Many types and styles of protective gloves are known in the art. Depending on the type of environment, nature of work, or desired properties, these gloves are made from a variety of materials, including woven cloth fabrics, leather, natural latex or synthetic polymer elastomeric materials, or combinations of such materials.
Gloves made of woven fabrics generally allow the user's skin to breathe through the fabric such that perspiration from the hand may be wicked away by the fabric. Knit gloves are often desirable in that they allow for a relatively comfortable fit on the hand of the user. Additionally, knit gloves demonstrate at least some degree of inherent flexibility in order to accommodate movement of the user's hands. Knitting processes used to create woven knit gloves, however, are typically slow and expensive.
Gloves that require greater protection against fluids, chemicals, or microscopic pathogens typically incorporate a barrier layer that is impervious to the undesirable substances. For example, surgical, examination, or work gloves typically are made using natural or synthetic rubber latex or other elastic polymer membranes.
In still other embodiments, gloves have been made in the past that include a combination of textile materials with elastomeric or film materials. For example, gloves have been made in the past that include an elastomeric shell that includes an internal lining composed of fibrous material, such as cotton flock. For instance, the flock may be composed of finely divided, ground, fibrous particles that are applied as a lining by spraying the flock particles onto an adhesive covered shell. The cotton flock lining is intended to provide a smooth, comfortable feel that cushions the hands and absorbs perspiration. The cotton flock lining may also insulate against hot and cold temperatures and may facilitate donning of the glove.
The cotton flock lining, however, may have various disadvantages and drawbacks. For instance, the flock particles and fibers may become detached from the internal lining and can migrate out of the glove. The cotton flock lining, in some applications, may also be difficult to attach to the inside surface of an elastomeric article. Further, in order to attach the cotton flocking to the inside surface of the article, a glue or adhesive is used that adds complexity to the process for making the glove.
In still other embodiments, multi-layered gloves have been produced that include a woven interior layer coated with a rubber-like material. Such gloves, however, generally have little elasticity and are typically reserved for heavy duty uses.
In view of the above, a need currently exists for an improved composite garment, such as a glove, that includes a cloth-like glove body that is at least partially coated with an elastomeric material. Specifically, a need exists for a composite glove that is relatively inexpensive to manufacture, that possesses both the benefits of a cloth-like lining and an elastomeric coating and that still has relatively good tactile properties such as elasticity and feel.
As used herein, the term “nonwoven fabric or web” means a web having a structure of individual fibers or threads which are interlaid, but not in an identifiable manner as in a knitted fabric. Nonwoven fabrics or webs have been formed from various processes such as, for example, meltblowing processes, spunbonding processes, and bonded carded web processes. The basis weight of nonwoven fabrics is usually expressed in ounces of material per square yard (osy) or grams per square meter (gsm) and the fiber diameters are usually expressed in microns. (Note that to convert from osy to gsm, multiply osy by 33.91).
As used herein, the term “spunbonded fibers” refers to small diameter fibers that are formed by extruding molten thermoplastic material as filaments from a plurality of fine, usually circular capillaries of a spinneret with the diameter of the extruded filaments then being rapidly reduced to fibers as by, for example, in U.S. Pat. No. 4,340,563 to Appel et al., and U.S. Pat. No. 3,692,618 to Dorschner et al., U.S. Pat. No. 3,802,817 to Matsuki et al., U.S. Pat. Nos. 3,338,992 and 3,341,394 to Kinney, U.S. Pat. No. 3,502,763 to Hartman, and U.S. Pat. No. 3,542,615 to Dobo et al., the entire contents of which are incorporated herein by reference in their entirety for all purposes. Spunbond fibers can be continuous and have diameters generally greater than about 7 microns, more particularly, between about 10 and about 20 microns.
As used herein, the term “meltblown fibers” means fibers formed by extruding a molten thermoplastic material through a plurality of fine, usually circular, die capillaries as molten threads or filaments into converging high velocity, usually hot, gas (e.g. air) streams which attenuate the filaments of molten thermoplastic material to reduce their diameter, which may be to microfiber diameter. Thereafter, the meltblown fibers are carried by the high velocity gas stream and are deposited on a collecting surface to form a web of randomly disbursed meltblown fibers. Such a process is disclosed, for example, in U.S. Pat. No. 3,849,241 to Butin et al., the entire contents of which are incorporated herein by reference in their entirety for all purposes. Meltblown fibers are microfibers that may be continuous or discontinuous with diameters generally less than 10 microns.
As used herein, the term “stretch-bonded laminate” refers to a composite material having at least two layers in which one layer is a gatherable layer and the other layer is an elastic layer. The layers are joined together when the elastic layer is extended from its original condition so that upon relaxing the layers, the gatherable layer is gathered. Such a multilayer composite elastic material may be stretched to the extent that the material gathered between the bond locations allows the elastic material to elongate. One type of stretch-bonded laminate is disclosed, for example, by U.S. Pat. No. 4,720,415 to Vander Wielen et al., the entire contents of which are incorporated herein by reference in its entirety for all purposes. Other composite elastic materials are disclosed in U.S. Pat. No. 4,789,699 to Kieffer et al., U.S. Pat. No. 4,781,966 to Taylor and U.S. Pat. Nos. 4,657,802 and 4,652,487 to Morman and U.S. Pat. No. 4,655,760 to Morman et al., the contents of which are incorporated herein by reference in their entirety.
As used herein, the terms “necking” or “neck stretching” interchangeably refer to a method of elongating a nonwoven fabric, generally in the machine direction, to reduce its width (cross-machine direction) in a controlled manner to a desired amount. The controlled stretching may take place under cool, room temperature or greater temperatures and is limited to an increase in overall dimension in the direction being stretched up to the elongation required to break the fabric, which in most cases is about 1.2 to 1.6 times. When relaxed, the web retracts toward, but does not return to, its original dimensions. Such a process is disclosed, for example, in U.S. Pat. No. 4,443,513 to Meitner and Notheis, U.S. Pat. Nos. 4,965,122, 4,981,747 and 5,114,781 to Morman and U.S. Pat. No. 5,244,482 to Hassenboehier Jr. et al., the entire contents of which are incorporated herein by reference in their entirety for all purposes.
As used herein, the term “reversibly necked material” refers to a material that possesses stretch and recovery characteristics formed by necking a material, then heating the necked material, and cooling the material. Such a process is disclosed in U.S. Pat. No. 4,965,122 to Morman, commonly assigned to the assignee of the present invention, the entire contents of which are incorporated by reference herein in its entirety for all purposes.
As used herein, the term “neck bonded laminate” refers to a composite material having at least two layers in which one layer is a necked, non-elastic layer and the other layer is an elastic layer. The layers are joined together when the non-elastic layer is in an extended (necked) condition. Examples of neck-bonded laminates are such as those described in U.S. Pat. Nos. 5,226,992, 4,981,747, 4,965,122 and 5,336,545 to Morman, the entire contents of which are incorporated herein by reference in their entirety for all purposes.
As used herein, the term “coform” means a meltblown material to which at least one other material is added during the meltblown material formation. The meltblown material may be made of various polymers, including elastomeric polymers. Various additional materials may be added to the meltblown fibers during formation, including, for example, pulp, superabsorbent particles, cellulose or staple fibers. Coform processes are illustrated in commonly assigned U.S. Pat. No. 4,818,464 to Lau and U.S. Pat. No. 4,100,324 to Anderson et al., the entire contents of which are incorporated herein by reference in their entirety for all purposes.
As used herein, the term “ultrasonic bonding” refers to a process in which materials (fibers, webs, films, etc.) are joined by passing the materials between a sonic horn and anvil surface, such as a roll. An example of such a process is illustrated in U.S. Pat. No. 4,374,888 to Bornslaeger, the entire contents of which are incorporated herein by reference in their entirety for all purposes.
As used herein, the term “elastic” refers to any material, including a film, fiber, nonwoven web, or combination thereof, which upon application of a biasing force, is stretchable to a stretched, biased length which is at least about 150 percent, or one and a half times, its relaxed, unstretched length, and which will recover at least 15 percent of its elongation upon release of the stretching, biasing force.
As used herein, the terms “elastomer” or “elastomeric” refer to polymeric materials that have properties of stretchability and recovery.
As used herein, the term “stretch” refers to the ability of a material to extend upon application of a biasing force. Percent stretch is the difference between the initial dimension of a material and that same dimension after the material has been stretched or extended following the application of a biasing force. Percent stretch may be expressed as [(stretched length +initial sample length)/initial sample length]×100. For example, if a material having an initial length of one (1) inch is stretched 0.50 inch, that is, to an extended length of 1.50 inches, the material can be said to have a stretch of 50 percent.
As used herein, the term “recover” or “recovery” refers to a contraction of a stretched material upon termination of a biasing force following stretching of the material by application of the biasing force. For example, if a material having a relaxed, unbiased length of one (1) inch is elongated 50 percent by stretching to a length of one and one half (1.5) inches the material would have a stretched length that is 150 percent of its relaxed length. If this exemplary stretched material contracted, that is recovered to a length of one and one tenth (1.1) inches after release of the biasing and stretching force, the material would have recovered 80 percent (0.4 inch) of its elongation.
As used herein, the term “polymer” generally includes but is not limited to, homopolymers, copolymers, such as for example, block, graft, random and alternating copolymers, terpolymers, etc. and blends and modifications thereof. Furthermore, unless otherwise specifically limited, the term “polymer” shall include all possible geometrical configurations of the molecule. These configurations include, but are not limited to isotactic, syndiotactic and random symmetries.
In general, the present disclosure is directed to polymer-coated garments that are not only relatively inexpensive to produce but also can have elastic properties. The garment can have a shape to fit over an extremity such as a hand, an arm, a foot, or a leg. In one particular embodiment, for instance, the polymer-coated garment comprises a glove.
For instance, in one particular embodiment, the glove comprises a hollow member defining an opening for receiving a hand therein. The hollow member has an interior surface configured to be placed adjacent to a hand when the glove is donned and an opposite exterior surface. In accordance with the present disclosure, the hollow member comprises an elastic laminate including at least one nonwoven layer.
A polymeric coating, such as an elastomeric coating covers at least a portion of the exterior surface of the hollow member. The elastomeric coating comprises a natural or synthetic polymer. The elastomeric coating may form a film on the exterior surface of the hollow member. The film may be continuous or may be discontinuous. For instance, the elastomeric coating may form a pattern on the exterior surface of the hollow member.
The elastomeric coating may penetrate through the hollow member so as to not only reside on the exterior surface of the hollow member but may also be present on the interior surface of the hollow member. Alternatively, the elastomeric coating may be present on the exterior surface so as to not substantially penetrate all the way through to the interior surface of the hollow member.
As described above, the hollow member is generally formed from an elastic laminate. The elastic laminate may comprise, for instance, a spunbond laminate, a neck-bonded laminate, and mixtures thereof. In one embodiment, for instance, the elastic laminate may have at least three layers. The three layers may include two outer nonwoven layers and a middle layer comprising elastic filaments, an elastic film, or an elastic nonwoven. If desired, the outer layers may be attached to the middle layer while the middle layer is in a stretched state such that the outer layers gather when the middle layer is in a relaxed state. The outer layers may comprise the same or different materials. For example, the outer layers may comprise spunbond webs, meltblown webs, coform webs and laminates thereof. In one embodiment, the outer layer forming the exterior surface of the hollow member may comprise a meltblown web, while the outer layer of the elastic laminate forming the interior surface of the hollow member may comprise a spunbond web.
In one embodiment, the hollow member may comprise a first panel attached to a second panel along a seam. The seam, for instance, may have a thickness of less than 1 mm and may have been formed by ultrasonically bonding the first panel to the second panel. Each panel may comprise a similar elastic laminate or different elastic laminates. For example, in one embodiment, one panel may comprise a neck-bonded laminate, while the second panel may comprise a spunbond laminate. For instance, in this embodiment, the neck-bonded laminate having one dimensional stretch characteristics may comprise a palm portion of the glove while a stretch-bonded laminate having two dimensional stretch characteristics may form a back portion of the glove.
The elastic laminate may have any suitable basis weight depending upon the glove being produced and its intended uses. The basis weight of the elastic laminate may vary, for instance, from about 20 gsm to about 400 gsm or greater.
The elastomeric coating may be made from any suitable film-forming polymer. For instance, the polymer used to form the elastomeric coating may comprise a natural rubber latex, a nitrile polymer, a polyurethane polymer, polyvinyl chloride, a silicone polymer, an acrylic polymer, a block copolymer, and the like. When using a block copolymer, the block copolymer may comprise a styrenic block copolymer such as a styrene-ethylene butylene-styrene block copolymer.
In one embodiment, a precoat may be present in the glove positioned between the elastomeric coating and the hollow member. The precoat may be added in order to facilitate bonding between the elastomeric coating and the hollow member, may be used to polymerize the elastomeric coating material, or may be used to control penetration of the elastomeric coating into the hollow member. In one embodiment, for instance, the precoat may comprise a coagulant composition for the natural or synthetic polymer. Alternatively, the precoat may comprise a hydrophobic composition that does not form a film on the exterior surface of the hollow member, but does serve to prevent penetration of the elastomeric material into the hollow member.
The elastomeric coating may cover the entire exterior surface of the hollow member or may only cover a portion of the exterior surface. For example, in one embodiment, the hollow member may include a palm portion, finger portions, and a back side portion. The elastomeric coating may be applied so as to only cover the palm portion and the finger portions. When the hollow member is made from first and second panels that are joined along a seam, in one embodiment, the elastomeric coating may at least cover the seam in order to reinforce the attachment between the panels.
In various embodiments, the finger portions of the glove may be configured to enclose the fingers of a wearer or may have open ends for allowing the fingers of a wearer to remain exposed. Further, the glove may include a cuff portion that extends only a relatively small amount past the hand of a wearer or may extend to the elbow of the wearer.
In forming the glove product, any suitable process may be used in order to coat the hollow member with the elastomeric material. In one embodiment, for instance, the hollow member may be dipped into an elastomeric coating composition that contains the natural or synthetic polymer. The natural or synthetic polymer may be present in an aqueous dispersion or in a solvent dispersion. After being coated on the hollow member, the glove may be subjected to heat in order to cause the elastomeric material to dry, cure and/or crosslink.
When contacted with the elastomeric coating composition, the hollow member may be dipped into the composition so that the elastomeric coating completely covers the hollow member or only covers the hollow member in certain areas. For example, in one embodiment, the elastomeric coating may be applied to the hollow member so as to only cover the palm portion and the finger portions of the glove.
In one embodiment, the hollow member may be placed on a former prior to being dipped into the elastomeric composition. The former may comprise, for instance, a ceramic or metal mold in the shape of a hand. By placing the hollow member on a former prior to applying the elastomeric coating, the resulting glove may assume a three-dimensional configuration after the elastomeric coating is dried and/or cured.
Other features and aspects of the present invention are discussed in greater detail below.
A full and enabling disclosure of the present invention, including the best mode thereof, directed to one of ordinary skill in the art, is set forth more particularly in the remainder of the specification, which makes reference to the appended figures in which:
Repeat use of reference characters in the present specification and drawings is intended to represent the same or analogous features or elements of the invention.
Reference will now be made in detail to embodiments of the invention, one or more examples of which are illustrated in the drawings. Each example is provided by way of explanation of the invention, and not meant as a limitation of the invention. For example, features illustrated or described as part of one embodiment can be used with another embodiment to yield still a third embodiment. It is intended that the present invention include these and other modifications and variations.
It is to be understood that the ranges mentioned herein include all ranges located within the prescribed range. As such, all ranges mentioned herein include all sub-ranges included in the mentioned ranges. For instance, a range from 100-200 also includes ranges from 110-150, 170-190, and 153-162. Further, all limits mentioned herein include all other limits included in the mentioned limits. For instance, a limit of up to 7 also includes a limit of up to 5, up to 3, and up to 4.5.
In general, the present disclosure is directed to a polymer-coated protective garment. The protective garment includes a hollow member that is shaped to receive an arm, a leg, a foot, or a hand of a wearer. For example, in one embodiment, the protective garment comprises a glove for receiving a hand. The glove can be used in numerous applications, such as for industrial applications, sports applications, medical applications, and the like.
The following description for exemplary purposes only is generally directed to a polymer-coated glove. It should be understood, however, that similar articles and garments can be constructed in accordance with the present disclosure.
Referring to
For instance, as shown in
Gloves and garments made in accordance with the present disclosure provide various advantages. For instance, the hollow member 12 made from an elastic laminate not only provides form-fitting properties but can also be made so as to be breathable. The hollow member 12 also has a lower coefficient of friction relative to the elastomeric material, thus facilitating donning or doffing of the glove. As will be described in more detail below, the hollow member 12 can also be made from elastic laminates that can be mass produced at a relatively low cost making the gloves disposable after one or two uses.
The elastomeric coating 14 as shown in
In the embodiments shown in
As described above, the hollow member 12 is generally formed from an elastic laminate. The elastic laminate may include at least one nonwoven web and at least one elastic layer. In general, the elastic laminate contains at least two layers of material but can also contain three layers, four layers, five layers, six layers or more. The elastic laminate as shown in
In one embodiment, the elastic laminate used to form the hollow member 12 comprises a stretch-bonded laminate. The stretch-bonded laminate, for example, may be capable of stretching from about 50% to 400% or greater. For example, in one embodiment, the stretch-bonded laminate may be capable of stretching 200 to 300%. The above amount of stretch not only provides comfort to the wearer but also works well in conjunction with the elastomeric coating 14.
The stretch-bonded laminate may be made in various different ways and may include various different layers. In one embodiment, the stretch-bonded layer may be liquid and gas permeable, only gas permeable, or impermeable to liquid and gases. In one embodiment, the stretch-bonded laminate can be made so as to be breathable. For instance, the stretch-bonded laminate may include pores or openings that permit liquids and gases to pass through.
Referring to
Referring to
The elastic strands 24 are attached to the outer layers 20 and 22 using any suitable method or technique. For instance, the elastic strands may be attached to the outer layers using an adhesive. The adhesive, for instance, may be sprayed on the outer layers and then attached to the elastic strands. Alternatively, the elastic strands may be thermally, chemically, or ultrasonically bonded to the outer layers.
When forming a stretch-bonded laminate, the elastic strands are attached to the outer layers 20 and 22 while the elastic strands 24 are in a stretched state. Once the strands are attached to the outer layers and relaxed, the outer layers gather together to form gatherable layers. In this manner, the stretch-bonded laminate 16 has inherent stretch properties in at least one direction.
The outer layers 20 and 22 may be made from any suitable material. For example, in one embodiment, the outer layers comprise nonwoven webs. The nonwoven webs may be elastic or non-elastic.
In general, the first and second non-woven webs 20 and 22 may be flexible sheet materials that can provide desired skin-like barrier and elastic properties, while also improving the overall tactile aesthetics or feeling for the wearer, by reducing stiffness often found with nonwoven fabrics and the tackiness and difficult donning properties associated with latex-based substrates. Given the particular structure of certain nonwoven fabrics, corrugation of the contact surface especially when gathered helps reduce the amount of surface area that actually contacts the wearer's skin, making the article 10 easier to don or doff. The physical structure of nonwoven materials also can produce capillary action to wick moisture away from the wearer's skin, hence reducing any sense of wetness or clamminess and keeping the wearer feeling dry and comfortable. The wrinkles may also act to enhance air flow between the glove 10 and the skin of the user.
In one embodiment, the outer layers 20 and 22 can be made from polymer-based nonwoven materials that have various cloth-like properties. A foundational substrate or a base nonwoven fiber web can be formed, for instance, from materials that may include synthetic fibers, pulp fibers, thermo-mechanical pulp, or mixtures of such materials. Non-woven web materials suitable for use in the present disclosure may include spunbond webs, meltblown webs, spunbond-meltblown-spunbond laminates, coform webs, spunbond-film-spunbond laminates, bicomponent spunbond webs, bicomponent meltblown webs, biconstituent spunbond webs, biconstituent meltblown webs, bonded carded webs, airlaid webs, and the like.
In one particular embodiment, for instance, the outer layers 20 and 22 may comprise spunbond webs that may be thermally bonded or through-air bonded. In one embodiment, for instance, the spunbond webs may contain bicomponent polyethylene/polypropylene filaments in a side-by-side arrangement.
The basis weight of the outer layers 20 and 22 can vary dramatically depending upon the particular application. For exemplary purposes only, the basis weight of the outer layers may generally be from about 10 gsm to about 300 gsm, such as from about 15 gsm to about 200 gsm. In various embodiments, for instance, the basis weight of the outer layers may be relatively low, such as from about 12 gsm to about 20 gsm. Alternatively, the outer layers may have a basis weight of from about 35 gsm to 175 gsm, such as from about 65 gsm to about 140 gsm. Further, the basis weight of the outer layers 20 and 22 may be similar or may be very different.
In one embodiment, one or both of the outer layers 20 and 22 may comprise elastic nonwoven webs. For instance, the webs may be formed from a block copolymer, such as a KRATON polymer manufactured by Kraton Polymers of Houston, Tex. The elastic nonwoven webs may comprise, for instance, spunbond webs or meltblown webs.
Various different types of stretch-bonded laminates are also disclosed in U.S. Pat. No. 5,385,775, U.S. Pat. No. 4,720,415, and U.S. Patent Application No. 2002/0104608, all of which are incorporated herein by reference.
As described above, after attachment of the first outer layer 20 and/or the second outer layer 22 to the elastic layer 18, the stretch-bonded laminate 16 may be released so that the elastic strands 24 return to their normal length, thus causing the first and second outer layers 20 and 22 to wrinkle.
In the embodiment illustrated in
For parallel strands, the elasticity may be one dimensional, but second dimensional elasticity can come from elastic fibers if present in the first and second nonwoven webs 20 and 22. If elastic fiber webs can be formed by spraying fibers perpendicular to the parallel strands, a knit-like microstructure is formed and may be vapor or liquid permeable. The grid type of arrangement of
Referring to
Similar to the above embodiments, the elastic film layer 18 may be stretched and then attached to the outer layers 20 and 22 for forming the laminate material. The use of an elastic film layer 18 may be desirable in some applications. For example, the film layer 18 may provide further protection to the hand of the wearer by serving as a barrier layer to the hand. The use of a film layer, for instance, may be incorporated into the glove 10 where the elastomeric coating 14 is not present. In addition, as will be described in greater detail below, the film layer 18 may prevent penetration of the elastomeric coating which may provide the glove with a higher degree of flexibility and comfort.
It should be understood that in addition to spunbond laminates, the glove of the present disclosure may be constructed from various other types of elastic laminates. In one particular embodiment, for instance, a neck-bonded laminate including reverse neck-bonded laminates may be used.
When incorporated into a glove, the elastic laminate may have uniform stretch properties or may have non-uniform stretch properties in one or more directions. For example, in one embodiment, the elastic laminate may be formed so that greater stretch and/or elasticity may be built into the laminate in particular areas, such as where the glove is expected to undergo greater tension. For example, greater amounts of stretch or elasticity may be incorporated into the hollow member in the palm area, in the cuff area, in the back side of the glove, or on the finger portions where the knuckles are located. The greater stretch or elastic areas, for instance, may comprise bands that extend across the elastic laminate.
For example, in one embodiment, the elastic laminate may comprise a stretch-bonded laminate containing outer layers made from a nonwoven web, such as a spunbond web. The spunbond webs may be formed on a forming surface containing cavities where greater amounts of fibers may deposit. These cavities, for instance, can have a rectangular shape that extends in the machine direction or the cross-machine direction. When laminated to an elastic layer, such as elastic filaments, the higher basis weight areas formed in the cavities on the forming surface may provide greater inherent stretch in those areas. For instance, the stretch or elasticity in those areas may be from about 5% to about 20% greater than the remainder of the laminate, such as from about 5% to about 10% greater.
The basis weight of the elastic laminate used to construct the hollow member 12 as shown in
When constructing the hollow member 12 as shown in
For example, in one embodiment, an elastic laminate having stretch in generally one direction may be used for the palm side of the glove while an elastic laminate having stretch in multiple directions may be used for the back side, where greater stretch is typically needed. In one particular embodiment, for instance, a neck-bonded laminate may be used to form the palm side of the glove containing a film layer while a stretch-bonded laminate containing elastic filaments may be used to construct the back side of the glove. In this embodiment, the spunbonded laminate has better elasticity which may be desirable on the back side of the glove since more flexibility is needed when the hand bends to form a fist. Also, the stretch-bonded laminate may allow gas flow therethrough so that the glove can be breathable, especially in applications where the back side of the glove is not coated with the elastomeric coating.
The neck-bonded laminate, on the other hand, may contain a polymer film layer so as to provide further barrier protection to the palm side of the hand where substances are more prone to contact the glove. The film layer also will maintain the elastomeric coating on the outside layer of the laminate.
In other embodiments, the elastic laminate used to form the palm side of the glove may be thicker and have a greater basis weight than the elastic laminate used to form the back side of the glove. In this embodiment, both elastic laminates may have a similar or different construction. The palm side, however, may be thicker and have a greater basis weight for providing greater protection against objects that are held with the glove.
When forming the hollow member 12 from a first elastic laminate and a second elastic laminate, the two panels may be attached together using any suitable method or technique. For instance, the panels may be adhesively bonded together, thermally bonded together, or ultrasonically bonded together. In still another embodiment, the panels may be sewn together to form the seam. For example,
In accordance with one exemplary embodiment of the present disclosure, the first and second stretch-bonded laminates 28 and 30 may be connected to one another through one or more “flush” seam bonds 36 as shown in
In a particular embodiment, the flush seam bonds 36 may be less than about 500 micrometers (μm) in width and about 500 μm in height. The flush seam bond 36 may also be less than 400 or 300 μm in width and 400 or 300 μm in height. Preferably, the flush seam bond 36 is less than 100 μm in width and 100 μm in height. In certain exemplary embodiments, the flush seam bond 36 width can be as narrow as about 50 μm. The width and height of the flush seam bond may be controlled, for instance, by varying the width, height and the cutting angle of the glove pattern on the bonding horn or bonding anvil, or ultrasonic sewing die.
With respect to ultrasonic bonding of the elastic laminates, the bonding seam 36 along the edges further functions as an anchor for the strands to prevent the strands from becoming loose when the seam 36 lines are formed. In one embodiment, a seam 36 line may be formed by employing an ultrasonic glove cut/seal fixture in which a flat top is present for cutting within an angle slope for simultaneous sealing. The slope part of the fixture may only melt the laminates so that the strands will be intimately bonded together for preventing the formation of loose strands. Preferably, the loose strands may be less than 50% after cut/seal, and in some embodiments, less than 75%, and in some embodiments, less than 85%, and in some embodiments, less than 90%.
When forming the seam 36, the seam may have a relatively uniform width or may have a non-uniform width. For example, in one embodiment, the seam may be wider or may include additional bonding points in high stress areas. The high stress areas may include between the thumb and the palm, between the fingers, and surrounding the opening of the glove.
Since gloves 10 may be in a variety of sizes and shapes, ultrasonic bonding installations, such as a plunge bonder, may not be able to place a whole hand glove facial onto a horn. For example, a glove 10 at 7×10 inches in size cannot be fabricated by a bonder that can only support a 6×9 inch horn. This is particularly true for large size gloves when the size is beyond the limit of a given ultrasonic bonder. In this case, it is possible to have more than one horn to make a hollow member 12. In some embodiments, two horns may be needed to make a hollow member 12. In other embodiments, four horns may be needed. Each horn can have a facial for bonding one area of the hollow member. Alternatively, the glove facial can be placed onto a large anvil and use a smaller horn to bond the glove in one or more successive plunge bonds. Rotary ultrasonic bonding can also be used with a pattern located on a cylindrical anvil.
It is also possible that three-dimensional shaped gloves or other garments can be made by stretching one laminate during bonding. In this case, the stretched laminate retracts to its normal length and causes the glove 10 to have a three-dimensional shape. Such a bonding process is especially useful for forming a glove that has open finger tips, as shown in
In certain embodiments, the hollow member can also be formed so as to include a hemline surrounding the opening for receiving the hand. The hem can be formed by either forming a cut/seal edge by ultrasonic sewing or employing a traditional hem-forming machine. The hem can be used to reinforce the strength of the cuff of the glove.
The hollow members may be arranged so that the opening for the hand of the user is located on an edge of the laminates. Once formed, the hollow members may be removed and collected. The process shown in
An inverting step may be employed to turn the hollow member so that the flush seam bonds 36 that have any height thereto are then located on the inside of the hollow member. However, the inverting step is not necessary in accordance with other exemplary embodiments. For example, the hollow member may be constructed and arranged so that the height of the flush seam bonds 36 are located on the outside of the hollow member. Additionally, the flush seam bonds 36 may be formed so that a height is negligible.
After the hollow member 12 is formed, the hollow member is then contacted with an elastomeric composition for forming a coating at least on a portion of the hollow member. For instance, as shown in
Particular styrenic block copolymers that may be used include styrene-ethylene butylene-styrene block copolymers, styrene-isoprene-styrene block copolymers, styrene-butadiene-styrene block copolymers, styrene-isoprene block copolymers, styrene-butadiene block copolymers, and the like. Block copolymers, for example, that may be used in the present disclosure are disclosed, for instance, in U.S. Pat. No. 5,112,900, U.S. Pat. No. 5,407,715, U.S. Pat. No. 5,900,452, and U.S. Pat. No. 6,288,159, which are all incorporated herein by reference.
In order to contact the hollow member 12 with the elastomeric coating composition, in one embodiment, the hollow member may be dipped into the composition. Once contacted with the elastomeric composition, the resulting glove may be heated in order to dry and/or cure the elastomeric coating.
The manner in which the elastomeric coating composition is contacted with the hollow member 12 can vary depending upon the particular application and the desired result. In one embodiment, for instance, the hollow member may contact the coating composition in a flat configuration. Alternatively, the hollow member may be placed on a hand-shaped former and then dipped into the elastomeric coating composition. It has been discovered that the above two processes may produce gloves having different physical characteristics.
For example,
When the hollow member, however, is placed on a hand-shaped former and dip coated a three-dimensional glove 10 as shown in
Referring to
The process illustrated in
In the embodiment illustrated in
As shown in
In addition to a dipping process as shown in
The amount the elastomeric coating composition penetrates through the thickness of the elastic member can also vary depending upon the particular application and the desired results. In one embodiment, for instance, it may be desirable to have the elastomeric coating composition penetrate through to the inside surface of the hollow member. In this embodiment, for instance, the elastic laminates may be completely impregnated by the elastomeric coating composition. In this manner, the elastic laminates that form the hollow member create a reinforcing matrix for the elastomeric coating.
In alternative embodiments, however, it may be desirable only for the elastomeric coating composition to penetrate only a portion of the thickness of the hollow member. For example, sufficient penetration of the hollow member may be needed in order for there to be suitable bonding between the elastomeric coating and the outside surface of the hollow member. Too much penetration, however, can increase the stiffness of the resulting article. Further, preventing penetration to the inside surface of the hollow member leaves, in one embodiment, a nonwoven material placed adjacent to the hand which provides softness. and comfort to the wearer. Further, as described above, when the nonwoven web forms the interior surface of the glove, the glove can be easily donned by the wearer.
In order to control penetration of the elastomeric coating composition, various methods and techniques may be used to control the coating process. For instance, in one embodiment, the hollow member may be formed from an elastic laminate containing a film as shown in
In addition to using a film layer in the elastic laminate, various other processing techniques may also be used to control penetration. For example, penetration of the coating composition can be controlled by varying the viscosity of the coating composition. For instance, by increasing the viscosity, penetration of the elastomeric coating composition into the hollow member can be reduced.
In addition, penetration of the coating composition can also be controlled by varying the pore size and/or the fiber size of the outer layer of the elastic laminate. For instance, smaller fiber sizes typically lead to smaller pore sizes which prevent penetration of the coating composition. In one embodiment, for instance, the elastic laminate may include an exterior surface comprising a meltblown web containing relatively small fibers. The meltblown web may be used to prevent the coating composition from impregnating the entire layer. Depending upon whether a spunbond or a meltblown web is used, the diameter of the fibers may range from about 10 microns to less than 1 micron.
In still another embodiment, penetration of the elastomeric coating can be controlled by controlling fiber packing density of the elastic laminate. For example, increasing the fiber packing density will generally inhibit the elastomeric coating composition from penetrating through the layer. For exemplary purposes only, when the elastic laminate contains nonwoven synthetic fibers, the packing density may vary from about 0.05 g/cc to about 0.3 g/cc.
In another embodiment, penetration of the elastomeric coating can be controlled by controlling the surface energy of the outside surface of the hollow member. For example, hydrophobic surfaces may react differently to the elastomeric coating than hydrophilic surfaces. For example, if the elastomeric coating composition comprises an aqueous composition, for some applications, a hydrophobic surface will prevent penetration of the coating composition.
When varying fiber size and packing density, it should be understood that such characteristics can change over the thickness of the elastic laminate. For example, the exterior surface of the laminate may be modified or otherwise constructed to control penetration, while the interior surface may have different characteristics. For example, in one embodiment, the elastic laminate may include two outer layers in which the outer layer forming the exterior surface of the hollow member has a small pore size while the outer layer forming the interior surface of the hollow member has a relatively large pore size. The same can hold true for packing density, fiber diameters, and surface energy.
In still another embodiment of the present disclosure, a precoat on the hollow member may be used in order to control penetration of the elastomeric coating composition. The precoat, for instance, may comprise a chemical composition applied to the exterior surface of the hollow member. The chemical composition may not form a film on the hollow member but may serve to control penetration of the elastomeric coating.
For example, in one embodiment, the precoat may comprise a coagulant composition for coagulating the natural or synthetic polymer contained within the elastomeric coating composition.
For example, the precoat composition may contain a coagulant which causes a film-forming polymer such as natural rubber latex or nitrile polymer to coagulate and polymerize on the outside surface of the hollow member. Coagulants that may be used may include, for instance, a solution of a coagulant salt such as a metal salt. Examples of coagulants include but are not limited to water soluble salts of calcium, zinc, aluminum, and the like. For example, in one embodiment, calcium nitrate in water or alcohol may be used as the coagulant composition. The amount of coagulant present in the solution may determine the amount of penetration of the elastomeric composition.
In order to apply the coagulant composition to the hollow member, the coagulant composition can be sprayed on the hollow member or the hollow member may be dipped into the coagulant composition. For instance, the hollow member may be applied to a hand-shaped former and dipped into the coagulant composition prior to being dipped into the elastomeric coating composition. Once applied, the coagulant may air dry leaving a residual coating on the hollow member.
Upon contact of the coating composition with the elastomeric composition, the coagulant causes the polymer contained in the elastomeric composition to become locally unstable and coagulate on the surface of the hollow member. In many applications, the coagulant itself does not form a separate layer on the article, but rather becomes part of the resulting film.
In addition to a coagulant composition, the precoat may comprise other chemical compositions. For example, in an alternative embodiment, the hollow member may be treated with a hydrophobic composition that controls and reduces penetration of the elastomeric coating.
Once the elastomeric coating composition is applied to the hollow member and dried and/or cured, the thickness of the resulting coating may vary. The thickness of the film, for instance, may be increased or decreased by increasing or decreasing the dwell time during which the hollow member contacts the coating composition. Total thickness of the elastomeric coating may also depend on various other parameters as well.
In order to increase the thickness of the elastomeric coating, in one embodiment, multiple layers of the elastomeric coating composition may be applied to the hollow member. For example, as shown in
When applying separate layers of an elastomeric coating composition to the hollow member, it should be understood that the layers can be made from the same material or from different materials. The layers may also have different thicknesses depending upon the particular application. Further, the second layer applied to the hollow member may be applied in the same areas as the first layer or may be applied in different areas. For example, in one embodiment, the second layer may only be applied to portions of the glove where further reinforcement is needed.
As described above, once the elastomeric coating is applied to the hollow member, the natural or synthetic polymer contained within the elastomeric coating may be dried, cured or vulcanized if necessary. In one embodiment, the polymer may be cured by high temperature reaction with a vulcanizing agent, such as sulfur, to cause cross-linking of the polymer chains. Curing may generally take place at temperatures of about 50° C. to about 200° C. although the temperature is dependent upon the particular polymer used. In addition to curing the polymer, the high temperature process may cause the evaporation of any volatile components remaining in the glove, including any water remaining in the layers. In other embodiments, the elastomeric coating may be air dried or cured at room temperature.
In general, the thickness of the elastomeric coating can vary from 3 mils or less to greater than 15 mils or less. For example, in one embodiment, the thickness of the elastomeric coating may be from about 3 mils to about 5.5 mils.
After the elastomeric coating is dried and/or cured, various post-processing steps may occur if desired. For example, in one embodiment, the gloves may be immersed into a leaching bath and leached. In addition, the articles may be subjected to a halogenation process, such as, for example, a chlorination process to improve the surface characteristics of the elastomeric coating. Halogenation, for instance, can control the tackiness of the resulting layer.
If desired, various other treatments may also be applied to the glove. For example, a skincare formulation or antimicrobial/antiviral agents may be applied to the glove if desired. In one embodiment, for instance, the inside surface of the hollow member can be treated with a composition intended to protect the skin of the wearer or to otherwise provide benefits to the skin. The skincare formulation, for instance, may comprise a moisturizer and various other therapeutic components. It should also be understood that the gloves can be made in any size or any suitable color.
The glove of the present disclosure may be used in all different types of applications. Particular embodiments of gloves in addition to the one illustrated in
Referring to
These and other modifications and variations to the present invention may be practiced by those of ordinary skill in the art, without departing from the spirit and scope of the present invention, which is more particularly set forth in the appended claims. In addition, it should be understood that aspects of the various embodiments may be interchanged both in whole or in part. Furthermore, those of ordinary skill in the art will appreciate that the foregoing description is by way of example only, and is not intended to limit the invention so further described in such appended claims.