Patent Publication Number: US-2018035773-A1

Title: A dust proof container, a dust mask assembly and a method of manufacturing a dust proof container

Description:
BACKGROUND 
     Dust proof containers are used in many circumstances. One particular instance when a dust proof container is particular useful is for the purpose of storing a dust mask when the dust mask is not in use. For instance, a worker may enter a dusty location, such as a workspace, a construction site, or a site in need of cleaning. The worker may wear a dust mask in order to prevent inhaling dust. The dust comprises fine particles of various materials, such as concrete, wood, fiberglass, metal, gypsum, silica or the like. 
     When the worker is leaving the dusty workspace, the dust mask may be removed and stored in a dust free location until the worker again needs to enter the dusty location. Dust masks need to be dust free on the inside, i.e. the side which is intended to cover the nose and mouth of the user, for several reasons. One reason being that in case the dust mask is dusty on the inside, this dust may be inhaled by the user when the user is wearing the mask. Another reason is that a dusty dust mask may not be able to fit tightly around the user&#39;s nose and mouth and in such cases the dust mask will not function properly. 
     In the prior art, dust proof containers exist, such as waterproof containers. An example may be a container having a sealable opening, e.g. a waterproof zipper. However, such waterproof zippers are generally not intended for dusty locations since dust may damage the sealing properties of the waterproof seal to such an extent that the seal will be jammed and/or leaking. 
     One relevant prior art document, CN 204015178U, discloses a storage bag for a dust mask. This bag is foldable and connected to the dust mask and thus, it cannot be ensured that the bag will not become dusty when the user enters the dusty location. 
     Another relevant prior art document, WO 2013/076678 A1, discloses a slide fastener comprising a pair of stringers which are overlapping in the closed position of the slide fastener. 
     One problem which may occur is that the dust proof container will become dusty when working within a dusty location. Dust may affect the sealing properties of the container such that it does not seal off correctly. Dust may also increase the wear of the opening mechanism of the container. 
     Thus, it is an object according to the present invention to provide technologies for achieving a dust proof container, which may be sealed off in a dusty location without damaging or degrading the sealing properties of the container. 
     SUMMARY OF THE INVENTION 
     At least the above object, or at least one of numerous further objects which will be evident from the below description of the present invention, is according to a first aspect of the present invention obtained by a dust proof container or a container for providing a dust free environment, the container defining an inner layer being made of an elastomeric material and an outer layer adhered to the inner layer and being made of a reinforcing web material, or alternatively, an inner layer being made of an elastomeric material being abrasion resistant and an outer layer adhered to the inner layer and being made of a low friction material or yet alternatively a unitary moulded single layer of elastomeric material being both abrasion resistant and defining a low friction, the container defining a sealable opening between a first edge of the container and a second edge of the container, the container further comprises a locking part located on the container at the opening, the locking part defining an open state in which the first edge and the second edge are spaced apart, and a closed state in which the elastomeric material at the first edge is contacting the elastomeric material at the second edge. 
     The elastomeric material may e.g. be rubber. In case two layers are used, the locking part is applied on the outer layer, and elastomeric material of the inner layer at the first edge is contacting the elastomeric material of the inner layer at the second edge in the closed state. In case a single layer of elastomeric material is used, it is understood that the locking part is applied on the outer surface of the elastomeric material, and the elastomeric material at the first edge is contacting the elastomeric material at the second edge in the closed state. 
     The expressions dust proof and dust free should be interpreted to mean that the container should not allow small solid particles generated from various industrial or constructional work into the container. It is not necessary for the present container to be entirely liquid or gas tight. The container may be of different sizes; however, preferably, the present container is made for being carried on or by a human. The container defines an inner space which is protected from dust, i.e. a dust free environment, and the size of the inner space is preferably sufficient for accommodating a dust mask. 
     In case two layers are used, the web material at the outer layer of the container should be substantially durable to withstand any tear and wear exposed to the container in a typical industrial or constructional environment. The outer layer in particular protects the inner layer of elastomeric material. Elastomeric materials are flexible but may easily break or be damaged when subjected to external forces from e.g. tools or abrasive materials. 
     In case a single layer is used, the container should be moulded as a unitary part, i.e. in one piece, and of a rubber composition which is durable and having a reasonably low friction. In this way it may be ensured that the dust free environment is not compromised and that the outer surface is easy to clean. The expression low friction is understood to mean that the outer surface is smooth and substantially free from any cavities and/or protrusions which may make the container difficult to clean and cause dust and other objects to attach the outside of the container 
     Alternatively, the inner layer is made of an elastomeric material, which is abrasion resistant meaning that it will be resistant and not break up when exposed to scratching, rubbing and other mechanical influences. The outer layer is then made of a low friction material, which is understood to exhibit a lower friction when rubbed against another object than the inner elastomeric material. The low friction material may e.g. be nylon, PTFE or a similar material. In this way, the container may be moulded in one piece eliminating the need for any stitches. 
     The opening is defined between opposing first and second edges of the container and allows access to the inner space of the container. The opening should during normal use be closed off and especially when the user enters a dusty area. The inner space will be kept dust free for accommodating a piece of equipment, such as a dust mask. 
     The locking part keeps the opening closed during such normal use of the container. When the inner space of the container is to be accessed, the locking part is operated in order to briefly expose said opening, where after the locking part is operated again to seal off the opening. 
     In order to allow the elastomeric material of the inner layer at the first edge to contact the elastomeric material of the inner layer at the second edge, the edges should be abutting each other and not overlap, since overlapping edges will not allow the elastomeric materials of the respective edges to come into contact. 
     By locating the locking part spaced apart from and outside the first and second edges constituting the opening of the container, the first and second edges may be protected from dust. However, the locking mechanism need not be made dust proof and may be made sufficiently rigid and durable to not be damaged by dust. 
     According to a further embodiment of the first aspect, the locking part in the closed state is covering the first edge of the container and the second edge of the container. In this way the edges, which constitute the sealing elements, which prevent dust to enter the inner space of the container, are protected from the outside. 
     According to a further embodiment of the first aspect, the locking part is a zipper, the zipper preferably being made of rigid plastic, metal, rubber, or alternatively having a rubber coating. The locking part is preferably a zipper, which allows the container to be quickly opened and thereafter quickly closed and sealed. The zipper should preferably be durable and mechanically resistant to dust, however, it must not be dust proof. The locking part may alternatively be made of e.g. Velcro. Alternatively, the zipper is made of rigid plastic or metal. The above materials are not necessarily waterproof, but sufficiently rigid to not be damaged by most dust particles. Yet alternatively, the zipper is made of rubber or a rubber coated material providing even more dust resistance. 
     According to a further embodiment of the first aspect, the zipper is permeable to dust particles having a size of less than 1 μm, preferably less than 10 μm, more preferably less than 100 μm, most preferably less than 1 mm. The above sizes are typical for the present dust particles generated by industrial work and/or construction work. Since the above particles are allowed to go through the zipper, these particles will not jam or damage the zipper. 
     According to a further embodiment of the first aspect, the zipper is stitched onto the container by stitches adjacent the first edge and the second edge, or alternatively, the zipper is adhered onto the container adjacent the first edge and the second edge. The zipper is preferably stitched onto the container, i.e. the first and second edges, which constitute the sealing element for sealing of the opening and making the container dust proof, which edges are protected from external forces from the outside by the zipper. The zipper should be stitched on such that when the zipper is closed, the opening is sealed. Even more preferably, the zipper is adhered onto the container adjacent the first edge and the second edge. In this way, no stitch holes will be made and the container will be more dust resistant. 
     According to a further embodiment of the first aspect, the elastomeric material is a foamed polymeric material such as neoprene or a porous material such as expanded PTFE, or a rubber material such as natural rubber. A foamed polymeric material or a porous material will allow the formation of open cells at the first and second edges. When the first and second edges contact to seal off the inner space, the open cells will allow any dust particles, which may have accumulated at the edge to enter the open cells and thus not inhibit the sealing performance of the edges. Alternatively, the elastomeric material is made of abrasion resistant material such as rubber, preferably natural rubber. 
     According to a further embodiment of the first aspect, the reinforcing web material is textile such as textiles made of bamboo, tomato or hemp materials. The textile may be e.g. natural textile such as cotton or synthetic textile such as nylon. The textile should be durable and be able to be adhered to the elastomeric material for supporting the elastomeric material. Preferably, the materials used are biologically degradable such as bamboo, tomato or hemp. 
     According to a further embodiment of the first aspect, the container further comprises a belt clip. The belt clip is used for attaching the dust proof container to a belt or other piece of clothing worn by the user. 
     According to a further embodiment of the first aspect, the container has a substantially cylindrical shape. A cylindrical shape, i.e. a cylinder bounded by two opposite circular surfaces, allows for a large inner space, suitable for accommodating e.g. a dust mask. 
     According to a further embodiment of the first aspect, the first and second edges of the dust proof container, when the locking part is in the closed state, define a circular arc. The dust proof container is preferably opened along the cylindrical wall of the cylindrically shaped container. 
     According to a further embodiment of the first aspect, the circular arc defines an angle of between 90° and 270°, preferably between 120° and 240′, more preferably 150° and 210°, most preferably 180°. Such arc length allows for a sufficiently large opening to be able to remove and introduce equipment, such as a dust mask. 
     According to a further embodiment of the first aspect, the low friction material is applied as a nano coating. The low friction material preferably exhibits dust repellent properties and/or easy to clean properties. 
     According to a further embodiment of the first aspect, the dust proof container defines an innermost layer being adhered to the inner layer opposite the outer layer, the innermost layer being made of a reinforcing web material such as textile. Optionally, such layer protects the elastomeric layer in case the container is used for other purposes such as storing nails etc. 
     At least the above object, or at least one of numerous further objects which will be evident from the below description of the present invention, is according to a second aspect of the present invention obtained by a dust mask assembly comprising a dust mask and a dust proof container. 
     The above assembly according to the second aspect is preferably used together with the container according to the first aspect. 
     At least the above object, or at least one of numerous further objects which will be evident from the below description of the present invention, is according to a third aspect of the present invention obtained by a method of manufacturing a dust proof container or a container for providing a dust free environment by:
         providing a container having an inner layer being made of an elastomeric material and an outer layer adhered to the inner layer and being made of a reinforcing web material, or alternatively, an inner layer being made of an elastomeric material being abrasion resistant and an outer layer adhered to the inner layer and being made of a low friction material,   defining a sealable opening between a first edge of the container and a second edge of the container,   applying a locking part onto the container on the outer layer at the opening, the locking part defining an open state in which the first edge and the second edge being spaced apart, and a closed state in which the elastomeric material of the inner layer at the first edge is contacting the elastomeric material of the inner layer at the second edge.       

     The above method according to the third aspect is preferably used together with the container according to the first aspect and/or the assembly according to the second aspect. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  illustrates a dust mask assembly according to the present invention. 
         FIG. 2  illustrates a zipper of a dust proof container according to the present invention. 
         FIG. 3  illustrates a clip of a dust proof container according to the present invention. 
         FIG. 4  illustrates a dust mask assembly according to a further embodiment of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view of a dust mask assembly  10 . The dust mask assembly  10  comprises a dust mask  12  and a dust proof container  14 . The dust mask  12  comprises a flexible pad  16 , which has a shape for covering the nose and mouth of a human user and sealing against the face surrounding the nose and mouth of said user. The dust mask  12  further comprises a resilient strap  18 , which is connected to the flexible pad  16 . The strap  18  is intended to be put around the head of the user for allowing the flexible pad  16  to remain on the face of the user and apply a sealing pressure onto the face surrounding the nose and mouth of said user. The flexible pad  16  further comprises a filter  20  for filtering the air and remove any dust particles contained in the air inhaled by the user from the surroundings. 
     The dust proof container  14  comprises an opening  22  for allowing the dust mask  12  to be introduced into the dust proof container  14 . The dust proof container  14  has an outer layer  24  and an inner layer  26 , whereby the outer layer  24  faces the outside of the dust proof container  14  and the inner layer  26  faces the inside of the dust proof container  14 . The outer layer  24  is made of a textile material in order to provide a wear resistant and substantially rigid outer surface of the dust proof container  14 . The inner layer  26  is made of neoprene in order to be completely dust proof. Optionally, the inner layer  26  is covered by an innermost layer of textile (not shown) which allows the inside of the dust proof container  14  to be wear resistant and substantially rigid. The dust proof container  14  must not be waterproof, but preferably capable of withstanding spray water such as rain. 
     The opening  22  may be closed by the user via a zipper  28  bridging the opening  22 . By closing the zipper, mutual edges  30  of the inner layer  26  will contact as will be shown in more detail in the next figure. 
       FIG. 2  is a perspective view of the dust proof container  14  and a close-up of the zipper  28  when the opening  22  is closed. The zipper  28  is stitched onto the dust proof container  14  outside the outer layer  24  and bridging the opening  22 . When the opening  22  is closed, the zipper  28  causes the first edge  30  and the second edge  30 ′, which together define the opening  22  of the dust proof container  14 , to contact each other and seal off the opening. The size and shape of the container  14  and the corresponding interior space of the container  14  should be appropriate for the dust mask to be stored inside the container  14  without crumpling the dust mask. A too small container  14  in relation to the dust mask may cause the dust mask to be jammed between the first edge  30  and the second edge  30 ′ so that no proper dust proof seal is established when the zipper  28  is closed. 
     The zipper  28  is preferably of a wear resistant type, which does not have to be dust proof. In this way, small dust particles which enter the zipper  28  will do minimal damage to the zipper  28 . The zipper  28  applies a contact force between the first edge  30  and the second edge  30 ′, which allows the first edge  30  and the second edge  30 ′ to establish a dust proof sealing between the corresponding edges of the inner layer. The inner layer is substantially protected from dust and being neoprene will establish a proper sealing even if slightly contaminated with dust. 
       FIG. 3  is a perspective view of the front side and the rear side of the dust proof container  14 . The rear side comprises a belt clip  34 . 
       FIG. 4  is a perspective view of a dust mask assembly  10 ′ according to a further embodiment of the present invention. In the present embodiment, the container is in principle made in one piece having a single layer  26 ′ made of elastomeric material such as rubber. The single layer  26 ′ is moulded in one piece. Further, the zipper  28 ′ is adhered onto the outer layer  24  at the edges  30 ′ thereby eliminating any need for stitches through the single layer  26 ′. The single layer  26 ′ is made of an abrasion resistant elastomeric material such as natural rubber, and the outer surface of the single layer  26 ′ is smooth in order to define a low friction when rubbed against other objects. Optionally, an outer layer  24 ′ is applied onto the inner/single layer  26 ′ constituting a low friction coating. The belt clip  34 ′ may also be applied by adhesion. To further enhance the dust proof environment inside the container, the zipper  28 ′ may be made of rubber or having a rubber coating. 
     LIST OF WITH PARTS REFERENCE TO THE FIGURES 
     
         
           10 . Dust mask assembly 
           12 . Dust mask 
           14 . Dust proof container 
           16 . Flexible pad 
           18 . Straps 
           20 . Filter 
           22 . Opening 
           24 . Outer layer 
           26 . Inner layer 
           28 . Zipper 
           30 . Edge 
           32 . Stitches 
           34 . Belt clip