ES2928010A1 - MELTING MACHINE FOR SOLID HEAT-FUEL PRODUCTS IN BLOCK FORM (Machine-translation by Google Translate, not legally binding) - Google Patents

Abstract

Melting machine for solid hot-melt products in the form of blocks, comprising means for pressing the solid hot-melt product, melting means for transforming the solid hot-melt product into a fluid state, a molten product tank (1.1) in which the molten hot melt product and an outlet assembly (19) of the hot melt product in a fluid state for delivery to the destination application, in which at least one distribution module (5) is available in the outlet assembly (19), ranging associated with a pump (8) that is driven by a corresponding motor (9) to drive the fluid hot melt product at the outlet towards the destination application, the pump (8) having a gas inlet (10), which is it connects to a pneumatic conditioning system (11) equipped in the machine itself, to receive a flow of gas that transforms the fluid hot melt product into a foam product for its application. (Machine-translation by Google Translate, not legally binding)

Description

DESCRIPTION

MELTING MACHINE FOR SOLID HEAT FUSIBLE PRODUCTS IN THE FORM OF

BLOCK

Technical sector

The present invention is related to the application of hot melt products, more specifically hot melt products that are supplied in block form, proposing a machine that allows said originally solid hot melt products to be melted, for feeding said products to their application in the form of foam and/or liquid.

state of the art

In many applications of protective or aesthetic coatings, joints between elements or gap filling, it is common to use hot melt products, which are originally supplied in a solid state, subjecting them to a fusion process that transforms them into a fluid state. in which they can be transported through hoses to exit nozzles to be deposited at the destination places.

In this sense, it is known to use hot melt products that are originally supplied in the form of pellets or small balls, being supplied from a feeding hopper to a heated tank, where the product is melted to be sent to the application. However, the invention that concerns us refers to equipment or machines that use hot melt products that are supplied in the form of a block or bar, normally made of polyolefin or reactive polyurethane (PO or PUR) that is packaged with aluminum foil. to prevent it from coming into contact with ambient humidity, since due to its high reactivity it would become a thermostable product before its final use. Therefore, machines are known that use this type of product in block or bar, and in which the lower part of the container with aluminum foil is removed, and it is melted by pressing the face without aluminum protective foil on a melting grid, falling in a fluid state into a collection tank, from where the molten product is conducted to the application.

In hot melt adhesives that become thermosetting due to a chemical reaction, such as PO or PUR, the properties of the product change when they remain molten for a long enough time. In this case, the chemical reaction takes place at the temperature at which the molten product is found without its contact with ambient humidity being necessary. To avoid this, the fusion of the block or bar is not done completely, but rather it is fused depending on the application needs. When product is no longer applied at the outlet, the block stops being pressed and the melting grid stops melting. In this way, it is possible to maintain the block of hot-melt product in optimal conditions.

On the other hand, it is known to apply hot-melt products in a liquid or semi-liquid state, as they result from melting, and also to transform the molten products into a form of foam for application, also called foam. For the transformation into foam, means external to the machine are used with which a contribution of gas is made to the molten product when it leaves the fusion machine, so that the mixture of the gas with the molten product provides the state in the form of foam.

In this case, in which the PO or PUR hot melt product must be in the form of a foam, the molten hot melt product is conventionally conveyed from the tank to the external means, to the gas supply machine and then to the application element. This conduction is done by incorporating a heating hose connected to the outlet of the tank and even a gas supply device.

The cost of carrying out the foaming using two machines, one for melting and the other for foaming, in addition to this hose, makes the application of the hot melt foam product significantly more expensive, in addition to the fact that the material that remains in the hose once the application is finished is useless. This fact makes cleaning and maintenance operations necessary every time production is interrupted for a long period, in addition, considering the high cost of this type of hot melt product, it makes its application more expensive. Nor should we forget the high temperature at which all the components of the melting and conditioning system of the molten product must be, for which energy consumption is quite high, and the consequent increase in the carbon footprint of the process compared to a process that uses more than one machine to achieve the foaming of a hot melt product.

Object of the invention

In accordance with the present invention, a machine is proposed for melting hot-melt products in the form of blocks or bars, preferably made of reactive polyurethane PUR or polyolefin PO, but without limitation in this regard, understanding by said products hot-melt adhesives that become thermosetting due to to a chemical reaction, having developed this machine with characteristics that make it advantageous for the application of hot melt products in the form of foam (foam) without it being necessary to lead them to a device external to the machine for the transformation to foam.

The proposed machine comprises a means for pressing the solid hot-melt product, a melting means for transforming the solid hot-melt product into a fluid state, a molten product tank in which the molten hot-melt product is collected, and an outlet assembly for the hot-melt product. in a fluid state for delivery to the destination application. In said machine, at the outlet assembly there is at least one distribution module available, being associated with a pump that is driven by a corresponding motor, to drive the fluid hot melt product at the outlet towards the destination application, the pump having a gas inlet, which is connected to a pneumatic conditioning system equipped in the machine itself, to receive a flow of gas that transforms the fluid hot melt product into a foam product for its application.

Thanks to this provision, the use of external means to obtain fluid product in the form of foam is avoided, reducing costs and maintenance of the whole machine, and likewise reducing the energy consumption of the set of means to achieve the application of the hot melt product PO or foamed PUR.

As mentioned, the properties of the hot melt product change when it remains molten for a sufficiently long time, and conventionally the fusion of the product is not carried out on demand (it stops melting when the application of the product at the outlet stops). In this way, an excess of hot melt product is melted, which can degrade and increase the costs of the application.

In order to avoid this, according to the invention, the melting machine includes means for controlling the volume of molten hot melt product in the molten product tank by actuation of the means. of pressing and of the melting medium of the solid thermofusible product from information obtained by a fluid level sensor included in the deposit of melted product. When the molten product reaches the proper level, the block is released from pressing with the pressing means and a melter grate of the melting means stops melting. In this way, it is possible to keep the block of hot melt product in optimal conditions, while the minimum quantity of hot melt product necessary for industrial application is in the molten product tank.

Preferably, according to the invention, the melting machine includes means for controlling the pressure and/or flow rate of the foamed hot melt product at the outlet by acting on the pump.

Preferably, the means for controlling the pressure of the foamed hot melt product at the outlet are configured to actuate the pump to keep said foamed product retained in the outlet circuit downstream of the pump at a constant pressure when the output of foamed hot melt product is interrupted. .

This automatic control, therefore, changes the operating mode when there is no product application at the outlet, thus measuring the pressure of the foamed hot melt product in the outlet circuit corresponding to the distribution module, acting on the rotation of the pump to introduce the amount of new foamed adhesive to said circuit to maintain constant pressure. During the use of the machine, in the absence of automatic control, when there are intermittent applications, the pump stops completely, and the foamed product loses its pressure and degrades, becoming unusable, making purging necessary. Thanks to said automatic control, by measuring the pressure of the foamed product, action is taken to maintain said foamed product at a constant pressure in the outlet circuit of the distribution module.

In the constructive assembly of the machine, the distribution module of the fluid or foamed product is arranged on supports that determine the position of said module in relation to anchoring fasteners that locate it precisely with respect to the functional coupling at the outlet of the product tank. casting of the machine to which it has to be connected, which facilitates assembly. In this way, it is avoided that a hose is necessary for conducting the adhesive until the application of the gas for transforming the liquid adhesive into foam.

With this configuration, it is possible to precisely position the distribution module so that it faces its coupling to the corresponding outlet of the machine's molten product tank, ensuring its hermetic coupling.

In order to achieve a precise coupling and greater ease of assembly, it is provided that the anchoring of the distribution module to the tank comprises a bolted connection that moves the distribution module vertically until its coupling with the tank of molten product.

In this way, the exact coupling of the outlet of the tank with the coupling of the distribution module is made, facilitating assembly and maintenance, guaranteeing the tightness of the coupling, which will preferably have a gasket for this purpose, preventing the hot-melt product from deteriorates.

According to a characteristic of the invention, in relation to the placement positions of the distribution module, the melter includes certain rails, on which the motor that is connected together with the pump to said distribution module is placed. In such a way that the motor is arranged in a sliding manner on said rails for its coupling together with the pumps to the distribution module, fixing it later on said rails preferably by screwing.

This configuration facilitates assembly and disassembly of the distribution module and its associated pump and motor, making it possible to easily replace the motor or pump for maintenance purposes.

According to another aspect of the invention, it is optionally proposed that the output means of the fluid product to be sent to the destination application consists of at least two distribution modules, that is, an additional distribution module is available in the output assembly being associated with a pump that is driven by a corresponding motor to drive the fluid hot melt product at the outlet towards the destination application. In this way, both modules are arranged directly connected to the molten product tank, the tank comprising as many outputs as there are coupled distribution modules.

In this arrangement, both or more distribution modules can comprise the associated pump for distributing foamed adhesive, or the additional module(s) comprise a pump that only drives the hot melt product for its fluid output.

Thus, a machine is obtained that allows solid hot-melt products to be melted in blocks for their application in a fluid state, allowing the melted hot-melt products to be provided in liquid or foam form in the same machine, depending on the application for which they are intended. which gives some very advantageous qualities to the realization of this machine, due to the versatility it offers.

Conventionally, an independent melting machine is used to apply the hot melt product in liquid form and another machine to transform the melted hot melt products into a foam form, an arrangement that complicates and significantly increases the cost of the hot melt transformation process, being It is necessary to have both machines when it is necessary to apply the product in both ways simultaneously. However, with the arrangement of both distribution modules, the cost and the space required are reduced.

Another feature of the invention is that the distribution modules are dimensionally configured to be interchangeable in their coupling. In this way, the modules together with their associated motor and pump can be arranged indistinctly in any of the coupling positions. This dimensional configuration will be determined by the same shape and size of the distribution modules, in addition to the fixing points. Being possible to dimension the elements and position of the anchors of the machine so that both distribution modules can be fixed indistinctly.

For all these reasons, the recommended machine has some advantageous constructive and functional characteristics, acquiring a life of its own and preferential character with respect to the conventional machines that currently exist to transform solid hot-melt products into a fluid application state.

Description of the figures

Figure 1 shows in perspective an embodiment of the machine object of the invention for melting hot melt products supplied in block form.

Figure 2 is a front elevation view of the melting machine for hot melt products represented in the previous figure.

Figure 3 is a side elevation view of the same melting machine for hot melt products.

Figure 4 is a longitudinal sectional view of the melting machine for hot melt products through the middle part of the tank.

Figure 5 is a perspective view of the machine without the component elements of the outlet assembly for the molten hot melt product.

Figure 6 is an enlarged partial detail of the area of figure 3 in which the outlet modules for the molten hot melt product are located.

Figure 7 is a rear perspective view of a distribution module of the machine object of the invention.

Figure 8 is a perspective view of a motor that can be coupled to a distribution module, showing the connection anchor.

Detailed description of the invention

The object of the invention refers to a machine intended for the fusion of solid block hot-melt products, preferably made of reactive polyurethane PUR or polyolefin PO, in order to transform it into a state of fluidity suitable for conducting it and depositing it in the places of application. in foam form and/or additionally in fluid form.

A machine of this type comprises a tank (1), which, as can be seen in figure 4, is divided into two parts, a storage tank (1.2) in which the block (2) of hot melt product is placed, and a lower fluid product tank (1.1) in which the hot melt product that is melted is collected, to supply it in fluid or foamed form through an outlet assembly (19) for its transport to the place of application.

For this, the solid hot melt product in the form of a block (2), once the aluminum layer in the lower part of the container has been removed, is pressed by means of a pneumatic actuator (3) against a melting grid (4.1) of some fusion means ( 4) that performs the fusion, the molten hot melt product falling into the fluid product tank (1.1), from which it passes to the output assembly (19) for delivery to the destination applications.

This melting of the hot melt product is carried out on demand and preferably the melting machine has a level sensor in the fluid product tank (1.1) that provides information to control means that control the displacement of the pneumatic actuator piston (3) and the input of heat by the melting means (4), to melt only the hot melt product that is going to be used. Said level sensor (not shown in the figures), will preferably be in the form of a capacitive sensor, which provides information to the machine control system to press the block (2) when the level of molten hot melt product is below said sensor.

In the practical embodiment of the figures, in the outlet assembly (19) there are two distribution modules (5) and (6), each of them associated with a pump (8) that is connected through a coupling. (7) to a motor (9) for its drive. In this way, a drive is exerted that provides the fluid hot melt with the necessary pressure to move it to one or more outlet fitting connections (15) (two outlet fitting connections (15) in the examples shown) corresponding to the module of distribution (5, 6) for your application.

In this arrangement, the pump associated with one of the distribution modules, for example, the distribution module (6) (not shown in the figures), is established in communication with the fluid product tank (1.1) and acts only as impulsion pump for providing pressure to the molten hot melt product that passes through said distribution module (6) of fluid hot melt product.

However, the pump (8) associated with the other distribution module, for the example shown, the distribution module (5) of hot melt product in the form of foam, is also established in communication with the fluid product tank (1.1), but in this case the corresponding pump (8) also has a pressurized gas inlet (10), which is connected to a pneumatic conditioning system (11) equipped on the machine itself.

The molten hot melt product that reaches this pump (8) is mixed with a flow of gas that transforms it into a product in the form of foam.

This pump (8) associated with the distribution module (5) of foamed hot melt product preferably comprises three parts, a first part with a set of pinions that sucks the molten adhesive from the distribution module (5) of foamed hot melt product, a second set of pinions where gas is introduced, and a third set of pinions to beat the mixture and produce the foam.

During normal operation when the foamed product is applied, the machine includes means for controlling the pressure and/or flow of the foamed product at the outlet by actuation of the pump (8), controlling the pressure and/or flow with which the foamed product comes out.

So that the application of foamed product can be applied in intermittent applications, without overpressure or deterioration of the already foamed product occurring within the output circuit due to pressure losses when the application of hot melt product stops at the machine outlet, the Control means for the pressure and/or flow rate of the foamed hot melt product are additionally configured to maintain said foamed product retained in the outlet circuit downstream of the pump (8) at a constant pressure when the output of foamed product is interrupted. In this way, a set pressure is maintained with small partial turns of the pump (8) to inject a bit of foamed hot melt product that compensates for pressure losses until it is required to reapply. This solution replaces the solution conventionally used for the application of the fluid adhesive in which, in order to avoid overpressure, preferably there is a bypass valve that, when the pressure exceeds a predefined value, recirculates the fluid product upstream of the pump for its inlet. in the same. However, this last solution is not valid for a foamed hot melt product since in recirculation more air would be applied to the already foamed mixture, altering its density and spoiling it.

In addition, according to a preferred embodiment of the invention, this type of pump (8) associated with the application of the foamed hot melt product comprises a heated jacket, since due to its dimensions the heat from the distribution module (5) is not sufficient to maintain the adhesive in optimal conditions and, therefore, the sleeve is necessary heatable to maintain the hot melt product in the molten state at the required temperature conditions.

With this, the resulting machine has the advantage that it can provide fluid hot melt product in liquid or semi-liquid form, through the distribution module (6) of liquid hot melt product, for applications that are appropriate, and also provide hot melt product fluid in the form of foam, through the distribution module (5) of foamed hot melt product, for applications in which this type of fluid product in the form of foam is needed, being able to even supply a joint outlet in combination through both distribution modules (5) and (6), which provides a very advantageous versatility of practical use of the machine.

As can be seen in figure 5, in the location assembly in the machine, the distribution modules (5) and (6) are arranged on supports (12), preferably in the form of a plate, which determine a proper positioning of said distribution modules (5) and (6) with respect to the tank (1). So that, as can be seen in more detail in figures 6 and 7, the distribution modules (5, 6) comprise some projections (16) that allow the distribution modules (5, 6) to be supported on the supports (12). .

Once supported for assembly, the distribution modules (5, 6) can slide on the supports (12) up to a stop (12.1) of the plate that limits its horizontal movement, facing the coupling mouth (17) with the corresponding output of the tank (1) (not shown), the tank (1) having as many outlets as distribution modules comprised by the machine. Once the distribution modules (5, 6) are located for their coupling to the tank (1), the module (5, 6) is vertically movable until its coupling thanks to the force exerted by some screws (14) on a fitting (18 ) arranged for this purpose in the tank (1), with the fitting (18) arranged in the tank (1) in correspondence with both ends of the distribution module (5, 6) or an anchorage defined for the purpose for the incorporation of the screws (14). In this way, the distribution module (5, 6) is brought closer to the outlet of the tank (1), which preferably with the inclusion of a sealing gasket ensures the hermetic connection, greatly facilitating the constructive assembly of the machine.

This arrangement allows both distribution modules (5, 6) to be interchanged indistinctly in the positions determined for this purpose in the melting machine, since dimensionally both modules (5, 6) have the same size, shape and fixing elements.

To further facilitate the assembly and disassembly of said modules, it is foreseen that, as can be seen in figure 5, the machine The melter includes some rails (13) on which the motors (9) are arranged. THANKS TO THIS CONFIGURATION, THE MOTOR (9) IS AVAILABLE IN A SLIDING WAY ON THE RAILS (13) REMAINING FACING FACING AND FACILITATING ITS USE coupling, together with its associated pump (8), to the distribution module (5, 6). Once coupled, the motor will be fixed by screwing on the rails (13) thanks to the anchoring elements that can be see in figure 7. In this way, the assembly of the distribution modules (5, 6) is facilitated, which contributes to the v e rs a tility for ex c h a n g e d owing to ques tions of use and/or maintenance.

Claims (9)

1. - Melting machine for solid hot-melt products in block form, comprising means for pressing the solid hot-melt product, melting means to transform the solid hot-melt product into a state of fluidity, a molten product tank (1.1) in which the molten hot melt product is collected and an outlet assembly (19) of the hot melt product in a fluid state for delivery to the destination application, characterized in that at least one distribution module (5) is available in the outlet assembly (19). ), being associated with a pump (8) that is driven by a corresponding motor (9), to drive the fluid hot melt product at the outlet towards the destination application, the pump (8) having a gas inlet (10), which is connected to a pneumatic conditioning system (11) equipped in the machine itself, to receive a flow of gas that transforms the fluid hot melt product into a foam product for its application. 2. Melting machine for solid hot-melt products in block form, according to claim 1, characterized in that it comprises means for controlling the volume of molten hot-melt product in the molten product tank (1.1) by actuating the pressing means (3 ) and/or the melting medium (4) of the solid hot melt product based on information obtained by a liquid level sensor in the melted product tank (1.1). 3. Melting machine for solid hot-melt products in block form, according to one of the preceding claims, characterized in that it comprises pressure and/or flow control means of the foamed hot-melt product at the outlet by actuation of the pump (8 ). 4. Melting machine for solid hot-melt products in block form, according to the preceding claim, characterized in that the means for controlling the pressure of the foamed hot-melt product at the outlet are configured to actuate the pump (8) to maintain said product. foam retained in the output circuit downstream of the pump (8) at a constant pressure when the output of foamed hot melt product is interrupted. 5. - Melting machine for solid hot-melt products in block form, according to one of the preceding claims, characterized in that the distribution module (5), (6) it is arranged on supports (12) that position it in relation to the anchors provided to establish its fastening, locating it precisely with respect to the couplings of the tank (1) to which said distribution module (5), (6) has to go connected. 6. Melting machine for solid hot-melt products in block form, according to claim 5, characterized in that the anchoring of the distribution module (5), (6) to the tank (1) comprises a bolted connection (14) that it moves the distribution module (5, 6) vertically until its coupling with the deposit of molten product (1.1). 7.- Melting machine for solid hot-melt products in block form, according to claims 5 or 6, characterized in that in relation to the placement positions of the distribution module (5), (6) some rails ( 13), on which the motor (9) is placed, which is connected together with the pumps (8) to said distribution module (5), (6). 8. - Melting machine for solid hot-melt products in the form of a block, according to any one of the preceding claims, characterized in that an additional distribution module (5), (6) is available in the output assembly (19), being associated with a pump (8) that is driven by a corresponding motor (9), to drive the fluid hot melt product at the outlet towards the destination application. 9. - Melting machine for solid hot-melt products in block form, according to the preceding claim, characterized in that the distribution modules (5, 6) are dimensionally configured to be interchangeable in their coupling.