Patent Publication Number: US-2005133964-A1

Title: Semisolid product dispensing head

Description:
REFERENCE TO EARLIER FILED APPLICATION  
      The present application claims the benefit of the filing date under 35 U.S.C. § 119(e) of provisional U.S. Patent Application Ser. No. 60/142,176, filed Jul. 1, 1999, which is hereby incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION  
      The present invention relates primarily to a dispenser for gel deodorants or other semisolid products, and particularly to the head of a deodorant dispenser and methods of making the head and otherwise treating porous media so as to have properties desired in a semisolid product dispenser.  
      Deodorants and antiperspirants (hereinafter jointly referred to as deodorants) are typically applied to the skin of the underarm from some form of dispenser. Years ago aerosol cans were commonly employed to dispense deodorants. Deodorants in solid form have become popular. The solid deodorant is held in a body that has a piston. A cap is removed from the body, and the piston is activated to force the solid deodorant upwardly until the top portion is exposed. The top portion can then be rubbed onto the underarm skin.  
      Most recently, clear, gel deodorants have been proposed. Other semisolid forms of deodorant, such as creams or soft sticks, have also been suggested. One of the benefits of such semisolid deodorants is that they are less expensive to manufacture, because the fluid nature of the semisolid deodorant allows it to be pumped and easily loaded into a dispenser as part of the manufacturing step. One of the difficulties with dispensing a gel or other semisolid is that there must be a surface onto which the semisolid deodorant is applied, which is then brought into contact with the underarm. One prior art gel deodorant dispenser used a type of a grate. Gel was forced upwardly from within a body holding the gel through holes in the grate. The gel stayed on top of this grate and was then wiped onto the skin of the underarm. The grate was rigid, and was formed by injection molding plastic into a mold. The holes were formed by core pins within the mold.  
      Another proposal was to take a woven screen material and insert mold the woven screen material into a frame, thus forming a head. However, because the woven screen material was not rigid, it was proposed to include supports within the head to force the screen material to take on a dome shape so that it could contact the skin of the underarm. Several problems have been encountered with this proposal. First, the supports inherently block some of the openings in the screen, and the gel comes out unevenly across the screen. However, if no supports are used, and the screen collapses, all of the gel under the screen will come out, causing an overdose.  
      Second, the opening size of the screen plays conflicting roles. If the opening size is too large, the gel material will flow out if the dispenser is tipped on its side. On the other hand, if the opening size is too small, the gel material has to be put under such pressure when it is forced through the screen that the gel structure is compromised. For example, the liquid portion of the gel may disassociate from solid portions, or oil and water emulsions of other semisolid deodorants may break. In addition, when a semisolid deodorant is over pressurized, it continues to ooze out even though the user no longer activates the piston, and in fact may have set the dispenser aside after using it. When the user comes back, the deodorant has come through the screen and dried on top of the screen.  
      Another problem with woven screen material is that it is difficult to provide openings consistently sized any smaller than 400 square microns (20 microns by 20 microns) when making a weave. It is nearly impossible to make an opening smaller than 5 microns by 5 microns using a woven screen. If a media with an opening of 2 microns or less is desired, a porous membrane usually has to be used. Thus, if the semisolid deodorant material has a low viscosity, it may not be possible to make a normal woven screen with a pore size that will prevent the material from leaking out.  
      Another problem with the use of a woven screen is that the percent open area of a screen gets smaller and smaller as the pore size is reduced. The strands or fibers making the screen must be large enough to give integrity to the screen. As they are placed closer and closer to one another to reduce the pore size, the ratio of open area to area blocked by the fibers is reduced. The problem with a low percentage open area is that the amount of material that can be forced through the screen is reduced as the percent open area is decreased.  
      Another problem with a woven screen material is that if it is stretched while being manufactured as part of the dispensing head, especially around the edges when a rounded shape piece of media is used, the openings are not uniform. More deodorant could come out of the larger openings than the openings in the middle of the piece of media.  
      Besides the porous media itself, there are other difficulties in making a head for a semisolid product dispenser. Because the semisolid product is a gel or some other fluid material, all of the passageways between where it is stored and where it is dispensed must be fluid tight so that the product does not leak out under pressure. If parts of the dispenser are made out of an inexpensive thermoplastic material such as polypropylene, it is difficult to form leak-free joints between the parts, as polypropylene does not normally form strong bonds between parts. At times, ultrasonically welded parts only look like they are bonded because polypropylene is soft and the parts deform instead of welding together. Later, when under pressure, the parts come apart. Such a joint would be unacceptable in a semisolid product dispenser, as the dispenser head could come apart when the product was forced through it, causing the gel deodorant or other semisolid product to gush out and make a mess in the hands of the user as the joint came apart. Other thermoplastic materials could be used, but their cost would be a significant disadvantage where the dispenser is made in mass quantities and only used once before being thrown away.  
     SUMMARY OF THE INVENTION  
      The foregoing problems, as well as other difficulties encountered during development of a semisolid product dispenser head, have been overcome by the present invention. A porous material made from an extrusion of strands of polymer has been found which provides desired properties in making a head for a semisolid product dispenser. Also, it has been discovered that the opening size and shapes of the openings of a porous media can be improved for use in a semisolid product dispenser by crushing the media between two hard surfaces, such as parts of a mold tool. Further, an ultrasonic weld joint has been developed which can be used to securely join inexpensive polypropylene.  
      In a first aspect, the invention is a method of making a head for a semisolid product dispenser comprising the steps of providing a piece of porous media having a desired shape with a perimeter and openings through the media in the area inside of the perimeter; compressing at least the portion of the media inside of the perimeter between two parts of a hard tool so as to crush the media, thereby reducing the size of the openings; and affixing the porous media to a head frame to form the semisolid product dispenser head.  
      In a second aspect, the invention is the method of making a head for a semisolid product dispenser comprising the steps of providing a piece of porous media made of multiple layers of extruded strands wherein the strands are generally coplanar and parallel to one another within each layer and the strands in one layer are non-parallel to strands in an adjoining layer and bonded to the strands in the adjoining layer at crossover points between the strands; and insert molding the piece of porous media with a thermoplastic material into a head frame to thereby produce a head for a semisolid product dispenser.  
      In a third aspect, the invention is an improved porous media where the porous media has multiple layers of extruded strands of polymer with the strands in each layer being generally coplanar and parallel to one another, the direction of the strands in one layer being non-parallel to the strands in an adjoining layer, the strands being bonded to the strands in the adjoining layer at crossover points between the strands, and the media having openings through the media defined by spaces between the strands in one layer superimposed over spaces between strands in the adjoining layer, improved in that the average size of the openings through the media are reduced by crushing the strands of one layer against the strands of an adjoining layer, thereby flattening the strands and reducing the size of the spaces between the strands.  
      In a fourth aspect, the invention is an improved dispenser for dispensing a semisolid product where the dispenser includes a hollow body containing a semisolid product and a piston to force the semisolid product out of the hollow body through a porous media affixed to a head secured on the body, improved in that the porous media comprises multiple layers of extruded strands of polymer wherein the strands in each layer are generally coplanar and parallel to one another, the direction of the strands in one layer being non-parallel to the strands in an adjoining layer, the strands being bonded to the strands in the adjoining layer at crossover points between the strands, and the media having openings through the media defined by spaces between the strands in one layer superimposed over spaces between strands in the adjoining layer.  
      In a fifth aspect, the invention is a method of reducing the pore size of a porous media comprising the steps of providing a porous media comprising multiple layers of extruded strands of polymer wherein the strands in each layer are generally coplanar and parallel to one another, the direction of the strands in one layer being non-parallel to the strands in an adjoining layer, the strands being bonded to the strands in the adjoining layer at crossover points between the strands, and the media having openings through the media defined by spaces between the strands in one layer superimposed over spaces between strands in the adjoining layer; and compressing the media between two opposing hard surfaces so as to flatten the individual strands, thus making the strands wider in a direction perpendicular to the hard surfaces, thereby reducing the size of the openings between the strands.  
      In a sixth aspect, the invention is a method of making a semisolid product dispenser comprising the steps of providing a head frame with a top end and a sidewall depending from the top end; providing a body member that mates with the head frame, defining a deodorant holding and distribution space between the top end and the body member; providing mating ultrasonic weld joint surfaces on the head frame and the body member that provide a weld joint and a positive stop; and ultrasonically welding the body member and head frame together.  
      In a seventh aspect, the invention is a semisolid product dispenser comprising a head frame having a top end and a sidewall depending from the top end, the top end having a porous media attached thereto; a body member having an outer wall inside of the sidewall, the head top end and body member having a semisolid product holding and distribution space between them; and the body member outer wall being ultrasonically welded to the head frame to provide a leak-free joint so that all semisolid product in said body member may be forced out of said holding and distribution space through the porous media.  
      In an eighth aspect, the invention is a method of reducing the pore size of a porous media comprising the steps of providing a porous media having a first average thickness with openings therethrough creating a first average pore size; and compressing the media between opposing surfaces on a core and a cavity of a mold tool so as to reduce the average thickness of the media and to reduce the size of the openings through the media to create a second average pore size smaller than the first average pore size.  
      In a ninth aspect, the invention is a method of making a head for a semisolid deodorant dispenser comprising the steps of providing a piece of generally flat porous media having a perimeter; forming the porous media into a dome shape; and attaching the perimeter to a head frame having a central opening therethrough such that the dome shape of the media is retained, the media and the dome shape formed being rigid enough such that even though the media is supported only by its edges, the dome does not collapse when the head is pressed against underarm skin with normal user force sufficient to spread deodorant forced through the media across the skin.  
      In a tenth aspect, the invention is a deodorant dispenser comprising a body holding a semisolid deodorant and a dispensing head, the dispensing head having a frame with a central opening therethrough and a porous media shaped in the form of a dome convex of the rest of the head, the media having a perimeter which is attached to the head frame, the dome extending over the central opening, and the media being sufficiently rigid when in the dome shape such that the dome does not collapse when the head is pressed against underarm skin with normal user force sufficient to spread semisolid deodorant forced through the media across the skin. 
    
    
     BRIEF DESCRIPTION OF SEVERAL VIEWS OF THE DRAWINGS  
       FIG. 1  is a cross-sectional perspective view of a preferred semisolid product dispenser incorporating aspects of the present invention using a woven media.  
       FIG. 2  is an exploded view of the top portion of the semisolid product dispenser of  FIG. 1  using an extruded media.  
       FIG. 3  is a cross-sectional view of the top portion of the semisolid product dispenser taken along line  3 - 3  of  FIG. 2 , except that a woven media is depicted.  
       FIG. 4  is a plan view of the preferred extruded, porous media used in the semisolid product dispenser of  FIG. 2 .  
       FIG. 5  is a cross-sectional view of the porous media taken along line  5 - 5  of  FIG. 4 .  
       FIG. 6  is a cross-sectional view of the semisolid product transfer member taken along line  6 - 6  of  FIG. 2 , showing a vent.  
       FIG. 7  is a cross-sectional view of the semisolid product transfer member taken along line  7 - 7  of  FIG. 2 .  
       FIG. 8  is a cross-sectional view of the head frame with a porous media insert molded therein, taken along line  8 - 8  of  FIG. 2 .  
       FIG. 9  is a cross-sectional view of the head frame of  FIG. 8  welded to semisolid product transfer member of  FIG. 7 .  
       FIG. 10  is a cross-sectional view of a mold tool used to make an alternative embodiment of a semisolid product dispenser head.  
       FIGS. 10A, 10B  and  10 C are each cross-sectional views of a part of the mold tool of  FIG. 10  in different operating positions.  
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS AND PREFERRED EMBODIMENTS OF THE INVENTION  
      The present invention will be described in terms of a dispenser for a gel deodorant because the currently preferred semisolid product dispenser is designed for a gel deodorant. However, it should be understood that the invention is applicable to other semisolid products, such as cream or soft-stick deodorants. Further, some aspects of the invention have utility in other products beside deodorant dispensers, such as shaving cream, insect repellant, medicinal agents and other compositions applied to the skin.  
      A preferred embodiment of the gel deodorant dispenser  10  of the present invention is shown in  FIGS. 1-9 . The dispenser  10  is made of three main sections, a body  20 , a neck  30  and a dispensing head assembly  50 . A cap  18  is usually included to cover the head assembly  50  when not in use.  
      The body  20  and neck  30  were developed by others. The details of their construction are not important except to the extent that the head  50  cooperates with the body  20  and neck  30 . However, as best understood by the present inventors, the preferred body  20  and neck  30  of the gel deodorant dispenser  10  are shown in  FIGS. 1 and 2 .  
      The body  20  is made with a base  23  and upstanding walls  21 , and is hollow so that it can house the gel deodorant material. A piston  22  is mounted on screw  24  so that as screw  24  is turned, the piston  22  rides up inside of walls  21 , forcing gel inside the body upward. The top of body  20  is closed by lid  28  except for two gel ports  25  ( FIG. 2 ). The top  26  of screw  24  is journaled in another opening through lid  28 .  
      The neck  30  includes two gel transfer tubes  35  that mate with gel ports  25  when the neck  30  is attached to body  20 . Also, neck  30  includes a structure for turning screw  24 , in this case a ratchet  36  and pawl  37 . In the embodiment depicted, the neck  30  has a window  31  ( FIG. 2 ) in which a push button  32  ( FIG. 1 ) is mounted. Button  32  is connected by a slide arm  34  to activate ratchet  36  mounted on the top of screw  24 . (The button  32  and slide arm  34  are not shown in  FIG. 2  for sake of clarity.) Guides  39  molded on the bottom of shelf  38  cooperate to guide the slide arm  34 . In addition to the openings for the gel transfer tubes  35 , the shelf  38  has two holes, a round hole where the top  26  of screw  24  comes up, and a rectangular hole under a pawl  37  so that the pawl  37  is free to flex as ratchet  36  is rotated forward. The pawl  37  prevents the ratchet  36  from turning backwards after having been activated by the slide arm  34 . In this way, as button  32  is pushed, ratchet  36  and screw  24  rotate, causing piston  22  to raise, forcing gel deodorant out of the hollow body  20 , through gel ports  25  and gel transfer tubes  35  to the head assembly. The sidewalls of the neck  30 , the gel transfer tubes  35 , the shelf  38 , the guides  39  and the pawl  37  are all molded as one piece.  
      As best shown in  FIG. 2 , head assembly  50  is made of three main parts, a porous media  60 , a head frame  70  and a gel transfer body member  80 . The porous media  60  generally starts out as a flat piece of material that is die-cut from a larger piece and then insert molded as the head frame  70  is injection molded. The gel transfer member  80  is molded separately, and then the head frame  70  and gel transfer member  80  are welded together, as explained in more detail below.  
      The porous media could be a woven screen (as shown in  FIGS. 1 and 3 ), but more preferably the porous media is a material supplied by Nalle Plastics Inc. of Austin, Tex. (shown in  FIGS. 2, 4  and  5 ), under the tradename of Naltex, and is preferably modified as described below. The Naltex material is made from at least two layers of extruded strands. The strands in each layer are generally coplanar and parallel to one another, as shown in  FIGS. 5 and 6 . The strands  62  in one layer are non-parallel to the strands  64  in an adjoining layer. The strands are bonded to the strands in the adjoining layer at crossover points between the strands.  
      One of the benefits of the Naltex material is that the surface is textured. The strands produce a ribbed effect on the surface. This ribbed effect helps to evenly spread a deodorant or other material as it is applied to the skin. It also prevents clogging that would be more likely to occur if the surface were smooth.  
      The media  60  has openings  66  ( FIG. 4 ) defined by spaces between the strands  62  in one layer that are superimposed over spaces between the strands  64  in the adjoining layer. The preferred material has the strands  62  in one layer oriented at an angle of between about 20° and 90° compared to the strand  64  of the adjoining layer. The preferred Naltex material is flattened as shown in  FIG. 5  so that strands  62  and  64  are flattened, thus reducing the size of the openings  66 , but still leaving a textured or ribbed surface. Since it is difficult to extrude a material with a small pore size, this step of crushing the media provides an innovative method of obtaining an inexpensive media with a desired small pore size for use in making a gel deodorant dispenser head assembly.  
      The head frame  70  is preferably molded from thermoplastic material, such as polypropylene. The head frame  70  has a top end  72  with a central opening  74  therethrough. Sidewalls  76  depending from the top end  72  extend around the entire perimeter of the head frame  70 . An internal ridge  78  ( FIG. 8 ) is formed on the inside of the frame member, just inside from the central opening  74 . This ridge  78  is used in an ultrasonic welding process, described below.  
      After the porous media  60  has been cut into an oval shape, it is loaded into an injection mold tool that is used to form the head frame  70 . As shown in  FIG. 8 , the core  102  of the tool has a lip  104  around the perimeter of the center portion of the core. This lip  104  is used to create a band  69  ( FIG. 2 ) around the perimeter  68  of the porous media where all the openings  66  are closed off. This band  69  is the result of the lip crushing the strands  62  and  64  of the media so tightly that none of the hot thermoplastic material in the molding step can flow through the openings between the strands  62  and  64  in the area of the band  69 . This prevents the hot plastic used to form the head frame from infiltrating into the central portion of the porous media and blocking the openings  66 . This band also serves another function in the finished product. As gel is forced through the media  60 , it cannot flow through the area where the band  69  is formed. As a result, there is a visible demarcation between where gel is forced through the media  60  and where gel is not forced through the media. Preferably that line of demarcation is inside of the inner edge of the central opening  74 .  
      Preferably, the perimeter  68  of the piece of media is bent inwardly (as shown in  FIG. 8 ) by a ridge formed on the mold tool cavity. This results in a clean appearance as the edge of the porous media  60  is encapsulated or embedded in the plastic of the head frame, rather than “floating” near the surface where it could be seen, or worse yet, make for sharp protruding edges.  
      The closing of the mold tool  102  preferably not only creates band  69 , but it also crushes the media so that the openings  66  are reduced in size. Hence, the gap between the core  102  and the cavity of the mold tool will be slightly less than the original thickness of the media  60 . The mold tool  102  also forms the media  60  into a dome shape as the core  102  is convex and the cavity is concave. The dome shape is then maintained once the tool is opened because the media  60  is sufficiently rigid to maintain the dome shape when its edges are embedded in the head frame top end  72 . The dome shape and the rigidness of the porous media  60  are preferably sufficient so that, even though the media is supported only at its edges, the dome does not collapse when the head  50  is pressed against underarm skin with normal user force sufficient to spread gel forced through the media across the skin. This rigidity thus prevents “overdosing.” 
      If the gel deodorant is found to come through the porous media at a faster rate in the area where the gel transfer tubes terminate than in other parts of the media, the mold tool can be modified to cause greater crushing of the media in the areas where flow needs to be retarded. The greater crushing causes the openings  66  in those areas to be smaller, thus retarding the flow. Either the core pin or the mold tool, or both, can be modified to reduce the gap between them in the areas where the gel transfer tubes empty out. This preferably produces a graduated size for the openings with respect to their position on the surface of the head, with a region having a smaller average pore size than the average pore size outside of the region. However, the amount of gel that comes through is preferably uniform across the surface of the head  50 , except that no gel comes through the area inside of band  69 .  
      The gel transfer body member  80  has outer walls that mate with the head frame  70 , inside the sidewalls  76 , defining a deodorant holding and distribution space  82  ( FIG. 3 ) between the top end  72  of the head frame, the porous media  60  and the gel transfer member  80 . The gel transfer member  80  also has two funnel-shaped members  84  that terminate in rounded ends  85  that fit in the top of gel transfer tubes  35 . As seen in  FIG. 3 , the top of each gel transfer tube  35  preferably has an internal rim  41  that co-acts with an external rib  86  on each of the ends  85  to form a snap fit, holding the head assembly  50  onto the neck  30  once the parts are assembled.  
      The gel transfer member  80  has a groove  88  ( FIGS. 6 and 7 ) which is used to form the ultrasonic weld. It also has an energy-directing point  91  which is used in the weld. Two vents  92  are located at the bottom of the groove  88 , directly opposite from one another on the sides of the gel transfer member. One of these vents  92  is shown in  FIG. 6 . The other vent is not shown. These vents allow any gas trapped in the groove  88  when the weld is made to escape out from between the parts.  
      The ridge  78  acts as a tongue and cooperates with groove  88  to form a tongue-and-groove joint, best seen in  FIG. 9 . This joint is a double shear joint, as the ridge  78  is wider at its bottom than the bottom  89  of groove  88 . Meanwhile, energy-directing point  91  melts into the underside of top end  72 . Thus, when the parts are welded together, there are two types of welds made.  
      In addition, the weld design incorporates a positive stop. A positive stop surface  93  on the gel transfer member  80  contacts a positive stop surface  79  on the head frame when the weld has progressed to a sufficient depth. By designing in a positive stop, the welding operation can be carried out for longer lengths of time without fear of destroying the pieces. Thus, a more solid and leak-free joint can be formed, even when polypropylene is used for the head frame  70  and gel transfer member  80 . Then, during use, these parts will not come apart, even when the gel is under pressure and the head is rubbed against underarm skin. Rather, all of the gel transferred to the gel transfer member  80  is forced out of the deodorant holding and distribution space  82  through the porous media  60 .  
      The Naltex material is preferably crushed in the mold tool. However, it would also be possible to put a sheet of Naltex material through calender rolls and crush the strands prior to cutting the porous media into a desired shape. One of the benefits of using the mold tool for the crushing operation is that the crushing can be done in the same step as the insert molding, and areas of reduced size openings can be made in the correct position with respect to the gel transfer tubes.  
      The crushing step usually reduces the thickness of the material to between about 20% and about 90% of its original thickness. The media preferably has a first average thickness of between about 0.01 and about 0.1 inches, most preferably about 0.05 inches. This preferred media is crushed to a second average thickness of between about 0.035 and about 0.04 inches. In the area of band  69  the preferred material is crushed to a thickness of about 0.02 inches. The compression step normally changes the shape of the openings. More importantly, it usually changes the size of the openings. The average opening size of the media in the area inside of the perimeter formed by band  69  will preferably be reduced by at least 10%, and more preferably by at least 30%, and even as much as 50% by crushing. A preferred material may have an average opening size greater than 30,000 square microns before crushing, and after being crushed will have an average opening size of less than 30,000 square microns. For a gel deodorant dispenser, preferably the opening size of the crushed media will be less than 40,000 square microns. More preferably, the average opening size will be between about 900 and about 30,000 square microns. Of course the desired opening size will depend on the viscosity and other properties of the deodorant. For some deodorant materials a preferred opening size after crushing would be less than 10,000 square microns, such as a 60 micron square opening. The open area may be reduced from about 20-30% to about 5% by the crushing operation.  
       FIGS. 10, 10A ,  10 B and  10 C depict another embodiment of the invention. In this embodiment, the porous media is formed as part of the injection molding of the head frame  170 , which is comparable to the head frame  70  in  FIGS. 1-9 . The mold tool  202  for forming the head frame  170  includes multitudes of small core pins  206  which are initially extended to abut the cavity tool  201 . As the head frame  170  is formed, the porous media  160  is also formed as part of the injection mold, and openings  166  in the porous media  160  result from the core pins  206 . After the first stage of the process ( FIG. 1A ), while the mold tool is still closed, the pins  206 , attached to plate  212 , are withdrawn ( FIG. 10B ). At this point, the mold tool front  210  is then closed more tightly against the mold cavity  201  ( FIG. 10C ). This results in the porous media  160  being crushed between the two hard mold tool parts  201  and  210 , which causes the holes  166  through the media  160  to become smaller. As a result, it is possible to make holes  166  in an injected molded media  160  smaller than the size of the core pins  206 . This is significant because there are practical limits on the size of core pins  206 . Therefore, if smaller holes  166  are desired in the media  160 , they can be formed in a crushing operation. Just as with crushing the porous media  60 , this crushing can take place in the same mold tool as is used to injection mold the head frame  170 .  
      The preferred Naltex material is extruded using two layers of strands, with about 33, and preferably about 36 strands per inch in each layer. This type of material may be ordered from Nalle Plastics as Naltex S 1970. It has a thickness of about 0.051 inches and openings of about 200 microns square (40,000 square microns). After being crushed the openings are about 170 microns by 150 microns (25,500 square microns).  
      The use of a crushing step to reduce pore size would also be applicable to porous media made from weaving, casting, needle punching, water jets and laser drilling, as well as extrusion and injection molding described above. The media from Naltex is made from polypropylene. However, the media could be made of other polymers such as polyethylene, nylon, polyester or combinations thereof. Polypropylene is preferred because it is inexpensive and easily crushed.  
      Preferably, the percent open area of the porous media will be between about 1% and about 50%, and more preferably at least 2%. The band  69  where the openings have been completely closed is preferably about one-eighth inch wide. In the preferred embodiment, the angles shown in  FIGS. 6-8  are A=5°, B=10°, C=5°, D=5° and E=1°. The energy directing point  91  preferably has a 45° slope on the point.  
      One of the benefits of using the positive stop surfaces  79  and  93  is that the position of the gel transfer member  80  with respect to the head frame  70  in the final head assembly  50  is very consistent. This results in the position of the external ribs  86  being precise with respect to the rest of the head assembly  50 . Thus when the head  50  is snapped onto the neck  30 , the ribs  86  catch under rims  41  to hold the neck and head securely.  
      Rather than affixing the porous media to the top end  72  of the head frame  70  by insert injection molding, the porous media could be welded onto the head frame by solvent welding, heat molding, ultrasonic welding or other methods of attachment.  
      It should be appreciated that the products, apparatus and methods of the present invention are capable of being incorporated in the form of a variety of embodiments, only a few of which have been illustrated and described above. The invention may be embodied in other forms without departing from its spirit or essential characteristics. For example, instead of molding the head frame and crushing the media in the same tool, those steps could be carried out in different tools. Instead of crushing the media to decrease its average pore size, other methods of reducing the pore size, such as the application of heat, could be used. Instead of using the body  20 , neck  30  and gel transfer body member  80 , the deodorant dispenser could simply have a hollow body with a piston inside, and the head frame  70  could be welded directly to that body.  
      The described embodiments are to be considered in all respects only as illustrative and not restrictive, and the scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.