Patent Publication Number: US-2022227557-A1

Title: Multi-layer covers with detachable segment and method of their production

Description:
The invention refers to closures and covers. In particular the invention refers to closures or covers of containers for facial tissues, wipes and in particular wet wipes, diapers and in general items that require to remain within a container and with no direct contact with the environment. 
     Closures or covers of containers are usually fabricated from a layer of self-adhesive material that adheres to the surface of the lid of the container. Such containers have an opening and a lid to cover the opening and to protect the interior of the container from the environment. In order to provide an adequate closure of the opening of the container, it is known to use a cover that adheres to the lid and to the area of the surface of the container that is around the lid. By doing so, the lid is protected and remains in its place. Known covers have a main section and a base section. The base section is attached to the box when the cover is in a closed position or lifted to allow access to the interior of the container. However, after the user lifts and attaches the main section of the cover to the surface of the container a few times, dirt damages the adhesive and subsequently the cover cannot adhere properly to the surface of the container around the lid. It is noted that as the main section of the cover adheres to the lid, the lid opens the opening of the container when the main section is lifted and closes the opening of the container when the main section adheres to the surface of the container. 
     The invention aims in a closure or a cover of a container and a container that overcomes the problems of the known containers. A further object of the invention is a closure that seals a container so that the content of the container is protected from the environmental conditions. A further object of the invention is a method to produce covers that may be lifted and adhere to a container that contains wet wipes and other similar items, as many times as needed, with no problems. A further object of the invention is an eco-friendly packaging for facial tissues, wipes and in particular wet wipes, diapers and other similar consumable products. 
     The invention is defined in the independent claims. 
     A cover according to the invention performs without problem during its life-time, is light and uses a relatively small amount of preferably recyclable material. The method of its production is efficient and it may be easily applied to cover openings of containers or other items. 
     Dependent claims contain features that offer further advantages. 
     A cover according to the invention includes an inner layer that has an inner face and an outer face and an outer layer that has an inner face and an outer face, whereby the inner face of the outer layer and the inner face of the inner layer comprise means to adhere the inner layer and the outer layer to each other, the outer face of the inner layer is at least partially coated with reclosable adhesive to adhere, in use, at least partially to a surface, the inner layer has a detachable segment, which adheres to the outer layer and which has an outer face that is part of the outer face of the inner layer and that it is at least partially or totally covered with reclosable adhesive and at least one of the inner layer and the outer layer comprises means to allow separation and subsequent withdrawal of the detachable segment from the cover. 
     The detachable segment may be ring shaped and surround the fixed segment. A ring shaped detachable segment may have any form, for example its inner periphery may have an oval shape. In another embodiment the detachable segment is C-shaped. Preferably, the detachable segment surrounds at least partially a fixed segment of the inner layer. Between the detachable segment and the fixed segment there is a cut that facilitates the separation of the detachable segment and the fixed segment and subsequent withdrawal of the detachable segment from the cover. The detachable segment has an inner face that is part of the inner face of the inner layer and that is coated at least partially or totally with release varnish. The inner face of the detachable segment adheres to an area of the inner face of the outer layer, which area is at least partially coated with reclosable adhesive. 
     The means facilitating separation and subsequent withdrawal of the detachable segment from the cover may be one or more cuts and/or one or more perforation lines provided on the inner layer. A cut may be achieved by engraving a layer. 
     In an embodiment of the invention, the cover has a base section including a portion of the inner layer and a portion of the outer layer, with a cut or a perforation line, preferably a cut, between the detachable segment and the inner layer of the base section. Optionally, the cover has a flap including a portion of the inner layer and a portion of the outer layer, with a perforation line between the detachable segment and the portion of the inner layer of the flap. 
     The cover may be applied on the external surface of a container with means to allow access in the interior of the container, preferably an opening. The detachable segment of the inner layer adheres at least partially to the external surface of the container with reclosable adhesive. Optionally, the container has a lid that covers the opening. The detachable segment adheres to the external surface of the container around the opening and optionally around the lid. When the container has a lid, the fixed segment of the inner layer of the cover adheres permanently to the lid. The base section is fixed to the container and the flap facilitates the user to lift the cover from the container. 
     The invention suggests a method of production of a roll with a plurality of covers, whereby each cover includes an outer layer, an inner layer with a detachable segment and means facilitating the withdrawal and removal of the detachable segment from the inner layer, the method comprising the following steps: (i) providing a roll with a liner and a self-adhesive layer with a first face that adheres with reclosable adhesive to the liner and a free face; (ii) applying a release varnish on predefined areas of the free face, whereby the predetermined areas correspond to the detachable segments of the covers under production; (iii) engraving or perforating the self-adhesive material of the roll to form a border of the detachable segment of the covers under production and producing the means other than said border facilitating the separation and removal of the detachable segments from the inner layer of the covers under production; (iv) adhering a further self-adhesive layer to the free face of the self-adhesive layer of the roll; (v) engraving the sandwich of the self-adhesive layer of the roll and the further self-adhesive layer, so as to produce a plurality of covers and waste material. 
     Preferably, the predefined areas on which the release varnish is applied, enclose at least partially areas of the outer face of the inner layer, on which no release varnish is applied, so as to be fixed to the further self-adhesive layer. 
     In preferred embodiments, the method comprises engraving the self-adhesive material of the roll to form a border between the detachable segment and a fixed segment of the inner layer of the covers under production and perforating the self-adhesive material of the roll to form a border between the detachable segment and a flap of the covers under production. The fixed segment and the flap of each cover are distinct elements with at least part of the detachable segment being in between. 
     Optionally, the liner is separated from the self-adhesive layer, the adhesive is cancelled or removed on areas of the first face of the self-adhesive layer, which correspond to flaps of the covers under production, and subsequently the liner and the self-adhesive layer are recombined. The separation of the liner from the self-adhesive material may be performed before, after or during application of the release varnish. 
     The covers have at least two layers. Some embodiments of the invention may include more than two layers, for example three or four. 
    
    
     
       Embodiments of the invention will be described with reference to the following Figures: 
         FIG. 1  presents a section of a cover on a container 
         FIG. 2  presents the layers of the cover of  FIG. 1  separated 
         FIG. 3  presents a 3-D view of the container with the cover of  FIG. 1   
         FIG. 4  presents the removal and withdrawal of the detachable segment of the cover 
         FIG. 5  presents an intermediate stage of production of a cover according to the invention 
         FIG. 6  presents a roll with covers towards the end of the production phase 
         FIG. 7  presents a roll with covers according to the invention 
     
    
    
       FIG. 1  shows a container  50  with an opening  55  and a lid  53  to cover the opening and to protect the interior of the container from the environment. A cover  20  covers the opening  55  and the lid  53  and protects the content of the container  50 . 
     The cover  20  has two layers, an inner layer  22  and an outer layer  24 , which adhere to each other. Each one of the inner layer  22  and the outer layer  24  has an inner face and an outer face. The inner face of the inner layer  22  and the inner face of the outer layer  24  adhere to each other. The outer face of the inner layer  22  adheres to the lid  53  of the container  50 . 
     The cover  20  has a main section  35 , a base section  37  and a flap  33 . The base section  37  is attached to the container  50 , either when the cover  20  is either in a closed position and prohibits access in the interior of the container  50  or lifted to allow access to the interior of the container  50 . In use, the flap  33  is to be held by the user, i.e. when (s)he lifts the flap  33  or places the cover  20  in the closed position. The plan view of the base section  35  may be almost orthogonal or orthogonal as it is depicted in  FIG. 6  or it may have other shapes, as for example it may have other shapes such as C, trough cross-section etc. 
     The layered structure of the cover  20  results that each section of the cover  20  has also two layers, i.e. an outer layer and an inner layer. Thus, the outer layer of main section  35 , the outer layer of the base section  37  and the outer layer of the flap  33  are portions of the outer layer  24  of the cover  20  and the inner layer of the main section  35 , the inner layer of the base section  37  and the inner layer of the flap  33  are portions of the inner layer  22  of the cover  20 . 
     The outer face of the inner layer  22 , i.e. the layer that is on the other side of the face that adheres to the outer layer  24 , has adhesive to attach the cover  20  to the lid  53  of the container  50 . When the lid  53  is in the closed position, the cover  20  adheres to the lid  53  as well as to the area of the container  50  that is around the lid  53 . In order to facilitate the user to lift the cover  20  from the container  50 , the outer face of the inner layer  22  of the flap  33  is free from adhesive. For example, this may be achieved during production by cancelling or removing the adhesive from the outer face of the inner layer  22  of the flap  33 . 
     The border  34  between the inner layer  22  of the main section  35  and the inner layer  22  of the flap  33  is preferably perforated to facilitate separation of the main section  35  and the flap  33 . Similarly the border  36  the between the inner layer  22  of the main section  35  and the inner layer  22  of the base section  37  is preferably engraved to facilitate separation of the main section  35  and the base section  37 . Other means to facilitate separation, for example perforations instead of cuts, may be used. The perforation lines  34  and the cuts  36  of a series of covers  20  are depicted in  FIG. 5 , which shows schematically an intermediate stage of the production of a roll including covers  20 .  FIG. 6  shows schematically the roll towards the end of the production, with the contour of individual covers shown in full lines. 
     During production, the inner layer  22  of the main section  35  is cut in two segments, a fixed segment  35   a  and a detachable segment  35   b . As shown in  FIG. 1  and  FIG. 2 , the inner layer  22  of the main section  35  is split by a cut  35   c  to an elongated fixed segment  35   a  and a ring-shaped, detachable segment  35   b  that surrounds the fixed segment  35   a . In another embodiment, the detachable segment may be C-shaped and surround partially the fixed segment. The fixed segment  35   a  is dimensioned so that it fits to the lid  53  of the container  50 . 
     The inner face of the detachable segment  35   b  that adheres to the inner face of the outer layer  24  is partially coated with release varnish. The inner face of the outer layer  24  that adheres to the inner face of the detachable segment  35   b  has a layer of reclosable adhesive, i.e. an adhesive that may be used a plurality of times. Such adhesives are usually used, when an item is to be adhered or stuck and removed from a surface more than once. Items that are joined with a reclosable adhesive may be separated without being damaged. 
     In order to prohibit the detachment of the fixed segment  35   a  from the outer layer  24 , the inner face of the fixed segment  35   a  that adheres to the inner face of the outer layer  24  is not coated with relish varnish. The shape, the dimensions and the means to impede the detachment of the fixed segment  35   a  from the outer layer  24  are only presented as one of many examples. In general these features are selected taking into consideration the features of the lid  53  of the container  50 . 
     The inner and the outer layers of each one of the base section  37  and the flap  33  adhere to each other with adhesive that is preferably provided on the inner surface of the outer layer  24 . 
     An example of a cover  20  has an inner layer  22  with a thickness within a range of 40 μm to 50 μm and an outer layer  24  within a range of 60 μm to 90 μm. In such an example the thickness of the cover  20  is less than 140 μm, so that the cover  20  may be soft and flexible. Preferably the inner layer  22  and the outer layer  24  are made of recyclable material, for example from polypropylene, i.e. PP. 
     The raw materials that are used for the production of a roll with adhesive covers include two rolls with a liner and a self-adhesive material. One of the rolls provides the inner layers of the covers and the other roll provides the outer layers of the covers.  FIG. 5  shows the roll of raw material, which provides the inner layer of the covers, at an intermediate stage of production. 
     A method of production of a roll with the adhesive covers that are presented above includes the following steps:
         Provide a first roll—raw material—with a liner  40  and a self-adhesive layer, i.e. face material, whereby the self-adhesive layer has a face in contact with the liner  40  and a free face. The face of the self-adhesive that is in contact with the liner  40  is coated with reclosable adhesive. In general, the use of reclosable adhesive allows the use of the adhesive a number of times, i.e. it allows to stick a surface that is provided with reclosable adhesive a plurality of times, without destroying it. The self-adhesive layer of the first roll will provide the inner layers  22  of the covers  20 .   Separate the liner  40  and the face material of the first roll.   Cancel/remove the adhesive on the areas of the self-adhesive layer, which correspond to the flap  33  of the covers  20  that are under production.   Recombine the liner  40  with the face material.   Engrave the self-adhesive layer to form the cut  35   c , which is a border line between the detachable segment  35   b  and the fixed segment  35   a  of each one of the covers  20  that are under production.   Perforate the self-adhesive layer to form the perforation line  34  between the detachable segment  35   b  and the flap  33  of each one of the covers  20  that are under production.   Engrave the self-adhesive layer to form the border  36  of the detachable segment  35   b  and the base section  37  of each one of the covers  20  that are under production. All three above mentioned engraving and perforation steps, which produce cuts  35   c  and  36  and perforation line  34 , or any two of these steps may be performed simultaneously. Alternatively they may be performed sequentially.   Coat the outer face of the self-adhesive, i.e. the face that is not in contact with the liner  40 , of the first roll with a release varnish. The coating is applied on the area of the outer face the liner  40 , which corresponds to the detachable segments  35   b  of the covers  20  under production. In use, the detachable segments  35   b  will adhere to the surface of the container  50  around the lid  53  of the container  50 .  FIG. 5  presents the first roll, upon completion of the above mentioned steps.   Provide a second roll—raw material—with a liner and a self-adhesive layer, i.e. face material, whereby the self-adhesive layer has a face in contact with the liner. The face of the self-adhesive that is in contact with the liner, i.e. the inner face, is coated with reclosable adhesive. The self-adhesive layer of the second roll will provide the outer layers  24  of the covers  20 .   Separate the liner and the face material of the second roll.   Attach the self-adhesive layer of the second roll on the self-adhesive layer of the first roll. The attachment is achieved by adhering the self-adhesive layer of the second roll to the self-adhesive layer of the first roll, which is partially coated with release varnish.   Cut the sandwich of the self-adhesive layer of the first roll and the self-adhesive layer of the second roll to produce the self-adhesive covers  20 .   Remove the waste material that is produced during the cutting of the covers  20  to obtain a liner  40  that carries a plurality of self-adhesive covers  20 . Such a roll is shown schematically in  FIG. 7  and an individual cover  20  on the liner  40  is shown schematically in  FIG. 3 . In  FIG. 3  the outer layer  24  is placed at a distance from the inner layer  22  in order to show the arrangement of the inner layer  22 .       

     The width of the rolls that are used for the production, i.e. the raw material, may accommodate one, two or more series of covers  20 . A solely indicative and preferable thickness of the self-adhesive layer of the first roll, i.e. the roll that provides the inner layer of the covers  20  is approximately 50 μm. 
     During production of the container  50 , the covers  20  are removed from the liner and placed on the top of the lid  53  of the container  50 , so that the fixed segment  35   a  covers the lid  53  and the detachable segment  35   b  adheres to the surface of the container  50  around the lid  53 . When the user wishes to remove an item from the container  50  s(he) lifts the cover  20  that carries the lid  53 , so as to provide access to the interior of the container  50  through its opening  55 . After lifting and re-sticking the cover  20  to the container  50  a number of times, the reclosable adhesive on the outer face of the detachable segment  35   b  becomes ineffective, because of dirt etc. Then the user lifts the cover  20  and removes the detachable segment  35   b , while the inner layer of the flap  33  and the inner layer of the base section  37  are separated from the main section  35 . The separation is facilitated by the perforation  34  and the cuts  36 . The fixed segment  35   a  remains adhered to the outer layer, with the lid  53  attached to it. Separation of the fixed segment  35   a  form the detachable segment  35   b  is facilitated by the cut  35   c.    
       FIG. 4  illustrates the sequence of the withdrawal and removal of the detachable segment  35   b  from the cover  20 : A designates the lifting of the cover  20  from a surface, B, C and D designate the removal of the detachable segment  35   b  and G designates the attachment of the cover  20  on the surface after the removal of the detachable segment  35   b . After the removal of the detachable segment  35   b , the cover  20  may still cover and seal the opening of the container  50 , with the inner surface of the outer layer of the main section  35  adhering with reclosable adhesive thereto. 
     An embodiment of the cover  20  according to the invention includes an inner layer  22  that has an inner face and an outer face and an outer layer  24  that has an inner face and an outer face, whereby the cover has a main section  35  that includes a portion of the inner layer  22  and a portion of the outer layer  24 , a base section  37  that includes a portion of the inner layer  22  and a portion of the outer layer  24  and a flap  33  that includes a portion of the inner layer  22  and a portion of the outer layer  24 , the main section  35 , the base section  37  and the flap  33  being three distinct sections. The inner face of the outer layer  24  and the inner face of the inner layer  22  comprise means to adhere the inner layer  22  and the outer layer  24  to each other, the outer face of the inner layer  22  is at least partially coated with reclosable adhesive to adhere, in use, at least partially to a surface. The portion of the inner layer  22  that is included in the main section  35  has a fixed segment  35   a  and a detachable segment  35   b , which detachable segment  35   b  adheres to the outer layer  24  and has an outer face that is part of the outer face of the inner layer  22  and is at least partially covered with reclosable adhesive, and between the detachable segment  35   b  and the fixed segment  35   a  there is a border  35   c  that facilitates separation of the detachable segment  35   b  and the fixed segment  35   a . Further, at least one of the inner layer  22  and the outer layer  24  comprises means other than said border  35   c  to allow separation and subsequent withdrawal of the detachable segment  35   b  from the cover  20 .