Patent Publication Number: US-11021292-B2

Title: Container comprising a thermoformed tub and dosing units located therein

Description:
FIELD OF THE INVENTION 
     The invention relates to a container comprising a thermoformed tub made of a plastics material and comprising at least one dosing unit located in a tub interior, which dosing unit comprises at least one active ingredient and a water-soluble casing for the active ingredient. 
     BACKGROUND OF THE INVENTION 
     It is nowadays conventional to provide active ingredients from the group consisting of laundry detergents, dishwasher detergents, pharmaceuticals, bodycare products, etc., in flowable or pourable form in pre-dosed units (dosing units) which are stored in plastics containers and offered on the market as such. Simple and cost-effective production of the plastics container consists in shaping a tub, which is open at the top, by means of thermoforming a plastics material sheet or a film, which tub is then closed by a separately produced lid. 
     Handling the dosing units is relatively easy and convenient for the user. This will be illustrated using the example of a detergent as the active ingredient. The user purchases a container filled with detergent dosing units. After opening the cover, the user takes a detergent dosing unit from the tub and puts it in the drum or in a detergent drawer of a washing machine. The water-soluble casing ensures that the user does not come into contact with the detergent, which makes dealing with the detergent safer and easier. Because the detergent is pre-dosed, the user does not have to dose the detergent themselves as well. This also makes dealing with the detergent easier. 
     High air humidity can result in the water-soluble casing of the dosing unit becoming somewhat sticky even when the tub is closed, and said casing can adhere to the base of the tub or to a wall of the tub extending from the base. This not only impedes easy handling of the detergent, but also carries the risk of the wrapping being damaged when the dosing unit is taken out. This in turn can lead to detergent leaking out of the dosing unit and lead to corresponding inconvenience. 
     BRIEF SUMMARY OF THE INVENTION 
     The object of the invention is therefore to provide a container, comprising at least one dosing unit filled with an active ingredient, that can be produced in a cost-effective manner and that allows easy and safe handling of the active ingredient inside the dosing unit. 
     According to the invention, the tub wall comprises a plurality of projections that are oriented from a datum plane of the tub wall towards the tub interior, a distance between adjacent projections being less than a length and less than a width of the dosing unit. The projections provide the tub wall with a surface structure on account of which an effective contact surface of the dosing unit on the tub wall is reduced. This reduction of the contact surface means that detrimental sticking or adhering of the dosing unit to the tub wall is prevented or at least reduced. Because the distance between adjacent projections is small in relation to the dimensions of the dosing unit, it is possible for full-surface contact of the dosing unit with the tub wall to be virtually eliminated. Even if the water-soluble casing has a certain degree of stickiness, the dosing unit can be more easily removed from the tub on account of the smaller contact surface between the tub wall and the wrapping. 
     The length of the dosing unit is intended to be the largest extension of the dosing unit in one of the three spatial directions. The width is intended to be the second largest extension. A height of the dosing unit is intended to be the smallest of the three spatial extensions. In one embodiment, the distance between adjacent projections is also less than the height of the dosing unit, i.e. less than the smallest of the three extensions in the x, y or z direction. 
     The distance between adjacent projections may be less than half of the length and less than half of the width of the dosing unit. As a result, it can be ensured that when the dosing unit is accordingly located in the tub (for example the longest edge of the dosing unit abuts the tub wall), the dosing unit abuts at least two projections. Depending on the distance from and orientation with respect to the tub wall, the dosing unit may even abut three, four or even 15 projections at the same time. 
     In one embodiment, the projections comprise a first ridge that extends in a longitudinal direction and additional ridges that are parallel to the first ridge. Preferably, the design of the additional ridges corresponds to the design of the first ridge. Accordingly, in this embodiment, the tub wall comprises ridges of identical design. The following description of the design of the first ridge may therefore apply correspondingly to the additional ridges. 
     A width of the first ridge may be less than a distance between adjacent ridges. For example, the width of the first ridge may be from 5 to 25 mm. In a preferred embodiment, the width of the first ridge is 10 mm. The distance between two adjacent ridges may be from 5 to 30 mm, said distance being 13 mm in one embodiment. 
     The first ridge may extend from the base towards an upper tub edge. The first ridge thus extends vertically when the base of the tub lies on a horizontal storage surface. The first ridge may extend substantially over the entire distance between the base and the upper tub edge. A ridge-free region may be formed in the immediate vicinity of the base and/or in the immediate vicinity of the upper tub edge. This region may have a vertical height of from 5 to 15 mm. Preferably, the vertical height of this region is less than the length and less than the width of the dosing unit. 
     In one embodiment, a height of the first ridge varies in the longitudinal direction. For example, the height of the first ridge may increase constantly, preferably linearly, from the base towards the upper tub edge. Starting from the base, the first ridge may thus begin at a height equal to 0 mm and end at a height of from 0.5 to 10 mm in the vicinity of the upper tub edge. In one embodiment, the first ridge ends in the vicinity of the upper tub edge at a height of from 1 to 3 mm. 
     It is also possible for the height of the first ridge to be constant in the longitudinal direction. In this embodiment, too, the height of the ridge may be from 0.5 to 10 mm or preferably from 1 to 3 mm. 
     In principle, the first ridge may have any desired ridge contour in cross section. In one embodiment, in cross section, the first ridge has a first ridge slope, a ridge summit and a second ridge slope, the first ridge slope and the second ridge slope bridging a gap between the ridge summit and the datum plane of the tub wall. The ridge summit is thus spaced apart from the datum plane of the tub wall, the distance between the datum plane and the ridge summit corresponding to the height of the ridge. The ridge summit thereby substantially forms the contact surface for the at least one dosing unit, which is located in the tub interior. 
     The first ridge slope and the second ridge slope may extend obliquely with respect to one another and form an angle of from 60 to 120°. In one embodiment, the angle is from 80 to 100°. 
     The tub wall may comprise a front wall, a rear wall, a first side wall and a second side wall, the front wall, the rear wall, the first side wall and the second side wall each comprising projections. As a result, it can be ensured that the tub wall comprises no (larger) regions that could lead to full-surface contact of the potentially sticky wrapping of the dosing unit with the tub wall. 
     A surface area of the base of the tub may be smaller than a surface area of a tub opening. In the embodiment comprising the front wall, rear wall, first side wall and second side wall, at least two opposing walls may diverge from the base towards the tub opening. 
     In cross section, the tub may have a substantially rectangular basic shape. The corners between two adjoining walls may be rounded. In one embodiment, the front wall is curved slightly outwards, while the rear wall and the two side walls are straight. 
     In order to close the tub, the container may comprise a lid having a frame that sits securely on the tub and having a flap that is pivotally fastened to the frame. In a closed position, the flap may be latched to the frame by latching means which are preferably designed to be childproof. Unintended opening of the container can therefore be prevented. 
     The water-soluble wrapping may be made of a water-soluble polymer such as polyvinyl alcohol. The dosing unit may comprise at least one second active ingredient, the wrapping in this case forming not only one chamber, but rather two separate chambers. The active ingredients may differ in terms of chemical composition, color and/or presentation form (liquid, solid, particle size). For example, a two-chamber dosing unit is possible in which one active ingredient is liquid and the other active ingredient is in particle form. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The invention is described in more detail with reference to the embodiments shown in the drawings, in which: 
         FIG. 1  is a perspective view of a tub of a container according to the invention; 
         FIG. 2  is a highly schematic cross section of the tub; 
         FIG. 3  is a section through another embodiment corresponding to the section along the line III-III in  FIG. 1 ; 
         FIG. 4  is a section through the embodiment from  FIG. 3  corresponding to the section along the line IV-IV in  FIG. 1 ; 
         FIG. 5  is a partial section along the line V-V in  FIG. 4 ; and 
         FIGS. 6A-6B  consist of two perspective views of a dosing unit. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       FIG. 1  is a perspective view of a thermoformed tub  10  made of plastics material. The tub  10  comprises a base  11  and a circumferential tub wall  12 , which extends from the base  11  to an upper tub edge  13 . The circumferential tub wall  13  delimits a tub opening  14 . The tub opening  14  can be closed by means of a lid (not shown). 
     The tub wall  11  comprises a front wall  15 , a rear wall  16 , a first side wall  17  and a second side wall  18 . Sectional views of the tub  10  shown in  FIG. 1  are given in  FIG. 3 to 5 . 
     The base  11  and the tub wall  12  delimit a tub interior  19 , which receives a plurality of dosing units. The dosing units are not shown in  FIG. 1 , but are shown in  FIG. 2 to 6 , where they are provided with the reference sign  50 . 
     The tub wall  12  comprises a plurality of ribs  20  which are arranged in parallel with one another and extend from the base  11  towards the upper tub edge  13 . The ridges  20  are each of identical design. 
       FIG. 2  shows a cross section through the tub  10 ; however, it should be noted that  FIG. 2  is merely a schematic representation of the tub  10  from  FIG. 1 . On account of the schematic portrayal, there are differences from the specific embodiment according to  FIG. 1  (for example with regard to the number of ridges  20 , the shape of the ridges, the design of the individual walls  15 ,  16 ,  17 ,  18 ). 
     Each of the ridges  20  comprises a first ridge slope  21 , a ridge summit  22  and a second ridge slope  23 , the ridges  20  all being oriented towards the tub interior  19 . The ridge slopes  21 ,  23  bridge a gap between a datum plane  24  of the tub wall  12 . In  FIG. 2 , this datum plane  24  is shown by a dotted line. The distance between the datum plane  24  and the ridge summit  22  corresponds to a height  25 . Because the ridge slopes  21 ,  23  converge obliquely starting from the datum plane  24 , which is illustrated in  FIG. 2  by an angle  26 , a width  27  of the first ridge  20  (measured in the datum plane  24 ) is greater than a width  28  of the ridge summit  22 . In the schematic view in  FIG. 2 , a distance  29  between two adjacent ridges is approximately the same as the width  27  of the ridge  20 . 
       FIG. 2  schematically shows four dosing units  50  in the tub interior  19 , each having a length L and a width B. A specific embodiment of said dosing unit  50  can be seen in  FIG. 6  (see  FIG. 6A, 6B ). Furthermore, a height H of the dosing unit  50  is indicated in  FIG. 6B . In the specific embodiment of the dosing unit in  FIG. 6 , the length L is intended to be 67 mm, the width B is intended to be 60 mm and the height H is intended to be 13 mm. 
     As can be seen in  FIG. 2 , the ridges  20  that are oriented towards the tub interior  19  prevent full-surface contact of the dosing units  50  with the tub wall  12 . The dosing unit  50  rests against the ridges  20 , in particular on the ridge summits  22  thereof, or against the tub wall  12  in the region of the datum plane  24 . However, on account of the ridges  20  and the associated surface structuring, the effective contact surface between the tub wall  12  and the dosing units  50  is greatly reduced compared to a tub wall having no ridges. On account of the reduced contact surface, the risk of the dosing units  50  adhering to the tub wall  12  is greatly reduced, as is the risk of problems occurring when removing the dosing units from the tub  10 . In the view in  FIG. 2 , the four dosing units  50  lie in a plane. In practice, the dosing units  50  may be arranged in the tub interior  19  in an entirely random manner. 
     The dosing unit  50  from  FIG. 6  comprises a water-soluble wrapping  51  made of polyvinyl alcohol. The wrapping  51  is composed of a thermoform film  52  and a cover film  53 . When thermoforming the thermoform film  52  into a thermoforming mold, a first pocket  54  and a second pocket  55  are formed. Said pockets  54 ,  55  receive a first active ingredient and a second active ingredient, respectively, for example in the form of a detergent and a detergent additive. After the active ingredients have been poured in, the cover film  53  is placed onto the open side of the pockets  54 ,  55  and seals the thermoformed thermoform film  52  such that two separate, closed chambers for active ingredients are produced. 
     As can be seen in  FIG. 3 , nine ridges  20  are provided on the rear wall  16 . It should be noted that the embodiment in  FIG. 3 to 5  differs slightly from the embodiment in  FIG. 1 . The embodiment from  FIG. 1 , for example, thus comprises only seven ridges  20  on the rear wall  16 . The longitudinal profile of each ridge  20  is rendered clear by the ridge  20   a  on the first side wall  17  (in this case the left-hand side wall). The height  25  of the ridge  20  increases with increasing distance from the base  11 . The ridge  20   a  begins at a ledge  30  close to the base and starts at a height of 0 mm (height indicated by  25 ). Said height  25  increases with increasing distance from the ledge  30  in a linear manner and reaches its maximum value immediately below the upper tub edge  13 , where the ridge  20   a  terminates. The height  25  in the vicinity of the upper tub edge  13  is, for example, from 12 to 1.8 mm. The width  27  should in this case be from 9 to 11 mm. The gap  29  should be from 12 to 14 mm. The volume of the tub  10  may for example be from 1000 to 5000 ml, preferably from 2000 to 4000 ml. 
       FIGS. 3 and 4  additionally show that the first side wall  17  and the second side wall  18  do not extend in parallel when viewed in a vertical direction, but rather diverge slightly, starting from the base  11 . The same applies to the front wall  15  and rear wall  16 . On account of the divergence of the walls  15 ,  16 ,  17 ,  18 , the surface area of the base  11  is smaller than the surface area of the tub opening  14 . It is also clear from  FIGS. 3 and 4  that the base  11  is slightly profiled. The base in this case has the basic shape of a hipped roof, the apex  31  of which does not extend over the entire width of the front wall  15  or rear wall  16 , but rather only over a central portion. 
       FIG. 5  also shows the trapezoidal basic shape of the ridge  20 . The angle  26  between the ridge slopes  21 ,  23 , which are inclined relative to the datum plane  24 , is in this case approximately 90°. Accordingly, each ridge slope  21 ,  23  has an angle of approximately 45° relative to the datum plane  24 . 
     In order to label/advertise the dosing units located inside the tub  10 , a circumferential sleeve can be placed around the tub wall. The sleeve is preferably made of paper or cardboard and may comprise a tear-off strip in order to allow easy removal of the sleeve if, after use of the container, the paper and plastics material are to be separated for the purposes of recycling. 
     On account of the relatively planar ridges  20 , the height of which increases only very slightly with the distance from the base  11 , the tub  10  can be produced in a cost-effective manner by means of a thermoforming process like a comparable tub that does not have surface-structured tub walls. The ridges  20  mean that the effective contact surface between dosing units  50  and the tub walls  12  is kept small. As a result, the dosing units, which potentially adhere to the tub walls due to a particular air humidity, can be easily removed from the tub  10 . 
     LIST OF REFERENCE SIGNS 
     
         
           10  tub 
           11  base 
           12  tub wall 
           13  upper tub edge 
           14  tub opening 
           15  front wall 
           16  rear wall 
           17  first side wall 
           18  second side wall 
           19  tub interior 
           20  ridge (first ridge, additional ridges; ridge  20   a ) 
           21  first ridge slope 
           22  ridge summit 
           23  second ridge slope 
           24  datum plane 
           25  height of the ridge 
           26  angle 
           27  width of the ridge 
           28  width of the ridge summit 
           29  distance between two ridges 
           30  ledge 
           31  apex 
           50  dosing unit 
           51  wrapping 
           52  thermoform film 
           53  cover film 
           54  first pocket 
           55  second pocket