AU2012101292A4 - Applicator and Method of Applying Liquids - Google Patents

Abstract

1. An applicator for a liquid chemical composition comprising: a closure for a container adapted to hold a liquid chemical composition, a shaft associated at a first end with the closure, and a roller adapted to rotate about the shaft, the roller having a surface adapted to carry the liquid chemical composition.

Description

PI/00/002 Regulation 3.2B AUSTRALIA Patents Act 1990 ORIGINAL COMPLETE SPECIFICATION INNOVATION PATENT Application No. Lodged: Innovation Title: Applicator and Method of Applying Liquids The following statement is a full description of this innovation, including the best method of performing it known to the Applicant: 2 APPLICATOR AND METHOD OF APPLYING LIQUIDS FIELD OF INVENTION [0001] The present invention relates to the field of applicators, particularly applicators for domestic or industrial applications. [0002] In one particular aspect the present invention is suitable for use in the application of industrial liquid chemical compositions such as adhesives and adhesive primers. [0003] It will be convenient to hereinafter describe the invention in relation to applying adhesive to PVC pipes however, it should be appreciated that the present invention is not limited to that use and can be used in a wide range of applications where a fluid needs to be evenly or neatly applied at a locus. BACKGROUND ART [0004] Throughout this specification the use of the word "inventor" in singular form may be taken as reference to one (singular) inventor or more than one (plural) inventor of the present invention. [0005] It is to be appreciated that any discussion of documents, devices, acts or knowledge in this specification is included to explain the context of the present invention. Further, the discussion throughout this specification comes about due to the realisation of the inventor and/or the identification of certain related art problems by the inventor. Moreover, any discussion of material such as documents, devices, acts or knowledge in this specification is included to explain the context of the invention in terms of the inventor's knowledge and experience and, accordingly, any such discussion should not be taken as an admission that any of the material forms part of the prior art base or the common general knowledge in the relevant art in Australia, or elsewhere, on or before the priority date of the disclosure and claims herein.

3 [0006] Liquid chemical compositions used for domestic and industrial purposes are supplied in a range of containers including pots, cans or bottles. Transferring the liquid chemical composition from the container to a locus can be difficult due to properties inherent in the liquid. [0007] For example, liquid chemical compositions such as coatings, cleaners, primers and adhesives often include toxic or volatile components that are associated with serious health and safety problems. Users can be put at risk by inhalation of vapour or skin contact with the liquid. In the plumbing and agricultural industries, this is a particular problem when priming fluid (primer) and adhesive are applied to the ends of PVC pipe sections, before the pipe ends are brought into contact to bond. [0008] There are many different approaches to transferring liquid chemical compositions from a container to a locus. Some manufacturers provide a brush with each container of liquid chemical composition however unless the brush is high quality (and therefore expensive) it is unlikely to have good liquid retention. Another problem associated with the brush is that it has to be returned multiple times to the container to be recharged with liquid in order to cover the entire locus. As a result, many liquids, particularly adhesives, are not applied in a consistent, even manner, resulting in the adhesive flowing outside the area to be bonded and dripping onto the user. Brush application also presents a risk of flicking liquid onto the user. [0009] Brushes also have to be cleaned by application of solvents otherwise the liquid chemical composition will harden, or become tacky, making it impossible to re-use the brush. Cleaning creates extra work, expense and disposal of the used solvent creates environmental issues. Alternatively, the user has to dispose of the brush and purchase a new brush, again incurring expense and creating environmental issues. In an attempt to overcome the problems and inconvenience associated with cleaning, some containers have a brush stored inside the container. However these brushes have the same application deficiencies as brushes supplied separately. [0010] A cheaper option for applying liquids such as primers and adhesives is to pour the liquid onto a cloth and wipe the liquid onto a locus to be bonded. The use of a cloth increases the likelihood of the liquid contacting the user's hands and increases exposure 4 to hazardous vapour. As the cloth dries, more liquid must be applied and this is usually wasteful of the liquid. The eventual disposal of the cloth creates another environmental issue. [0011] Attempts have been made to overcome the problems associated with application of liquid chemical compositions. For example, Australian patent 2007234493 discloses a plumber's liquid applicator for applying liquid to join pipes or fittings. The applicator includes a handle and a stem extending from the handle, with an absorber mounted to the site for insertion in the fitting. However, once the liquid is absorbed by the absorber it is difficult to deposit it evenly on the pipe surface as the liquid must be daubed on. [0012] Accordingly there is a need for an improved method of applying liquids to a locus. SUMMARY OF INVENTION [0013] An object of the present invention is to provide an improved applicator for liquid chemical compositions. [0014] A further object of the present invention is to alleviate at least one disadvantage associated with the related art. [0015] It is an object of the embodiments described herein to overcome or alleviate at least one of the above noted drawbacks of related art systems or to at least provide a useful alternative to related art systems. [0016] In a first aspect of embodiments described herein there is provided an applicator for liquid chemical compositions, the applicator comprising: a closure for a container adapted to hold a liquid chemical composition, a shaft associated at an end with the container closure, and 5 a roller adapted to rotate about the shaft, the roller having a surface adapted to carry the liquid chemical composition. [0017] Typically, the liquid chemical composition is a liquid for joining plumbing or agricultural pipes or fittings and may include a single liquid chemical component or multiple chemical components. Typically the liquid chemical component will include solvents such as ketones, aldehydes, esters and alcohols. The liquid may be in the form of a neat chemical, solution, emulsions, colloid, suspension or combinations thereof. For example the liquid chemical may be a primer or adhesive for polymeric pipes and fittings, particularly PVC pipes or fittings. [0018] The roller typically comprises a barrel having an inner surface for enclosing at least part of the shaft, and an outer surface bearing a material for carrying the liquid chemical composition. The length of the roller may be chosen to provide even application of the liquid chemical composition to ensure adequate bonding depending on the nature of the liquid being applied and the locus. Tests were carried out to determine suitable roller lengths, for example, for the application of adhesive to PVC pipe ends. Roller length of about 40 to 45 mm applied sufficient depth of adhesive, the slightly longer length allowing for some error in application. Roller length of up to 50 mm also worked well but the increased length caused increased tendency for drip formation. Roller length of about 75mm, caused significant drip formation and was difficult to use, and would not be suitable for smaller containers, Accordingly in a preferred embodiment the roller is 40 to 75mm in length, more preferably 40 to 50 mm in length. [0019] Typically the material is integral with the outer surface of the barrel. The barrel may be rotatably attached to the shaft by any convenient means and is typically adjacent a second end of the shaft. The material may be made integral with the surface of the barrel by any convenient form of bonding such as melt sealing or adhesion. Suitable bonds can be readily determined by testing. For example, materials glued to the barrel with standard liquid type adhesives and immersed in various solvent blends tend to fail after 4 hours. Gluing using hot melt type adhesives fails after 48 hours immersion in solvent. By contrast, thermobonding tends not to fail even after 3 weeks immersion in various solvent blends.

6 [0020] The applicator may be constructed of any material that is unreactive to the components of the liquid chemical composition. For example, polymeric material such as polypropylene may be an appropriate material of construction. The surface may for example, be constructed of a microfiber material, such as wool or polyester microfiber. In particular, various fabrics were tested by immersion in various solvents and adhesives for 14 days and natural fibres such as wool and cotton, plus synthetic materials such as wool-like polyester, microfiber and velour performed best and are particularly preferred. Synthetic materials such as acrylic fibre (frayed slightly) and nylon fibre (curled at the edges) were less robust. [0021] Further tests were carried out to determine an appropriate nap length for the material surface to obtain good liquid retention and drip resistance. Nap length of 4mm exhibited good liquid pick up, and some limited drip. Nap length of 6mm exhibited good pick up of liquid, with some dripping. Nap length of 10 mm exhibited excellent pick up, but excessive dripping. Nap length of 10mm also presented problems associated with returning the roller into the container. Accordingly, in a preferred embodiment the material forming the surface of the roller has a nap length of between 3 and 9mm, more preferably between 4 and 8mm. [0022] The closure may be any convenient closure known in the relevant industry. The closure may be releasably attached to the container by any convenient means. For example the closure may engage a threaded neck of the container, or snap fit to the container. Preferably the closure forms a hermetic seal with the container. An o-ring, gasket or other member may be included to resist leakage of the liquid chemical composition. [0023] In a second aspect of embodiments described herein there is provided a an applicator for liquid chemical compositions comprising: a container adapted to hold a liquid chemical composition a releasable closure for the container, a shaft associated at an end with the container lid, and 7 a roller adapted to rotate about the shaft, the roller having a surface adapted to absorb the liquid chemical composition. [0024] The applicator typically resides in the container, immersed in the liquid chemical composition. When required for use, the closure is released from engagement with the container and lifted to remove the shaft and roller from the container. Sufficient liquid chemical composition should be retained on the surface of the roller to coat a locus, such as the ends of two pipe sections to be joined. The application of the liquid chemical composition using the roller provides an even layer and thus resists formation of drips. [0025] In another aspect of embodiments described herein there is provided a method of applying a liquid chemical composition using the applicator of the present invention, the method including the step of rotating the roller across a locus. [0026] Other aspects and preferred forms are disclosed in the specification and/or defined in the appended claims, forming a part of the description of the invention. [0027] In essence, embodiments of the present invention stem from the realization that an appropriately configured roller stored in the liquid chemical composition can be used to provide improved application. [0028] Advantages provided by the present invention comprise the following: e minimal exposure of the user to the liquid chemical compositions, * neat, even coating of a liquid chemical composition at a locus, e an applicator may be reused multiple times until all the liquid chemical composition in the container is consumed, and 0 good liquid retention that permits the entire locus to be coated in a single application, 8 [0028] Further scope of applicability of embodiments of the present invention will become apparent from the detailed description given hereinafter. However, it should be understood that the detailed description and specific examples, while indicating preferred embodiments of the invention, are given by way of illustration only, since various changes and modifications within the spirit and scope of the disclosure herein will become apparent to those skilled in the art from this detailed description. BRIEF DESCRIPTION OF THE DRAWINGS [0029] Further disclosure, objects, advantages and aspects of preferred and other embodiments of the present application may be better understood by those skilled in the relevant art by reference to the following description of embodiments taken in conjunction with the accompanying drawings, which are given by way of illustration only, and thus are not limitative of the disclosure herein, and in which: * Figure 1 illustrates one embodiment of the applicator of the present invention; and * Figure 2 illustrates the applicator of Figure 1 in perspective view. [0030] Figure 1 depicts an applicator (1) according to the present invention. The applicator (1) includes a closure (5) which can be releasably attached to a container (not shown) for a liquid chemical composition. One end of a shaft (10) is associated with the closure (5), the other end of the shaft being adjacent a roller (15). The outer surface (20) of the roller has a surface adapted to absorb the liquid chemical composition. The applicator can reside in a closed container, immersed in the liquid chemical composition until needed. When the applicator is required for use, the closure is released from engagement with the container and lifted, concomitantly removing the shaft and roller from the container. Liquid chemical composition absorbed on the surface of the roller is then deposited by rotating the roller across a locus. This provides an even layer and avoids formation of drips.

9 [0031] Figure 2 is a perspective view of the applicator of Figure 1 which more clearly shows the relationship of the closure (5) to the roller (15), which are located adjacent either end of the shaft (10). [0032] While this invention has been described in connection with specific embodiments thereof, it will be understood that it is capable of further modification(s). This application is intended to cover any variations uses or adaptations of the invention following in general, the principles of the invention and including such departures from the present disclosure as come within known or customary practice within the art to which the invention pertains and as may be applied to the essential features hereinbefore set forth. [0033] As the present invention may be embodied in several forms without departing from the spirit of the essential characteristics of the invention, it should be understood that the above described embodiments are not to limit the present invention unless otherwise specified, but rather should be construed broadly within the spirit and scope of the invention as defined in the appended claims. The described embodiments are to be considered in all respects as illustrative only and not restrictive. [0034] Various modifications and equivalent arrangements are intended to be included within the spirit and scope of the invention and appended claims. Therefore, the specific embodiments are to be understood to be illustrative of the many ways in which the principles of the present invention may be practiced. In the following claims, means-plus-function clauses are intended to cover structures as performing the defined function and not only structural equivalents, but also equivalent structures. [0035] "Comprises/comprising" and "includes/including" when used in this specification is taken to specify the presence of stated features, integers, steps or components but does not preclude the presence or addition of one or more other features, integers, steps, components or groups thereof. Thus, unless the context clearly requires otherwise, throughout the description and the claims, the words 'comprise', 'comprising', 'includes', 'including' and the like are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to".

Claims (5)

1. An applicator for a liquid chemical composition comprising: a closure for a container adapted to hold a liquid chemical composition, a shaft associated at a first end with the closure, and a roller adapted to rotate about the shaft, the roller having a surface adapted to carry the liquid chemical composition.

2. An applicator according to claim 1 wherein the liquid chemical composition is chosen from the group comprising a primer or an adhesive for polymeric pipes and fittings.

3. An applicator according to claim 1 or claim 2 wherein the roller has an outer surface comprising a nap length of between 3 and 9mm.

4. An applicator according to any one of the preceding claims further comprising a container adapted to hold a liquid chemical composition, wherein the shaft and the roller reside in the container when not in use.

5. A method of applying a liquid chemical composition using the applicator of any one of the preceding claims, the method comprising the step of rotating the surface of the roller across a locus.