directions to prevent the thicker side of the tapered multilayer interlayer from moving or shifting its position towards the middle of the roller and causing the thinner side of the sheet to wrinkle or bunch, which would eventually lead to process stoppage and / or sheet tearing.

[0085] When the positioning roller or heating unit (or rollers) are tilted, the position of the roller end corresponding to the thinner side of the sheet must be at least slightly higher in the Z direction of the Cartesian coordinates than the position of the positioning roller end corresponding to the thicker side of the sheet, as shown in Figure 5. In addition, in the Y direction, the position of the positioning roller or heating unit end corresponding to the thinner side of the sheet should be equal to or lower than the position of the roller end corresponding to the thicker side of the sheet. One or both ends of the positioning roller or heating unit can be tilted (in the Z and / or Y direction) to achieve changes and prevent the sheet from wrinkling when it is unfolded, as shown in Figure 5 and explained further below.

[0086] Figures 5(a) and 5(b) are diagrams showing the positions of the positioning rollers tilted relative to the Cartesian axis. In Figure 5(a), the roller end corresponding to the thicker side of the sheet is located at the origin, while in Figure 5(b), the midpoint of the roller width is located at the origin. The rectangle shown with dashed lines inside the roller represents the positioning roller or heating unit, where the rectangle is drawn slightly outside the roller to clearly show the dashed lines.

[0087] There may be one or more additional positioning rollers or tension rods (or similar devices known in the art) placed between the positioning rollers (described below) and the separation point. In this case, when defining the present invention and the amount of tilt, the positioning rollers or tension rods (or other devices used to help position the sheet and provide the required tension) will be referred to as "positioning rollers", and when the heating unit is also used as a positioning roller, the positioning roller described may be referred to as a heating unit when determining the amount of tilt required in the Z and / or Y direction to facilitate the unfolding of the tapered interlayer. As described above, and as shown in the figures, in some embodiments, there may also be fewer positioning rollers. In addition, as needed, there may be additional rollers, tension rods, etc. (not shown).

[0088] Figure 6(a) to Figure 6(h) is a series of graphs showing the inclination of the positioning rollers relative to Cartesian coordinates. Figure 6(a) to Figure 6(d) , the roller end corresponding to the thicker side of the sheet is at the origin, while for Figure 6(e) to Figure 6(h), the midpoint of the roller width is at the origin. In Figures 6(a) and 6(e), the coordinates X, Y, Z and the axes ab, cd and ef are fixed to the roller. In Figures 6(b) and 6(f), the roller is tilted by an angle φ around the axis ab, which has no effect on preventing wrinkles. In Figures 6(c) and 6(g), the roller is tilted by an angle θ around the axis cd. In Figures 6(d) and 6(h), the roller is tilted by an angle -ψ around the axis ef.

[0089] Figure 7(a) to Figure 7(d) 7(a) and 7(c) are diagrams showing the inclination angle θ of the positioning roller toward the Z direction when viewed from the XZ plane, wherein FIG. 7(a) and FIG. 7(c) are before the roller is inclined, and FIG. 7(b) and FIG. 7(d) are after the roller is inclined. For FIG. 7(a) and FIG. 7(b), the roller end corresponding to the thicker side of the sheet is located at the origin, while for FIG. 7(c) and FIG. 7(d), the midpoint of the roller width is located at the origin.

[0090] Figure 8(a) to Figure 8(d) is a view of the positioning roller tilted toward the Y direction at an angle -ψ from the XY plane, where Figure 8(a) and 8(c) 8(a) and 8(b) are before tilting, and FIG8(b) and FIG8(d) are after tilting. For FIG8(a) and FIG8(b), the roller end corresponding to the thicker side of the sheet is located at the origin, while for FIG8(c) and FIG8(d), the midpoint of the roller width is located at the origin.

[0091] The unwinding unit (1) may be motorised or non-motorised and is ideally capable of handling roll widths of, for example, up to 1.4m and roll weights of 500kg (or more), although other lengths and weights may be used.

[0092] If desired, an optional edge trimming unit (2) can trim either side of the sheet or both sides of the sheet along the longitudinal direction of the sheet before the sheet is transferred to the heating unit (5). For example, trimming can be performed to keep the sheet width consistent, to separate and collect only the desired sheet portions, and / or to prevent tearing from the edges. Such situations would include, but are not limited to, trimming the inclined portion of the sheet, or trimming the edge of a sheet without a core layer. Generally speaking, trimming at least about 25 mm from each edge with a fixed blade may help. This can be done before the roll is placed on the unwinding unit (1), or at any point between the unwinding unit (1) and the heating unit (5).

[0093] One or more tension rollers (3) are usually motorized and allow the sheet to be pulled from the unwinding unit (1) and fed to the heating or annealing unit (5). Unless the tension is set appropriately so that the sheet flattens as it passes through the tension rollers, the sheet may wrinkle in the cross-machine direction, causing uneven heating and thus processing problems.

[0094] For example, reference Figure 2A first positioning roller (4) with optional cooling follows the tensioning roller (3) and is preferably located near the main heat energy source of the heating unit (5) or annealing unit (5) in order to establish a sufficient level of sheet tension by positioning the sheet on the correct path before the sheet reaches the heating unit (5). This roller has optional cooling capabilities in order to fine-tune the sheet temperature. This roller is usually not motorized, but it can be motorized if necessary.

[0095] The heating unit (5) is in contact with either or both of the skin layers so that the interfacial bonding energy between at least one of the skin layers and the core layer becomes sufficiently low. This enables one of the skin layers to be mechanically separated from the rest of the sheet when a tensile force is applied. The heat source can be a single or multiple heated rollers, or an infrared heater, or any combination of the two (or other heat sources known in the art), which can be placed on one or both sides of the sheet. For commercial operation, it is important that the interface or orientation angle (e.g., Figure 3 The first layer is the layer removed from the rest of the sheet during the entire operation. If not, the layer recovered at the first layer collection unit may also contain part of the rest of the sheet, such as the core layer. Therefore, it is preferred that thermal energy is provided to the sheet mainly by conduction through the heated roller.

[0096] The temperature of the sheet surface (typically the first or skin layer) closest to the source of thermal energy achieved by the annealing unit may range from about ambient or room temperature to about 70°C, or from about 25°C to about 70°C, or from 30°C to 65°C, or from 35°C to 60°C, or at least about 25°C, at least about 30°C, at least about 35°C or more, or below about 70°C, below about 65°C, or below 60°C, or as described elsewhere herein. This can be measured with an IR thermometer at the outlet of the heating unit. If the temperature of the sheet surface is too low, mechanical separation of the sheet may not occur, and the sheet may therefore tear. If the temperature of the sheet surface is too high, the mechanical integrity of the sheet may be reduced, making it difficult to handle or process, and stable operation of the mechanical separation process may be difficult. The annealing or heating unit (3) is preferably a motorized roller.

[0097] In other aspects, the temperature of the sheet surface closest to the heat energy source (typically the first or skin layer) achieved by the annealing unit is at least about 25°C, or at least about 26°C, or at least 27°C, or at least 28°C, or at least 30°C, or at least 32°C, or at least 35°C, and at most about 70°C, or at most about 65°C, or at most about 60°C, or at most about 55°C, or at most about 50°C.

[0098] An inclined positioning roller (6) with optional cooling (when present) is located on the other side of the main heat energy source of the heating unit (5) or annealing unit in order to establish a sufficient level of sheet tension by positioning the sheet on the correct path before the sheet reaches the separation point. This roller may have optional cooling capabilities in order to fine-tune the sheet temperature. The positioning roller (6) with optional cooling may be a spreader roller designed to eliminate wrinkles in the sheet by surface action in the transverse direction so that the sheet becomes wrinkle-free and ready to be cleanly separated when the sheet reaches the separation point. This roller is usually not motorized.

[0099] Tapered multilayer interlayers present greater challenges when unrolling and separating the first or skin layer from the core-skin bilayer. The pulling force during the mechanical separation process is consumed not only when separating the interface, but also when stretching the skin layer and the bilayer. Because the sheet is tapered, there is an imbalance (or difference) in the thickness of the sheet in the cross-direction. When being separated, the thicker side of the sheet inevitably requires more force than the thinner side. As the sheet is unrolled and pulled, the thicker side of the sheet gradually travels toward the middle of the second positioning roller, causing wrinkling on the thinner side, which can cause process interruptions. Over time, the separation line or process changes from linear to a higher-order curve (because the separation point does not remain linear, but has a curve, such as a parabola, or a smile or frown shape), and eventually, it becomes impossible to continue unrolling and separating the layers without tearing the sheet.

[0100] To overcome this problem and prevent the tapered multilayer interlayer from shifting and wrinkling, the inventors have discovered that by precisely tilting one of the rollers, such as the positioning roller (i.e., positioning roller (6)) or the heating unit (5) located between the heating unit and the separation point in the Z direction, in the Y direction, or in both the Z and Y directions, the thicker side of the tapered multilayer interlayer can be prevented from shifting its position toward the middle of the second positioning roller (6) and causing wrinkling of the thinner side of the sheet. The tilted roller should be the roller closest to the separation point (or just before the separation point), depending on the configuration. When the positioning roller (6) or the heating unit (5) is tilted, it is critical that the position of the roller end corresponding to the thinner side of the sheet is higher than the position of the roller end corresponding to the thicker side of the sheet in the Z direction of the Cartesian coordinates defined in Figure 5. In addition, in the Y direction, the position of the roller end corresponding to the thinner side of the sheet should be equal to or lower than the position of the roller end corresponding to the thicker side of the sheet. As shown in Figure 5, one or both ends of the positioning roller (6) or the heating unit (5) can be tilted to achieve the change.

[0101] As shown in Figure 5(a), the effect of the tilting of the precision positioning roller (6) may be sufficient to tilt one end of the roller. However, if the machine is modified so that both ends of the positioning roller (6) can be tilted (as shown in Figure 5(b)), even finer adjustments can be made on the equipment and in the process to control the separation of the sheets and prevent wrinkling.

[0102] The tilt of the positioning roller or heating unit (or other roller) relative to the Cartesian coordinates is determined by Figure 6(a) to Figure 6(h) Further explanation. Figure 6(a) to Figure 6(d) , the roller end corresponding to the thicker side of the sheet is at the origin, while for Figure 6(e) to Figure 6(h) , the midpoint of the roller width is at the origin. In Figures 6(a) and 6(e), the coordinates XYZ and the axes ab-cd-ef are fixed to the roller. As shown in Figures 6(b) and 6(f), when the roller is tilted by an angle φ about the axis ab, there is no effect and the roller simply rotates in its original position. In Figures 6(c) and 6(g), the roller is tilted by an angle θ about the axis cd. In Figure 6(c), the roller end corresponding to the thinner side of the sheet is tilted toward the Z direction, while in Figure 6(g), the roller end corresponding to the thinner side of the sheet is tilted toward the Z direction, and the roller end corresponding to the thicker side of the sheet is tilted toward the -Z direction. Due to such tilting in Figures 6(c) and 6(g), the difference or difference in the Z-direction position between the two roller ends is the same. In Figures 6(d) and 6(h), the roller is tilted by an angle -ψ about the axis ef. In Fig. 6(d), the roller end corresponding to the thinner side of the sheet is inclined toward the -Y direction, while in Fig. 6(h), the roller end corresponding to the thinner side of the sheet is inclined toward the -Y direction, and the roller end corresponding to the thicker side of the sheet is inclined toward the Y direction. As a result of such inclination in Fig. 6(d) and Fig. 6(h), the difference in the Y-direction position between the two roller ends is the same.

[0103] Figures 7 and 8 provide views of the Z direction tilted from the XZ plane, and views of the Y direction tilted from the XY plane, respectively. As shown in Figure 7, because the sheet is under tension when it passes through the positioning roller (6), tilting the roller toward the Z direction will cause the thicker side of the sheet to move on the Z axis, making it difficult for the sheet to shift its position toward the middle of the roller (or, in other words, keep the sheet in place so that it does not wrinkle). In Figure 8, tilting the positioning roller (6) or the heating unit (5) toward the Y direction (especially the -Y direction) will fix the thicker side of the sheet on the Y axis under pulling tension, making it difficult for the sheet to shift its position toward the middle of the roller.

[0104] The positioning roller (6) may be motorized or non-motorized. It may have a completely cylindrical shape in the width direction of the roller, or it may have a journal portion at one or both ends of the roller. In either case, the surface of the positioning roller facing or contacting the sheet may be smooth, or it may have some surface roughness and / or pattern, and it may be a material such as stainless steel, carbon steel, Teflon, natural or synthetic rubber. In addition, the positioning roller (6) may be flat or slightly tapered to spread the sheet as it leaves the roller. Optionally, it may be heated or cooled.

[0105] In order to allow the positioning roller to tilt, the position of the positioning roller end can be made adjustable. For example, cutting the movable range of all bolts on the panel holding the bearing portion of the roller will allow the position of the roller to be adjusted. For example, the metal plates on both sides of the panel can hold the bolts, and the entire component including the metal plate and the bolts holding the roller can be tilted as needed within the cutting range. The maximum tilt of the positioning roller in the Z direction is about 1% of the roller length between the two panels (or sides) that hold the roller in place. The tilt of about 1% of the roller length corresponds to 10 milliradians of angle θ. For some rollers or methods, the desired tilt in the Z direction is 0.8% or less (angle θ is 8 milliradians or less). In some aspects, the positioning roller can be tilted by 0.9%, 0.8%, 0.7%, 0.6%, 0.5%, 0.4%, 0.3%, 0.2%, 0.1% or less. The maximum tilt of the positioning roller in the Y direction is 0.5% of the roller length between the two panels holding the roller, which corresponds to 5 milliradians of angle -Y. For some rollers, the desired tilt in the Y direction is 0.4%, 0.3%, 0.2%, 0.1% or less (angle -Y is 4 milliradians or less). In some aspects, the positioning roller can be tilted 0.3%, 0.2%, 0.1% or less. These lengths or angles include the displacement or angle from both ends of the positioning roller (6).

[0106] In order to allow the heating unit or roller to tilt (for example, when there is no positioning roller or other roller before the separation point), the position of the end of the heating unit can be made adjustable. For example, cutting the movable range of all bolts on the panel holding the bearing portion of the roller will allow the position of the roller to be adjusted. For example, the metal plates on both sides of the panel can hold the bolts, and the entire component including the metal plates and the bolts holding the rollers can be tilted as needed within the cutting range. The maximum tilt of the heating unit in the Z direction is about 1% of the roller length between the two panels (or both sides) that hold the roller in place. The tilt of about 1% of the roller length corresponds to 10 milliradians of angle θ. For some rollers or methods, the desired tilt in the Z direction is 0.8% or less (angle θ is 8 milliradians or less). In some aspects, the heating unit can be tilted by 0.9%, 0.8%, 0.7%, 0.6%, 0.5%, 0.4%, 0.3%, 0.2%, 0.1% or less. The maximum tilt of the heating unit in the Y direction is 0.5% of the roller length between the two panels of the holding roller, which corresponds to 5 milliradians of angle-Y. For some rollers, the desired tilt in the Y direction is 0.4%, 0.3%, 0.2%, 0.1% or less (angle-Y is 4 milliradians or less). In some aspects, the heating unit can be tilted 0.3%, 0.2%, 0.1% or less. These lengths or angles include displacements or angles from both ends of the heating unit.

[0107] The required tilt can be very slight, such as at least 0.01 mrad or more, depending on various factors, such as the wedge angle of the sheet, the roll width, the number of positioning rolls (if any). In an embodiment, the tilt of a roll (such as a positioning roll or a heating unit) can be very slight and only about 0.01 mrad or more.

[0108] As the tapered multilayer sheet moves through the process, the tapered multilayer sheet is then mechanically separated between a first layer pulling roller for the first layer or skin layer (7) and a remaining portion pulling roller for the remaining portion or core-skin bilayer (8). The first layer pulling roller (7) for the skin layer is located downstream of the positioning roller (6) for separation, and it captures the skin layer that is mechanically separated from the rest of the sheet. The remaining portion pulling roller (8) for the core-skin bilayer is also downstream of the positioning roller (6) for separation and the heating or annealing unit (5), and it captures the remaining portion or core-skin bilayer. When there is no second positioning roller (6), or alternatively, when there are no additional rollers after the second positioning roller (6), the remaining portion pulling roller for the core-skin bilayer (8) is downstream of the heating or annealing unit (5) and / or any additional rollers (not shown), and it captures the remaining portion or core-skin bilayer.

[0109] For commercial operation, it is important that the mechanically separated sheet interfaces or orientation angles (e.g. Figure 3 The first layer is the layer removed from the rest of the sheet during the entire continuous operation. If not, the layer recovered at the first layer collection unit may also contain part of the rest of the sheet, such as the core layer.

[0110] like Figure 3 , Fig.11 and Fig.12 As shown, according to the present invention, angle α is the angle defined by the first layer and the tapered multilayer sheet at the separation point after the sheet leaves the second positioning roller. Angle β is the angle defined by the tapered multilayer sheet and the remaining portion of the multilayer sheet at the separation point after the sheet leaves the second positioning roller. Figure 3 , Fig.11 and Fig.12 , the angle γ defined by the first layer and the remaining portion of the tapered multilayer sheet after the separation point is shown. As shown, the sum of the three angles α+β+γ is 360°.

[0111] According to the invention, it is important that the angle α is equal to or less than the angle β, in particular the latter, and that such a state is maintained throughout the duration of the continuous sheet separation operation. Typically, the separation machine is designed so that the angle γ is equal to or less than 180° and equal to or greater than 30° throughout the duration of the continuous sheet separation operation.

[0112] Therefore, according to the present invention, angle α can be, for example, from about 30 to about 150°, or from about 35 to about 160°, or from about 40° to about 165°. In addition, angle β can be, for example, from about 90° to about 180°, or from about 95° to about 150°, or from 100° to 120°. Similarly, angle γ can be from about 30° to about 180°, or from 45° to 150°, or from 50° to 120°.

[0113] In other aspects, the angle according to the present invention may be as follows, where Δ is the difference β minus α:

[0114] Y=180°; α=60°; β=120° Δ60°

[0115] Y=150°; a=90°; β=120° Δ30°

[0116] Y=120°; α=90°; β=150° Δ60°

[0117] Y=100°; α=80°; β=180° △100°.

[0118] In one aspect, in order to minimize wrinkling of the sheet after mechanical separation, the distance between the first pulling roller (7) for the skin layer and the remaining pulling roller (8) for the core-skin bilayer (defined as the distance between the centers of the two rollers (7) and (8)) can be, for example, less than 50% of the width of the sheet being processed. We define this number as ψ. It may be more desirable if ψ is less than 30%, or less than 20%, or less than 15% of the width of the sheet being processed.

[0119] Furthermore, the first pulling roll (7) and the remaining pulling rolls (8) for the surface layer can be spreader rolls to prevent wrinkles from forming on the mechanically separated layers. As used herein, the term "spreader roll" refers to a roll designed to eliminate wrinkles by surface action in the transverse direction.

[0120] The tension roller (9) for the surface layer is preferably motorized synchronously with the first pulling roller (7) for the surface layer, just as the tension roller (10) for the core-surface double layer is preferably motorized synchronously with the remaining pulling roller (8) for the core-surface double layer, so as to help drive the entire mechanical separation process and stably transfer the separated first layer or surface layer and the remaining part or core-surface double layer to the surface layer collection unit (11) and the core-surface double layer collection unit (12), respectively.

[0121] The skin collection unit (11) can be a motorized winder, or a granulator, or a container, or any other collection device. Here, the recovered skin is collected for reuse, such as in an extrusion process. Alternatively, only the skin can be collected in a container or the like for further processing, with or without a gripping system to stably feed the sheet into the container.

[0122] The core-skin bilayer collection unit (12) can also be a motorized winder, or a granulator, or a container, or any other collection device. The collected core-skin bilayer can be reused for extrusion, or further mechanical processing or transferred for chemical recycling. Similarly, the core-skin bilayer can be collected only in a container or the like for further processing, with or without a clamping system that stably feeds the sheet into the container.

[0123] The total sheet thickness processable on the apparatus disclosed in the present invention typically ranges from about 0.254 mm to about 5.080 mm, or 0.508 mm to 2.540 mm, or 0.762 mm to 1.270 mm, although other sheet thicknesses are possible.

[0124] Based on the sheet unwinding speed, the operating speed at which such mechanical separation occurs on the device disclosed in the present invention can be, for example, about 2 m / min to about 20 m / min, or 5 m / min to 10 m / min. The operating speed of both pulling rollers is 1.1 to 2.5 times the unwinding speed. In other words, the operating speed at the separation point is 2.2 m / min to 50 m / min, or 5.5 m / min to 25 m / min.

[0125] The start-up of the mechanical separation device can be carried out as follows: [a] starting from the center of the top of the three-layer sandwich sheet, cut the sheet diagonally in two directions, one at a time, so that the top of the sheet is in the shape of an arrow, [b] at the top of the arrow shape, peel off a surface layer from the three-layer sandwich sheet by hand, and then continue to separate the sheet for about 25 cm, [c] manually press the separated first surface layer and core-surface double layer firmly on the pulling roller (7) for the surface layer and the pulling roller (8) for the core-surface double layer, respectively, and start the thread by pushing the machine very slowly (for example, less than 1.0 m / min), [d] pass the surface layer through the pulling roller (7) for the surface layer and reach the tension roller (9) for the surface layer, [e] pass the core-surface double layer through the pulling roller (8) for the core-surface double layer and reach the tension roller (10) for the core-surface double layer, [f] gently push all motorized rollers to ensure that a stable process is established, and [g] increase the speed to the target value and reach a stable state.

[0126] It should be understood that once in a stable state, the tapered multilayer sandwich sheet travels through the device as follows. The sheet is unwound from the unwinding unit (1) and the optional edge trimming unit (2), then passes through the tension roller (3) at ambient temperature, and then reaches the first positioning roller (4). The (optional) first positioning roller (4) with optional cooling can be cooled to, for example, approximately ambient temperature, or the temperature from the tap, or about 10°C to about 30°C, or 15°C to 30°C, or 20°C to 25°C, so that the temperature of the surface of the sheet reaches, for example, about 15°C to about 30°C, or 20°C to 25°C.

[0127] The sheet is then contacted with a heating unit (5), preferably a heated roller, which heats the surface of the sheet closest to the heat energy source to a temperature of about 35°C to about 80°C, or 43°C to 75°C, or 45°C to 65°C, or as described elsewhere herein.

[0128] In an embodiment, after the sheet is heated by the heating unit (5), the sheet is then conveyed to a second positioning roller (6) with optional cooling, which is located on the other side of the heating unit (5) or the main heat energy source of the heating unit (5), opposite to the first positioning roller. The second positioning roller (6) can be cooled to a temperature, for example as described above, so that the surface of the sheet has a temperature of about 5°C to about 40°C, or 10°C to 30°C, or 12°C to 35°C. Alternatively, the surface of the sheet in contact with the second positioning roller (6) can be cooled to a temperature of at least 5°C, or at least 10°C, or at least 12°C, or at least 15°C, at most about 40°C, or at most 35°C, or at most 30°C. In other embodiments, there is no optional second positioning roller (6), and the sheet is conveyed directly from the heating unit (5) to the separation point. In this case, the heating unit also serves as a positioning roller and is tilted accordingly.

[0129] After the sheet passes through the second positioning roller (6) or the heating unit (5) (if there is no second positioning roller (6)), the tapered multilayer sheet is mechanically separated, the first layer being pulled by the first pulling roller (7) for the skin layer and the remainder of the sheet being pulled by the remaining pulling roller (8), oriented as previously described. As described above, this mechanical separation is initiated during start-up, after which the method and apparatus of the present invention ensures continued clean separation of the two layers during continuous operation.

[0130] As described above, in order to minimize wrinkling of the sheet after mechanical separation, in one aspect, the distance between the first layer of pulling rollers (7) for the skin layer and the remaining portion of pulling rollers (8) for the core-skin bilayer (defined as the distance between the centers of the two rollers (7) and (8)) is less than about 30% of the width of the sheet being processed. It may be more desirable if the distance between the centers of the two rollers (7) and (8) is less than 25%, or less than 20%, or less than 15%.

[0131] As described above, in one important aspect, the tapered multilayer interlayer sheet comprises a tapered multilayer PVB interlayer, such as a tapered or wedge-shaped trilayer having a skin / core / skin cross section. Although a particular PVB interlayer has been described, a variety of interlayer materials may be used.

[0132] When the interlayer comprises polyvinyl butyral (PVB), the PVB resin can be prepared by reacting polyvinyl alcohol ("PVOH") with butyraldehyde in the presence of an acid catalyst, isolating, stabilizing and drying the resin using a known acetalization process. Such acetalization processes are disclosed in, for example, U.S. Pat. Nos. 2,282,057 and 2,282,026 and Wade, B. 2016, Vinyl Acetal Polymers, Encyclopedia of Polymer Science and Technology. 1–22 (online, Copyright 2016 John Wiley & Sons, Inc.), the entire disclosure of which is incorporated herein by reference. The resin is commercially available in a variety of forms, such as Solutia Inc., a wholly owned subsidiary of Eastman Chemical Company. Resin.

[0133] As used herein, the residual hydroxyl content in PVB (calculated as % vinyl alcohol or % PVOH by weight) refers to the amount of hydroxyl groups remaining on the polymer chain after processing is completed. For example, PVB can be made by hydrolyzing poly(vinyl acetate) into poly(vinyl alcohol) (PVOH), and then reacting PVOH with butyraldehyde. In the process of hydrolyzing polyvinyl acetate, generally not all acetate side groups are converted into hydroxyl groups. Further, the reaction with butyraldehyde generally does not cause all hydroxyl groups to be converted into acetal groups. Therefore, in any finished PVB resin, there will generally be residual acetate groups (as vinyl acetate groups) and residual hydroxyl groups (as vinyl hydroxyl groups) as side groups on the polymer chain. As used herein, residual hydroxyl content and residual acetate content are measured based on weight percentage (wt%) according to ASTM D1396.

[0134] The PVB resins of the present disclosure typically have a molecular weight of greater than 50,000 Daltons, or less than 500,000 Daltons, or about 50,000 to about 500,000 Daltons, or about 70,000 to about 500,000 Daltons, or about 100,000 to about 425,000 Daltons, as measured by size exclusion chromatography using low angle laser light scattering. As used herein, the term "molecular weight" means weight average molecular weight.

[0135] Various adhesion control agents ("ACAs") may be used in the interlayers of the present disclosure to control the adhesion of the interlayer sheets to the glass. In various embodiments of the interlayers of the present disclosure, the interlayer may include about 0.003 to about 0.15 parts of ACA per 100 parts of resin; about 0.01 to about 0.10 parts of ACA per 100 parts of resin; and about 0.01 to about 0.04 parts of ACA per 100 parts of resin. Such ACAs include, but are not limited to, ACAs disclosed in U.S. Pat. No. 5,728,472 (the entire disclosure of which is incorporated herein by reference), residual sodium acetate, potassium acetate, magnesium bis(2-ethylbutyrate), and / or magnesium bis(2-ethylhexanoate).

[0136] Other additives may be incorporated into the interlayer to enhance its performance in the final product and to impart certain additional properties to the interlayer. Such additives include, but are not limited to, dyes, pigments, stabilizers (e.g., UV stabilizers), antioxidants, antiblocking agents, flame retardants, IR absorbers or blockers (e.g., indium tin oxide, antimony tin oxide, lanthanum hexaboride (LaB 6 ) and cesium tungsten oxide), processing aids, flow enhancing additives, lubricants, impact modifiers, nucleating agents, thermal stabilizers, UV absorbers, dispersants, surfactants, chelating agents, coupling agents, adhesives, primers, reinforcing additives and fillers, and other additives known to those of ordinary skill in the art.

[0137] Although the described embodiments refer to the polymer resin as PVB, it will be understood by those of ordinary skill in the art that the polymer may be any polymer suitable for use in a multilayer panel. Typical polymers include, but are not limited to, polyvinyl acetal (PVA) (such as poly(vinyl butyral) (PVB) or isomeric poly(vinyl isobutyral) (PVisoB)), aliphatic polyurethane (PU), poly(ethylene-co-vinyl acetate) (EVA), polyvinyl chloride (PVC), poly(vinyl chloride-co-methacrylate), polyethylene, polyolefins, ethylene acrylate copolymers, poly(ethylene-co-butyl acrylate), silicone elastomers, epoxy resins, and acid copolymers derived from any of the foregoing possible thermoplastic resins such as ethylene / carboxylic acid copolymers and ionomers thereof, combinations of the foregoing, and the like. PVB and its isomeric polymers PVisoB, polyvinyl chloride, and polyurethanes are particularly useful polymers for interlayers in general; PVB (and its isomeric polymers) are particularly preferred.

[0138] In another aspect, the diffusion interlayer can be a multilayer interlayer. For example, the multilayer middle layer can be composed of PVB / / PVisoB / / PVB. Other examples include PVB / / PVC / / PVB or PVB / / PU / / PVB. Further examples include PVC / / PVB / / PVC or PU / / PVB / / PU. Alternatively, both the skin layer and the core layer can be PVB using the same or different starting PVB resins.

[0139] In one aspect, the first or skin layer of the multilayer interlayer sheet comprises a PVB polymer having a Tg of, for example, from about 20° C. to about 45° C., or from 25° C. to 40° C., or from 28° C. to 35° C. Alternatively, the Tg of the poly(vinyl butyral) may be at least about 20° C., or at least 25° C., or at least 28° C., up to about 45° C., or up to 40° C., or up to 35° C.

[0140] In one aspect, the Tg of the layer adjacent to the first layer can be at least 12°C lower, or at least 15°C lower, or at least 20°C lower, or at least 30°C lower than the Tg of the first or skin layer.

[0141] Unless otherwise indicated, all numerals representing the number of components, characteristics (such as molecular weight, reaction conditions, etc.) used in the specification and claims are to be understood as being modified by the term "about" in all cases. Therefore, unless otherwise indicated, the numerical parameters set forth in the following specification and the appended claims are approximate values, which can be varied according to the desired characteristics to be sought to be obtained by the present invention. At a minimum, each numerical parameter should be interpreted at least according to the numerical value of the significant figures reported and by applying common rounding techniques. In addition, the scope described in the disclosure and claims is intended to specifically include the entire scope, rather than just one or more endpoints. For example, the scope defined as 0 to 10 is intended to disclose all integers between 0 to 10 (such as, for example, 1, 2, 3, 4, etc.), all fractions between 0 to 10 (such as 1.5, 2.3, 4.57, 6.1113, etc.) and endpoints 0 and 10.

[0142] Notwithstanding that the numerical ranges and parameters setting forth the broad scope of the invention are approximations, the numerical values ​​set forth in the specific examples are intended to be reported precisely as measured. Any numerical value, however, inherently contains certain errors necessarily resulting from the standard deviation found in their respective testing measurements.

[0143] It should be understood that the reference to one or more process steps does not exclude the presence of additional process steps before or after the steps in the combination or the insertion of process steps between those steps explicitly identified. In addition, the use of letters, numbers or the like to represent process steps, components or other aspects of information disclosed or claimed in the application is a convenient way to identify discrete activities or components, and the listed letters may be arranged in any order unless otherwise indicated.

[0144] As used herein, the singular forms "a", "an", and "the" include plural referents unless the context clearly dictates otherwise. For example, reference to C n Alcohol equivalents are intended to include various types of C n Alcohol equivalents. Thus, even if language such as "at least one" or "at least some" is used in one place, it does not mean that the use of "a", "an", and "the" elsewhere excludes plural referents unless the context clearly dictates otherwise. Similarly, the use of language such as "at least some" in one place does not mean that "all" is meant to be used without the use of such language elsewhere, unless the context clearly dictates otherwise.

[0145] As used herein, the term "and / or," when used in a list of two or more items, means that any one of the listed items may be used alone, or any combination of two or more of the listed items may be used. For example, if a composition is described as containing components A, B, and / or C, the composition may contain only A; only B; only C; a combination of A and B; a combination of A and C, a combination of B and C; or a combination of A, B, and C.

[0146] The present invention can be further illustrated by the following examples of its embodiments, but it should be understood that these examples are included for illustrative purposes only and are not intended to limit the scope of the present invention unless otherwise specifically stated.

[0147] Example

[0148] Example 1

[0149] In a mechanical separation device for processing a tapered (wedge-shaped) multilayer PVB interlayer, such as that shown in the figure, one end of a positioning roller located between the heating unit and the separation point is modified so that the roller end can be tilted toward a Z direction that is orthogonal to an imaginary line defined by connecting the point where the multilayer interlayer leaves the heating unit and the separation point (e.g., Figure 48). When not tilted, the panel-to-panel (or side-to-side) distance (i.e., the distance of the roller plus any journals or other features used to hold the roller in place) holding the roller in place is 1,778 mm.

[0150] The end of the positioning roller was tilted towards the Z direction by 7.112 mm, or 4 milliradians. The wedge angle of the separated multilayer PVB interlayer was 0.41 milliradians. The sheet width was 1.0 m. The interlayer was fed to the mechanical separation device and fed to the positioning roller so that the thinner side of the sheet passed over the tilted side of the positioning roller. The interlayer was delivered at 10 m / min and mechanically separated at 20 m / min without process instabilities (i.e., the first skin layer was successfully separated from the core-skin bilayer).

[0151] Example 2

[0152] In the mechanical separation device for processing tapered multilayer PVB interlayers, both ends of the positioning rollers located between the heating unit and the separation point are modified so that the roller ends can be tilted toward the Z direction as described above. When not tilted, the panel-to-panel distance of the positioning rollers is maintained at 1,778 mm.

[0153] One end of the positioning roller was tilted towards the Z direction by 3.556 mm, or 4 milliradians. The other end of the positioning roller was also tilted towards the Z direction by 3.556 mm, or 4 milliradians. The wedge angle of the separated multilayer PVB interlayer was 0.41 milliradians. The sheet width was 1.0 m. The interlayer was fed to the mechanical separation device and fed to the positioning roller so that the thinner side of the sheet passed over the tilted side of the positioning roller. The interlayer was delivered at 10 m / min and mechanically separated at 20 m / min without process instabilities (i.e., the first skin layer was successfully separated from the core-skin bilayer).

[0154] Example 3

[0155] In a mechanical separation apparatus for processing a wedge-shaped multilayer PVB interlayer, one end of a positioning roller located between the heating unit and the separation point is modified so that the roller end can be tilted toward the Z direction, as previously described. The same end of the positioning roller is also modified so that the roller end can be tilted toward the Y direction, which is defined by an imaginary line connecting the point where the multilayer interlayer leaves the heating unit and the separation point. When not tilted, the panel-to-panel distance of the positioning roller is maintained at 1,778 mm.

[0156] The end of the positioning roller was tilted towards the Z direction by 7.112 mm, or 4 milliradians. It was tilted towards the Y direction by -0.003 mm, or -5 milliradians. The wedge angle of the separated multilayer PVB interlayer was 0.41 milliradians. The sheet width was 1.0 m. The interlayer was fed to the mechanical separation device and fed to the positioning roller so that the thinner side of the sheet passed over the tilted side of the positioning roller. The interlayer was delivered at 5 m / min and mechanically separated at 10 m / min without process instabilities (i.e., the first skin layer was successfully separated from the core-skin bilayer)

[0157] Example 4

[0158] In the mechanical separation device for processing wedge-shaped multilayer PVB interlayer, there is no second positioning roller after the heating unit. As mentioned above, one end of the heating unit is slightly tilted toward the Z direction. When not tilted, the panel-to-panel distance of the heating unit is maintained at about 1,778 mm.

[0159] The end of the positioning roller was tilted toward the Z direction by more than about 0.01 millirads and less than about 0.05 millirads. The wedge angle of the separated multilayer PVB interlayer was about 0.15 millirads. The sheet width was 1.0 m. The interlayer was fed to the mechanical separation device and fed to the heating unit so that the thinner side of the sheet passed through the inclined side of the heating unit. The interlayer was delivered at 5 m / min and mechanically separated at 10 m / min without process instability (i.e., the first skin layer was successfully separated from the core-skin bilayer).

[0160] Comparative Example 1

[0161] Processing of a wedge-shaped multilayer PVB interlayer in an unmodified mechanical separation apparatus where the positioning rollers were not tilted in the Z and / or Y directions. The panel-to-panel distance of the positioning rollers was maintained at 1,778 mm.

[0162] The wedge angle of the multilayer PVB interlayer was 0.41 milliradians. The sheet width was 1.0 m. When the mechanical separation process was initiated, the separation line in the interlayer width direction became a high-order curve (i.e., a nonlinear separation point, such as a parabola, frown shape, or other curve that is not a relatively straight line). Even at a very low delivery speed of 2 m / min and a pulling speed of 5 m / min, it was impossible to continue the operation.

[0163] Table 1 below shows the details of Examples 1 to 4 and Comparative Example 1 and whether stable separation was achieved.

[0164] Table 1

[0165]

Claims

1. A continuous method for separating a first layer from a remainder of a tapered multilayer interlayer sheet, the method comprising: a. heating the tapered multilayer interlayer sheet to a temperature of about 25 ℃ to about 70 ℃; as well as b. then separating the first layer of the tapered multilayer interlayer sheet from the remaining portion by pulling the first layer and the remaining portion of the tapered multilayer interlayer sheet in different directions, wherein during the continuous process, an angle α defined by the first layer and the tapered multilayer interlayer sheet at a separation point is less than or equal to an angle β defined by the tapered multilayer interlayer sheet and the remaining portion of the tapered multilayer interlayer sheet at the separation point, and wherein the tapered multilayer interlayer sheet has a thicker side and a thinner side, and wherein the positioning roller positioned before the separation point is positioned so that it is tilted in the Z direction up to about 1% of the length of the positioning roller, or in the Y direction up to about 0.5% of the length of the positioning roller, or in the Z direction up to about 1% of the length of the positioning roller and in the Y direction up to about 0.5% of the length of the positioning roller, so as to prevent the thicker side of the tapered multilayer interlayer sheet from shifting toward the middle of the positioning roller during the continuous process.

2. The continuous process of claim 1, wherein in step a) the positioning roller heats the tapered multilayer interlayer sheet.

3. The continuous method of claim 1, wherein the multilayer interlayer sheet is heated by a heating unit in step a).

4. The method of claim 1, wherein the positioning roller is positioned so that it is tilted in the Z direction up to about 1% of the length of the positioning roller and in the Y direction up to about 0.5% of the length of the positioning roller.

5. The method of any of the preceding claims, wherein the first layer comprises a poly(vinyl butyral) polymer having a Tg of about 25°C to about 40°C.

6. The method according to any one of the preceding claims, wherein in step a) the tapered multilayer interlayer sheet is heated to a temperature of 30°C to 70°C.

7. The method of any of the preceding claims, wherein at least a portion of the remainder of the tapered multilayer interlayer sheet comprises a poly(vinyl butyral) polymer having a Tg at least 15°C lower than the Tg of the first layer.

8. A method as claimed in any one of the preceding claims, wherein In the separating step, the first layer is pulled by the first layer pulling roller, and the remaining portion of the tapered multilayer interlayer sheet is pulled by the remaining portion pulling roller, and Wherein when the separation occurs, the distance between the first layer pulling roller and the remaining portion pulling roller is maintained less than about 50% of the width of the sheet.

9. The method of any of the preceding claims, further comprising cooling one or more of the first layer and the remaining portion of the tapered multilayer interlayer sheet to below the Tg of the poly(vinyl butyral) of the first layer or the Tg of the poly(vinyl butyral) of the remaining portion of the tapered multilayer interlayer sheet.

10. The method of any one of the preceding claims, further comprising cooling the first layer to a temperature of about 15°C to about 30°C.

11. The method of any of the preceding claims, further comprising cooling the remaining portion of the tapered multilayer interlayer sheet to a temperature of about -15°C to about 0°C.

12. The method of any one of the preceding claims, wherein the distance between the first layer pulling roller and the remaining portion pulling roller when the separation occurs is less than about 15% of the width of the sheet.

13. The method of any of the preceding claims, wherein the distance between the first layer pulling roller and the remaining portion pulling roller when the separation occurs is less than about 5% of the width of the sheet.

14. A method as claimed in any one of the preceding claims, wherein the tapered multilayer interlayer sheet comprises a core layer with skin layers on each side.

15. The method of any one of the preceding claims, wherein the first layer comprises a first skin layer, and wherein the first skin layer is thicker than another skin layer.

16. The method of any one of the preceding claims, wherein the first layer comprises a first skin layer, and wherein the first skin layer is thinner than another skin layer.

17. The method of any one of the preceding claims, wherein the positioning roller is tilted in the Z direction by at least 0.01 millirads and less than 0.05 millirads.

18. A continuous process for separating a first layer from a remainder of a tapered poly(vinyl acetal) multilayer interlayer sheet, the process comprising: a. heating the tapered multilayer interlayer sheet to a temperature of about 25 ℃ to about 70 ℃; as well as b. then separating the first layer of the tapered multilayer interlayer sheet from the remaining portion by pulling the first layer and the remaining portion of the tapered multilayer interlayer sheet in different directions, wherein during the continuous process, an angle α defined by the first layer and the tapered multilayer interlayer sheet at a separation point is less than or equal to an angle β defined by the tapered multilayer interlayer sheet and the remaining portion of the tapered multilayer interlayer sheet at the separation point, and wherein the tapered multilayer interlayer sheet has a thicker side and a thinner side, and wherein the heating unit located before the separation point is positioned so that it is tilted in the Z direction up to about 1% of the length of the heating unit roller, or tilted in the Y direction up to about 0.5% of the length of the heating unit roller, or tilted in the Z direction up to about 1% of the length of the heating unit roller and tilted in the Y direction up to about 0.5% of the length of the heating unit roller to prevent the thicker side of the tapered poly(vinyl acetal) multilayer interlayer sheet from shifting toward the middle of the heating unit.

19. The method of claim 18, wherein the first layer comprises a poly(vinyl butyral) polymer having a Tg of about 25°C to about 40°C.

20. The method of claim 18 or claim 19, wherein the tapered multilayer interlayer sheet is heated to a temperature of 30°C to 70°C in step a).

21. The method of any one of claims 18 to 20, wherein at least a portion of the remainder of the tapered multilayer interlayer sheet comprises a poly(vinyl butyral) polymer having a Tg at least 15°C lower than the Tg of the first layer.

22. The method of any one of claims 18 to 21, wherein the heating unit is tilted in the Z direction by at least 0.01 millirad and less than 0.05 millirad.

23. An interlayer comprising the first layer obtained in the method as claimed in any one of the preceding claims.

24. A composition comprising the first layer obtained in the process as claimed in any one of the preceding claims.

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