Patent Application
20070156105
The present invention may relate to the field of plastics molding, for example, for an ostomy device. Particular aspects of the invention may relate to a molding method, molding apparatus, and to a molded product usable in an ostomy device. The invention may be especially applicable to blow molding a component of an ostomy device.
In the technically specialized field of ostomy devices, fusion is a commonly used technique for bonding together two plastics components. Examples of fusion techniques include solvent bonding, heat welding and ultrasonic welding. These techniques generally involve at least partly melting and fusing the two components together after the components have been formed as separate parts. However, such processes necessitate additional manufacturing equipment and processing steps, and add to the cost and complexity of manufacture. There is also a risk of failure of, or leakage from, the weld, resulting from occasional welding errors or anomalies. The manufacturing complexity and risk of failure may be exacerbated when one or both of the components is a blow molded component. A blow molded component typically has a thin wall that may be at least partly deformable, and this can make welding complicated shapes difficult. Should a failure or leak occur during use by an ostomate, not only is this highly embarrassing and unhygienic for the ostomate, it may also lead to customer rejection of the product in this highly personal field.
Broadly speaking, in one aspect of the invention, a method of forming an ostomy device component may include blow molding a (second) portion of the component into intimate contact with a preformed (first) portion.
The intimate contact achieved during the blow molding operation can enable a strong and permanent bond to be achieved between the two portions, without requiring any additional welding or other fusion step after the molding operation. The blow molding operation may thus achieve two simultaneous effects of (i) imparting a desired shape to the blow molded (second) portion, and (ii) integrally bonding the two portions together.
The invention can therefore avoid the additional welding steps of the conventional manufacturing techniques, leading to improved quality components, and more efficient manufacture.
As used herein, the term “blow molding” may mean any molding process that uses a pressure differential between an internal pressure and an external pressure, to cause a plastics body (e.g. parison) to expand and to adopt a shape define by a surrounding mold.
The material from which the second portion is blow molded may be a body of material that is independent of the first portion. The material from which the second portion is blow molded may, prior to the blow molding operation, be unattached to the first portion.
The first portion may be any preformed part. For example, the first portion may be preformed by injection molding, blow molding, vacuum forming, machining or casting. The first portion could alternatively comprise any of a fabric, textile or non-woven polymer material. The first portion may be a molded part or a sheet material, for example, plastics film. The first portion may itself be a sub-assembly of multiple parts.
The first portion may be generally rigid (or at least more rigid than the second portion). Alternatively, the first portion may be substantially flexible (or at least more flexible than the second portion).
The first and second portions may be formed of material having substantially the same or similar melting temperatures. Such a technique has been found to provide good bonding between the first and second portions.
The first portion may comprise the same or a similar plastics material to the second portion. Alternatively, the materials used for the first and second portions may be different. The first and second portions may achieve a plastics bond, or a mechanical bond, or a combination of both.
Broadly speaking, a second aspect of the invention may relate to a mold apparatus that may be used in the above method. The, or a, mold apparatus may include a first mold region for accommodating and/or preforming a first preformed portion, and a second mold region for defining a blow mold shape of a second portion.
Broadly speaking, a third aspect of the invention may provide an ostomy device component produced by the method of the first aspect and/or the mold apparatus of the second aspect.
Broadly speaking, a fourth aspect of the invention may provide an ostomy device component that includes integrally molded first and second portions, at least one portion (e.g. the second portion) being a blow molded part.
The first and second portions of the component may include any of the aforementioned features.
The first portion may, in one form, comprise a ring-shaped member and/or a cover member. The first portion may be configured as a coupling member for coupling to a counterpart coupling member. Additionally or alternatively, the second portion may, in one form, comprise a generally tubular portion. The tubular portion may be collapsible and/or extendable in a direction generally parallel to the axis of the tubular portion. The tubular portion may have an open end and/or a closed end. The tubular portion may have a concertina and/or bellows profile. The tubular portion may be flexible and/or bendable. The tubular portion may define an ostomy collection chamber.
The above aspects of the invention may be used independently or in combination, as desired.
Other aspects, features and advantages of the invention may be described in the appended claims and/or in the following description and drawings. Protection is claimed for any novel feature and/or combination of features described herein and/or illustrated in the drawings whether or nor emphasis has been placed thereon.
Non-limiting preferred embodiments of the invention are now described, by way of example only, with reference to the accompanying drawings, in which:
a-e are schematic diagrams illustrating molding of the component of
Referring to
The first portion 14 may be configured to support the shape of the tubular second portion 16. The first portion 14 may be configured to provide structural support for the second portion 16. The first portion 14 may additionally or alternatively be configured as a coupling member for coupling to a counterpart annular coupling member (shown in phantom at 18 in
The first and second portions 14 and 16 may be of material (e.g. plastics) having the substantially the same, or similar, melting temperatures. The first and second portions 14 and 16 may be of the same, or similar, plastics material. For example, the plastics material may be an ethylene vinyl acetate, although a wide variety of similar and dissimilar plastics may be used, as desired.
It may be preferred to form the first portion 14 by injection molding. For example, the first portion 14 may have a relatively thick wall thickness (e.g. about 1 mm, or more) that is better suited to formation by injection molding than blow molding. The coupling configuration 20 of the first portion 14 may also have a level of intricacy that may be suited to injection molding, but may be difficult to achieve by blow molding. In contrast, it may be preferred to form the second portion 16 by blow molding. For example, the second portion 16 may have a relatively thin wall thickness (e.g. about 1 mm or less, typically between 0.1 and 0.3 mm) that may be better suited to formation by blow molding than injection molding. Also, blow molding may enable the second portion 16 to be formed consuming far less plastics material than injection molding, thus leading to significant material economy.
a-e may illustrate a mold apparatus 30 and mold method for forming the component of
The mold apparatus 30 may generally comprise mold segments or shells 32 (e.g. mold halves) that together define a mold cavity 34. The mold shells 32 may include at least one first mold region 36 shaped to accommodate the preformed first portion 14, and at least one second mold region 38 shaped to define the final shape of the second portion 16. In the present embodiment, the first mold region 36 may comprise an annular recess or groove for receiving the pre-formed ring-shaped first portion 14. The second mold region 38 may comprise a bellows shaped surface 38a for defining the bellows profile of the second portion 16, and a lip surface 38b for defining a radially directed lip 26 of the second portion 16 at the opposite end of the second portion 16 to the first portion 14. The second mold region 38 may be configured to mold the second portion 16 either in a fully extended condition, or in a partly extended condition, or in a fully or substantially collapsed condition.
Referring to
The above technique of blow molding a portion 16 of the component into intimate contact with a preformed portion 14 has been found to provide excellent bonding characteristics between the two portions 14 and 16. The blow molding operation forces the material of the two portions into firm contact, and enables a strong and uniform bond to be achieved with an excellent reliability and repeatability, leading to consistently high manufacturing quality. The quality and reliability may exceed that achievable economically by the prior art technique of welding the two portions together after both portions have been formed as separate parts.
Avoiding such a welding step may also improve the manufacturing efficiency because it may no longer be necessary to provide dedicated welding equipment and welding process steps for bonding two discrete portions together.
The blow molding technique may comprise one or more of: extrusion blow molding, injection blow molding, vacuum forming, pressure forming, and/or plug assist thermoforming.
In the illustrated embodiment, the adjoined faces of the first and second portions 14 and 16 may be generally planar. Alternatively, the adjoined faces may be keyed or embossed in order to increase the engagement between the first and second portions 14 and 16, which may increase the strength of the bond.
Although the foregoing embodiments have been described in the form of a component including a ring-shaped first portion 14 and a tubular second portion 16, this is merely for the purposes of illustration. The invention may be used to form a wide variety of different component shapes and configurations in the ostomy field.
The techniques of the present invention are especially advantageous and beneficial in the field of ostomy devices. The manufacture of such devices presents unique challenges in terms of forming low-cost, lightweight devices that are straightforward to use and comfortable to wear. At the same time, security and hygiene are of utmost importance to the wearer. Ostomy devices should have a high integrity against leakage, and be robust enough to withstand body movements and accidental knocks without accidentally releasing body waste.
The present invention permits a multi-part component including at least a blow molded part to be integrally formed by a process which is efficient from the point of view of manufacture, yet also achieves the degree of strength and reliability demanded for the specialized field of ostomy devices.
The foregoing description is merely illustrative of preferred forms of the invention. Many modifications, improvements and equivalents may be used within the scope and/or spirit of the invention.
| Number | Date | Country | |
|---|---|---|---|
| 60569543 | May 2004 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 11120762 | May 2005 | US |
| Child | 11686096 | Mar 2007 | US |
