IT201800002157A1 - SURFACE SPRAY TREATMENT DEVICE - Google Patents

Description

DESCRIPTION

SPRAY SURFACE TREATMENT DEVICE

The present invention relates to a spray surface treatment device, ie a device exploiting a jet of a gas under pressure to deliver a painting product (powder or liquid), of the type specified in the preamble of the first claim.

As known, the devices for spray surface treatment and, in particular, spray paint, are usually constituted by a pressurized air supply system (such as a compressor); a paint product tank; and an airbrush (manual or automatic) connected both to the pressurized air supply system and to the tank designed to deliver a fluid output from the spray gun given by the mixing of the product with the pressurized air.

The varnishing product can be of various types: watercolor, ink, oil, tempera, acrylic or solvent. It can be in both powder and liquid form. The known art described includes some important drawbacks.

A first drawback is in the fact that the surface treatment and, to be more precise, the painting thus performed are often of low quality as it presents defects and non-conformities that can only be found at the end of the process and therefore require expensive post-treatment interventions, both economically both temporally, to correct such imperfections and / or defects.

It is emphasized how it can happen that the defects present are so high that it is necessary to carry out the entire treatment again.

These aspects are determined by the fact that the fluid produced exiting the spray gun is very susceptible to environmental conditions (temperature, humidity, presence of electrostatic charges, etc.) and therefore requires, for each application, a precise and accurate choice of parameters. of the fluid produced.

It is emphasized that this choice, being made by the operator on the basis of his own experience, is almost never the optimal one.

This aspect is evident in the painting where the possibility of including powders or other impurities is added.

It should be noted that to reduce the susceptibility of the fluid produced to environmental conditions, the operator often selects working pressures that are much higher than those actually necessary, resulting in an increase in the product used per unit of surface area and therefore an increase in the costs of surface treatment. Furthermore, the surface treatment devices are forced to work in much more wearing conditions and therefore tend to break more frequently.

In this situation, the technical task underlying the present invention is to devise a spray surface treatment device capable of substantially obviating at least part of the aforementioned drawbacks.

Within the scope of said technical task, it is an important object of the invention to obtain a spray surface treatment device which allows to carry out, in a simple, fast and repeatable way, a surface treatment substantially free of defects and therefore of high value and cost. content. Another important object of the invention is to provide a spray surface treatment device that cannot be influenced by environmental parameters such as, for example, temperature and humidity.

The technical task and the specified purposes are achieved by a spray surface treatment device as claimed in the attached claim 1. Examples of preferred embodiment are described in the dependent claims. Preferred embodiments are highlighted in the dependent claims.

The features and advantages of the invention are clarified below by the detailed description of preferred embodiments of the invention, with reference to the accompanying drawings, in which:

Fig. 1 shows a spray surface treatment device according to the invention; And

Fig. 2 schematises the operation of the spray surface treatment device.

In this document, measurements, values, shapes and geometric references (such as perpendicularity and parallelism), when associated with words such as "about" or other similar terms such as "almost" or "substantially", are to be understood as unless of measurement errors or inaccuracies due to production and / or manufacturing errors and, above all, unless there is a slight divergence from the value, measurement, shape or geometric reference to which it is associated. For example, these terms, if associated with a value, preferably indicate a divergence of no more than 10% of the value itself.

Furthermore, when used, terms such as "first", "second", "superior", "inferior", "main" and "secondary" do not necessarily identify an order, relationship priority or relative position, but can simply be used to more clearly distinguish different components from each other.

The measurements and data reported in this text are to be considered, unless otherwise indicated, as carried out in the ICAO International Standard Atmosphere (ISO 2533).

Unless otherwise specified, as reflected in the following discussions, terms such as "processing", "computing", "determination", "computation", or the like, are considered to refer to the action and / or processes of a computer or similar device electronic computation that manipulates and / or transforms data represented as physical, such as electronic quantities of registers of a computer system and / or memories into, other data similarly represented as physical quantities within computer systems, registers or other storage, transmission devices or information display.

With reference to the Figures, the spray surface treatment device according to the invention is globally indicated with the number 1.

The spray surface treatment device 1 is adapted to paint or perform other surface treatments by emitting and in detail depositing a painting product. In particular, it is adapted to varnish / paint by emitting a flow obtained by mixing a gas under pressure with at least one varnishing product. Preferably, the spray surface treatment device 1 can be used to paint or perform surface treatments metal elements (such as for example in bodywork) or polymeric or natural elements (such as wood).

The spray surface treatment device 1 can comprise at least one paint product tank 2.

The spray surface treatment device 1 can comprise at least one airbrush 3 adapted to use a feed gas to pulverize (or atomise) the paint product contained in the tank 2 and then to spray a mixture of feed gas and paint product on the surface to be to deal.

The airbrush 3 is in connection of fluid passage with the tank 2.

The airbrush 3 can be of a known type. It can for example be a single action airbrush; a double action airbrush; a turbine airbrush; an airbrush pistol.

The tank 2 can be integral with the airbrush 3 which is therefore identifiable in a known airbrush or a pistol airbrush.

The spray surface treatment device 1 may comprise a feed system 4 adapted to supply the spray gun 3 with a feed gas under pressure so as to allow the spray gun to spray a mixture of feed gas (coming from the feed system 4) and paint product (coming from tank 2).

This mixture almost identifies the spray pattern.

The feeding system 4 is in fluid passage connection with the airbrush 3.

The feed gas made available by the feed system 4 substantially has an ozone (O3) content substantially between 0.1 and 100,000 ppmv (parts per million by volume), in particular between 0.1 and 50,000 ppmv and more in particularly between 0.1 and 10,000 ppmv.

This feed gas has a methane (CH4) content practically between 1 and 5,000 ppmv and in particular between 1 and 100 ppmv.

The feed gas has a carbon monoxide (CO) content substantially between 0.1 and 5,000 ppmv and in particular between 0.1 and 100 ppmv.

The feed gas has a nitrogen (N2) content substantially between 790,000 and 1,000,000 (suitably 999,990) ppmv and in particular between 880,000 and 980,000 ppmv.

The feed gas has an argon (Ar) content substantially between 100 and 100,000 ppmv by volume and in particular between 5,000 and 10,000 ppmv.

The feed gas has a carbon dioxide (CO2) content substantially between 5 and 100,000 ppmv by volume, in particular between 10 and 20,000 ppmv and more particularly between 10 and 10,000 ppmv.

The feed gas has an oxygen (O2) content substantially between 10 and 210,000 ppmv and in particular between 20,000 and 50,000 ppmv.

Conveniently, the supply gas is air depleted of oxygen (O2) and consequently having an advantageously higher content of one or more of ozone, methane, carbon monoxide, carbon dioxide, nitrogen and argon suitably present in the concentrations described above.

Preferably the feed gas is oxygen-depleted air comprising ozone, methane, carbon monoxide, carbon dioxide, nitrogen and argon suitably present in the concentrations described above.

The term “air” indicates the gas present in correspondence with the troposphere and in particular near the earth's crust.

The feed gas can be ionized. It can therefore selectively have a negative or positive charge. Alternatively, the supply gas can be pulsed charge and therefore characterized by a charge variation frequency suitably between two limit values. These limit values can be positive, negative and / or null.

Optionally, the supply gas can be thermoregulated so as to present a different temperature from that of the environment. In particular, it can be brought to a heating temperature higher than that of the environment or cooled to a cooling temperature lower than that of the environment.

The heating temperature can be at least equal to 20 ° and in detail practically between 30 ° C and 100 ° C and more precisely between 30 ° C and 60 ° C. The cooling temperature can be almost between -10 ° C and 40 ° C and in detail between 5 ° C and 20 ° C.

The feed system 4 may be a feed gas storage tank. Alternatively, the feeding system 4 can comprise several gas tanks each containing at least one of the above-described components of the feeding gas and optionally of air and an apparatus for mixing the components according to the contents described above.

Preferably, the supply system 4 is adapted to generate the supply gas by exploiting air suitably under pressure.

The power supply system 4 may comprise at least one filter 41 designed to eliminate dust and other impurities from the suitably pressurized air entering the system 4.

Filter 41 is suitable for obtaining a purity level of at least class 1 (said class is defined in accordance with ISO 8573-1: 2010).

Filter 41 represents the first element encountered by the air entering the supply system 4.

The filter 41 can be of a known type.

The power supply system 4 may be able to generate said feed gas by removing at least part of the oxygen from the air, suitably under pressure. It can thus comprise at least one separator 42 suitable for obtaining a supply gas with a reduced oxygen content and in detail characterized by a content of at least one component different from the gas, ie air, entering the separator 42. Said at least one component can be one or more of ozone, methane, carbon monoxide, carbon dioxide, nitrogen and argon.

The separator 42 can be downstream (according to the advancement of the gas / air) with respect to the filter 41 so as to receive the gas coming out of the same filter 41.

The separator 42 can be adapted to obtain the supply gas by extracting at least part of the oxygen from the air and suitably of the water vapor.

Preferably the separator 42 extracts at least part of the oxygen, water vapor, helium and hydrogen from the air.

The separator 42 can be a suitably polymeric membrane (more suitably a hollow fiber one) suitable for using one or more membranes at least partially impermeable to the elements to be discarded, at least partially, from the air (oxygen, water vapor, helium and hydrogen) and permeable to one or more of ozone, methane, carbon monoxide, carbon dioxide, nitrogen and argon.

Conveniently, the separator 42 can comprise one or more membranes at least partially permeable to ozone, methane, carbon monoxide, carbon dioxide, nitrogen and / or argon.

Alternatively, the separator 42 can be of the PSA (Pressure Swing Adsorption) type, ie a separator using PSA as a working principle, in other words the affinity of the elements to be discarded from the air with an adsorbent material. This type of separator 42 can comprise molecular sieves of the activated carbon type.

Preferably the separator 42 is a suitably polymeric membrane and more suitably a hollow fiber one.

It should be noted that the feeding system 4 can be and in detail is devoid of a thermal regulation apparatus and for the precision of heating upstream of the separator 42 and preferably of the filter 41 and therefore of the air entering the separator 42 and preferably in the filter 41. Consequently, the air entering the separator 42 and preferably the filter 41 has a temperature equal to the external one. Preferably, the spray surface treatment device 1 is devoid of a thermal regulation apparatus and for the precision of heating upstream of the power supply system 4 and therefore capable of heating the air entering the power supply system 4.

The feed system 4 may comprise a feed gas ionizer 43.

The ionizer 43 can be downstream (according to the advancement of the gas / air) with respect to the separator 42 so as to receive the gas coming out of the same separator 42.

The ionizer 436. Is adapted to at least partially ionize the oxygen in said supply gas, transforming it at least partially into ozone. It can be adapted to produce ozone in the supply gas, preferably by electroionization of said gas.

The desired ozone content is therefore obtainable by ionization and / or said extraction of at least part of the oxygen.

In particular, the ionizer 43 can be adapted to generate a magnetic field of such intensity (greater than the dielectric strength of the supply gas) that the ions in the supply gas are excited and, striking any residual oxygen in the supply gas, ionize it, causing the formation of additional ozone.

The ionizer 43 is adapted to modify the electric charge of said supply gas and for example charge it electrically or make it statically / electrically neutral. It comprises at least one electrode and at least one generator suitable for placing said at least one electrode under electrical voltage (with negative and / or positive charge) and therefore for electrically charging (negative and / or positive) the supply gas.

This charge can be constant or pulsed.

Preferably the at least one generator is adapted to place said at least one electrode at a voltage substantially between 0.1 kV and 100 kV.

In particular, the ionizer 43 comprises two generators, one of which is adapted to generate a negative voltage causing a negatively charged supply gas and one adapted to generate a positive voltage causing a positively charged supply gas.

The power supply system 4 may comprise a regulator 44 of the temperature of the supply gas and therefore of the mixture of supply gas and paint product leaving the spray gun 3.

The regulator 44 is adapted to heat the feed gas to the heating temperature.

Alternatively or in addition, the regulator 44 is adapted to cool the supply gas to the cooling temperature.

The regulator 44 is downstream of the separator 42 so as to heat the air coming out of the same separator 42. Preferably it is downstream of the ionizer 43.

The regulator 44 can be of a known type.

It is evident that the regulator 44 is adapted to heat the feed gas to the heating temperature.

The regulator 44 is therefore the only control element and in particular for heating the supply gas of the power supply system 4 and for the precision of the spray surface treatment device 1.

Alternatively, the supply system 4 can be without the temperature regulator 44.

Finally, the spray surface treatment device 1 can comprise a control unit adapted to control the operation of the spray surface treatment device 1; and, preferably interface means (such as push-button panel or knob) suitable for allowing an operator to control, even remotely, the operation of the spray surface treatment device 1. The control unit is suitable for regulating the dispensing of paint product and in particular of the mixture of supply gas and paint product. In particular, the control unit is designed to define a continuous delivery or a pulsed charge delivery at a frequency preferably selectable by the operator through said interface means.

The control unit is designed to control the regulator 44 and therefore the temperature of the supply gas.

The invention comprises a new spray surface treatment process 10 which can be implemented by the spray surface treatment device 1 previously described in structural terms.

The spray surface treatment process 10 is characterized by painting or carrying out other surface treatment by delivering a mixture of paint product and a pressurized feed gas comprising at least one or more of ozone, methane, carbon monoxide, carbon dioxide , nitrogen and argon suitably present in the concentrations described above. Preferably the feed gas is oxygen-depleted air comprising ozone, methane, carbon monoxide, carbon dioxide, nitrogen and argon suitably present in the concentrations described above.

The characteristics (composition, temperature, etc.) of the supply gas are described above and therefore not reported here for convenience.

The spray surface treatment process 10 can comprise a deposition step 11 in which the feed gas and the paint product are mixed together and then delivered towards the surface to be painted.

In particular, the supply gas is conveyed to the painting product and affects said painting product causing its atomization / pulverization and thus allowing its mixing with the supply gas and the consequent formation of the mixture (spray fan.)

In particular, the deposit step 11 can provide for the delivery of said mixture with constant and / or pulsed charge.

This phase 11 can be performed by the airbrush 3.

Prior to the deposit step, the spray surface treatment process 10 may comprise a step 12 of the supply gas by subtracting at least part of the oxygen from suitably pressurized air.

The extraction of oxygen from the air can be performed from the separator 42 through for example PSA or preferably a suitably polymeric membrane and more suitably hollow fiber or alternatively.

The extraction of oxygen is performed by working unheated air since the power supply system 4 is devoid of a thermal regulation apparatus upstream of the separator 42.

Conveniently, the spray surface treatment process 10 can comprise a filtration step 13, prior to the manufacturing step 11, in which dust and other impurities are eliminated from the air.

Class 1 air is preferably obtained in the filtration step 13 according to ISO 8573-1: 2010.

The filtration step 13 can be carried out by the filter 41.

The spray surface treatment process 10 can comprise an ionization step 14, subsequent to the manufacturing step 12 and prior to the deposition step 11, in which the feed gas is ionized.

In this ionization step 14, the supply gas can be electrically charged in negative or positive.

The ionization step 14 can be performed by the ionizer 43.

The spray surface treatment process 10 can comprise a thermoregulation step 15 of the feed gas prior to the deposition step.

In the thermoregulation step 15 the gas can be brought to the cooling and / or heating temperature.

The thermoregulation step 15 is preferably subsequent to the manufacturing step and, to be more precise, to the ionization step.

The thermoregulation phase 15 can be carried out by the regulator 44.

The device 1 and consequently the spray surface treatment process 10 according to the invention achieve important advantages.

A first important advantage is represented by the fact that the separator 42 processes air substantially at room temperature and therefore not heated.

In fact, while all the known devices heat the air before carrying out the oxygen removal, thus obtaining an increase in the capacity of the separator 42, the inventor realized that the increase in the temperature of the incoming air and so on processing in the separator 42 causes a rapid and considerable decline in the processing capacity of the separator itself. Consequently, the decay of the capacity of the separator 42 rapidly cancels the increase given by the higher temperature of the air being processed and immediately leads to a quick impossibility of using the air coming out of the separator 42 correctly.

By virtue of this, the surface treatment device 1, unlike known devices where frequent replacement / regeneration of the separator was necessary, is characterized by a longer lasting separator 42 and therefore requires less frequent maintenance interventions and above all equipped with a greater constructive simplicity and reliability and lower consumption.

It is evident that this advantage, given by the absence of air heating means upstream of the separator 42, is particularly evident in the separator 42 if membrane.

An important advantage is in the innovative use of a supply gas characterized by the described ozone content which allows for a slight abrasion of the surface to be painted which is therefore cleaned of any residues allowing for optimal deposition and adhesion of the paint product.

An important advantage is given by the carbon monoxide content of the supply gas which allows to avoid oxidation of the surface to be colored. Another advantage is given by the fact that the particular supply gas, by virtue of its own characteristics, minimizes the surface tension of a liquid or powder coating product allowing a greater fractionation of the coating product and therefore a reduction in drops / particles of very large size. reduced and homogeneous.

This aspect allows to deposit drops of reduced size and therefore to have a produced film of reduced thickness and therefore lower cost.

An advantage is in the particular concentration of oxygen which, in addition to allowing the creation of ozone, is optimal for optimizing the drying of some paint products. In fact, some of them are added with fillers (for example sliding, drying and antioxidant additives) which dry by absorption of oxygen, thickening to form a solid film and therefore a thick and hardened film on the surface.

Another advantage is given by the particular content of carbon dioxide which, in addition to cleaning the surfaces to be treated, has a great ability to penetrate and diffuse into the surfaces allowing greater adhesion of the paint product during spraying, greater homogeneity of the film and absence of posterior swellings. These aspects translate into the need for a lower use of solvents in spraying, thus reducing the volatile organic components that are harmful to the environment.

Other advantages are in the particular argon content which guarantees protection against oxidation and premature wear of the electrodes predisposed to ionization of the carrier fluid, and in the particular methane content which effectively dissolves organic solvents and acts as a temperature stabilizer.

An important advantage is also the possibility of thermoregulating the supply gas by avoiding temperature variations of the mixture leaving the airbrush and thus ensuring greater uniformity and therefore quality of the paint or other surface treatment.

Another important advantage is given by the particular nitrogen content which, for example, stabilizes the flow making it the mixture produced by the surface treatment device 1 less subject to turbulence.

Finally, it is pointed out that the mixture produced by the surface treatment device 1 is anhydrous (or in any case with a low content of water vapor) thus avoiding all the problems that are typical of known devices due to the presence of water vapor.

The invention is susceptible of variants falling within the scope of the inventive concept defined by the claims. In this context, all the details can be replaced by equivalent elements and the materials, shapes and dimensions can be any.

Claims (10)

CLAIMS 1. Spray surface treatment device (1) suitable for depositing a pulverized paint product and comprising: - a tank (2) for said painting product; - feeding system (4) adapted to supply said surface treatment device (1) with a feeding gas; - an airbrush (3) adapted to use said feed gas to pulverize said paint product contained in said tank (2) and then spray a mixture of said feed gas and said paint product; and characterized by the fact that - said supply system (4) comprises at least one separator (42) suitable for obtaining said supply gas with reduced oxygen content by subtracting oxygen from the air and is devoid of a thermal regulation apparatus upstream of said separator (42) so as to allowing said separator (42) to process air at a temperature equal to the external one. Spray surface treatment device (1) according to claim 1, wherein said feeding system (4) is devoid of a heating apparatus upstream of the separator (42). Spray surface treatment device (1) according to at least one preceding claim, wherein said feeding system (4) comprises a filter (41) adapted to eliminate dust and other impurities from said air entering said separator (42) ; and in which said feeding system (4) is devoid of a thermal regulation apparatus upstream of said filter (41). Spray surface treatment device (1) according to at least one preceding claim, wherein said separator (42) comprises at least one polymeric and hollow fiber membrane. Spray surface treatment device (1) according to at least one claim 1-3, wherein said separator (42) is of the PSA type. Spray surface treatment device (1) according to at least one preceding claim, wherein said feed system (4) comprises a regulator 44 for the temperature of said feed gas downstream of said separator (42). Spray surface treatment device (1) according to at least one preceding claim, wherein said feed system (4) is adapted to supply said airbrush (3) with said pressurized feed gas comprising a nitrogen content substantially comprised between 790,000 and 1,000,000 ppmv, of carbon dioxide substantially between 5 and 100,000 ppmv, of argon (Ar) substantially between 100 and 100,000 ppmv, oxygen (O2) substantially between 10 and 210,000 ppmv. 8. Spray surface treatment device (1) according to at least one preceding claim, wherein said feed system (4) is adapted to supply said airbrush (3) with said pressurized feed gas comprising an ozone content substantially comprised between 0.1 and 50,000 ppmv, a methane content substantially between 1 and 100 ppmv, a carbon monoxide content substantially between 0.1 and 100 ppmv. Spray surface treatment device (1) according to at least one preceding claim, wherein said feed system (4) comprises an ionizer (43) of said feed gas located downstream of said separator (42). 10. Process of surface spray treatment (10) a mixture of a paint product and a feed gas and characterized in that it comprises a step (12) for producing said feed gas by subtracting at least part of the oxygen from suitably pressurized unheated air.