Patent Document

FIELD OF THE INVENTION 
     This invention relates generally to disposable absorbent articles and more specifically to disposable absorbent articles, e.g., light incontinent pads, light menstrual cycle pads, and the like, that are flexible in the interest of comfort while exhibiting enhanced resistance to leakage. 
     BACKGROUND OF THE INVENTION 
     Disposable absorbent sanitary articles, e.g., such as pantiliner pads, frequently make use of one or more lines or grooves to deter the egress of liquid out of the article. For example, U.S. Pat. No. 5,807,365 (Luceri) discloses a disposable shield of a generally dog-bone shape comprising a thin, highly absorbent pad having a body-contacting surface, an absorbent layer, a liquid barrier, a positioning adhesive for attaching the pad to an undergarment, and a release layer to protect the adhesive prior to use. The pad further comprises densified areas forming unbroken concentric rings having the same general shape as the shield itself. These rings are made by fusing all pad layers together in a pattern embosser to create densified areas resistant to the flow of liquid therethrough. The densified areas are made contiguous such that fluid, when introduced or deposited on the pad, will be prevented or hindered from flowing to the edges of the pad. Moreover, the concentric rings serve to separate, or compartmentalize, the pad into distinct absorbing areas which are isolated from each other. 
     U.S. Pat. No. 5,795,344 (Chappell) discloses an absorbent article, such as a sanitary napkin having a cover, a baffle and an absorbent between the cover and baffle and includes a single, unbroken embossed channel positioned inward from the peripheral edge of the article. The channel impedes the flow of fluid toward the edges of the absorbent article and increases absorbent utilization in the absorbent article. The channel can be produced various ways, such as by application of heat, including hot calendar embossing or by using ultrasonic means. 
     U.S. Pat. No. 5,891,118 (Toyoshima et al) discloses elongated absorbent articles that includes an antileakage groove formed along each longitudinal side portion of the article. The antileakage groove may be continuous or discontinuous and only extends partially into the thickness of the article. 
     Other United States Patents disclosing absorbent articles or pads with channels, grooves or embossed or debossed lines are: U.S. Pat. No. 4,624,666 (DeRossett et al), U.S. Pat. No. 4,758,240 (Glassman), U.S. Pat. No. 5,104,396 (Oatley et al), U.S. Pat. No. 5,447,506 (Lindquist), U.S. Pat. No. 5,451,442 (Pieniak et al) and U.S. Pat. No. 5,613,960 (Mizutani). 
     Pantiliners or other sanitary disposable absorbent articles or pads are also commercially available that make use of at least one barrier line to prevent the egress of liquid from a peripheral portion of the article. For example, a “regular maxipad” sold under the trademark FRESH TIMES® by The Kendall Confab Retail Group, a division of the assignee of this invention, basically comprises an hour-glass shaped pad having an outer sheet or cover formed of a fluid-impervious, e.g., plastic, material, an inner liner formed of a fluid-pervious, e.g., non-woven, material, and an absorbent core, e.g., fluff and/or SAP, etc., interposed therebetween. In order to prevent leakage of the liquid which is absorbed through the inner liner into the core, the FRESH TIMES® pad is embossed, e.g., heat sealed, along a broken line generally conforming to the periphery of the pad. The breaks or gaps in the line are provided in the interest of maintaining flexibility of the pad so that it can conform to the crotch area of the wearer. To that end, the embossed line is broken at two points along both of the long sides of the pad spaced from the center of those sides and just at the interface with the ends of the line. The unbroken portions of the embossed line serve as a barrier to prevent the migration of liquid through it and out of either marginal side edge of the pad or out of either marginal end edge of the pad. 
     While all of the foregoing absorbent articles are suitable for their intended purposes, they never the less leave something to be desired from the standpoint of retention of fluid, (e.g., resistance to leakage) flexibility and conformability to the body of the wearer. 
     SUMMARY OF THE INVENTION 
     This invention relates to a disposable absorbent article, e.g., pantiliner or other absorbent pad, arranged to be worn by a wearer to trap and collect fluid waste products of the wearer and a method of making the absorbent article. The pad being an elongated generally planar member having a periphery, e.g., of a general hour-glass shape, including a pair of longitudinal extending, e.g., concave, sides interconnecting respective ones of a pair of ends, e.g., convex ends. 
     The pad basically comprising a top-sheet, a fluid absorbent core, and a cover sheet. The top sheet is formed of a fluid pervious material, e.g., a non-woven material, and is disposed over the absorbent core. The absorbent core comprises a fluid absorbing material, e.g., cellulosic fluff and super-absorbent particles, and is disposed over the cover sheet. The cover sheet is formed of a fluid impervious material, e.g., a plastic film. 
     The top-sheet, the fluid absorbent core and the cover sheet are bonded together along plural concentric lines located adjacent the sides and plural concentric lines adjacent the ends, e.g., plural concentric lines which are themselves concentric with the periphery of the pad. The plural concentric lines form a barrier resistant to the egress of fluid out of the periphery of the pad and include at least one gap therein to facilitate the bending of the pad. 
     In accordance with one aspect of the method the concentric lines are produced by the application of pressure, e.g., thermal bonding, to compress the material of the top-sheet, the fluid absorbent core and the cover sheet together to form a line resistant to the passage of fluid therethrough. 
    
    
     DESCRIPTION OF THE DRAWING 
     FIG.1 is a plan view of one preferred embodiment of an absorbent article or pad constructed in accordance with the subject invention; 
     FIG. 2 is an enlarged, exploded, cross sectional view taken along line  2 — 2  of FIG. 1; 
     FIG. 3 is a plan view, similar to FIG. 1, but showing an alternative embodiment of an absorbent article or pad constructed in accordance with the subject invention; 
     FIG. 4 is a plan view, similar to FIGS. 1 and 3, but showing still another alternative embodiment of an absorbent article or pad constructed in accordance with the subject invention; and 
     FIG. 5 is a plan view, similar to FIGS. 1,  3  and  4  but showing yet another alternative embodiment of an absorbent article or pad constructed in accordance with the subject invention. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Referring now to the various figures of the drawing wherein like reference characters refer to like parts, there is shown in FIG. 1 a disposable absorbent article  20  constructed in accordance with one embodiment of this invention. It should be pointed out that as used herein the term “disposable” means that article is designed to be used until soiled, either by urination or otherwise, and then discarded, rather than being washed and used again. 
     In the embodiment of FIG. 1 the article  20  is in the form of a pantiliner pad. While the following description will focus on pantiliners, it should be clear that the subject invention can be used for any type of pad-like absorbent article to be worn by a person within an undergarment for trapping urine or menses. 
     The pantiliner  20  basically comprises a thin generally planar structure. In particular, the pad may be any thickness in the range of 1 mm to 12 mm, with 3.0 mm being one preferred thickness for a pantiliner. As can best be seen in FIG. 2, the pad is formed of a liquid pervious inner liner or layer  22 , a liquid absorbent, e.g., air-laid composite, core  24 , and an outer cover or moisture barrier  26 . The inner layer may be of any liquid pervious material. One particularly suitable material is a 15 gsm wettable nonwoven coverstock, made of spun bond polypropylene, available from BBA Nonwovens. The inner layer  22  is disposed directly on-top of the absorbent core  24  and, if desired may be secured thereon by a low add-on adhesive (not shown). One particularly suitable material for the adhesive is available from National Starch and Chemical of Bridgewater, N.J. under the trade designation 34-5637. The inner layer  22  may be formed of other material fibers (e.g., polyethylene, bi-component, polyester, rayon, cotton, etc.), fiber combinations (e.g., spunbond, air laid, wet laid, carded, hydroentangled, etc.), and basis weights may be used as well. In fact, if desired, the inner layer  22  may be formed of a liquid impermeable material, e.g., three dimensional polymeric film, having plural apertures or pores extending therethrough so as to make the material liquid permeable. One particularly suitable polymeric film is that disclosed in U.S. Design Letters Pat. No. 362,120, which patent is assigned to the same assignee as this invention and whose disclosure is incorporated by reference herein. 
     The outer layer or moisture barrier  26  is disposed directly over the other side of the absorbent core  24 , i.e., on the opposite side from the inner layer  22 , and, if desired may be secured thereon by a high add-on adhesive (not shown, like that which may be used to secure the inner layer  22  to the core  24 ). 
     The core  24  can be made up of any suitable absorbent material, as well as combinations of different types of absorbent material(s). For example, in one preferred embodiment shown herein the absorbent core  24  is formed of an air-laid absorbent material, such as wood pulp, and which optionally can contain a super absorbent polymer powder (SAP) and a binder. Examples of SAP include polyacrylamides, polyvinyl alcohol, polyacrylates, various grafted starches, and the like. One particularly suitable super absorbent material is a cross-linked polysodium acrylate, which can be purchased from Chemdal Corporation, Palatine, Ill., under the trade designation ASAP 2100. 
     If desired the pad may include a fluid acquisition or transfer layer (not shown) located between the inner layer  22  and the core  24 . As is known a fluid acquisition layer serves to manage, transport, accommodate and/or direct high volumes and flow rates of urine into the core. The fluid acquisition layer can be of any type construction, e.g., a thru-air bonded/carded web, a spunbond bicomponent non-woven web, a web of crosslink cellulosic fibers, apertured  3 D (three dimensional) film or the like. 
     In order to hold the pad  20  in place within the wearer&#39;s undergarment, it includes a stripe  28  (FIG. 2) of a “positioning” adhesive on the outer surface of the moisture barrier  26  extending along the longitudinal central axis of the pad for substantially the length of the pad. Any suitable positioning adhesive can be used for the stripe, such as a pressure sensitive hot melt adhesive. One particularly suitable material for the positioning adhesive  28  is available from National Starch and Chemical of Bridgewater, N.J. under the trade designation 34-5598. In order to protect the positioning adhesive stripe  28  from degradation or being soiled by debris, a single release strip  30  (e.g., a release paper) is releasably secured over the stripe. The release strip  30  can be formed of any suitable adhesive protective, yet easy to release, material. One particularly suitable material for the adhesive release strip  30  is available from DCP Lohja Inc. of Willowbrook, Ill. under the trade designation ESP 39. 
     As best seen in FIG. 1 the periphery or outer profile of the inner layer  22  and the moisture barrier  26  is of a general “dog-bone” shape having a pair of convex arcuate ends  32 A and  32 B and a pair of slightly concave arcuate sides  32 C and  32 D. The inner layer  22  and the moisture barrier  26  are each of the exact same size and are disposed coincident with each other. The core  24  is of the same general shape as the inner layer  22  and the moisture barrier  26 , but is slightly smaller in size, and is centered within the confines of the coincident peripheries of the inner layer and moisture barrier. The marginal portions of the inner layer  22  and the moisture barrier  26  which extend beyond the periphery of the core  24  are secured together along their respective inner surfaces by any suitable means, e.g., thermal or ultrasonic bonding, or by an adhesive (not shown) to form a peripheral seal line  36 . One particularly suitable material for the adhesive is available from National Starch and Chemical of Bridgewater, N.J., under the trade designation 34-5637. 
     In accordance with one exemplary embodiment of this invention the longitudinal dimension of the pad, i.e., the maximum distance between the arcuate ends  32 A and  32 B along the central longitudinal axis is approximately 13 inches (33 cm), whereas the lateral dimension measured transversely across the pad at the center of the longitudinal, i.e., the minimum distance between the arcuate sides  32 C and  32 D is approximately 2 inches (5 cm). 
     In order to prevent the migration of liquid, e.g., urine or menses, laterally out of the pad  20 , as well as to ensure that such liquid is directed throughout the pad into its core  24  for trapping therein, the pad  20  includes a plurality of concentric barrier lines (to be described later). Each of the concentric barrier lines is arranged to form a somewhat dense wall across which fluid cannot flow, while helping to direct or “channel” the fluid to flow therealong. 
     As will be appreciated by those skilled in the art from the explanation to follow, the manner of formation of the concentric barrier lines results in the portion of the pad  20  along each line being denser than the contiguous areas of the pad to result in a reduced or restricted flexibility along the line. This factor would render a pad having respective continuous, i.e., unbroken, concentric barrier lines somewhat inflexible and uncomfortable. In order to overcome this characteristic, each concentric barrier line of the subject invention is broken to form at least one gap therein, so that the pad can readily flex or bend at the location of the at least one gap. Moreover, fluid (e.g., urine and/or menses) can flow through the at least one gap from one area of the pad that is bounded by a barrier line into another area of the pad that is bounded by another barrier line, thereby spreading the fluid throughout the core, while the unbroken portions of the concentric barrier lines preclude the egress of the fluid from the periphery of the pad. 
     In the embodiment  20  shown in FIG. 1 there are three concentric barrier lines  38 , 40 , and  42 . Each of the lines  38 ,  40  and  42  is of the same general shape as the periphery of the pad  20 . Each line includes a pair of convex arcuate end sections and a pair of concave side sections. The end sections of the barrier line  38  are designated by the reference numbers  38 A and  38 B. The end sections of the barrier line  40  are designated by the reference numbers  40 A and  40 B, and the end sections of the barrier line  42  are designated by the reference numbers  42 A and  42 B. The side sections of the barrier line  38  are designated by the reference numbers  38 C and  38 D. The side sections of the barrier line  40  are designated by the reference numbers  40 C and  40 D, and the side sections of the barrier line  42  are designated by the reference numbers  42 C and  42 D. 
     Each section of each barrier line is produced by applying pressure and/or heat to the portions of the pad along the line to compress and increase the density of the materials along those lines, e.g., to compress the core  24 . Depending upon the construction of the pad, the compression and/or heat applied to the materials making up the pad (particularly its core) causes the interstitial space between the individual fibers making up the core (any other layers of the pad composed of fibrous material) to compress or become densified to the point at which such densified areas are insufficient to allow liquid to flow therethrough. The application of pressure and heat can be accomplished using conventional thermal or ultrasonic bonding techniques or by pattern embossing. In some applications the use of pressure alone may be sufficient to produce a dense barrier line which remains after the pressure is removed. Moreover, an adhesive may be used when pressure is applied to create the dense barrier line. In fact, it is contemplated that water can be used in lieu of an adhesive for use with a core of suitable material so that after the pressure is released and the core dries the previously wet and compressed portions of the core will remain compressed, thereby forming the barrier lines. 
     As will be appreciated by those skilled in the art most leakage from a pad is along the marginal sides along the center portion of the pad. Thus, each of the side sections  38 C and  38 D of the barrier line  38 , each of the side sections  40 C and  40 D of the barrier line  40 , and each of the side sections  42 C and  42 D of the barrier line  42  extend for a substantial distance along the respective sides  32 C and  32 D of the pad  20  and are centered along the longitudinal axis of the pad. These relatively long side sections prevent liquid from exiting the pad laterally. The end sections  38 A and  38 B of the barrier line  38 , the end sections  40 A and  40 B of the barrier line  40 , and the end sections  42 A and  42 B of the barrier line  42  extend for a substantial distance along the respective ends of the pad and are centered about the longitudinal axis of the pad to preclude liquid from gaining egress at the ends of the pad. 
     A short, e.g., 0.125 inch to 1 inch, gap  44  is located between the ends of the barrier line sections  38 A and  38 C of line  38 , between the ends of the barrier line sections  40 A and  40 C of line  40 , and between the ends of the barrier line sections  42 A and  42 C of line  42 . Another short, e.g., 0.125 inch to 1 inch, gap  46  is located between the ends of the barrier line sections  38 B and  38 C of line  38 , between the ends of the barrier line sections  40 B and  40 C of line  40 , and between the ends of the barrier line sections  42 B and  42 C of line  42 . Still another short, e.g., 0.125 inch to 1 inch, gap  48  is located between the ends of the barrier line sections  38 B and  38 D of line  38 , between the ends of the barrier line sections  40 B and  40 D of line  40 , and between the ends of the barrier line sections  42 B and  42 D of line  42 . Finally, another short, e.g., 0.125 inch to 1 inch, gap  50  is located between the ends of the barrier line sections  38 D and  38 A of line  38 , between the ends of the barrier line sections  40 D and  40 A of line  40 , and between the ends of the barrier line sections  42 D and  42 A of line  42 . 
     The short gaps  44 - 50  enable the pad  20  to flex or bend at their respective locations so that the pad can be bent into a generally cup-shaped member from end to end to accommodate the crotch of the wearer when the pad is worn within an undergarment. Moreover, since the barrier lines are concentric, e.g., spaced from each other by approximately 0.24 inch (6 mm) fluid (e.g., urine and/or menses) can flow through the gaps  44 - 50  from the area bounded by the innermost of the barrier lines, i.e., line  42 , into the areas between that line and the intermediated barrier line  40 , and through those gaps into the areas between the intermediate line  40  and the outermost of the barrier lines, i.e., line  38 , thereby spreading the fluid throughout the core. The unbroken portions of the concentric barrier lines, as described above, serve as a wall across which the fluid cannot flow, thereby precluding the egress of the fluid from the virtually the entire periphery of the pad. In this regard, while there is no barrier wall at the gaps, it is unlikely that any liquid will gain egress from the pad at these locations since they are relatively short in length so that virtually all of the liquid will be trapped in the core of the pad bounded by the unbroken portions of the barrier lines. 
     In FIG. 3 there is shown an alternative embodiment of a pantiliner pad  100  constructed in accordance with this invention. The pad  100  is identical in construction to the pad  20  described heretofore except for the construction of the end sections of each of its barrier lines. In the interest of brevity the common components of the pads  20  and  100  will be given the same reference numbers and the details of their construction and operation will not be reiterated. Thus, as can be seen the end sections of each of the barrier lines  38 ,  40  and  42  is in the form of a broken or segmented line. In particular, one end section of the barrier line  38  is in the form of broken line  138 A having a plurality of short segments  102  which are spaced from each other by respective very narrow gaps  104 . The opposite end section of the barrier line  38  is in the form of a broken line  138 B having a plurality of short segments  102  which are spaced from each other by respective very narrow gaps  104 . In a similar manner one end section of the barrier line  40  is in the form of broken line  140 A having a plurality of short segments  102  which are spaced from each other by respective very narrow gaps  104 . The opposite end section of the barrier line  40  is in the form of a broken line  140 B having a plurality of short segments  102  which are spaced from each other by respective very narrow gaps  104 . So too, one end section of the barrier line  42  is in the form of broken line  142 A having a plurality of short segments  102  which are spaced from each other by respective very narrow gaps  104 . The opposite end section of the barrier line  42  is in the form of a broken line  142 B having a plurality of short segments  102  which are spaced from each other by respective very narrow gaps  104 . 
     The short segments of each of the end sections of the barrier lines are formed in the same manner as the barrier lines  38 ,  40  and  42  described heretofore and each can be of the same length as the others of that section or can be of different lengths. The segments  102  can be in the range of 0.08 inch (2 mm) to 0.8 inch (20.3 mm). So too, each of the gaps can be of the same length as the others of that section or can be of different lengths. The gaps  102  can be in the range of 0.08 inch (2.0 mm) to 0.8 inch (20.3 mm). 
     As should be appreciated by those skilled in the art, by providing the short segmented end sections  138 A and  138 B,  140 A and  140 B, and  142 A and  142 B, with the multitude of gaps  104  therein, the end portions of the pad  20  can be quite flexible and readily able to conform to the wearer&#39;s anatomy. Moreover, since there is less of a tendency for liquid to gain egress from the pad at its ends, than at its center, the fact that there are broken barrier lines at the ends of the pad should not result in any substantial leakage from the ends, particularly since the end segments  102  will act as a barrier to the egress of liquid and will serve to channel or direct the liquid into other portions of the pad  100 . 
     In FIG. 4 there is shown another alternative embodiment of a pantiliner pad  200  constructed in accordance with this invention. The pad  200  arranged to be even more flexible than the pads  20  and  100 , and is identical in construction to those pads  20  and  100  except for the construction of each of its barrier lines. In the interest of brevity the common components of the pads  20 ,  100  and  200  will be given the same reference numbers and the details of their construction and operation will not be reiterated. Thus, as can be seen each of the barrier lines  238 ,  240  and  242  is in the form of a broken or segmented line similar to the end line sections  138 A and  138 B,  140 A and  140 B, and  142 A and  142 B of the pad  100 . In particular, the innermost barrier line  242  is in the form of a segmented line having a plurality of short segments  102  which are spaced from each other by respective very narrow gaps  104 . The intermediate or middle barrier line  240  is also in the form of broken line having a plurality of short segments  102  which are spaced from each other by respective very narrow gaps  104 , while the outermost barrier line  238  is also in the form of broken line having a plurality of short segments  102  which are spaced from each other by respective very narrow gaps  104 . Each of the gaps  104  of each concentric barrier line is aligned with a corresponding gap of the immediately adjacent barrier line. 
     The shape of each of the barrier lines  238 ,  240  and  242  is of the same general shape as the barrier lines described with reference to pads  20  and  100 . Moreover, the short segments of each of the barrier lines  238 ,  240  and  242  are formed in the same manner as described heretofore and each can be of the same length as the others of that section or can be of different lengths. The segments  102  can be in the range of 0.08 inch (2.0 mm) to 0.8 inch (20.3 mm). So too, each of the gaps can be of the same length as the others of that section or can be of different lengths. The gaps  102  can be in the range of 0.08 inch (2.0 mm) to 0.80 inch (20.3 mm). 
     As should be appreciated by those skilled in the art, by providing barrier lines of short segments spaced from one another by a multitude of small gaps, particularly where the gaps are aligned with one another as is the case in this embodiment, the resulting pad  200  has the ability to bend or flex readily over virtually its entire length and width, so that it can closely conform to the body of the wearer in the interest of comfort. The fact that the barrier lines are broken along their entire length should not result in any substantial leakage from the pad through them, since the gaps are small and each of the segments  102  will act as a barrier to the egress of liquid and will serve to channel or direct the liquid into other portions of the pad  200 . 
     If more leakage protection is desired, without a substantial loss in flexibility, the pad may be constructed in accordance with the embodiment shown in FIG.  5 . In particular, in FIG. 5 there is shown another alternative embodiment of a pantiliner pad  300  constructed in accordance with this invention. The pad  300  is identical in construction to the pads  200  except for the construction of each of its barrier lines  338 ,  340  and  342 . In the interest of brevity the common components of the pads  200  and  300  will be given the same reference numbers and the details of their construction and operation will not be reiterated. Thus, as can be seen each of the barrier lines  338 ,  340  and  342  is in the form a broken line similar to the barrier lines  238 ,  240  and  242 , except that the line segments are somewhat longer in length and the gaps between the segments of one barrier line are offset or staggered from the gaps between the segments of the immediately adjacent barrier line. In particular, the innermost barrier line  342  is in the form of broken line having a plurality of short segments  302  which are spaced from each other by respective very narrow gaps  304 . The intermediate or middle barrier line  340  is also in the form of broken line having a plurality of short segments  302  which are spaced from each other by respective very narrow gaps  304 , while the outermost barrier line  338  is also in the form of broken line having a plurality of short segments  302  which are spaced from each other by respective very narrow gaps  304 . Each of the gaps  304  of each concentric barrier line is offset or staggered with respect to a corresponding gap of the immediately adjacent barrier line, thereby creating a tortuous path through which the liquid in the pad must flow if it is to gain egress from the pad. In particular, any liquid (e.g., urine and/or menses) in the portion of the pad located within the confines of the innermost barrier line  342  can flow through any of its gaps  304  into the space between that line and the intermediate barrier line  340 . The liquid will be prevented from flowing radially outward by the presence of the staggered line segments  302  of the intermediate line, so it will have to flow along those line segments. Any liquid which reaches the gaps of the intermediate barrier line  340  can then flow out of those gaps into the space between the intermediate barrier line and the outermost barrier line  338 . The liquid will be prevented from flowing radially outward by the presence of the staggered line segments  302  of the outermost barrier line, so it will have to flow along those line segments. 
     The segments of each of the barrier lines  338 , 340  and  342  are formed in the same manner as described heretofore and each can be of the same length as the others of that section or can be of different lengths. The segments  302  can be in the range of 0.08 inch (2.0 mm) to 0.80 inch (20.3 mm). So too, each of the gaps can be of the same length as the others of that section or can be of different lengths. The gaps  304  can be in the range of 0.08 inch (2.0 mm) to 0.80 inch (20.3 mm). 
     As should be appreciated by those skilled in the art, by providing barrier lines of short segments spaced from one another by a multitude of small staggered gaps, the resulting pad  300  has the ability to bend or flex readily over virtually its entire length and width in the interest of comfort, yet will exhibit excellent fluid retention characteristics. 
     It should be pointed out at this juncture that pads constructed in accordance with this invention can be of various shapes and/or sizes and/or constructions. Moreover, the pads can include any plural number of broken barrier lines, with the shape of those lines being either the same as that of the pad or of different shapes. 
     Without further elaboration the foregoing will so fully illustrate my invention that others may, by applying current or future knowledge, adopt the same for use under various conditions of service.

Technology Category: 1