Abstract:
An apparatus and method for cleaning tools such as laminating tools used in the manufacture of glass reinforced plastic. The apparatus includes a bath having two sections, each containing a cleaning fluid such as an ester solvent and an aqueous solvent respectively, and a heating tank placed under the sections so that the solvents can be heated. In use, an operator cleans a tool in each section in turn. Additional features include a compressed air drier, filters to remove solid deposits, barriers and a bunded base to prevent spillage or leakage, and drains to remove the fluids from each section.

Description:
RELATED APPLICATION DATA 
       [0001]    This application is related to co-pending European Patent Application No. 08250895.3, filed Mar. 14, 2008, which is hereby incorporated in its entirety herein by reference. 
       FIELD OF THE INVENTION 
       [0002]    The present invention is directed to an apparatus and method for cleaning tools. The invention is particularly suitable for cleaning laminating tools used in the manufacture of glass reinforced plastic (GRP). 
       BACKGROUND OF THE INVENTION 
       [0003]    During GRP manufacture, laminating tools such as rollers and brushes are used to apply layers of resin to glass fibre. Traditionally, the cleaning of these tools has involved the use of the solvent acetone, which is very effective at removing resin deposits from the tools. However, a significant disadvantage of acetone is that it is volatile and highly flammable. With the high risk of an explosion should the acetone ignite, it is preferable to use a less hazardous alternative for cleaning the tools. 
         [0004]    One such alternative which has been used in the recent past has been the refined dimethyl esters of adipic, glutaric and succinic acids, otherwise known as dibasic esters. Unlike acetone, these esters are non-volatile, biodegradable and pose no harm to users or the environment. However, whilst dibasic esters have these desirable advantages or acetone, one significant drawback of this alternative is the comparatively poor cleaning performance at ambient temperature. 
       BRIEF SUMMARY OF THE INVENTION 
       [0005]    It is an aim of the present invention to obviate or mitigate the aforementioned disadvantages. 
         [0006]    According to a first aspect of the present invention, there is provided an apparatus for cleaning tools, the apparatus comprising:
       a bath having first and second sections adapted to receive first and second cleaning fluids; and   a heating tank positioned beneath the bath, the heating tank containing a heating means adopted to heat the first and second sections of the bath.       
 
         [0009]    Preferably, the apparatus further comprises at least one drying means. Preferably, the at least one drying means comprises a compressed air drier adapted to be connected to a compressed air supply. 
         [0010]    Preferably, the heating means comprises a heating oil and a heating element extending into the tank to heat the oil. Preferably, the heating tank further comprises a pressure relief valve. 
         [0011]    Preferably, the heating element includes a thermostat located in the heating tank. Preferably, the heating element also includes a timing device. 
         [0012]    Preferably, the first and second sections of the bath include a removable filter means adapted to remove solid deposits from the fluids contained therein. 
         [0013]    Preferably, the bath and heating tank are fixed to a support frame. Preferably, the frame comprises a first portion which supports the bath and heating tank, and a second lower portion adapted to firm a platform upon which an operator may stand. 
         [0014]    In a preferred embodiment the platform extends along one longitudinal side of the bath. Alternatively, the platform may extend along two or more sides of the bath. 
         [0015]    Preferably the apparatus further comprises a bunded based to prevent leakage of spilled fluids. The frame is located within the footprint of the base. 
         [0016]    Preferably, each of the first and second sections of the bath includes a drain valve. 
         [0017]    Preferably, at least one longitudinal edge of the bath includes an inclined lip potion projecting upwardly and outwardly from the bath. Preferably, the lip portion is provided with a mesh screen extending substantially horizontally towards the centerline of the bath. 
         [0018]    Preferably, the bath includes an integral barrier member adapted to prevent fluid from spilling over a side of the bath. The barrier member is integral with a longitudinal side of the bath. Alternatively, the barrier member extends longitudinally along the centerline of the bath. 
         [0019]    According to a second aspect of the invention, there is provided a method of cleaning tools, comprising:
       providing a cleaning apparatus in accordance with the first aspect of the invention;   filling the first section of the bath with an ester solvent fluid;   filling the second section of the bath with an aqueous solvent fluid;   heating the fluids in the first and second sections;   cleaning a tool first in the heated ester solvent fluid and subsequently in the aqueous solvent fluid.       
 
         [0025]    Preferably, the method further comprises draining the tool of fluid following each cleaning step. 
         [0026]    Preferably, the method further comprises a final step of drying the tool using compressed air. 
         [0027]    Preferably the ester solvent fluid includes a dibastic ester. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS  
         [0028]    Preferred embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: 
           [0029]      FIG. 1  is a perspective view of a first embodiment of a tool cleaning apparatus; 
           [0030]      FIG. 2  is a plan view of the apparatus shown in  FIG. 1 ; 
           [0031]      FIG. 3  is an end view of the apparatus showing in  FIG. 1 ; as presented by arrow III in  FIG. 2 . 
           [0032]      FIG. 4  is a side view of the apparatus shown in  FIG. 1 ; 
           [0033]      FIG. 5  is an end view of the apparatus showing In  FIG. 1 ; as presented by the arrow V in  FIG. 2 ; 
           [0034]      FIG. 6  is a perspective view of a second embodiment of a tool cleaning apparatus; 
           [0035]      FIG. 7  is a plan view of the apparatus shown in  FIG. 6 ; 
           [0036]      FIG. 8  is an end view of the apparatus of  FIG. 6 ; as represented by the arrow VIII in  FIG. 7 ; 
           [0037]      FIG. 9  is a side view of the apparatus shown in  FIG. 6 ; and 
           [0038]      FIG. 10  is an end view of the apparatus shown in  FIG. 6 , represented by the arrow X in  FIG. 7 . 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0039]      FIGS. 1-5  show various views of a first embodiment of a tool cleaning apparatus, generally designated  2 . The apparatus comprises a frame  4 , which is divided into a first and second frame portions  6 ,  8 . Each frame portion  6 ,  8  includes two pairs of legs extending substantially vertically. The legs of the first frame portion  6  are longer than those of the second frame portion  8 , with the result that the first frame portion  6  is elevated relative to the second frame portion  8 . Fixed to the top of the first frame portion  6  is a bath  10 . Preferably, the bath  10  has a tray member  12  fixed to a first end thereof and a barrier member, or splashback,  14  fixed along one side of the bath  10  to prevent any liquids contained in the bath from spilling over the rear of the bath  10 . Fixed to the top of the second frame portion  8  is a footplate, or grille,  16 . The combination of the second frame portion  8  and the footplate  16  forms a platform on which one or more operatives will stand when using the bath  10 . The frame  4  sits within a bunded base  18  which prevents any spilt liquids from leaving the area of the apparatus  2 . 
         [0040]    The bath  10  is divided into two sections  20 ,  22  which are open to atmosphere and separated by a first dividing wall  24  which extends laterally across the bath  10 . A heating tank  26  lies beneath the bath sections  20 ,  22  and is defined by the walls of the bath  10  and a second dividing wall  28  which separates the heating tank  26  from the first and second sections  20 ,  22 . The heating tank  26  lies beneath the first and second sections  20 ,  22  such that the second dividing wall  28  forms both the base of the first and second sections  20 ,  22  and the top of the heating tank  26 . 
         [0041]    As best seen in  FIGS. 1 ,  3  and  5 , an upwardly and outwardly projecting lip  30  is formed at the top of the side of the bath  10  adjacent the platform. The lip  30  results in the circumference of the top of the bath  10  being greater than the circumference of the base of the bath  10 . As seen in  FIG. 2 , one or more mesh screens  32  are fixed to the lip  30  and extend substantially horizontally from the lip  30  towards the centerline of the bath  10 . Tools which have been soaked in the bath  10  can be squeezed through the mesh screen  32  such that any liquid drained from the tools is retained in the bath  10 . The barrier member  14  at the rear of the bath may also have one or more mesh screen  32  extending therefrom. 
         [0042]      FIG. 2  also illustrates a pair of removable filter trays  34 ,  36  which can be intermittently placed in the first and second sections  20 ,  22  in order to remove any large deposits of material which have been cleaned from the tools but remain in the liquid in the sections  20 ,  22 . Each tray has a handle  35  and a mesh, or apertured, base. Thanks to the base, when the trays  34 ,  36  are removed from the sections  20 ,  22  they pick up any sizable deposits by tallow any liquid to drain back into the sections  20 ,  22 . 
         [0043]      FIG. 3  shows a first end  40  and the bath  10 . The first end  40  accommodates a pressure relief valve  42  for relieving pressure in the heating tank  26 , and a first drain valve  44  to which a drain hose  45  (as seen best in  FIG. 1 ) may be connected. The first drain valve  44  is adapted to drain the first section  20 . Also provided at the first end  40  is an electrical heating element  46  projecting into the heating tank  26 , and a second drain valve  48  adapted to drain the heating tank  26 . 
         [0044]      FIG. 4  shows a side view of the bath  10  and the various components described above.  FIG. 4  also illustrates a compressed air drier  50  which is attached to the second end  41  of the bath, which itself is seen best in  FIG. 5 . The second end  41  also accommodates a filler port  52  adapted to permit filling of the heating tank  26 , and a third drain valve  54  adapted to permit the draining of the second section  22 . 
         [0045]    The method of operation of the first embodiment shown in  FIGS. 1-5  will now be described. Initially, the sections  20 ,  22  of the bath  10  are filled with their respective cleaning fluids. The first section  20  is the larger of the two and is filled with an ester solvent mixture, while the smaller second section  22  is filled with an aqueous solvent mixture. The ester solvent mixture preferably includes a dibasic ester. An example of a suitable solvent is Estasol® as manufactured by Haltermann Products of Hamburg, Germany. The cleaning fluids are poured directly into the open tops of the section  20 ,  22 . 
         [0046]    If it is not already filled, the heating tank  26  is also filled at this time via filler port  52 . The heating tank  26  is preferably filled with heating oil. The heat is generated by the intrinsically safe electrical element  46  which projects into the heating tank  26 . The element  46  can either be controlled manually via an on/off switch, or else a timer is provided so that the oil is only heated during certain time periods. 
         [0047]    The electrical element  46  also has a thermostat (not shown) which controls the temperature of he oil in the heating tank  26 . The thermostat is preferably set to maintain the oil temperature at approximately 50 deg C. Heat from the oil is transferred to the fluids in the first and second sections  20 ,  22  via the second dividing wall  28 . It has been found by the applicant that heating the oil to approximately 50 deg C. results in a temperature of approximately 35 deg C. for the fluids in the first and second sections  20 ,  22 . The air drier is also connected to a supply of compressed air at a minimum of 80 psi. 
         [0048]    Should the thermostat fail and the electrical element  46  increase in the bath temperature, the temperature probe (circuit breaker)  48  will detect at 55 deg C. and shut down the element. 
         [0049]    Once the fluids have been heated, an operator can begin cleaning tools. In the first instance, the operator will clean the tools in the first section  20  containing the ester solvent mixture. The tools are then preferably squeezed against the mesh screen  32  by the operator to drain any cleaning fluids back into the first section  20 . The process is then repeated by the operator using the aqueous solution within the second section  22 . Once the tools have been cleaned and drained using both cleaning fluids, the tools are preferably dried using the air drier  50 . The drying of the tools ensures that any liquid present is removed and the tools are ready for reuse as quickly as possible. If any liquid was retained by the tools, this could have an adverse effect on any laminating procedures undertaken with those tools. 
         [0050]    As explained above, large deposits of resin which have been cleaned from the tools can be removed from the sections  20 ,  22  using the removable filter trays  34 ,  36 . The operator can choose to top up the fluids in each section  20 ,  22  to maintain the maximum cleaning efficiency, or else the fluids can be drained into drums via the respective drain valves  45 ,  54  and replaced with fresh fluids. 
         [0051]      FIGS. 6-10  illustrate a second embodiment of the present invention. Whereas the first embodiment of the apparatus  2  was intended for use by one or two operators, the second embodiment, generally, designated  2 , can be used by a greater number of operators. The apparatus is substantially the same as that of the first embodiment, although several modifications have been made to accommodate additional operators. The second frame portion  6  and associated footplate  16  extend around at least two sides, and preferably the entire circumference, of the bath  10 . To facilitate this further, the barrier/splashback has been moved such that it extends longitudinally along the centre of the bath  10  and both sides of the bath  10  include a lip  30  and associated mesh screens  32 . Each end  40 ,  41  of the bath  10  accommodate the same components as the first embodiment, with the exception that a pair of air driers  50  is now provided on the second end  41 . 
         [0052]    The apparatus  2  is filled, drained and operated in the same manner as the first embodiment described above. 
         [0053]    The present invention provides an apparatus and method for cleaning laminating tools which does without the need for volatile organic chemicals such as acetone. Furthermore, thanks to the direct heating of the sections containing the cleaning fluids, the cleaning performance of the non-volatile ester solvent mixture is improved. 
         [0054]    Preferably, the drain valves for each of the three sections are ball valve arrangements. The apparatus is provided with a residual current device and earthing for electrical protection. 
         [0055]    Preferably, the frame, bunded base and footplates are manufactured from galvanized steel. Preferably, the bath and associated components are manufactured from stainless steel. 
         [0056]    The division of the total possible volume of he first and second sections of the bath is preferably 60:40 in favour of the first section, which is consequently 1.5 times the size of the second section. Alternatively, the division may be 70:30 in favour of the first section. 
         [0057]    Modifications and improvement may be incorporated without departing from the scope of the invention.