Coextruded polymeric articles (including layers) having projections are known in the art. For example, it is known to provide a co-extruded, layer structures where the layer is partitioned, not as coextensive layers in the thickness direction, but as stripes or strands along the width dimension of the layer. This has sometimes been called “side-by-side” co-extrusion.
There is a desire for additional polymeric articles with projections that offer different configurations and/or properties (e.g., adhesive properties) over conventional articles. Some adhesive systems that switch from a state of relatively low or no adhesion to a state of much higher adhesion upon application of a certain trigger (commonly called “adhesion on demand” systems) are known. Many of these systems use triggers such as solvents, ultra violet light, heat, or magnetic forces, to create tiered adhesive performance once or repetitively. These systems are limited in applications for several reasons. For many of these triggers, the adhesive system must contain specific chemical groups, which restricts usage to applications where those chemical groups can be tolerated. These systems can be used only where a particular trigger is available and can be effectively applied to the adhesive system. Further, some triggers are difficult or inconvenient for consumers to use. Certain triggers, as well as the chemical groups in the adhesive that respond to such triggers, can be cost-prohibitive.
There is a need for “adhesion on demand” systems where the trigger is applicable to all adhesive chemistries, the trigger is more broadly or even universally available, the trigger is easy to apply, not only industrially, but by a consumer, and the adhesion-on-demand system is not exceedingly expensive.
In one aspect, the present disclosure describes a first coextruded polymeric article comprising first and second opposed major surfaces, wherein a plurality of projections extend from only the first major surface (i.e., the second major surface is free of any projections), wherein each projection has at least first and second opposed sides and a height from the first major surface to a distal end, wherein at least a majority by number (i.e., at least 50 percent by number; in some embodiments, at least 55, 60, 65, 70, 75, 80, 85, 90, 95, or even 100 percent) of the projections have a protrusion extending from only the first side and extending in one direction not more than to the first major surface and extending in an opposite direction to less than the height of the respective projection (i.e., less than to the distal end of the respective protrusion), wherein the projections extend to the second major surface, wherein there are regions extending between the first and second major surfaces that are between projections, wherein the regions comprise a first material, the projections comprise a second material, and the protrusions comprise a third material, wherein the second and third materials are different, and wherein at least one of the second or third materials comprise adhesive. “Different” as used herein means at least one of (a) a difference of at least 2% in at least one infrared peak, (b) a difference of at least 2% in at least one nuclear magnetic resonance peak, (c) a difference of at least 2% in the number average molecular weight, or (d) a difference of at least 5% in polydispersity. Examples of differences in polymeric materials that can provide the difference between polymeric materials include composition, microstructure, color, and refractive index. The term “same” in terms of polymeric materials means not different.
In some embodiments, connected projections and adjacent protrusions have a demarcation line therebetween. This construction can be formed by methods described herein where materials are coextruded in a manner that results in a distinct line of orientation visible at the polymer boundary between connected projections and protrusions. This demarcation line or boundary region between connected projections and protrusions can be detected using Differential Scanning calorimetry. Comparing by temperature modulated differential scanning calorimetry a region containing mostly a demarcation line (Region 1) versus a region that does not substantially contain material from the demarcation line (Region 2) a difference in heat flow/heat capacity is observed that is believed to be consistent with an energy release or reduction in molecular orientation/internal stress. That is, although not wanting to be bound by theory, it is believed that the thermal signatures of the regions may be a combination of material thermal transitions and the material response to retained thermal/processing history. In some embodiments, there is a demarcation line between connected regions and projections.
In another aspect, the present disclosure describes a first method for making the first coextruded polymeric article described herein, the method comprising:
providing an extrusion die comprising a plurality of shims positioned adjacent to one another, the shims together defining a first cavity, a second cavity, a third cavity, and a die slot, wherein the die slot has a distal opening, wherein the die slot is comprised of a first plurality of orifices, a second plurality of orifices, and a third plurality of orifices, wherein the plurality of shims comprises a first plurality of a repeating sequence of shims that together provide a fluid passageway between the second cavity and a second orifice, a second plurality of a repeating sequence of shims that together provide a fluid passageway between the first cavity and a first orifice and also together provide a fluid passageway between the third cavity and a third orifice, and a third plurality of shims that together provide a fluid passageway between the first cavity and a first orifice;
providing via extrusion a first material to the first cavity of the extrusion die, a second material to the second cavity of the extrusion die, and a third material to the third cavity of the extrusion die, wherein the second and third materials are different, and wherein at least one of the second material and the third material comprises an adhesive;
extruding a layer from the distal opening of the die slot; and
quenching the extruded layer.
In another aspect, the present disclosure describes a second method for making the first coextruded polymeric article described herein, the method comprising:
providing an extrusion die comprising a plurality of shims positioned adjacent to one another, the shims together defining a first cavity, a second cavity, a third cavity, and a die slot, wherein the die slot has a distal opening, wherein the die slot is comprised of a first plurality of orifices, a second plurality of orifices, and a third plurality of orifices, wherein the plurality of shims comprises a first plurality of a repeating sequence of shims that together provide a fluid passageway between the second cavity and a second orifice, a second plurality of a repeating sequence of shims provide a fluid passageway between the third cavity and a third orifice, and a third plurality of shims that together provide a fluid passageway between the first cavity and a first orifice;
providing via extrusion a first material to the first cavity of the extrusion die, a second material to the second cavity of the extrusion die, and a third material to the third cavity of the extrusion die, wherein the second and third materials are different, and wherein at least one of the second material and the third material comprises an adhesive;
extruding a layer from the distal opening of the die slot; and
quenching the extruded layer.
In another aspect, the present disclosure describes a second coextruded polymeric article comprising first and second opposed major surfaces, wherein a plurality of projections extend from only the first major surface (i.e., the second major surface is free of any projections), wherein each projection has at least first and second opposed sides and a height from the first major surface to a distal end, wherein at least a majority by number (i.e., at least 50 percent by number; in some embodiments, at least 55, 60, 65, 70, 75, 80, 85, 90, 95, or even 100 percent) of the projections have a protrusion extending from only the first side and extending in one direction not more than to the first major surface and extending in an opposite direction to less than the height of the respective projection (i.e., less than to the distal end of the respective protrusion), wherein the projections extend to the second major surface, wherein there are regions extending between the first and second major surfaces that are between projections, wherein the regions comprise a first material, the projections comprise a second material, and the protrusions comprise a third material, wherein at least two of the first, second, or third materials are different, and wherein the first, second, or third materials each comprise an adhesive.
In another aspect, the present disclosure describes a first method for making the second coextruded polymeric article described herein, the method comprising:
providing an extrusion die comprising a plurality of shims positioned adjacent to one another, the shims together defining a first cavity, a second cavity, a third cavity, and a die slot, wherein the die slot has a distal opening, wherein the die slot is comprised of a first plurality of orifices, a second plurality of orifices, and a third plurality of orifices, wherein the plurality of shims comprises a first plurality of a repeating sequence of shims that together provide a fluid passageway between the second cavity and a second orifice, a second plurality of a repeating sequence of shims that together provide a fluid passageway between the first cavity and a first orifice and also together provide a fluid passageway between the third cavity and a third orifice, and a third plurality of shims that together provide a fluid passageway between the first cavity and a first orifice;
providing via extrusion a first material to the first cavity of the extrusion die, a second material to the second cavity of the extrusion die, and a third material to the third cavity of the extrusion die, wherein at least two of the first, second, and third materials are different, and wherein each of the first material, the second material, and the third material comprises an adhesive;
extruding a layer from the distal opening of the die slot; and
quenching the extruded layer.
In another aspect, the present disclosure describes a second method for making the second coextruded polymeric article described herein, the method comprising:
providing an extrusion die comprising a plurality of shims positioned adjacent to one another, the shims together defining a first cavity, a second cavity, a third cavity, and a die slot, wherein the die slot has a distal opening, wherein the die slot is comprised of a first plurality of orifices, a second plurality of orifices, and a third plurality of orifices, wherein the plurality of shims comprises a first plurality of a repeating sequence of shims that together provide a fluid passageway between the second cavity and a second orifice, a second plurality of a repeating sequence of shims provide a fluid passageway between the third cavity and a third orifice, and a third plurality of shims that together provide a fluid passageway between the first cavity and a first orifice;
providing via extrusion a first material to the first cavity of the extrusion die, a second material to the second cavity of the extrusion die, and a third material to the third cavity of the extrusion die, wherein at least two of the first, second, and third materials are different, and wherein each of the first material, the second material, and the third material comprises an adhesive;
extruding a layer from the distal opening of the die slot; and
quenching the extruded layer.
Embodiments of coextruded polymeric articles described herein can include adhesive articles, household cleaning products (e.g., a mop, a duster, a brush, a cleaning cloth, or a lint roller), and wall attachments.
Embodiments of coextruded polymeric articles described herein can provide a tiered performance, such that for some property of merit (e.g., an adhesive level), the coextruded polymeric article exhibits one level of or value for that property in a base condition or state of use, and at least one different level of or value for that property when in at least one triggered condition or state of use.
Referring to
In some embodiments, at least one of the first, second, or third materials of the first coextruded polymeric article described herein independently comprise at least one of a thermoplastic resin (e.g., at least one of, including copolymers and blends thereof, a polyolefin (e.g., polypropylene and polyethylene), polyvinyl chloride, a polystyrene, nylon, a polyester (e.g., polyethylene terephthalate) or an elastomer (e.g., an ABA block copolymer, a polyurethane, a polyolefin elastomer, a polyurethane elastomer, a metallocene polyolefin elastomer, a polyamide elastomer, an ethylene vinyl acetate elastomer, and a polyester elastomer)). In some embodiments, at least one of the first, second, or third materials of the first coextruded polymeric article described herein independently comprise an adhesive. In some embodiments, at least one of the first, second, or third adhesives of the first coextruded polymeric article described herein are independently at least one of, including copolymers and blends thereof, an acrylate copolymer pressure sensitive adhesive, a rubber-based adhesive (e.g., those based on at least one of natural rubber, polyisobutylene, polybutadiene, butyl rubber, or styrene block copolymer rubber), a silicone polyurea-based adhesive, a silicone polyoxamide-based adhesive, a polyurethane-based adhesive, or a poly(vinyl ethyl ether)-based adhesive.
In some embodiments, the first and second materials of the first coextruded polymeric article described herein are the same. In some embodiments, the first and second materials of the first coextruded polymeric article described herein are different. In some embodiments, the first and third materials of the first coextruded polymeric article described herein are the same.
Referring to
In some embodiments, the first and second coextruded polymeric articles described herein have a (machine direction) length of at least 5 mm (in some embodiments, at least 10 mm, 25 mm, 50 mm, 1 cm, 5 cm, 10 cm, 50 cm, 75 cm, 1 m, 5 m, 10 m, 25 m, 50 m, 100 m, 500 m, or even at least 1000 m). In some embodiments, the protrusions and projections extend along the length of the coextruded polymeric article (i.e., have respective lengths of at least 5 mm (in some embodiments, at least 10 mm, 25 mm, 50 mm, 1 cm, 5 cm, 10 cm, 50 cm, 75 cm, 1 m, 5 m, 10 m, 25 m, 50 m, 100 m, 500 m, or even at least 1000 m)).
In another aspect, the present disclosure describes a first method for making the first coextruded polymeric article described herein, the method comprising:
providing an extrusion die comprising a plurality of shims positioned adjacent to one another, the shims together defining a first cavity, a second cavity, a third cavity, and a die slot, wherein the die slot has a distal opening, wherein the die slot is comprised of a first plurality of orifices, a second plurality of orifices, and a third plurality of orifices, wherein the plurality of shims comprises a first plurality of a repeating sequence of shims that together provide a fluid passageway between the second cavity and a second orifice, a second plurality of a repeating sequence of shims that together provide a fluid passageway between the first cavity and a first orifice and also together provide a fluid passageway between the third cavity and a third orifice, and a third plurality of shims that together provide a fluid passageway between the first cavity and a first orifice;
providing via extrusion a first material to the first cavity of the extrusion die, a second material to the second cavity of the extrusion die, and a third material to the third cavity of the extrusion die, wherein the second and third materials are different, and wherein at least one of the second material and the third material comprises an adhesive; extruding a layer from the distal opening of the die slot; and quenching the extruded layer.
In another aspect, the present disclosure describes a second method for making the first coextruded polymeric article described herein, the method comprising:
providing an extrusion die comprising a plurality of shims positioned adjacent to one another, the shims together defining a first cavity, a second cavity, a third cavity, and a die slot, wherein the die slot has a distal opening, wherein the die slot is comprised of a first plurality of orifices, a second plurality of orifices, and a third plurality of orifices, wherein the plurality of shims comprises a first plurality of a repeating sequence of shims that together provide a fluid passageway between the second cavity and a second orifice, a second plurality of a repeating sequence of shims provide a fluid passageway between the third cavity and a third orifice, and a third plurality of shims that together provide a fluid passageway between the first cavity and a first orifice;
providing via extrusion a first material to the first cavity of the extrusion die, a second material to the second cavity of the extrusion die, and a third material to the third cavity of the extrusion die, wherein the second and third materials are different, and wherein at least one of the second material and the third material comprises an adhesive;
extruding a layer from the distal opening of the die slot; and
quenching the extruded layer.
In another aspect, the present disclosure describes a first method for making the second coextruded polymeric article described herein, the method comprising:
providing an extrusion die comprising a plurality of shims positioned adjacent to one another, the shims together defining a first cavity, a second cavity, a third cavity, and a die slot, wherein the die slot has a distal opening, wherein the die slot is comprised of a first plurality of orifices, a second plurality of orifices, and a third plurality of orifices, wherein the plurality of shims comprises a first plurality of a repeating sequence of shims that together provide a fluid passageway between the second cavity and a second orifice, a second plurality of a repeating sequence of shims that together provide a fluid passageway between the first cavity and a first orifice and also together provide a fluid passageway between the third cavity and a third orifice, and a third plurality of shims that together provide a fluid passageway between the first cavity and a first orifice;
providing via extrusion a first material to the first cavity of the extrusion die, a second material to the second cavity of the extrusion die, and a third material to the third cavity of the extrusion die, wherein at least two of the first, second, and third materials are different, and wherein each of the first material, the second material, and the third material comprises an adhesive;
extruding a layer from the distal opening of the die slot; and
quenching the extruded layer.
In another aspect, the present disclosure describes a second method for making the second coextruded polymeric article described herein, the method comprising:
providing an extrusion die comprising a plurality of shims positioned adjacent to one another, the shims together defining a first cavity, a second cavity, a third cavity, and a die slot, wherein the die slot has a distal opening, wherein the die slot is comprised of a first plurality of orifices, a second plurality of orifices, and a third plurality of orifices, wherein the plurality of shims comprises a first plurality of a repeating sequence of shims that together provide a fluid passageway between the second cavity and a second orifice, a second plurality of a repeating sequence of shims provide a fluid passageway between the third cavity and a third orifice, and a third plurality of shims that together provide a fluid passageway between the first cavity and a first orifice;
providing via extrusion a first material to the first cavity of the extrusion die, a second material to the second cavity of the extrusion die, and a third material to the third cavity of the extrusion die, wherein at least two of the first, second, and third materials are different, and wherein each of the first material, the second material, and the third material comprises an adhesive;
extruding a layer from the distal opening of the die slot; and
quenching the extruded layer.
Coextruded polymeric articles described herein (including those shown in
Referring again to
In some embodiments, the shims will be assembled according to a plan that provides a sequence of shims of diverse types. Since different applications may have different requirements, the sequences can have diverse numbers of shims. The sequence may be a repeating sequence that is not limited to a particular number of repeats in a particular zone. Or the sequence may not regularly repeat, but different sequences of shims may be used. The shape of the passageways within, for example, a sequence of shims, may be identical or different. Examples of passageway cross-sectional shapes include round, square, and rectangular shapes. In some embodiments, the shims that provide a passageway between one cavity and the dispensing slot might have a flow restriction compared to the shims that provide a passageway between another cavity and the dispensing slot. The width of the distal opening within, for example, a different sequence of shims, may be identical or different. For example, the portion of the distal opening provided by the shims that provide a passageway between one cavity and the dispensing slot could be narrower than the portion of the distal opening provided by the shims that provide a passageway between another cavity and the dispensing slot.
Individual cavities and passageways provide a conduit for polymer to orifices to create the protrusions, the projections, and the film base region. These individual flowstreams merge together to form a continuous, solid coextruded polymeric article, at the die slot portion of the die. Spacer shims provide connecting slots to form demarcation lines connecting the protrusions, projections and regions.
In some embodiments, extrusion dies described herein include a pair of end blocks for supporting the plurality of shims. In these embodiments, it may be convenient for one, or even all, of the shims to each have at least one through-holes for the passage of connectors between the pair of end blocks. Bolts disposed within such through-holes are one convenient approach for assembling the shims to the end blocks, although the ordinary artisan may perceive other alternatives for assembling the extrusion die. In some embodiments, the at least one end block has an inlet port for introduction of fluid material into one, or both, of the cavities.
In some embodiments, the shims will be assembled according to a plan that provides a repeating sequence of shims of diverse types. The repeating sequence can have diverse numbers of shims per repeat. For a first example, a repeating sequence utilizing 5 shims is described below to create the orifice pattern shown in
In some embodiments, the assembled shims (conveniently bolted between the end blocks) further comprise a manifold body for supporting the shims. The manifold body has at least one (e.g., in some embodiments, at least two, three, four, or more) manifold therein, the manifold having an outlet.
An expansion seal (e.g., made of copper or alloys thereof) is disposed to seal the manifold body and the shims, such that the expansion seal defines a portion of at least one of the cavities (in some embodiments, a portion of both the first and second cavities), and such that the expansion seal allows a conduit between the manifold and the cavity.
Typically, the passageway between cavity and dispensing orifice is up to 5 mm in length. Sometimes the fluid passageways leading to one array has greater fluid restriction than the fluid passageways leading to one or more of the other arrays.
The shims for dies described herein typically have thicknesses in the range from 50 micrometers to 125 micrometers, although thicknesses outside of this range may also be useful. Typically, the fluid passageways have thicknesses in a range from 50 micrometers to 750 micrometers, and lengths less than 5 mm (with generally a preference for smaller lengths for decreasingly smaller passageway thicknesses), although thicknesses and lengths outside of these ranges may also be useful. For large diameter fluid passageways, several smaller thickness shims may be stacked together, or single shims of the desired passageway width may be used.
The shims are tightly compressed to prevent gaps between the shims and polymer leakage. For example, 12 mm (0.5 inch) diameter bolts are typically used and tightened, at the extrusion temperature, to their recommended torque rating. Also, the shims are aligned to provide uniform extrusion out the extrusion orifice, as misalignment can lead to strands extruding at an angle out of the die which inhibits desired bonding of the net. To aid in alignment, an alignment key can be cut into the shims. Also, a vibrating table can be useful to provide a smooth surface alignment of the extrusion tip.
In practicing methods described herein, the polymeric materials might be solidified simply by cooling. This can be conveniently accomplished passively by ambient air, or actively by, for example, quenching the extruded first and second polymeric materials on a chilled surface (e.g., a chilled roll). In some embodiments, the first and/or second and/or third polymeric materials are low molecular weight polymers that need to be cross-linked to be solidified, which can be done, for example, by electromagnetic or particle radiation. In some embodiments, it is desirable to maximize the time to quenching to increase the bond strength.
Referring now to
Shim 500 has several holes 547 to allow the passage of, for example, bolts, to hold shim 500 and others to be described below into an assembly. Shim 500 also has dispensing surface 567, and in this embodiment, dispensing surthce 567 has indexing groove 580 which can receive an appropriately shaped key to ease assembling diverse shims into a die. The shim may also have identification notch 582. to help verify that the die has been assembled in the desired mariner. This embodiment has shoulders 590 and 592 which can assist in mounting the assembled die with a mount of the type shown in
Referring to
Shim 600 has several holes 647 to allow the passage of, for example, bolts, to hold shim 600 and others to be described below into an assembly. Shim 600 also has dispensing surface 667, and in this embodiment, dispensing surface 667 has indexing groove 680 which can receive an appropriately shaped key to ease assembling diverse shims into a die. The shim may also have identification notch 682 to help verify that the die has been assembled in the desired manner. This embodiment has shoulders 690 and 692 which can assist in mounting the assembled die with a mount of the type shown in
Referring to
Shim 700 has several holes 747 to allow the passage of, for example, bolts, to hold shim 700 and others to be described below into an assembly. Shim 700 also has dispensing surface 767, and in this embodiment, dispensing surface 767 has indexing groove 780 which can receive an appropriately shaped key to ease assembling diverse shims into a die. The shim may also have identification notch 782 to help verify that the die has been assembled in the desired manner. This embodiment has shoulders 790 and 792 which can assist in mounting the assembled die with a mount of the type shown in
Shim 700 has dispensing opening 756, but it will be noted that this shim has no connection between dispensing opening 756 and any of the cavities 762a, 762b, 762c, or 762d. Shim 700 is a spacer shim and provides a sidewall for passageways of adjacent shims. Opening 756 provides a continuous dispensing slot for extrusion. This continuous slot enables polymers streams to merge together to form demarcation lines in the coextruded polymeric article between die orifices.
Referring to
Shim 800 has several holes 847 to allow the passage of, for example, bolts, to hold shim 800 and others to be described below into an assembly. Shim 800 also has dispensing surface 867, and in this embodiment, dispensing surface 867 has indexing groove 880 which can receive an appropriately shaped key to ease assembling diverse shims into a die. The shim may also have identification notch 882 to help verify that the die has been assembled in the desired manner. This embodiment has shoulders 890 and 892 which can assist in mounting the assembled die with a mount of the type shown in
Referring to
Shim 900 has several holes 947 to allow the passage of, for example, bolts, to hold shim 900 and others to be described below into an assembly. Shim 900 also has dispensing surface 967, and in this embodiment, dispensing surface 967 has indexing groove 980 which can receive an appropriately shaped key to ease assembling diverse shims into a die. The shim may also have identification notch 982 to help verify that the die has been assembled in the desired manner. This embodiment has shoulders 990 and 992 which can assist in mounting the assembled die with a mount of the type shown in
Referring to
Referring to
Referring to
Shim 1200 has several holes 1247 to allow the passage of, for example, bolts, to hold shim 1200 and others to be described below into an assembly. Shim 1200 also has dispensing surface 1267, and in this embodiment, dispensing surface 1267 has indexing groove 1280, which can receive an appropriately shaped key to ease assembling diverse shims into a die. The shim may also have identification notch 1282 to help verify that the die has been assembled in the desired manner. This embodiment has shoulders 1290 and 1292, which can assist in mounting the assembled die with a mount of the type shown in
Shim 1200 is an alternate to shim 800. A die stack with a sequence of shims 500, 600, 600, 500, 1200, 700, 900, 900 generates the orifice configuration shown in
Referring to
In this embodiment, inlet fittings provide a flow path for three streams of molten polymer through end blocks 2244a and 2244b to cavities 562a, 562b, and 562c, and 562d. Compression blocks 2204 have notch 2206 that conveniently engages the shoulders on shims (e.g., 590 and 592) on 500. When mount 2230 is completely assembled, compression blocks 2204 are attached by, for example, machine bolts to backplates 2208. Holes are conveniently provided in the assembly for the insertion of cartridge heaters 52.
Referring to
In some embodiments, at least one of the first, second, or third adhesive of the second coextruded polymeric article described herein are independently at least one of, including copolymers and blends thereof, an acrylate copolymer pressure sensitive adhesive, a rubber-based adhesive (e.g., those based on at least one of natural rubber, polyisobutylene, polybutadiene, butyl rubber, or styrene block copolymer rubber), a silicone polyurea-based adhesive, a silicone polyoxamide-based adhesive, a polyurethane-based adhesive, or a poly(vinyl ethyl ether)-based adhesive.
In some embodiments, the first and second materials of the second coextruded polymeric article described herein are the same. In some embodiments, the first and third materials of the second coextruded polymeric article described herein are the same.
In some embodiments, there are at least 5 (in some embodiments, at least 10, 15, 20, 25, 30, 35, or even up to 40) projections per cm.
In some embodiments, the projections of a coextruded polymeric article described herein are generally parallel to each other and generally perpendicular to the first major surface.
In some embodiments, the projections have a surface contacting the protrusion associated with a projection, wherein said surface is planar. In some embodiments, the projections have a surface contacting the protrusion associated with a projection, wherein said surface exhibits at least one depression. In some embodiments, the projections have a surface contacting the protrusion associated with a projection, wherein said surface exhibits at least one obtrusion.
In some embodiments, the projections of a coextruded polymeric article described herein have an aspect ratio (i.e., height to thickness) of at least 2:1 (in some embodiments, at least 3:1, or even at least 4:1).
In some embodiments, the projection of a coextruded polymeric article described herein are spaced apart not more than 2 mm (in some embodiments, not more than 1 mm).
In some embodiments, the projections of a coextruded polymeric article described herein have a height and thickness and the thickness is along the length of each respective projections.
In some embodiments, the protrusions a coextruded polymeric article described herein do not contact the first major surface.
In some embodiments, the height of the protrusions of a coextruded polymeric article described herein are in a range from 0.1 mm to 5 mm (in some embodiments, in a range from 0.1 mm to 2 mm, or even 0.1 mm to 1 mm).
In some embodiments, the protrusions of a coextruded polymeric article described herein have a longest cross-sectional dimension in the direction normal to the projections in a range from 0.05 mm to 0.5 mm (in some embodiments, in a range from 0.05 mm to 0.2 mm, or even 0.05 mm to 0.1 mm).
In some embodiments, regions of a coextruded polymeric article described herein have a distance between protrusions in a range from 0.25 mm to 5 mm (in some embodiments, in a range from 0.25 mm to 2 mm, or even 0.25 mm to 1 mm).
In some embodiments of a coextruded polymeric article described herein, there is a distance between the first and second major surfaces are in a range from 0.05 mm to 5 mm (in some embodiments, in a range from 0.05 mm to 3 mm, 0.05 mm to 2 mm, or even 0.1 mm to 1 mm).
In some embodiments, the extension of the protrusion of a coextruded polymeric article described herein is from not more than to the first major surface to less than the height of the protrusion (in some embodiments, in a range from 1% of the protrusion length to 75% of the protrusion length, 1% of the projection length to 50% of the protrusion length, or even 10% of the protrusion length to 50% of the protrusion length).
One exemplary use for articles described herein is as a coextruded polymeric adhesive article, wherein an adhesive is initially not exposed to contact to a substrate brought into proximity of the article, and can subsequently be exposed to contact to the substrate after mechanical movement of the projections of the article, such as through hand-pressure in a shearing mode.
In some embodiments, polymeric materials used to make coextruded polymeric articles described herein may comprise a colorant (e.g., pigment and/or dye) for functional (e.g., optical effects) and/or aesthetic purposes (e.g., each has different color/shade). Suitable colorants are those known in the art for use in various polymeric materials. Exemplary colors imparted by the colorant include white, black, red, pink, orange, yellow, green, aqua, purple, and blue. In some embodiments, it is desirable level to have a certain degree of opacity for one or more of the polymeric materials. The amount of colorant(s) to be used in specific embodiments can be readily determined by those skilled in the art (e.g., to achieve desired color, tone, opacity, transmissivity, etc.). If desired, the polymeric materials may be formulated to have the same or different colors.
Another exemplary use for coextruded polymeric articles described herein is as a household cleaning product (e.g., a mop, a duster, a brush, a cleaning cloth, or a lint roller) whose effectiveness is increased by the movement inherent to its use.
Another exemplary use for coextruded polymeric articles described herein is as an adhesive article that can be adhesively attached to a substrate by slight shearing motion (e.g., a wall attachment which can be positioned without any adhesion), and subsequently adhered to the wall by gentle hand pressure accompanied by a slight shearing movement. The wall attachment can be subsequently removable by peeling. Another exemplary coextruded polymeric adhesive article has two levels of adhesiveness, which can be applied to a substrate at a low level of adhesiveness, repositioned as needed, and then subsequently be made to be highly adhesive by applying gentle hand pressure accompanied by a slight shearing movement. Yet another exemplary coextruded polymeric adhesive article has three levels of adhesiveness and two-sided adhesiveness. Such coextruded polymeric articles can behave as any described above, and then, on the still exposed surface (the surface opposing the surface already adhered to a substrate) can exhibit adhesiveness with respect to an additional substrate or article. For example, the coextruded polymeric article can be positioned against a wall, repositioned freely in a state of no or little adhesiveness. A gentle hand pressure can be applied accompanied with a slight shearing movement to provide a high level of adhesiveness. Then use of a third level of adhesiveness existing on the side of the coextruded polymeric adhesive article opposite the side adhered to the wall (which may be the same or different from either of the first two levels of adhesiveness) can be made to affix other objects to the wall such as posters, handbills, and other decorative materials, either permanently or removably, either once or repeatedly.
It is also within the scope of the present disclosure that properties in addition to adhesiveness can be triggered to exhibit tiered behavior in embodiments of coextruded polymeric articles described herein. For example, various chemical properties can also be utilized to provide channeling webs or tapes. An exemplary coextruded polymeric article could have hydrophobic projections and hydrophilic protrusions.
Water, for instance, gently encountering such a coextruded polymeric article from the side having the projections would bead-up on the coextruded polymeric article, unless it approached with a determinate level of force or pressure, whereupon it would penetrate between projections deeply enough to encounter hydrophilic protrusions, and would be wicked down-channel due to hydrostatic forces, while still unable to penetrate through the layer to any appreciable extent.
providing an extrusion die comprising a plurality of shims positioned adjacent to one another, the shims together defining a first cavity, a second cavity, a third cavity, and a die slot, wherein the die slot has a distal opening, wherein the die slot is comprised of a first plurality of orifices, a second plurality of orifices, and a third plurality of orifices, wherein the plurality of shims comprises a first plurality of a repeating sequence of shims that together provide a fluid passageway between the second cavity and a second orifice, a second plurality of a repeating sequence of shims that together provide a fluid passageway between the first cavity and a first orifice and also together provide a fluid passageway between the third cavity and a third orifice, and a third plurality of shims that together provide a fluid passageway between the first cavity and a first orifice;
providing via extrusion a first material to the first cavity of the extrusion die, a second material to the second cavity of the extrusion die, and a third material to the third cavity of the extrusion die, wherein the second and third materials are different, and wherein at least one of the second material and the third material comprises an adhesive;
extruding a layer from the distal opening of the die slot; and quenching the extruded layer.
providing an extrusion die comprising a plurality of shims positioned adjacent to one another, the shims together defining a first cavity, a second cavity, a third cavity, and a die slot, wherein the die slot has a distal opening, wherein the die slot is comprised of a first plurality of orifices, a second plurality of orifices, and a third plurality of orifices, wherein the plurality of shims comprises a first plurality of a repeating sequence of shims that together provide a fluid passageway between the second cavity and a second orifice, a second plurality of a repeating sequence of shims provide a fluid passageway between the third cavity and a third orifice, and a third plurality of shims that together provide a fluid passageway between the first cavity and a first orifice;
providing via extrusion a first material to the first cavity of the extrusion die, a second material to the second cavity of the extrusion die, and a third material to the third cavity of the extrusion die, wherein the second and third materials are different, and wherein at least one of the second material and the third material comprises an adhesive;
extruding a layer from the distal opening of the die slot; and quenching the extruded layer.
providing an extrusion die comprising a plurality of shims positioned adjacent to one another, the shims together defining a first cavity, a second cavity, a third cavity, and a die slot, wherein the die slot has a distal opening, wherein the die slot is comprised of a first plurality of orifices, a second plurality of orifices, and a third plurality of orifices, wherein the plurality of shims comprises a first plurality of a repeating sequence of shims that together provide a fluid passageway between the second cavity and a second orifice, a second plurality of a repeating sequence of shims that together provide a fluid passageway between the first cavity and a first orifice and also together provide a fluid passageway between the third cavity and a third orifice, and a third plurality of shims that together provide a fluid passageway between the first cavity and a first orifice;
providing via extrusion a first material to the first cavity of the extrusion die, a second material to the second cavity of the extrusion die, and a third material to the third cavity of the extrusion die, wherein at least two of the first, second, and third materials are different, and wherein each of the first material, the second material, and the third material comprises an adhesive;
extruding a layer from the distal opening of the die slot; and quenching the extruded layer.
providing an extrusion die comprising a plurality of shims positioned adjacent to one another, the shims together defining a first cavity, a second cavity, a third cavity, and a die slot, wherein the die slot has a distal opening, wherein the die slot is comprised of a first plurality of orifices, a second plurality of orifices, and a third plurality of orifices, wherein the plurality of shims comprises a first plurality of a repeating sequence of shims that together provide a fluid passageway between the second cavity and a second orifice, a second plurality of a repeating sequence of shims provide a fluid passageway between the third cavity and a third orifice, and a third plurality of shims that together provide a fluid passageway between the first cavity and a first orifice;
providing via extrusion a first material to the first cavity of the extrusion die, a second material to the second cavity of the extrusion die, and a third material to the third cavity of the extrusion die, wherein at least two of the first, second, and third materials are different, and wherein each of the first material, the second material, and the third material comprises an adhesive;
extruding a layer from the distal opening of the die slot; and
quenching the extruded layer.
Advantages and embodiments of this invention are further illustrated by the following examples, but the particular materials and amounts thereof recited in these examples, as well as other conditions and details, should not be construed to unduly limit this invention. All parts and percentages are by weight unless otherwise indicated.
A co-extrusion die as generally depicted in
The inlet fittings on the two end blocks were each connected to three conventional single-screw extruders. The extruders feeding two cavities were loaded with polyethylene copolymer (obtained under the trade designation “ELVALOY 1609” from DuPont Company, Wilmington, Del.). The polypropylene for the first cavity was dry blended with 3% yellow color concentrate (obtained under the trade designation “10038103” from PolyOne Distribution, Romeoville, Ill.). The polypropylene for the second cavity was dry blended with 3% green color concentrate (obtained under the trade designation “PP64643536” from Clariant, Minneapolis, Minn.). The extruder feeding the third cavity was loaded with acrylate copolymer adhesive (obtained under the trade designation “R 55586” from 3M Company, St. Paul, Minn.). The 4th cavity was not used.
The melt was extruded vertically into an extrusion quench takeaway. The quench roll was a smooth temperature controlled chrome plated 20 cm diameter steel roll. The quench temperature was controlled with internal water flow. The web path wrapped 180 degrees around the chrome steel roll and then to a windup roll.
Other process conditions are listed below:
An optical microscope was used to measure the film profile resulting in the following measurements:
An optical image of the resulting article is shown in
Foreseeable modifications and alterations of this disclosure will be apparent to those skilled in the art without departing from the scope and spirit of this invention. This invention should not be restricted to the embodiments that are set forth in this application for illustrative purposes.
This application claims the benefit of U.S. Provisional Patent Application Nos. 62/618261, filed Jan. 17, 2018 and 62/632121, filed Feb. 19, 2018, the disclosures of which are incorporated by reference herein in their entireties.
Filing Document | Filing Date | Country | Kind |
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PCT/IB2019/050278 | 1/14/2019 | WO | 00 |
Number | Date | Country | |
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62618261 | Jan 2018 | US | |
62632121 | Feb 2018 | US |