WO2020094529A1

WO2020094529A1 - Apparatus for, and method of, controlling the mixing of components of curable resin systems

Info

Publication number: WO2020094529A1
Application number: PCT/EP2019/079997
Authority: WO
Inventors: Darren James EAGLES; Andrew David MILLS
Original assignee: Gurit (Uk) Ltd
Priority date: 2018-11-05
Filing date: 2019-11-01
Publication date: 2020-05-14
Also published as: GB2578731B; GB201818039D0; GB2578731A

Abstract

A mixture control unit (4) and weighing device (6) are used by an operator initially to weigh a desired amount of resin. The mixture control unit (4) then calculates the required addition of hardener achieve the correct mixture ratio within a preset tolerance. If too much hardener is added by the operator, the mixture control unit (4) then directs the operator to achieve the required subsequent addition of resin to achieve the correct mixture ratio within the preset tolerance. If too much resin is then added by the operator, the mixture control unit (4) then directs the operator to achieve the required subsequent addition of hardener to achieve the correct mixture ratio within the preset tolerance. The mixture control unit (4) utilises a feedback control to direct the operator iteratively to the correct mixture ratio within the preset tolerance.

Description

APPARATUS FOR, AND METHOD OF, CONTROLLING THE MIXING OF COMPONENTS OF CURABLE RESIN SYSTEMS

The present invention relates to an apparatus for, and a method of, controlling the mixing of components of curable resin systems.

It is well known to use curable resin systems is a variety of applications, for example for making fibre-reinforced resin composite materials for the manufacture of structural and decorative components in a variety of industrial sectors. The curable resin system typically comprises at least one monomer of a thermosetting resin and a curing agent. A variety of different curable thermosetting resins are known which require a monomer and a curing agent, such as epoxy resins, vinyl resins, polyester resins, etc. For example, the thermosetting resin may comprise an epoxy resin having one or more epoxide functional groups on the epoxy resin monomer. The epoxy resin may comprise a single epoxy resin monomer or a blend of epoxy resin monomers. The curing agent for the epoxy resin may be selected from curing agents known in the art as being suitable for curing epoxide resins, optionally together with at least one additional curing agent additive or modifier, and/or accelerator. The curing agent is selected to correspond to the epoxy resin used and to achieve the desired cured resin properties using the desired curing conditions. For example, known epoxy resin curing agents may typically be selected from a dicyandiamide, sulphanilamide, urone, urea, imidazole, Fenuron, amine, halogenated boron complex, anhydride, lewis base, phenolic novolac, or a nitrogen containing compound.

Curable resin systems are sold to a customer as a two component system. The first component is the curable resin component and the second component is the curing agent component, which may also include an accelerator. The first and second components are required to be homogeneously mixed prior to use to form a homogeneous mixture of the first and second components which is then subsequently shaped/moulded and cured to form a cured thermosetting resin product. It is important that the two components are mixed at the correct ratio in order to maintain correct product performance.

Operators of curable resin systems suffer from the problem that it can be difficult reliably and repeatably to achieve the correct mixture ratio between the curable resin component and the curing agent component when mixing curable resin systems, for example epoxy resin systems formulated for curing at ambient temperature.

Typically, an operator weighs out a portion of a“resin” (i.e. the curable resin component) into a mixing vessel, then adds the corresponding correct amount of“hardener” (i.e. the curing agent component) to the vessel and subsequently mixes the“resin” and“hardener” together. Different curable resin compositions products have different mixture ratios and therefore it can be difficult or time consuming for the operator to calculate the amount of hardener to add to a resin system, since that depends on the specific resin system being used and the amount of cured resin material required in the product.

Confidence in achieving the correct mixture ratio is important in the composite materials industry. With a vast majority of resin systems there is no visual indication that components have been dispensed at the correct ratio, and therefore the only time that the use of the correct ratio can be reliably identified by the typical operator is when the resin system has been mixed and used to produce the resultant cured product.

If the resin system is mixed so as to be“off-ratio”, then either the curable resin material does not solidify, or the overall performance of the composite material resin system is decreased, causing scrap products. Also, as a general rule, too low an amount of the curing agent for a given amount of resin may cause an insufficient or reduced cure of the resin material, with unacceptable or reduced cured product performance, whereas too high an amount of the curing agent for a given amount of resin may cause an excessively exothermic cure or, again, reduced or unacceptable product performance.

As an example, if an incorrect ratio of resin and hardener is inadvertently used, an entire structure such as a yacht hull may need to be discarded, and the corresponding moulds would need to be“washed out” and rebuilt, resulting in a significant loss of time and money.

The present invention aims to provide an apparatus for, and a method of, mixing components of curable resin systems which can minimise or eliminate human error from mixture ratio calculations during the mixing together of resin and hardener of a curable resin system. Accordingly, in a first aspect, the present invention provides a method according to claim

1.

In a second aspect, the present invention provides an apparatus according to claim 21.

Preferred features of these aspects of the present invention are defined in the respective dependent claims.

The preferred embodiments of the present invention utilise a mixture control unit forming a HMI (human machine interface) that can be connected to many commercially available weighing devices, i.e. weighing scales.

The mixture control unit may comprise a custom-made device which has been programmed, in hardware and/or in software, to implement the method of the present invention. Alternatively, the mixture control unit may comprise a known device comprising an operator interface and a processor, for example a smartphone, a tablet computer, a laptop computer, a personal computer etc., which has been programmed, for example by an installed software application or“app”, to implement the method of the present invention. The mixture control unit may comprise a display screen, which may be a touchscreen, and may be configured to input and/or output data by any known interface mechanism, for example touch, sound, etc. The database may be in the mixture control unit, or alternatively may be provided in a remote server which is accessible via the worldwide web or internet (i.e. the data may be stored in the“cloud”).

In the preferred embodiments of the present invention, a recipe database is built into the mixture control unit which stores the mixture ratios for different commercially available curable resin products. The operator starts by selecting the required product from the menu and then weighing the required amount of resin on the weighing device, for example by adding the required amount of resin to a weighing container on the weighing device. Once the desired amount of resin has been added, a processor in the mixture control unit calculates the corresponding amount of hardener that needs to be added to ensure that the correct mixture ratio is achieved. The interface, via a display, then guides the operator to add the correct amount of hardener. Should the operator accidently or inadvertently add too much hardener so that the correct mixture ratio is not achieved, then the mixture control unit can recalculate how much additional resin should be added to achieve the correct mixture ratio, guiding the operator to add extra resin to compensate for the excess hardener. This process can continue iteratively until the correct mixture ratio of the resin and hardener components has been added.

The preferred embodiments of the present invention can provide that a display device in the mixture control unit provides a graphical and numerical visual indicator that shows the operator how much additional material is required to be able to mix a resin system to the correct mixture ratio.

Due to the varying viscosity of typical curable resin systems, mixture ratio accuracy can be difficult to achieve by weighing, using manual handling. This generates scrap material should the mixture ratio be identified as being wrong either during the weighing process, or thereafter. The preferred embodiments of the present invention can provide a HMI (human machine interface) which advises the operator if the measured mixture ratio of the weighed components is incorrect, and instructs the operator how to achieve a recalculated mixture ratio if the weight ratio of the initially dispensed and weighed components is incorrect. At the end of the mixture protocol, the HMI can confirm to the operator that the finally dispensed and weighed components are balanced to the desired mixture ratio within a preset tolerance, for example a preset tolerance defined by the manufacturer of the curable resin system, and which typically has been predetermined by the manufacturer as a result of testing and analysis.

The preferred embodiments of the present invention particularly relate to apparatus and methods requiring the weighing out of a two-part resin system, comprising a curable resin component and a hardener component, which may be selected from any known thermosetting resin system, such as epoxy resins, vinyl resins, polyester resins, etc. Although an epoxy resin system is described below in the detailed description of the preferred embodiments of the present invention, the present invention has application to any resin system which requires at least two component parts to be weighed in a desired mixture ratio. The preferred embodiments of the present invention particularly relate to apparatus and methods requiring the weighing out of a two-part resin system, comprising a curable resin component and a hardener component, for industrial use in composite material manufacture. However, the apparatus and method may be further modified so that further components may be accurately weighed in proportion to the amount of curable resin present in the curable resin system. For example, the apparatus and method may be modified to calculate and weigh, directly or indirectly with respect to a desired weight ratio relative to the base curable resin, not only the curing agent but also a further component such as an accelerator, a filler such as fumed silica, syntactic beads or microballoons, a colorant, etc., which the operator may desire to add to the curable resin at the point of use.

The preferred embodiments of the present invention can provide a semi-automated weighing scale system and associated weighing protocol which can avoid or overcome the following problems that are typically associated with known resin weighing and mixing apparatus and methods:

i) Scale interference at the start of the weighing process, for example scale not set to zero - the preferred method and apparatus can instruct/require the operator to zero the weighing scale before weighing the first component, both before and after a container to contain the weighed component/mixture is placed on the weighing scale, so that a true tare weight of the components is correctly weighed.

ii) Mixture ratio calculations - avoids the need for operators independently/manually to calculate mixture ratios and scale the ratio to the amount of resin being used and/or eliminates errors in the operator mixing at the wrong mixture ratio if they were to forget the correct mixture ratio.

iii) Physically adding too high or too low amounts of hardener component to the resin - alerts operators if they use too little or too much of each component.

iv) Human errors - the apparatus and method can iteratively direct the operator towards the correct mixture ratio.

v) Speed of use - operators can quickly weigh resin systems allowing them to work more quickly than if they had to check mixture ratios and independently/manually calculate quantities of each component required. The preferred embodiments of the present invention can provide a number of technical advantages over the known method for calculating and implementing resin/hardener mixture ratios when using curable resin systems.

For example, the preferred embodiments of the present invention can remove the use of random modifications by individual operators to the implemented mixture ratio calculation for a given commercial resin/hardener system. Certain manufacturer-specific resin products have an identifiable product code and that specific product is typically associated with a corresponding specific mixture ratio. Since the database can store the resin by reference to a specific product code, rather than by a generic chemical description, the method and apparatus of the preferred embodiments of the present invention can ensure that the correct mixture ratio can be used for the manufacturer-specific resin product having the selected product code. This in turn means that the manufacturer-specific resin product can be reliably and repeatably formulated into a curable resin/hardener mixture to produce the required optimal properties and performance in the resultant cured product.

The method and apparatus of the preferred embodiments of the present invention can visually display weights and product additions during the weighing-out process. This provide a dynamic visual guide to the operator to provide the operator with confidence that the curable resin/hardener mixture is being correctly formulated.

The method and apparatus of the preferred embodiments of the present invention can allow or accommodate human errors, and can permit further attempts to obtain the correct mixture ratio rather than require speculation from the operator in order to try to guess that the correct amount of resin/hardener component has been added. By providing a feedback loop that can recalculate an additional amount of a component to add in the event that a different component has been added in excess of a target weight to achieve a target mixture ratio, human error by inadvertent addition of excess resin or hardener to the mixture can be accommodated to ensure that nevertheless the correct mixture ratio is ultimately achieved.

The method and apparatus of the preferred embodiments of the present invention can allow relatively lower-skilled members of the work force of a manufacturing facility to be able reliably and repeatably to be able to formulate resin/hardener mixtures at the specific correct ratio with minimal additional training. This functionality thereby allows technically more experienced or qualified colleagues to focus on higher skilled processes, for example manual application of the formulated resin/hardener mixtures into a complex mould to form a composite material product.

The apparatus of the preferred embodiments of the present invention is lightweight, mobile and has an operator-friendly operator interface, which is intuitive and requires no extensive training to use. The apparatus can be readily coupled to a variety of commercial weighing devices for different manufacturers, provided that the weighing device can output a digital signal that can be processed by the processor of the apparatus.

Preferred embodiments of the present invention will now be described by way of example only with reference to the accompanying drawings, in which: -

Figure 1 is a schematic side view of an apparatus for controlling the mixing of components of a curable resin system in accordance with an embodiment of the present invention, the apparatus comprising a mixture control unit and a weighing device;

Figure 2 is a schematic illustration of the database and processing system in the mixture control unit of the apparatus of Figure 1 ;

Figure 3 is a schematic illustration of data stored in a database processing system in the mixture control unit of the apparatus of Figure 1 ;

Figure 4 is a schematic illustration of a process flow of the method of controlling the mixing of components of a curable resin system in accordance with an embodiment of the present invention, the method using the apparatus of Figure 1 ; and

Figures 5 a to 5k are schematic illustrations of the human machine interface (HMI) displayed to the operator by the display device of apparatus of Figure 1 during the process flow illustrated in Figure 4.

Referring to Figure 1, there is shown an apparatus, designated generally as 2, for controlling the mixing of components of a curable resin system in accordance with an embodiment of the present invention. The apparatus 2 comprises a mixture control unit 4 and a weighing device 6. The weighing device 6 comprise a typical commercial weighing scale for laboratory or industrial use, and comprises a platen 8 upon which a mass to be weighed is placed. A load cell 10, shown in phantom, is located beneath the platen 8 and generates an electrical signal representative of the measured weight of the mass on the platen 8. The weighing device 6 and the mixture control unit 4 are connected, for example by a cable 12, so that the electrical signal representative of the measured weight of the mass on the platen 8 is conveyed to the mixture control unit 4. Although a wired connection between the mixture control unit 4 and weighing device 6 is illustrated, the connection may be a wireless connection using a known wireless protocol, for example a Bluetooth connection.

In use, material 11 to be weighed is dispensed into a container 13 on the platen 8. A bulk measuring device 9 may be provided which detects the volume, or depth, of the material 11 in the container 13, to provide an indication to the operator of the dispensed amount of material 11. For example, the bulk measuring device 9 may comprise a light emitter 17 coupled with a light receiver 19, for example using a laser beam, to measure the height of the dispensed material 11, or to preset a desired level of the dispensed amount of material 11. A temperature sensor 21 may be provided to measure the ambient temperature, or the temperature of the material 11 in the container 13. The output of the temperature sensor 21 may be employed to control the measuring function dependent upon the measured temperature; for example, the measuring function could be disabled in the event that the measured temperature is outside a preset threshold range.

In the illustrated embodiment of the present invention, the mixture control unit 4 and the weighing device 6 are separate physical units. This provides the advantage that the mixture control unit 4 can be individually provided to a composite material processor who may already own a weighing device, which lowers the capital cost to an operator of the apparatus of the invention. Also, the individual mixture control unit 4 is lightweight, portable and mechanically robust. As described above, the mixture control unit may comprise a custom- made device which has been programmed, in hardware and/or in software, to implement the method of the present invention or a known device comprising an operator interface and a processor, for example a smartphone, a tablet computer, a laptop computer, a personal computer etc., which has been programmed by software to implement the method of the present invention. However, in an alternative embodiment of the present invention, the mixture control unit 4 and the weighing device 6 may be integrated into a single physical unit. The mixture control unit 4 comprises a housing 14 containing a processing system. The mixture control unit 4 also comprises an operator interface 15, which comprises a display device 16, which comprises a human machine interface (HMI) between the mixture control unit 4 and the operator. The display device 16 is an alphanumeric display in the illustrated embodiment. However, in alternative embodiments, the display device 16 may comprise a touch-screen display, and may display icons for control of the apparatus. The mixture control unit 4 of the illustrated embodiment further comprises a plurality of physical switches 18, 20, 22, in the form of push-button controls, which are also part of the operator interface 15 and human machine interface (HMI). However, in alternative embodiments, no, or different, physical switches may be provided, for example when the display device 16 comprises a touch-screen display so that all control functions may be provided by the touch-screen display.

Also, in the illustrated embodiment, input commands are provided by the operator to the mixture control unit 4 by touch, using the physical buttons and/or the touch-screen. In alternative embodiments, voice control, a foot switch or a motion sensor may at least partly be utilised to control the operation of the mixture control unit 4. The mixture control unit 4 is preferably constructed to provide hands-free control of the operator interface 15 to make operation easier when the operator’s hands are either contaminated with resin or being used to hold containers.

In addition, in the illustrated embodiment, output information is provided visually to the operator by the mixture control unit 4 by the display device 16; in some embodiments, sounds, e.g. synthesised voice information or other noises such as beeps, may at least partly be utilised, either additionally to the display device 16 or alternatively to the display device 16, to inform the operator about the function or operation of the mixture control unit 4. For example, sounds may be emitted and/or received by an audio mechanism 23 in the mixture control unit 4, which audio mechanism 23 may comprise a speaker or other sound emitter and/or a microphone or other sound receiver in the mixture control unit 4.

Referring to Figures 2 and 3, the processing system 30 in the mixture control unit 4 is implemented in hardware and software, and comprises a memory 32, storing a database 34, connected to a processor 46. As shown in Figure 2, the database 34 is programmed to store a menu 36 comprising a plurality of first data 38 and a plurality of second data 40. Each first data 38 identifies a respective curable resin component. Preferably, each first data 38 comprises a unique product code of a respective commercially-available curable resin component. This identifies an individual commercially available resin identified by the manufacturer’s product code. The second data 40 is associated with a respective first data 38, and each second data 40 defines a target mixture ratio 42 between the curable resin component of the respective first data 38 and a respective curing agent for the curable resin component. Preferably, the second data 40 defines a mixture ratio between the curable resin component of the respective unique product code of the first data 38 and a respective curing agent having a second unique product code of the respective curing agent. The menu 36 may also include further data 44 identifying the respective curing agent for each first data by the second unique product code of the respective curing agent.

As shown schematically in Figure 3, the processor 46 comprises a display module 50 programmed to output a display signal to the display device 16. The display signal is configured to cause the display device 16 to display one or more of the first data 38.

In alternative embodiments the display module 50 is more generally an interface module which can output information to the operator visually and/or audibly.

The processor 46 further comprises a selection module 52 programmed to select a first data 38 from the plurality of first data 38 based upon an input selection command. An operator interface 54, coupled to the selection module 52, is provided to enable the operator to select a first data 38 from the menu 36. The operator interface 54 is selected from a display device 16 and/or one or more physical switch mechanisms, such as physical switches 18, 20, 22, and additionally or alternatively the display device may comprise a touch-sensitive display screen. Typically, the operator interface 54 includes a scrolling device, for example embodied by switch 22, for scrolling through the menu 36 by using the one or more physical switch mechanisms and/or the touch-sensitive display screen. The selection module 52, and the mixture control unit 4 in general, can receive input information from the operator visually, audibly and/or by touch. For example, non-contact input methods may be used, such as voice control.

In an alternative embodiment, a database is not employed to store the first and second data. Instead, the first data 38, identifying a first component of the curable resin system, may be input into the operator interface 54, for example manually, and the second data 40, defining a mixture ratio between the first component and a second component of the curable resin system is provided to the mixture control unit 4, for example by using the operator interface.

In any embodiment, the first data 38 preferably identifies a curable resin component and the second data 40 preferably identifies a mixture ratio between the respective curable resin component and the respective curing agent therefor. As described above, first data 38 and the second data 40 may relate to any first and second components of a curable resin system.

The display module 50 is programmed to output to the display device 16 a signal to cause the display device 16 to display an instruction to weigh the first component. As described above, additionally or alternatively the instruction may be outputted audibly.

The processor 46 further comprises a first input module 58 programmed to receive third data identifying a measured weight of the first component. The mixture control unit 4 comprises an input port 48 configured for wired or wireless connection to the weighing device 2 to provide the third data to the processor 46. The processor 46 is configured to receive third data representative of a measured weight of a first component of the curable resin system, the first component being selected from either a curable resin component or the respective curing agent therefor.

The display module 50 is programmed to output to the display device 16 a signal to cause the display device 16 dynamically to display in real time the third data identifying a measured weight of the first component. As described above, additionally or alternatively the third data may be outputted audibly. The processor 46 is programmed to calculate, from the third data and second data associated with the selected first data, fourth data identifying a target weight of a second component of the curable resin system to provide the target mixture ratio between the first and second components, the second component being selected from the other of the curable resin component and the respective curing agent therefor. The processor 46 accordingly further comprises a calculation module 64 programmed to calculate fourth data from the third data and from the second data associated with the selected first data.

The display module 50 is programmed to output to the display device 16 a signal to cause the display device 16 to display the fourth data. As described above, additionally or alternatively the fourth data may be outputted audibly.

The processor 46 further comprises a second input module 66 programmed to receive fifth data identifying a measured weight of the second component corresponding to a measured mixture ratio between the first and second components.

The display module 50 is programmed to output to the display device 16 a signal to cause the display device 16 dynamically to display in real time the fifth data identifying a measured weight of the second component. As described above, additionally or alternatively the fifth data may be outputted audibly.

The processor 46 further comprises a comparison module 70 programmed to compare the fifth data and the fourth data. The comparison module 70 provides a first comparison signal when the measured and target mixture ratios of the first and second components do not correspond within a preset tolerance. The comparison module 70 provides a second comparison signal when the measured and target mixture ratios of the first and second components do correspond within the preset tolerance.

The processor 46 further comprises an output module 72 programmed to output a first display signal to the display device 16 in response to the first comparison signal and a second display signal to the display device 16 in response to the second comparison signal. The first display signal causes the display device 16 to indicate that an additional amount of the first component or second component should be dispensed to be weighed. The second display signal causes the display device 16 to indicate that the target mixture ratio for the selected curable resin component and the respective curing agent has been weighed. Again, the output signal may additionally or alternatively comprise an audible signal.

The processor 46 further comprises a first feedback module 74 programmed to output a first feedback signal to the display device 16 to cause the display device 16 to display an instruction to weigh an additional dispensed amount of the first component when the measured weight of the second component is higher than the preset tolerance of the target weight of the second component. Again, the output signal may additionally or alternatively comprise an audible signal.

The processor 46 further comprises a second feedback module 76 programmed to output a second feedback signal to the display device 16 to cause the display device 16 to display an instruction to weigh an additional dispensed amount of the second component when the measured weight of the second component is lower than the preset tolerance of the target weight of the second component. Again, the output signal may additionally or alternatively comprise an audible signal.

The operation of the apparatus for use in a computer-implemented method of controlling the mixing of components of a curable resin system will now be described with reference to the process flow diagram of Figure 4 and the illustrations of the human machine interface (HMI) displayed to the operator of Figures 5a to 5k.

In a brief summary, the mixture control unit 4 and weighing device 6 are used by the operator initially to weigh a desired amount of resin. The mixture control unit 4 then calculates the required addition of hardener achieve the correct mixture ratio within the preset tolerance. If too much hardener is added by the operator, the mixture control unit 4 then directs the operator to achieve the required subsequent addition of resin to achieve the correct mixture ratio within the preset tolerance. If too much resin is then added by the operator, the mixture control unit 4 then directs the operator to achieve the required subsequent addition of hardener to achieve the correct mixture ratio within the preset tolerance. The mixture control unit 4 utilises a feedback control to direct the operator iteratively to the correct mixture ratio within the preset tolerance. The mixture control unit 4 may include a visual and audio alarm/indicator that warns the operator when they are close to the required weight of resin or hardener. This allows the operator to slow down the addition of resin or hardener to avoid adding too much material. Whilst the mixture control unit 4 can compensate for adding too much material, this warning function makes the weighing operation more efficient and faster to complete.

In the computer-implemented method of controlling the mixing of components of a curable resin system, in a selecting step an operator selects from a menu a unique product code of a curable resin component to be weighed. The selecting step uses the operator interface 15 in the mixture control unit 4.

As shown in Figure 5a, in an initial display step SO, the display device 16 displays a unique product code 90 of a curable resin component. In the illustrated embodiment the code is “SP106 Fast” which is a product code for an epoxy resin system of the Applicant Gurit (UK) Limited. The unique product code comprises first data 38 stored in menu 36 as described above. Figure 5a also shows that a ratio 92, in this embodiment“ 100: 18”, is displayed which is the target mixture ratio between the selected resin and the respective curing agent.

As described above, individual first data 38 are displayed on the display device 16 and the operator can, in a scrolling step S l, scroll through the menu 36, for example by pressing switch 20, which is below an icon or display element 80 marked“»” on the display device 16. After the correct resin has been displayed, the resin may be selected in the selecting step S2 by pressing switch 22, which is below an icon or display element 82 marked“OK?” on the display device 16. The selecting step S2 therefore selects a specific unique commercial curable resin product, and pressing the switch 22 constitutes an input selection command by the operator which is responsive to first data 38 being displayed on the display device 16.

The switch 18 is a reset switch, which is below an icon or display element 84 marked “Reset” on the display device 16. If the operator notices that an incorrect resin has been inadvertently selected, or for any other reason, the operator interface 15 in the mixture control unit 4 can be reset to a“start” display on the display device 16. The reset switch 18 may be pressed at any time during the process flow to return to the“start” display on the display device 16.

As described above, each first data 38 is associated with a second data 40 which defines a mixture ratio between the curable resin component of the respective unique product code and a respective curing agent having a second unique product code of the respective curing agent. The first and second data 38, 40 are stored in the menu 36 in the database 34.

Thereafter, the operator interface 15 in the mixture control unit 4 functions to zero the apparatus prior to accurate weighing of resin.

After the correct resin has been selected, as shown in Figure 5b in a display step S3 the processor 46 functions to cause the display device 16 to display the message“Clear platform to zero scales”. This is an instruction to the operator to check and empty the weighing device 6.

After the instruction has been displayed, in a zeroing step S4 the mixture control unit 4 may be set into a zero weight mode by pressing switch 22, which again is below the icon or display element 82 marked“OK?” on the display device 16.

It is now confirmed that the weighing device 6 and mixture control unit 4 are ready to measure a desired tare weight of the desired resin.

After the zeroing step S4, in a display step S5, as shown in Figure 5c the processor 46 functions to cause the display device 16 to display the message“Put empty container on scales”. This is an instruction to the operator to put an empty container on the weighing device 6.

After the instmction has been displayed, in step S6 the operator presses switch 22, which again is below the icon or display element 82 marked“OK?” on the display device 16. This action confirms that an empty container is on the weighing device 6.

The weighing device 6 and mixture control unit 4 are now in a resin tare weighing mode. In a display step S7, as shown in Figure 5d the processor 46 functions to cause the display device 16 to display the message“Add resin:”, which is an instruction to weigh the resin (i.e. the first component).

In a weighing step S8, the desired resin is then dispensed into the container and the dispensed amount of the resin is weighed on the weighing device 6. During weighing step S8, as shown in Figure 5e the measured weight of the resin is dynamically displayed in real time by the display device 16 as the resin is dispensed onto the weighing device 6.

The weighing step S8 provides the third data identifying a measured weight of the resin, i.e. first component.

After the desired amount of resin has been weighed, in step S9 the operator presses switch 22, which again is below the icon or display element 82 marked“OK?” on the display device 16. This confirms the resin weight and causes the weighing device 6 and mixture control unit 4 to commence a curing agent weighing mode.

Thereafter, in calculating step S lOa, using the processor 46, fourth data is calculated from the third data (i.e. the measured weight of the resin) and from the second data 40 associated with the selected first data 38 (i.e. the target mixture ratio of the required curing agent for the selected resin). The fourth data identifies a target weight of the curing agent (i.e. a second component of the curable resin system) to provide the target mixture ratio between the first and second components, i.e. the curable resin component and the respective curing agent therefor.

After the calculating step S lOa, in a display step S 1 la, the target weight of the curing agent is displayed on the display device 16, as shown in Figure 5f. In display step Sl la, the processor 46 functions to cause the display device 16 to display the message“Add x.xxxkg hardener:”, which is an instruction to weigh the specified weight of the curing agent (i.e. the second component). In a second weighing step Sl2a, the desired weight of curing agent is then dispensed by the operator into the container (i.e. the same container which contain the dispensed resin) and the dispensed amount of the curing agent is weighed by the weighing device 6. During weighing step S12a, as shown in Figure 5g, the measured weight of the curing agent (i.e. hardener) is dynamically displayed in real time by the display device 16 as the curing agent is dispensed onto the weighing device 6. In weighing step Sl2a the total amount of the combination of the resin (i.e. first component) weighed in step S8 and the hardener (i.e. second component) weighed in step Sl2a is measured thereby indirectly weighing the dispensed amount of the hardener (i.e. second component).

After the dispensing has terminated, the second confirming step Sl3a provides the fifth data identifying a measured weight of the dispensed amount of the curing agent, i.e. second component. The third data and the fifth data provide a measured mixture ratio between the first and second components, i.e. the selected resin and the respective curing agent.

In a comparing step S14, the fifth data (the measured weight of the curing agent) and the fourth data (the target weight of the curing agent) are compared using the processor 46.

If, in the comparing step S 14, the measured and target mixture ratios of the first and second components correspond within a preset tolerance, then in display step SD15 the processor 46 functions to cause the display device 16 to display the message“Mixture ratio correct”, which is an instruction to the operator that the weighing protocol can be terminated since the correct relative amounts of the curable resin component and the curing agent component have been dispensed into the container and weighed.

However, in contrast, the comparing step S14 provides a first comparison signal when the measured and target mixture ratios of the first and second components do not correspond within a preset tolerance.

When the first comparison signal is provided, and the measured mixture ratio is lower that the target ratio, i.e. too much curing agent has been added, and outside a preset tolerance, a first feedback loop is implemented. The first feedback loop returns the process flow to the calculating step S10, and in particular to a modified calculating step SlOb, in which an additional amount of the resin required to achieve the target mixture ratio is calculated.

In the first feedback loop, in a feedback step FS1 a first display signal is output from the processor 46 to the display device 16 in response to the first comparison signal.

As shown in Figure 5h, the first display signal causes the display device 16 to indicate to the operator that an incorrect mixture ratio has been dispensed and that an additional amount of the first component, i.e. the resin, should be dispensed to be weighed. In feedback step FS 1, the processor 46 functions to cause the display device 16 to display the message “Incorrect mix ratio add more resin...”, which is an instruction to dispense and weigh additional resin to be added to the container.

Therefore in response to provision of the first comparison signal, when the measured weight of the curing agent (i.e. the second component) is higher than the preset tolerance of the target weight of the second component, an instruction is displayed on the display device 16 to weigh an additional dispensed amount of the resin (i.e. the first component). The additional amount of resin is dispensed and weighed to provide sixth data representing, directly or indirectly, a measured total weight of the resin.

In calculating step S lOb the processor 46 calculates seventh data from the fifth data, i.e. the measured weight of the dispensed amount of the curing agent, and the second data representing the target mixture ratio. The seventh data represents, directly or indirectly, a revised target weight of the resin. In display step 1 lb the additional amount of resin required to be added to achieve the revised target weight of the resin is displayed, for example by displaying the message“Add x.xxxx kg resin”. The resin is then dispensed and weighed in step SI 2b, and the final measured weight confirmed in step Sl3b.

In the subsequent comparing step S14 the measured and target mixture ratios are again compared by comparing the sixth and seventh data. If the correct amount of resin has been added, then the process proceeds to step S15 as described above.

If insufficient additional resin has been added, then the first feedback loop is repeated. If excess additional resin has been added, then a second feedback loop is implemented. The second feedback loop returns the process flow to the calculating step S 10, and in particular to the calculating step SlOa, in which an additional amount of the hardener required to achieve the target mixture ratio is calculated.

In the second feedback loop, in a feedback step FS2 a second display signal is output from the processor 46 to the display device 16 in response to the first comparison signal. The second display signal causes the display device 16 to indicate to the operator that an incorrect mixture ratio has been dispensed and that an additional amount of the second component, i.e. the hardener, should be dispensed to be weighed. In feedback step FS2, the processor 46 functions to cause the display device 16 to display the message“Incorrect mix ratio add more hardener...”, which is an instruction to dispense and weigh additional hardener to be added to the container.

Therefore in response to provision of the second comparison signal, when the measured weight of the resin (i.e. the first component) is higher than the preset tolerance of the target weight of the curing agent (i.e. the second component), an instruction is displayed on the display device 16 to weigh an additional dispensed amount of the curing agent (i.e. the second component). The curing agent is dispensed and weighed to provide eighth data

In calculating step SlOa the processor 46 calculates, to provide ninth data, a revised target weight of the hardener. This calculation uses the sixth data representing the total weight of resin and the second data representing the target mixture ratio. In display step 1 la the additional amount of hardener required to be added to achieve the revised target weight of the hardener is displayed, for example by displaying the message“Add x.xxxx kg hardener”. The hardener is then dispensed and weighed in step S l2a, and the final measured weight confirmed in step Sl3a.

In the subsequent comparing step S 14 the measured and target mixture ratios are again compared by comparing the eighth and ninth data. If the correct amount of hardener has been added, then the process proceeds to step S 15 as described above. Otherwise, either the first or second feedback loops are again implemented. It can be seen that providing the first and second feedback loops the operator is iteratively directed to achieve the correct mixture ratio by the additional of additional resin or hardener as required if excess hardener or resin has inadvertently been added. This ensures that the operator receive positive dynamic instruction to achieve the correct mixture ratio even in the event that excess or otherwise incorrect amounts of hardener or resin have inadvertently been weighed.

This ensures that the measured and target mixture ratios of the first and second components ultimately correspond within the preset tolerance.

In the illustrated embodiment, the first component is the selected curable resin component and the second component is the respective curing agent therefor. Therefore the resin is initially dispensed and weighed and the required amount of curing agent is then calculated. In alternative embodiments, the first component is the curing agent and the second component is the selected curable resin component. Therefore the curing agent is initially dispensed and weighed and the required amount of curable resin is then calculated. As described above, the preferred embodiments of the present invention store a mixture ratio of first and second components, for example a curable resin component and a curing agent component, in a database, which is in a memory within the mixture control unit or in a remote server. After the first, or second, component has been selected, the required mixture ratio is retrieved from the database. This provides a“built-in recipe” system within the mixture control unit to select the appropriate mixture ratio to use for any given combination of first and second components.

However, in alternative embodiments, the required mixture ratio may be input into the mixture control unit on an individual, on-demand basis using a variety of different techniques and devices or equipment. For example the required mixture ratio may be input into the mixture control unit by barcode scanning, voice recognition, scanning of a radio frequency (RF) chip or coil, or by manual input of a required mixture ratio, for example by use of a variable dial or numerical touch pad. In the illustrated embodiment, the selected curable resin component and the curing agent are dispensed and weighed into a single common container. In alternative embodiments, the selected curable resin component and the curing agent may be dispensed and weighed in respective individual containers, and the weighed first and second components are then physically mixed after weighing.

As described above, the preferred embodiments of the present invention particularly relate to apparatus and methods requiring the weighing out of a two-part resin system, comprising a curable resin component and a hardener component, which may be selected from any known thermosetting resin system, such as epoxy resins, vinyl resins, polyester resins, etc.. The present invention has application to any resin system which requires at least two component parts to be weighed in a desired ratio. Also, although the present invention particularly relates to apparatus and methods requiring the weighing out of a two-part resin system, comprising a curable resin component and a hardener component, the apparatus and method may be further modified so that further components, such as an accelerator, a filler such as fumed silica, syntactic beads or microballoons, a colorant, etc., may be accurately weighed in proportion to the amount of curable resin present in the curable resin system.

In the illustrated embodiment, the mixture control unit comprises a custom-made device which has been programmed, in hardware and/or in software, to implement the method of the present invention. Alternatively, as described above, the mixture control unit may comprise a known device comprising an operator interface and a processor, for example a smartphone, a tablet computer, a laptop computer, a personal computer, etc., which has been programmed, for example by an installed software application or“app”, to implement the method of the present invention. The mixture control unit may comprise a display screen, which may be a touchscreen, and may be configured to input and/or output data by any known interface mechanism, for example touch, sound, etc. The database may be in the mixture control unit, or alternatively may be provided in a remote server which is accessible via the worldwide web or internet (i.e. the data is stored in the“cloud”).

Various modifications to the preferred embodiments of the present invention, as defined by the appended claims, will be apparent to those skilled in the art.

Claims

1. A computer-implemented method of controlling the mixing of components of a curable resin system, the method comprising the steps of:

i. inputting, using an operator interface in a mixture control unit, first data identifying a first component of a curable resin system;

ii. before or after step i, providing in the mixture control unit second data defining a target mixture ratio between the first component and a second component of the curable resin system;

iii. before or after either or both of steps i and ii, weighing, using a weighing device, a dispensed amount of the first component of the curable resin system, to provide third data representing, directly or indirectly, a measured weight of the first component;

iv. calculating, using a processor, fourth data from the third data and from the second data, the fourth data representing, directly or indirectly, a target weight of the second component of the curable resin system to provide the target mixture ratio between the first and second components;

v. weighing, using the weighing device, a dispensed amount of the second component to provide fifth data representing, directly or indirectly, a measured weight of the second component corresponding to a measured mixture ratio between the first and second components;

vi. comparing, using the processor, the fifth data and the fourth data to provide in the processor a comparison signal when the measured and target mixture ratios of the first and second components do not correspond within a preset tolerance or to provide in the processor a termination signal when the measured and target mixture ratios of the first and second components do correspond within the preset tolerance;

vii. outputting, from the processor, a first notification signal to the operator interface in response to the comparison signal, the first notification signal causing the operator interface to indicate to the operator that an additional amount of the first component or the second component should be dispensed to be weighed; and viii. outputting, from the processor, a second notification signal to the operator interface in response to the termination signal, the second notification signal causing the operator interface to indicate to the operator that the target mixture ratio for the first component and the second component has been weighed.

2. A method according to claim 1 wherein in step i the first data is selected, using the operator interface, from a menu comprising a plurality of first data stored in a database.

3. A method according to claim 2 wherein the database also stores a plurality of second data, each second data being associated with a respective first data, and in step ii the second data associated with the selected first data is provided from the database.

4. A method according to any one of claims 1 to 3 wherein in step i the first data is output to the operator by the operator interface, and the inputting is made by an input selection command by the operator responsive to the first data being output by the operator interface.

5. A method according to any one of claims 1 to 4 wherein in steps vii and viii the first and second notification signals are output to the operator interface to cause first and second notifications, respectively, to be output to the operator by the operator interface.

6. A method according to any one of claims 1 to 5 further comprising the steps, after step vi, in response to provision of the comparison signal, of:

a. when the measured weight of the second component is higher than the preset tolerance of the target weight of the second component, providing an output indication to the operator from the operator interface to weigh an additional dispensed amount of the first component;

b. weighing, using the weighing device, an additional or total dispensed amount of the first component to provide sixth data representing, directly or indirectly, a measured total weight of the first component;

c. calculating, using the processor, seventh data from the fifth data and from the second data, the seventh data representing, directly or indirectly, a revised target weight of the first component;

d. comparing, using the processor, the sixth data and the seventh data to provide the comparison signal when the measured and target mixture ratios of the first and second components do not correspond within the preset tolerance or the termination signal when the measured and target mixture ratios of the first and second components do correspond within the preset tolerance; e. outputting, from the processor, the first notification signal to the operator interface in response to the comparison signal; and

f. outputting, from the processor, the second notification signal to the operator interface in response to the termination signal.

7. A method according to claim 6 further comprising the steps, after step d, in response to provision of the comparison signal, of:

A. when the measured weight of the second component is lower than the preset tolerance of the target weight of the second component, providing an output indication to the operator from the operator interface to weigh an additional dispensed amount of the second component;

B. weighing, using the weighing device, an additional or total dispensed amount of the second component to provide eighth data representing, directly or indirectly, a measured total weight of the second component;

C. calculating, using the processor, ninth data from the sixth data and from the second data, the ninth data representing, directly or indirectly, a revised target weight of the second component;

D. comparing, using the processor, the eighth data and the ninth data to provide the comparison signal when the measured and target mixture ratios of the first and second components do not correspond within the preset tolerance or the termination signal when the measured and target mixture ratios of the first and second components do correspond within the preset tolerance;

E. outputting, from the processor, the first notification signal to the operator interface in response to the comparison signal; and

8. A method according to any one of claims 1 to 7 wherein before weighing step iii an instruction to weigh the first component is output to the operator by the operator interface.

9. A method according to any one of claims 1 to 8 wherein during weighing step iii the measured weight of the first component is dynamically output to the operator in real time by the operator interface as the first component is dispensed onto the weighing device and/or during weighing step v the measured weight of the second component is dynamically output to the operator in real time by the operator interface as the second component is dispensed onto the weighing device.

10. A method according to any one of claims 1 to 9 wherein between steps iv and v the target weight of the second component is output to the operator by the operator interface.

11. A method according to any one of claims 1 to 10 wherein any one or any combination of or all of step vi, step vii and step viii is carried out dynamically in real time during step v.

12. A method according to any one of claims 1 to 11 wherein in step v the total amount of the combination of the first component weighed in step iii and the second component weighed in step v is measured thereby indirectly weighing the dispensed amount of the second component.

13. A method according to any one of claims 1 to 12 wherein in step i the operator interface is a touch-sensitive display screen, a display device, a physical switch mechanism, a sound emitter, a sound receiver, or any combination thereof.

14. A method according to claim 13 when appendant on claim 2 or any claim dependent thereon wherein in step i individual first data of the menu are displayed and the first data is selected by scrolling through the menu.

15. A method according to any one of claims 1 to 14 wherein the mixture control unit comprises a device comprising the operator interface, the processor which has been programmed to process the first and second data and a memory.

16. A method according to any one of claims 1 to 14 wherein the mixture control unit comprises a smartphone, a tablet computer, a laptop computer, or a personal computer which has been programmed by an installed software application to process the first and second data and comprises the operator interface, the processor and a memory.

17. A method according to any one of claims 1 to 16 wherein the first data identifies a respective curable resin component, and the second data defines a target mixture ratio between the curable resin component of the respective first data and a respective curing agent for the curable resin component.

18. A method according to claim 17 wherein the first data comprises a unique product code of the respective curable resin component and/or the second data defines a mixture ratio between the curable resin component of the respective unique product code and a respective curing agent having a second unique product code of the respective curing agent.

19. A method according to any one of claims 1 to 18 wherein the operator interface and the processor are comprised in the mixture control unit, and the mixture control unit comprises an input port configured for wired or wireless connection to a remote weighing device comprising a load cell for outputting a measured weight signal to the processor.

20. A method according to any one of claims 1 to 19 wherein the first component is the curable resin component and the second component is the respective curing agent therefor.

21. An apparatus for controlling the mixing of components of a curable resin system, the apparatus comprising:

a mixture control unit comprising an operator interface configured to receive input first data identifying a first component of a curable resin system, the mixture control unit being configured to be provided with second data defining a target mixture ratio between the first component and a second component of the curable resin system; and a processor programmed, in hardware and/or in software, to receive first data from the operator interface, second data provided to the mixture control unit, and third data representative, directly or indirectly, of a measured weight of the first component of the curable resin system, and to calculate, from the third data and the second data, fourth data representing, directly or indirectly, a target weight of the second component of the curable resin system to provide the target mixture ratio between the first and second components, the processor comprising:

an interface module programmed to or output an interface signal to the operator interface, the interface signal being configured to cause the operator interface to output to an operator information concerning the operation of the mixture control unit;

a first input module programmed to receive the third data;

a calculation module programmed to calculate the fourth data from the third data and from the second data;

a second input module programmed to receive fifth data representing, directly or indirectly, a measured weight of the second component corresponding to a measured mixture ratio between the first and second components; a comparison module programmed to compare the fifth data and the fourth data to provide a comparison signal when the measured and target mixture ratios of the first and second components do not correspond within a preset tolerance or to provide a termination signal when the measured and target mixture ratios of the first and second components do correspond within the preset tolerance; and

an output module programmed to output a first notification signal to the operator interface in response to the comparison signal, the first notification signal causing the operator interface to output an indication that an additional amount of the first component or second component should be dispensed to be weighed and a second notification signal to the operator interface in response to the termination signal, the second notification signal causing the operator interface to output an indication that the target mixture ratio for the first component and the second component has been weighed.

22. An apparatus according to claim 21 wherein the mixture control unit further comprises a database programmed to store a menu comprising a plurality of first data, each first data identifying a respective curable resin component, and a plurality of second data, each second data being associated with a respective first data, and each second data defining a target mixture ratio between the curable resin component of the respective first data and a respective curing agent for the curable resin component.

23. An apparatus according to claim 22 wherein the processor further comprises a selection module programmed to select a first data from the plurality of first data based upon an input selection command, wherein the interface module is configured to output to the operator interface a signal configured to cause the operator interface to output to an operator one or more of the first data to be selected by the selection module.

24. An apparatus according to any one of claims 21 to 23 wherein the processor further comprises a first feedback module programmed to output a first feedback signal to the operator interface to cause the operator interface to output an indication to an operator to weigh an additional dispensed amount of the first component when the measured weight of the second component is higher than the preset tolerance of the target weight of the second component.

25. An apparatus according to any one of claims 21 to 24 wherein the processor further comprises a second feedback module programmed to output a second feedback signal to the operator interface to cause the operator interface to output an indication to an operator to weigh an additional dispensed amount of the second component when the measured weight of the second component is lower than the preset tolerance of the target weight of the second component.

26. An apparatus according to any one of claims 21 to 25 wherein the interface module is programmed to output to the operator interface a signal to cause the operator interface to output an indication to an operator to weigh the first component.

27. An apparatus according to any one of claims 21 to 26 wherein the interface module is programmed to output to an output device of the operator interface a signal to cause the output device dynamically to output to an operator in real time the third data representing, directly or indirectly, a measured weight of the first component and/or the fifth data representing, directly or indirectly, a measured weight of the second component.

28. An apparatus according to any one of claims 21 to 27 wherein the interface module is programmed to output to an output device of the operator interface a signal to cause the output device to output to an operator the fourth data.

29. An apparatus according to any one of claims 21 to 28 wherein the operator interface is a touch-sensitive display screen, a display device, a physical switch mechanism, a sound emitter, a sound receiver, or any combination thereof.

30. An apparatus according to any one of claims 21 to 29 wherein the mixture control unit comprises a device comprising the operator interface, the processor which has been programmed to process the first and second data, and a memory.

31. An apparatus according to any one of claims 21 to 30 wherein the mixture control unit comprises a smartphone, a tablet computer, a laptop computer, or a personal computer which has been programmed by an installed software application to process the first and second data and comprises the operator interface, the processor and a memory.

32. An apparatus according to any one of claims 21 to 31 wherein the mixture control unit comprises an input port configured for wired or wireless communication from to a weighing device, comprising a load cell, for outputting a measured weight signal to the mixture control unit for processing by the processor.