Patent Application
20080135572
The present disclosure relates to wipes and in some embodiments “wet wipes,” which are stored in a dispenser having an orifice. A wipe is dispensed through the orifice by exerting a pulling force on the wipe. During dispensing, at least a portion of the wipe thickens. The present disclosure further relates to a method of signaling the thickness of a wet wipe during dispensing.
Many consumers of disposable pre-moistened nonwoven wipes, particularly baby wipes, desire a soft, cloth-like wipe that is economical. It is believed that consumers react to visual and tactile properties in their assessment of wipes. Thus, thickness and texture may signal to a consumer that a wipe has the properties of cloth.
To provide consumers with value and/or the convenience of disposability, wipes are typically made from low cost materials, such as nonwoven webs, plastic sheets, films, layers of pulp and the like. While these materials may provide for adequate cleaning of surfaces, they may fall short in providing the soft, cloth-like cleaning experience desired by at least some consumers.
Various approaches have been utilized to provide softer, more cloth-like wipes. One non-limiting approach has been to increase the thickness of wipes. Unfortunately, compressive forces encountered by wipes under typical storage and/or shipment conditions may reduce the thickness of the wipes. This can be especially problematic for wipes that are stored in a pre-moistened state, i.e., “wet wipes”.
Accordingly, it would be desirable to provide a means of recovering at least a portion of the thickness that can be lost during the storage and/or shipment of wipes, particularly wet wipes.
It would also be desirable to provide a means of signaling to a consumer that wipes, particularly wet wipes, have the cloth-like properties of thickness and/or texture.
In at least one embodiment, there is provided an apparatus for dispensing wipes. The apparatus includes a dispenser. The dispenser includes an interior storage space for storing a plurality of wipes and an orifice for providing access to wipes stored in the interior storage space. The apparatus also includes a plurality of wipes disposed in the interior storage space of the dispenser. Each wipe disposed in the interior storage space has (i) an x,y plane; (ii) an activation force; and (iii) a thickness. When at least one of the wipes is removed from the interior storage space by pulling at least a portion of the wipe through the orifice with a dispensing force that is greater than the activation force, at least a portion of the wipe increases in thickness from 20% to 200%.
These and other embodiments, aspects, and advantages are encompassed within the present invention, and will become better understood with regard to the following description and appended claims.
The accompanying figures show non-limiting embodiments incorporating various aspects of the present invention.
A “Wipe” as used herein, refers to a cleaning article that comprises a substrate of one or more layers of nonwoven web.
The terms “nonwoven web” or “web” are used interchangeably herein, and refer to a layer of individual fibers or threads that are interlaid, but not in an identifiable manner as in a knitted or woven web. Nonwoven webs may be made via processes known in the art, including but not limited to: carding; airlaying; and wetlaying. Processes comprising filament spinning from resin and integrated webforming include, but are not limited to: spunbonding; meltblowing; coforming; and forming spunbond-meltblown-spunbond composites. Fiber bonding processes of use may include, but are not limited to: spunlacing (i.e., hydroentanglement); cold calendering; hot calendering; air thru bonding; chemical bonding; needle punching; and combinations thereof.
“Fiber” as used herein, refers to the unit which forms the basic element of the nonwoven web disclosed herein. Fibers include staple fibers, fibers longer than staple fibers that are not continuous, and continuous fibers, which are sometimes referred to in the art as “substantially continuous filaments” or simply “filaments”. The method in which the fiber is prepared will determine if the fiber is a staple fiber or a continuous filament.
“Composite” as used herein, refers to superimposed layers of nonwoven web that are bonded together to form a wipe. Layers of material(s), such as pulp for example, may be interposed between the layers of nonwoven web and may be bonded together with the layers of nonwoven web to form a wipe. Bonding methods of use include, but are not limited to: spunlacing (hydroentanglement); hydroforming; and combinations thereof. Without wishing to be bound by theory, bonding steps of use in the present disclosure cause the fibers of the different layers of the composite to intertwine with one another. It is believed that the intertwining of the fibers between the layers holds the layers together such that the layers are no longer distinct and will not delaminate when pulled apart. This is in contrast to a laminate that is separable into the base layers from which it is comprised.
“Planar” as used herein refers to being in a single geometric plane, such as a plane defined by x and y axes, i.e., an “x,y plane”. In contrast, “non-planar” refers to being in more than one single geometric plane. For example, something which is three dimensional, i.e., has length, width, and height, or x, y and z axes, is non-planar.
“Protruding” as used herein, refers to extending out of a plane.
“Pre-moistened” and “wet” are used interchangeably herein and refer to wipes which are moistened with a liquid composition. The wipes may be moistened prior to packaging in a generally moisture impervious container or wrapper. Alternatively, the wipes can be sold dry and a liquid composition may be subsequently added thereto. The wipes, which can also be referred to as “wet wipes” and “towelettes,” may be suitable for use in cleaning hard surfaces, or for personal cleansing of babies, as well as older children and adults.
“Liquid composition” refers to any liquid, including, but not limited to: a pure liquid such as water, an aqueous solution, a colloid, an emulsion, a suspension, a lotion, a solution and mixtures thereof. The term “aqueous solution” as used herein, refers to a solution that is at least 20%, 40%, or even at least 50% water by weight, and is no more than 95%, or no more than 90% water by weight.
“Saturation loading” and “lotion loading” are used interchangeably herein and refer to the amount of liquid composition applied to the wipe. In general, the amount of liquid composition applied may be chosen in order to provide maximum benefits to the end product comprised by the wipe. Saturation loading is typically expressed as grams of liquid composition per gram of dry wipe and is measured using the method described below.
“Surface tension” as used herein, refers to the force at the interface between a liquid composition and air. Surface tension is typically expressed in dynes per centimeter (dynes/cm).
“Visible” as used herein refers to being visually detectable by a person with 20/20 vision when viewed at a distance of 30.48 centimeters (cm), under the unimpeded light of an ordinary incandescent 60 watt light bulb. “Visibly distinct” as used herein refers to the existence of a visible difference between items or areas of items that are compared to each other.
“Activation force” as used herein, refers to the force required to cause a portion of a substrate as described herein to protrude out of the plane of the substrate at least 3 mm. Typically, the activation force will be in a direction that is substantially parallel to the cross-machine direction (CD) and substantially perpendicular to the major rib axis, described in more detail herein below. It is to be understood that other directional forces having a directional component substantially parallel to the CD and/or substantially perpendicular to the major rib axis may also be suitable, as long as the applied force causes a portion of the substrate to protrude out of the x,y plane of the substrate as described herein.
“Dispensing force” refers to the force required to remove a wipe from a wipes container. Typically, the dispensing force is the force exerted by a user of the wipes pulling one or more wipes all the way or substantially all the way out of the container. The dispensing force may be in a direction that is substantially parallel to the activation force or even within forty-five degrees of the direction of the activation force, but need not necessarily be so.
“Color” as used herein refers to a property of a surface or substance resulting from absorption of certain wavelengths of light and reflection of others. Typically, wavelengths of light between (approximately) 370-760 μm are adequate to excite the retinal receptors of a person.
“Contrasting color” as used herein refers to colors that have a ΔL, Δa and/or Δb value of greater than 3, according to the Hunter L, a, b color scale.
“Comprising” as used herein means that various components, ingredients or steps can be conjointly employed in practicing the present invention. Accordingly, the term “comprising” encompasses the more restrictive terms “consisting essentially of” and “consisting of.”
The term “machine direction” (also “MD”) as applied to a film or nonwoven material, refers to the direction that was parallel to the direction of travel of the film or nonwoven as it was processed in the forming apparatus. The “cross-machine direction” (also “CD”) refers to the direction perpendicular to the machine direction and in the plane generally defined by the film or nonwoven material.
Markush language as used herein encompasses combinations of the individual Markush group members, unless otherwise indicated.
As noted above, the activation force of a wipe is the force applied to the wipe which causes the wipe to thicken (i.e., extend out of the x,y plane of the wipe). Without wishing to be bound by theory, it is believed that thickening occurs as a result of at least a portion of the textured regions protruding out of the x,y plane of the wipe when the wipe is removed from a suitable dispenser. Activation forces of the wipes of the present disclosure may be from 0.4 to 1.5 N, from about 0.6 to 1.2 N, or from 0.8 to 1.0 N. Both the activation force and the thickness of a wipe (before and during activation) are measured according to the method described below.
A useful dispensing force may be one that is greater than the activation force of the wipe being dispensed. Without wishing to be bound by theory, it is believed that the dispensing force required to pull a wipe from a dispenser is a function of at least two forces: (1) pull-out force; and (2) separation force. Dispensing force is measured as described below. Examples of useful dispensing forces include forces from 0.4 to 5.0 Newtons (N), from 1.0 to 4.5 N, or from 2.0 to 4.0 N.
The “pull-out force” as referred to herein is the amount of force that is needed for a single wipe to be pulled through a dispenser orifice. Non-limiting factors that may impact pull-out force include the orifice geometry, the flexibility of the material from which the orifice is made, and the friction generated between the orifice and the wipe as the wipe is pulled through the orifice.
The “separation force” as referred to herein is the amount of force that is needed to overcome wipe to wipe interactions. Wipe to wipe interactions may be described by the bond established between wipes due at least in part by surface-to-surface adhesion resulting from fiber interaction and in the case of wet wipes, lotion interaction.
Considering the foregoing, the components of the present apparatuses may be chosen so as to provide a dispensing force that is greater than the activation force of the wipes. Any suitable combination of elements may be of use and may include a choice of: a dispenser, a dispenser orifice; a wipes configuration in the dispenser; wipes; and wipe texture.
Any dispenser capable of holding wipes in the desired configuration and including a suitable orifice may be of use. One of skill in the art may chose from a number of known dispensers depending upon the desired result. For example, suitable dispensers may be liquid impermeable. Thus, in embodiments in which it is desirable to store wet wipes in a dispenser, a liquid impermeable dispenser may be used. However, it is to be understood that liquid permeable containers are also contemplated.
According to the present disclosure, a wipe may be viewed against an area of the dispenser proximate the orifice during dispensing, i.e., the dispenser may serve as a backdrop to viewing a wipe during dispensing. Thus in some embodiments, at least a portion of the dispenser proximate to the orifice has a contrasting color to that of the wipe. Without wishing to be bound by theory, it is believed that the contrasting color increases the visibility of the increase in thickness of a wipe during dispensing. In some embodiments, the inside of the dispenser lid may be a contrasting color. In some embodiments, an area adjacent to the orifice may be a contrasting color. In some embodiments, the whole dispenser lid may be a contrasting color. In yet further embodiments, the whole dispenser may be a contrasting color. For example, in some embodiments the wipes are a hue of white, whereas the dispenser is purple.
In some embodiments, the dispensers may comprise an indicium which signals to the consumer that the wipes inside the dispenser increase in thickness during dispensing. Any suitable indicium is of use. Non-limiting examples include: words, phrases, symbols, figures and cartoons.
Any one of a number of orifice shapes, sizes and or materials may be used in the current invention, as long as the orifice is configured so that the wipe, when dispensed through the orifice, is subjected to a dispensing force that is greater than the activation force of the substrate. A smaller orifice, relative to the dimensions of the wipe, may result in an increased dispensing force, as the forces acting on the wipe as it passes through a relatively smaller hole typically increase.
The orifice may be a simple two-dimensional opening, or the orifice may include an opening that is partially or completely covered by one or more flaps, except during dispensing. Without being bound by theory, it is believed that the presence of flaps over the opening increases the dispensing force. The flexibility of flaps may be adapted such that when a wipe is pulled through the orifice, the flaps partially engage the surface of the wipe without tearing the substrate or otherwise undesirably altering the integrity of the substrate.
With regard to orifice shape, any suitable two-dimensional polygonal, curved or other stylized shape may be used herein. Non-limiting examples of orifice shapes that may be useful in the current invention include circles, ovals, S-shaped openings, squares, rectangles, triangles and/or any other stylized shape based thereon.
Further, the orifice may be made from a relatively rigid material such as thermoplastic materials including polypropylene (PP), polyethylene (PE), polystyrene, polyethyleneterephthalate (PET), polypropylene/polyethylene co-polymers, and combinations thereof. A relatively rigid orifice made from a thermoplastic material will typically have a thickness of 1 mm or from 0.4 mm to 2 mm. However, it is to be understood that any thickness of orifice may be suitable for use herein, as desired. The orifice may be made from a relatively flexible material such as a thermoplastic material such as films and/or laminate films made from polypropylene, polyethylene, polystyrene, polyethyleneterephthalate, polyvinylchloride, oriented polypropylene, and combinations thereof. A relatively flexible orifice made from a thermoplastic material will typically have a thickness of 70 um, or from 20 um to 400 um. The relatively flexible orifice material may also be an elastomeric material such as a thermoplastic elastomer such as styrenic elastomers, styrene-butadiene-styrene elastomers, Styrene-ethylene-butadiene-styrene elastomers, plasticized PVC, and combinations thereof. In certain embodiments, a relatively flexible orifice made from a thermoplastic elastomer may have a thickness of from 10 um to 3 mm. The relatively rigid orifices may result in increased dispensing forces compared to relatively flexible material at least in part due to the relative differences in flexibility in the two materials.
The orifice may be an oval with dimensions of 55 mm by 25 mm made from polypropylene/polyethylene co-polymers with a thickness of 1 mm for dispensing a wipe with dimensions of 180 mm by 180 mm.
The orifice may be a circle with diameter of 48 mm made from polypropylene/polyethylene co-polymers with a thickness of about 1 mm for dispensing a wipe with dimensions of 190 mm by 105 mm.
The orifice may be an S-shaped opening with dimensions of 55 mm by 25 mm made from polypropylene/polyethylene co-polymers with a thickness of about 1 mm for dispensing a wipe with dimensions of 200 mm by 160 mm or for dispensing a wipe with dimensions of 179 mm by 170 mm.
The orifice may be an oval with dimensions of 60 mm by 30 mm made from a PP/PET laminate film with a thickness of 70 um for dispensing a wipe with dimensions of 200 mm by 160 mm or for dispensing a wipe with dimensions of 179 mm by 170 mm.
The orifice may be an oval with dimensions of 38 mm by 20 mm made from a PP/PET laminate film with thickness of 70 um for dispensing a wipe with dimensions of 200 mm by 160 mm.
The orifice may be an oval with dimensions of 45 mm by 30 mm made from a PP/PET laminate film with thickness 70 um for dispensing a wipe with dimensions of 200 mm by 160 mm or for dispensing a wipe with dimensions of 179 mm by 170 mm.
The orifice may be a circle with a diameter of 25 mm made from a PP/PET laminate film with thickness 70 um for dispensing a wipe with dimensions of 190 mm by 105 mm.
One non-limiting example of a wipes configuration includes a plurality of wipes folded and stacked in a container. Another example includes wipes that wound into a roll. Wipes may be folded in any of various known folding patterns; non-limiting examples include C-folding, Z-folding and quarter-folding. Use of a Z-fold pattern may enable a folded stack of wipes to be interleaved with overlapping portions. In some embodiments, the individual wipes may be attached end-to-end by known means including, but not limited to, using adhesives. Wipes configurations are disclosed more fully in commonly assigned U.S. Pat. No. 6,960,349.
In some embodiments, the wipes may include a continuous strip of material which has perforations between each wipe and which may be arranged in a stack or wound into a roll for dispensing, one after the other, from a container. In some embodiments the aforementioned continuous strip of material is lengthened by adhering it to a further like strip on one or both of its ends before it is stacked or wound into a roll.
The wipes of the present disclosure may include one or more layers of nonwoven web.
The wipes may also include one or more layers of other material, as desired. The present wipes may have a basis weight of from 30 to 120 grams per square meter (gsm); from 40 to 70 gsm; or from 50 to 60 gsm.
The nonwoven suitable for use herein may be made by any means commonly known in the art, such as, for example spunbonding and meltblowning. Likewise, the nonwovens suitable for use herein may be consolidated using any means commonly known in the art, such as, for example hydroentanglement, thermal calender bonding, through air thermal bonding, chemical bonding, needlepunching, and the like. As used herein, the term “hydroentanglement” generally means a process of making a nonwoven through the treatment of a starting substrate. The treatment typically comprises the steps of supporting a layer of loose fibrous material on an apertured member, and subjecting the layer to water pressures that are sufficient to cause the individual fibers to mechanically entangle with other fibers and possibly other web layers of a substrate. The apertured member can be made from any suitable surface including, but not limited to: a woven screen, a perforated metal plate, and the like. In certain embodiments, the method of making a nonwoven web may include the steps of carding followed by hydroentanglement. The nonwoven webs of the present disclosure may have a dry basis weight of from 15 to 150 grams/meter2 gsm, from 20 to 100 gsm, or from 30 to 90 gsm.
Nonwoven webs and fibrous layers used herein may be made from fibers chosen to provide desired end properties in the wipe including, but not limited to: softness, thickness, and strength. Specifically, it may be desirable to provide wipes that are strong enough to withstand the mechanical stress associated with providing the thicker wipes described herein. Examples of suitable fibers include thermoplastic fibers, non-thermoplastic fibers and mixtures thereof. The fibers and combinations of fibers may additionally comprise a certain percentage of each layer of the laminates as: multi-component, or conjugate fibers, such as bicomponent fibers; biconstituent fibers; non-round fibers; and combinations thereof.
Wipes comprising more than one layer may be composites. The layers that make up a composite are held together via inter-layer bonding. Inter-layer bonding may be achieved via any suitable method that provides for intertwining of enough fibers between the layers such that the composite will typically not de-laminate. Non-limiting examples of such inter-layer bonding processes include, but are not limited to spunlacing (hydroentanglement); hydroforming; and combinations thereof. Although a structure of separate layers may permit preferential distribution of fiber types, it may be desirable for the constituent layers to perform as a unitary web when utilized as a wet wipe. This may be particularly desirable in a baby wipes application, since de-lamination of the layers during use typically detracts from the consumer benefits delivered from such a wet wipe. Methods of manufacturing composites are discussed in further detail in U.S. Ser. No. 60/787467.
Referring now to
Wipes according the present disclosure may have a plurality of first and second regions that provide a sensation of texture to a user. The texture may cause a user to perceive the wipes as having the thickness and feel typically associated with cloth, even when the wipes are pre-moistened. The texture may also provide the wipes with good cleaning and liquid retention characteristics.
Whether a particular part of the wipe forms a peak or a valley may depend whether force is applied uniformly along opposing sides of the wipe or intermittently. For example, when a user holds the wipe with his or her hands on opposite edges of the wipe and attempts to stretch the wipe, the force exerted by the user may be observed as causing the surface of the wipe to form one or more substantially straight-line peaks between the portion of the user's hand actually contacting the wipe (e.g., the user's fingers). Without being limited by theory, it is believed that the peaks may form as a result of “necking,” whereby the material is contracting in a direction substantially perpendicular to the strain of the substrate. The peaks may be formed at a plurality of regions in the wipe surface, for example where the user's hands are applying force to discrete regions of the wipe and the regions are spaced apart. The portions of the wipe that are disposed between the regions having force applied thereto may manifest as valleys between the peaks.
The first and second regions of the wipes may be visually distinct from one another. In addition to first regions being visually distinct from second regions, the first regions may bound the second regions such that the second regions form visually distinct patterns on a web of the present disclosure. Examples of such visually distinct patterns are disclosed herein, and include, but are not limited to: regular patterns of diamond-shapes; wavy, undulating patterns; regular patterns of triangle-shapes; strips; blocks of first and second regions intermittently spaced; islands of second regions in first regions or vice versa; combinations of shapes and/or patterns; and the like. The size of the second region and/or the visual pattern formed from the relationship of the first and second region may vary, as desired. In some instances, it may be desirable to have only one second region per 2.54 linear cm in the CD of the wipe. In other instances, it may be desirable to have 2 second regions per 2.54 linear cm in the CD of the wipe. In still other instances, it may be desirable to have between 2 and 5 second regions per 2.54 linear cm in the CD of the wipe.
Referring to
The wipe 50 includes a strainable network of distinct regions. As used herein, the term “strainable network” refers to an interconnected and interrelated group of regions which are able to be extended at least 10% in a predetermined direction. Additionally, the strainable network may provide the wipe 50 with elastomeric properties such that it exhibits elastic-like behavior in response to an applied and subsequently released force.
The strainable network may include a plurality of first regions 60 and a plurality of second regions 66. The wipe 50 may also include one or more transitional regions 65 located at the interface between the first regions 60 and the second regions 66. The transitional regions 65 may exhibit complex combinations of the behavior of both the first region 60 and the second region 66. It is recognized that the various embodiments of the present disclosure may have transitional regions; however, the present disclosure is largely defined by the behavior of the web material in the first regions 60 and second regions 66, since the overall wipe behavior is not significantly dependent upon the complex behavior in the transitional regions 65.
While first regions 60 are described herein as a plurality of first regions 60, it is appreciated that in some embodiments, such as the embodiment of
The wipe 50 has a first surface, (facing the viewer in
It is not necessary that intersecting first regions 61 and 62 be generally straight, as in the embodiment shown in
In some embodiments, the width 68 of the first regions 60 may be from 0.05 cm to 0.254 cm, and in further embodiments it may be from 0.076 cm to 0.127 cm. However, other width dimensions for the first regions 60 may be suitable. In one embodiment, such that as shown in
One notable attribute of first regions 60 is the formation of a generally “reticulated structure”, a portion of which is illustrated in
First regions 60 may be substantially macroscopically planar. The first regions 60 may remain substantially unmodified by subsequent processing such that they experience little or no out of plane deformation. That is, the material within the first regions 60 may be in substantially the same condition before and after any processing steps undergone by the wipe 50. Thus, the first regions may substantially be in the x,y plane of the wipe.
The second regions 66 may include a plurality of protrusions, or raised rib-like elements 74. The rib-like elements may comprise ridges and furrows. The rib-like elements 74 may be embossed or SELFed to form what can generally be described as fan-folded structures. As shown in
The major rib axis 70 and minor rib axis 71 of the raised rib-like elements may be oriented relative to the plane of the wipe in ways other than shown in
As the wipe 50 is subjected to an applied elongation force in the transverse direction, indicated by arrows 80 in
Accordingly, as the wipe 50 is subjected to the applied elongation force, the reticulated structure of the first regions 60 experience deformation and tend to straighten out. The deformation of the first regions 60 in turn causes the second regions 66 to extend or lengthen in substantially the same direction as the direction of applied elongation force and shorten in a direction perpendicular thereto. In addition, other modes of deformation may be observed, as disclosed more fully below.
As can be seen in
While it may generally be desirable to minimize the portions of first regions 60 that do not have both major and minor rib axis components 70, 71 (i.e., first regions that are parallel to one axis or the other), benefits of the wipes described herein may be realized with substantial areas of first regions 60 aligned with either the major or minor axes of second regions 66. Such a configuration may be useful in retaining MD tensile strength when major rib axes 70 are in parallel alignment with longitudinal axis L, which in turn corresponds to the MD during web processing. Other configurations are contemplated, such as having some first regions 64 parallel to major rib axes 70, but having the major rib axes 70 in parallel alignment with transverse axis T, which, in turn, can correspond to the CD during web processing.
The composites of the present disclosure may be imparted with first and second regions, 60 and 66, comprising further patterns as described in the commonly assigned Patent applications and publications listed in the following subsection. For example, referring to
The present wipes and/or nonwoven layers from which they are made may be imparted with texture via methods described in the following Patent applications and publications: U.S. Pat. Nos. 5,143,679; 5,518,801; 5,650,214; 5,691,035; 5,914,084; 6,114,263; 6,129,801; 6,383,431; 5,628,097; 5,658,639; and 5,916,661; WO Publication Nos.: 2003/0028165A1; WO 2004/059061; WO 2004/058117; and WO 2004/058118; U.S. Publication Nos.: 2004/0131820A1; 2004/0265534A1; WO 2004/0131820A1 (U.S. patent application Ser. No. 10/737,306); and WO 2005/0281976A1 (U.S. patent application Ser. No. 11/155,805).
The physical properties relating to the activation, i.e., thickening of wipes encompassed within the present disclosure, as well as the physical properties of known wipes, are measured as follows. The resulting data is discussed at length in the Examples section below. The physical properties that are measured include: saturation load; dispensing force; wipe thickness; wipe surface texture; and activation force. Each test measurement was conducted at room temperature unless otherwise specified.
1. Saturation Load
The saturation load, often expressed as percent saturation, is defined as the percentage of the dry substrate's mass that the lotion mass represents. For example, a saturation load of 1.00 (equivalently, 100% saturation) indicates that the mass of lotion on the substrate is equal to the dry substrate mass.
The following equation is used to calculate saturation load of one wipe:
2. Dispensing Force
The dispensing force required to remove a wipe from a dispenser with an orifice is performed in a conditioned room maintained at 23° C.±2° C. (73° F.±5° F.) and 50%±5% relative humidity. Start the computer. Install the bottom plate onto the lower stationary shaft of an MTS brand tensile tester. Install a 50 Newton load cell onto the upper moving crosshead and screw-on the manual clamp. Remove lid of tub to be tested and place the tub at the bottom plate with the orifice centered to the clamp. To ensure that the dispenser will not be displaced while executing the test, use double-sided adhesive tape to fix it in position. Enable the MTS tensile tester and move the crosshead up/down, so that the clamp is at maximum altitude 2 cm above the tub-orifice (Start Point). Restart the tensile tester, start the TestWorks™ software and calibrate the load cell (calibrate the tensile tester according to the manufacture's instructions or SOP before beginning any testing).
For one orifice-product combination the measurement of one series is advisable. One series=30 wipes. Load is recorded in grams-force or Newtons.
3. Activation Force
Activation Force is measured according to EDANA method 20.2-89 using an MTS tensile tester to record the relationship between force and strain or load and strain for a 50 mm wide sample. For this test, samples are cut to 180 mm length in the MD and 50 mm length in the CD. Due to the size of the samples, an initial jaw separation of 100 mm is used.
4. Wipe Thickness
Wipe thickness is measured with a ProGage™ Thickness Tester (SN 44722) from Thwing-Albert, N.J., USA, and EDANA 30.4-89 instrument requirements. For this test, 5 samples are cut to 90 mm in CD and 180 mm in MD. The samples are first tested for thickness under normal relaxed conditions. Then the samples are tested under strained or elongated conditions. For the strained or elongated conditions reference lines were marked 60 mm apart on the samples perpendicular to the direction of strain. The samples are then manual strained or elongated in 5 mm increments up to 80 mm which correspond to 8.3%, 16.7%, 25%, and 33% strain. The thickness at each of these strained or elongated conditions in then recorded.
5. Wipe Surface Texture
The surface texture of a wipe is measured using an optical 3D measuring device also known as MikroCAD Optical Profilometer by GFM™ (GFMesstechnik GmbH, Germany). The measuring device utilizes a CCD (Charged Coupled Device) camera coupled with a stripe light projector (SLP) where the object to be measured is angular lighted under a defined angle (45°) with an array of equidistant stripes. The projected stripe patterns (recorded by the camera) have a cos2 dependent intensity distribution and can be evaluated as interferograms. Thus, height information is included in stripe position as well as the grey value providing high resolution of surface geometries. Image analysis software provided by GFM™ (ODSCAD 5.075 E) is utilized for characterizing texture (heights and ridges) on nonwoven samples.
Test samples of a wipe are cut to 18 cm length in the MD and 10 cm length in the wipes' CD. For these samples the MikroCAD optical profilometer from GFMesstechnik GmbH is used to measuring texture (height, ridges) for the samples. The measurement is performed on both sides of the samples in a relaxed state without any strain and after about 25% strain in the CD. All the images are scaled and calibrated before measuring the actual heights in millimeter (mm) or micrometers (μm). A dot is marked on each of samples to enable a repeatable positioning of the instrument from side to side.
Each of examples 1, 2 and 3, provides a wipe having a unique surface texture when dispensed through a suitable dispenser orifice.
A pre-moistened wipe is prepared according to the present disclosure as follows. A polyethylene-polypropylene bicomponent fiber substrate, manufactured by BBA Fiberweb, Simpsonville, S.C., U.S.A., is the starting spunbond. This spunbond is a 15 gsm spunlaid nonwoven comprising about 3.0 denier fibers (denier is the mass in grams per 9,000 linear meters of fiber) that are thermally bonded. The pulp is about 38 gsm Southern Softwood Kraft pulp with no additional wet chemical additives such as wet strength resins. The composite is formed by layering two outer layers of the spunbond nonwovens with an inner layer of pulp and hydroentangling to the extent that the fibers from the layers are intertwined. The composite is then processed to impart a texture with substantial first and second regions, for example by SELFing. The composite has a basis weight of 68 gsm. The substrate also had a lotion load of about 3.0 g/g by weight of the substrate.
A pre-moistened wet wipe currently sold under the Pampers™ brand, by the Procter & Gamble Company, Ohio, USA, comprises about 60% polypropylene and 40% rayon staple fibers which are hydroentangled together to form a substrate. During hydroentanglement, a circular pattern designated 910P and supplied by the Reiter Company, France is imparted or hydro-molded into the substrate. The substrate also has a design of clouds and ducks which is imparted into the substrate via thermal calendering. The basis weight of the substrate is about 58 gsm. The substrate has a lotion load of about 3.4 g/g by weight of the substrate.
A pre-moistened wet wipe currently sold under the Huggies™ brand by Kimberly-Clark, Wisconsin, USA, contains outer layers of a homogenous mixture of pulp and meltbown polypropylene fibers and an inner layer of elongated elastic synthetic fibers oriented in the machine direction. The layers are thermally bonded together to create a rippled texture. The basis weight of the substrate is about 70 gsm. The substrate also had a lotion load of about 3.4 g/g by weight of the substrate.
Peak dispensing force is measured using the method described supra. The force required to pull example 1 through the dispensing orifice ranges from about 1.5 to 4 Newtons. Thus, the force to activate a wipe, i.e., increase its thickness and texture, is less than the force required to dispense the wipe through the orifice.
Without being bound by theory, the substantial increases in thickness and texture under strain results from the relative modulus of elasticity difference between the first and second regions. Under the overall strain on the wipe, the first regions tend to deform to a lesser extent than the second regions, enabling expansion of the second regions. The relative flexibility of the second regions may also allow for them to: (1) visibly increase in height, and/or (2) undergo displacement such that they protrude below the plane of the wipe during dispensing.
The dimensions and values disclosed herein are not to be understood as being strictly limited to the exact numerical values recited. Instead, unless otherwise specified, each such dimension is intended to mean both the recited value and a functionally equivalent range surrounding that value. For example, a dimension disclosed as “40 mm” is intended to mean “about 40 mm”.
All documents cited in the Detailed Description are, in relevant part, incorporated herein by reference; the citation of any document is not to be construed as an admission that it is prior art with respect to the present disclosure. To the extent that any meaning or definition of a term in this document conflicts with any meaning or definition of the same term in a document incorporated by reference, the meaning or definition assigned to that term in this document shall govern.
While particular embodiments of the present disclosure have been illustrated and described, it would be obvious to those skilled in the art that various other changes and modifications can be made without departing from the spirit and scope of the disclosure. It is therefore intended to cover in the appended claims all such changes and modifications that are within the scope of this disclosure.
This application claims the benefit of U.S. Provisional Application 60/856,145, filed Nov. 2, 2006.
| Number | Date | Country | |
|---|---|---|---|
| 60856145 | Nov 2006 | US |
