Device for evaporating volatile substances

Abstract

The invention refers to a device for evaporating volatile substances comprising: a container of a liquid volatile substance, and a vapour permeable membrane (1) and a thermoplastic porous or fibrous laminate (2) bonded together. Said container is closed at its opening by said vapour permeable membrane (1) and the fibrous laminate (2), wherein the fibrous laminate (2) is welded to the thermoformed part of the container.

Claims

1. A device for evaporating volatile substances comprising: a first portion comprising a container having a volume adapted to hold a liquid volatile substance, the first portion comprising a peripheral part and an opening that provides access to the volume, the first portion further comprising a first layer of a thermoformed material and a second layer of a sealing material, the second layer of the sealing material having a first surface located on the peripheral part and a second surface within the volume, and a second portion comprising a vapour permeable membrane and a fibrous laminate bonded together, wherein the fibrous laminate is a reinforcing substrate adapted to reinforce the vapour permeable membrane, wherein the fibrous laminate of the second portion is welded to the peripheral part of the first portion, wherein said first portion is closed at the opening by said second portion, thereby enclosing the volume, wherein the fibrous laminate extends through the opening, is in contact with the second surface of the sealing material within the volume, and fills a part of the volume, wherein the liquid volatile substance is disposed in the volume, wherein the fibrous laminate is arranged in contact with the liquid volatile substance so that the liquid volatile substance evaporates through the vapour permeable membrane.

2. The device according to claim 1 wherein the fibrous laminate is selected to have a melting point lower than the melting point of the vapour permeable membrane.

3. The device according to claim 1 wherein the vapour permeable membrane is an elastomeric monolithic membrane.

4. The device according to claim 3 wherein the elastomeric monolithic membrane comprises a material selected from the group comprising: an elastomeric polyester, polyamide block ether, polyurethane, and polyolefin elastomer.

5. The device according to claim 1 wherein the fibrous laminate is selected from the group comprising: non woven material, polyolefin non woven, polypropylene or polyethylene non woven.

6. The device according to claim 5 wherein the fibrous laminate includes a non woven material made of fibers with a polypropylene core and a polyethylene shell.

7. The device according to claim 1 wherein the vapour permeable membrane and the fibrous laminate are laminated together by thermally and mechanically bonding these two elements.

8. The device according to claim 1 wherein the vapour permeable membrane and the fibrous laminate are laminated together by applying in a discrete form an adhesive in between.

9. The device according to claim 1 wherein the vapour permeable membrane and the fibrous laminate are laminated together by applying in between of a continuous layer of an adhesive material which is permeable to the volatized substances.

10. The device according to claim 1 wherein the fibrous laminate is a polyethylene spunbound non woven having a grammage within the range 50 to 150 g/m2.

11. The device according to claim 1 wherein the container is a thermoformed container made of polyethylene terephthalate/polyethylene vinyl alcohol/polyethylene.

12. The device according to claim 1 wherein a removable barrier film is provided on the outer surface of the vapour permeable membrane.

Description

DESCRIPTION OF THE DRAWINGS

(1) To complete the description that is being made and with the object of assisting in a better understanding of the characteristics of the invention, in accordance with a preferred example of practical embodiment thereof, is a set of drawings wherein by way of illustration and not restrictively, the following has been represented:

(2) FIG. 1drawing (a) shows a perspective view of a schematic representation of the multilayered membrane of the invention formed by a thermoplastic fibrous laminate bonded to a monolithic vapour permeable membrane, and drawing (b) is a similar representation than figure (a) with a removable barrier film over the membrane, and provided above a container prior to the welding process.

(3) FIG. 2drawing (a) is an schematic elevational view of the membrane structure placed above a container prior to the welding process, and drawing (b) is a similar representation than drawing (a) once the membrane structure has been welded to the container.

(4) FIG. 3shows schematically the effect of the manufacturing process of the invention, wherein drawing (a) shows a plan view of a sealing flange of a sealing tool used for welding the multilayered membrane to a container; drawing (b) shows a plan view of the multilayered membrane before welding; and drawing (c) shows a plan view of the multilayered membrane after welding, wherein it has been represented how the area of the membrane to which the sealing flange has been applied has a different appearance because the fibrous material is erased because it has been fused.

PREFERRED EMBODIMENTS OF THE INVENTION

(5) The device for evaporating volatile substances of the invention, in a preferred embodiment comprises a container (6) of a liquid volatile substance (8), with an opening (10) and at least a part of the container in the periphery of said opening made of a thermoformed material.

(6) The device further comprises a vapour permeable membrane (1) and a thermoplastic fibrous laminate (2) bonded together, so that the container is closed by said vapour permeable membrane (1) and the fibrous laminate (2), in such a manner that the fibrous laminate (2) is welded to the thermoformed part of the container.

(7) A film of a sealing material (7) compatible with the fibrous laminate, is provided on the internal surface of the container and on a perimetral lip (11) of the container around the opening (10).

(8) During the manufacturing process, the sandwiched structure formed by the membrane (1), laminate (2) and barrier (3), is placed on the perimetral lip (11) closing the container as shown in FIG. 2b, so that the laminate (2) is arranged internally to the container. In the welding process, heat and pressure is applied by a sealing flange (4) of a sealing tool, to the periphery of the membrane structure, until the perimetral part of the thermoplastic laminate fuses with the container forming thereby a sealing ring (9), which prevent any liquid leak to the outside.

(9) As shown in FIG. 3c, the area of the fibrous laminate that has been erased in the welding process, change its visual appearance and this effect is used in the present invention to determine the quality of the welding process.

(10) FIG. 2 shows the container in a non-operative position (horizontally). However, in use the device, would the place in another position (for example vertically) so that the liquid volatile substance (8) is in contact with the fibrous laminate (2) and it can evaporate through the membrane.

(11) Preferably, the membrane is a monolithic membrane with elastomeric behaviour, for example an elastomeric polyester, polyamide block ether or polyurethane or Polyolefin elastomer.

(12) The fibrous substance can be whatever fabric made of a thermoplastic material (a plastic that can be molten).

(13) Preferably it is a non woven material, or a polyolefin non woven, or a PP or PE non woven, or an hybrid PP/PE non woven where fibre has a PP core and a PE shell. Alternatively, the laminate may consist of a laminate of open foam.

(14) The lamination between the membrane and the fibrous material can be done without any adhesive, by thermally/mechanically bonding the two layers, but preferably, the adhesion is done by applying an adhesive.

(15) Preferably, the adhesive is applied in a discrete form (not a continuous layer), by points, or by lines, in order to avoid the adhesive decrease the permeation speed (acts as a barrier). The adhesive, may also be applied in the form of a thin continuous layer of adhesive made of material permeable to the volatile substance.

(16) Preferably the container is made of a thermoformed material, wherein the upper layer of this material is made of a material compatible with the fibrous laminate. Optimally it is the same, so that, in case the fibrous laminate is a non woven made of PE or hybrid PP/PE (as described above), the upper layer of the container will be done of PE as well.

(17) The device also incorporates an aluminium foil (3) with a plastic layer on the side of the membrane, that is partially compatible with the membrane material, that means, that can bonds to the membrane but not in a permanent way. The aluminium foil (3) avoids evaporation of the volatile substance before the first use.

Example 1

(18) Membrane is a polyester elastomer of 70 microns thickness.

(19) Adhesive is a poluyrethane solventless based adhesive applied in crossed lines.

(20) Non woven is a PE spunbound non woven of 50 g/m2.

(21) Thermoformed container is made of PET/EVOH/PE.

Example 2

(22) Membrane is a polyester elastomer of 70 microns thickness.

(23) Adhesive is a poluyrethane solventless based adhesive applied in a thin continuous layer.

(24) Non woven is a PE spunbound non woven of 50 g/m2.

(25) Thermoformed container is made of PET/EVOH/PE.