LOADING OF ABRASIVE MATERIAL DESCRIPTION

The present invention concerns the equipment and machines for industrial sandblasting processes carried out with abrasive material constituted by bicarbonate of various types, for example sodium bicarbonate and/or other bicarbonate compounds, and more specifically it concerns a new sandblasting machine equipped with a system for controlling the loading of abrasive material.

At present, when it is necessary to remove paint from metallic and non-metallic objects and to clean the rigid surfaces of objects in general, on which there are solid dirt deposits that are difficult to remove and/or resistant polluting dirt, such as grease, oil or similar substances, a cleaning process is carried out through a mechanical action, which consists in projecting granules of solid material towards the object by means of pressurized air or water, in such a way that their abrasive action removes all the substances that are firmly adhering to the surface to be cleaned.

In brief, a pressurized air flow is conveyed into a Venturi tube that draws the abrasive material in granules and projects it at high speed on the surface to be cleaned through a jetting nozzle.

In order to favour the elimination of the dirt or paint which has been removed, water is added to the flow of air and abrasive material when needed.

The abrasive material is usually contained in tanks or hoppers under controlled pressure or atmospheric pressure, according to the type of sandblasting machine and to the device used to draw and send out the abrasive material.

Sandblasting machines are known, which are provided with abrasive material ejection devices, for example but not necessarily consisting of two parts: a drawing element and an accelerator, wherein the drawing element comprises a first Venturi chamber connected to one or more tanks of abrasive material and to a compressed air line, while the accelerator comprises a second Venturi chamber connected to said dispenser, to a compressed air line and optionally to a duct designed to convey water for humidifying the jet.

By adjusting the air pressure inside the accelerator, it is possible to vary the abrasive material ejection speed according to the characteristics of the object to be cleaned and to the specific operation to be carried out (simple cleaning, paint removal, abrasion etc.). Sandblasting machines are known which use bicarbonate, for example sodium bicarbonate and/or other bicarbonate compounds, as abrasive material, which in addition to producing an abrasive effect on the surfaces has a reduced pollution load, due to the absence of surfactants, and has a detergent as well as a disinfectant action. Furthermore, using bicarbonate as abrasive material, it is also possible to effectively treat surfaces having different characteristics, for example surfaces having a different degree of porosity or surfaces to be disinfected, by varying the grain size of the abrasive material used and the quantity of water mixed during the ejection step, in such a way as to vary, in the emitted jet, also the quantity of bicarbonate dissolved therein and the quantity of bicarbonate in non-dissolved form.

Consequently, according to the type of surface to be treated and to the type of dirt to be removed, it is convenient to use bicarbonate having a specific composition and a specific grain size, with or without additives suited to improve its fluidity and/or rinsability and/or solubility.

Vice versa, the use of bicarbonate having, for example, a larger grain size than that suitable for a specific type of surface to be treated could result in scarce cleaning efficiency, as the abrasive material can neither reach the interstices having a smaller size nor be dissolved to an extent sufficient to guarantee the total disinfection of the surface itself.

In order to overcome the drawbacks described above, a new type of sandblasting machine provided with a system for controlling the loading of the abrasive material has been designed and constructed.

The main object of the present invention is to provide a sandblasting machine that is able to guarantee that the type and quality of the abrasive material used are correct, even according to the type of surface to be treated and to the operations to be carried out.

It is another object of the present invention to provide a sandblasting machine that allows a quick loading of the correct type of abrasive material to be used.

It is another object of the present invention to provide a sandblasting machine that prevents the accidental or undesired use of abrasive material which is not certified or is different from the optimal or recommended material.

These and other direct and complementary objects are achieved by the new sandblasting machine provided with a system for controlling the loading of the abrasive material and comprising an ejection device that in turn comprises:

at least one seat where it is possible to position one or more bottles or containers holding the abrasive material to be ejected;

means for drawing the abrasive material from the inside of said one or more bottles or containers;

one or more bottles or containers housed in said at least one seat, at least one of said bottles being provided with at least one label, preferably but not exclusively an electronic label or tag, containing the identification data of the abrasive material held in the same bottle;

at least one control unit suited to read said data contained in said label applied to said bottle or container of the abrasive material;

and wherein said control unit is configured in such a way as to give/deny the consent for the withdrawal of abrasive material from said bottle according to said data contained in said label applied to said bottle.

In the preferred solution, said label is an electronic label, wherein said control unit and said electronic label or tag operate with RFID technology.

According to the invention, however, said label can alternatively bear a bar code or a QR code or another code suited to be quickly read by means of optical devices and specifying the data that univocally identify the bottle and its contents. Each of said bottles is preferably made of a rigid material that univocally defines the maximum volume in which the abrasive material can be contained.

Furthermore, each of said bottles preferably but not necessarily has at least one transparent part intended to display the level of the abrasive material contained therein. The container or bottle is filled with a specific abrasive material which is certified in terms of weight, quality and characteristics, for example having a specific grain size, wherein said data related to weight, grain size, chemical composition, production lot with date can be checked by reading said label, which specifies and certifies said data related to the abrasive material contained therein, in addition to guaranteeing the traceability of the product.

As already explained, the grain size is particularly important, as it determines the abrasion capacity of the material itself, its fluidity in term of flow regularity and suitability for dispensings, as well as its solubility when mixed with water.

At least one of said bottles or containers comprises an opening or mouth for the extraction of its contents, wherein said opening or mouth is provided with a closing and sealing diaphragm that, once the bottle has been filled, guarantees the quality, type and quantity of the contents.

The new sandblasting machine thus comprises means for drawing the abrasive material from said bottle and means designed to position the bottle and maintain the latter in the correct position in said at least one seat during use.

For example, said bottle, with closed diaphragm, is placed in said seat upside down, wherein when the bottle is correctly inserted in said seat the diaphragm can be opened, for example by means of a needle, blade or in any case a specific drawing device that perforates the diaphragm in order to extract its contents when necessary.

When said bottle is inserted in the corresponding seat or before it is inserted therein, said control unit reads the data or communicates with said electronic label or tag associated with the bottle itself. If the data read by said control unit coincide with the set data and are consistent with them, the control unit authorizes the use of the bottle, for example authorizes the sandblasting machine to use the material contained in the bottle for its intended use.

According to the invention, the new sandblasting machine comprises also means for controlling the emptying process of one or more of said bottles, and in particular of said bottles with label or electronic label. Said control means comprise, for example, a weighing scale suited to monitor the weight of one or more bottles, wherein, when the weighing scale measures a weight value that is lower than a predetermined value, it signals to the control unit that it is necessary to replace the respective bottle.

Furthermore, if the measured value of the weight of said bottle exceeds the weight value previously measured on the same bottle, the control unit can signal this situation as an irregularity and deny the consent for withdrawal from a specific bottle with label or electronic label.

When the bottle is empty or almost empty, this prevents it from being filled again with abrasive material whose quantity, type and grain size are not correct and whose origin is not certified, which would affect the quality of the sandblasting treatment and even the good functioning of the sandblasting machine.

According to the invention, as an alternative to or in combination with the features described above, said needle, blade or in any case specific device of said drawing means can also be specially shaped, for example hook-shaped, in such a way that it perforates the diaphragm when inserted in the mouth of the bottle and, once the contents of the bottle have run out, the extraction of said needle causes the diaphragm and possibly also said electronic label to be broken, thus preventing the bottle from being re-used.

Conveniently, said abrasive material is bicarbonate, for example sodium bicarbonate, a mixture of the same or a similar compound.

Therefore, with reference to the above description, the following claims are expressed.