WO2020012056A2

WO2020012056A2 - Machine for testing specimens having a surface with a non-stick coating

Info

Publication number: WO2020012056A2
Application number: PCT/ES2019/070490
Authority: WO
Inventors: Guillermo Guerrero Vacas; Óscar RODRÍGUEZ ALABANDA; Pablo ROMERO CARRILLO; Miguel Ángel RODRÍGUEZ VALVERDE; Miguel Ángel CABRERIZO VÍLCHEZ
Original assignee: Universidad De Granada; Universidad de Córdoba
Priority date: 2018-07-12
Filing date: 2019-07-12
Publication date: 2020-01-16
Also published as: WO2020012056A3; ES2842025A2; ES2842025R2

Abstract

The invention describes a machine formed by a frame in the form of a closed rectangular prism, and a top cover and a bottom cover that fit to the perimeter of the frame and seal it. The machine also comprises an intermediate cover having at least one opening made in the body thereof and configured to accommodate a flat sheet specimen with a non-stick coating. The machine can include a system of electrical resistors with adjustment and control of the temperature inside the machine, and a system with a floating cover to exert pressure inside a mould.

Description

MACHINE TO TEST TESTS WHOSE SURFACE HAS AN ANTIADHERENT COATING

FIELD OF THE INVENTION

The present invention consists of a machine that allows tests to be carried out to measure adhesion strength and work on flat specimens coated with non-stick material that are brought into contact with masses, foams or others, under conditions similar to those produced in the molds. to manufacture these products in the industry.

The preferred application of the present invention is intended for the field of food and more specifically in baking, and the industrial field of the manufacture of polyurethane foams and their different production lines.

STATE OF THE TECHNIQUE

The problem solved by the present invention is related to the development of a machine or device that focuses on replicating the formation of solid or liquid products, among others, and pouring them into a closed container on which simulates the conditions of expansion, curing or baking of these products and, in this way, assess the adhesion of these doughs, foams, liquids, or others, to the non-stick or non-stick coatings of some specimens, usually flat, housed inside these molds. The specimens are designed and housed in a strategic way to be able to be extracted or taken off and to be able to assess the strength and take-off work. The machine allows this process to be cyclically reiterated and in this way to study the influence of wear, aging, friction, etc., due to the takeoff effect and the physical effects of the solid-coating interaction. Additionally, the force and take-off work is measured through a dynamometric equipment external to the set.

Non-stick coatings like any other coating have a shelf life. They wear out over time due to friction and fatigue to which they are subjected. The main objective of the present invention is to design a machine that allows to determine the loss of properties due to the repeated use of the effects of solids that are then transformed into foamed materials, masses, liquids or others, used on surfaces equipped with a nonstick . Therefore, it is a question of establishing stable test conditions that allow us to assess the influence of the aging of the coatings due to the successive interaction between the solid (masses, foams) or liquid and the coating, after successive cycles of application and take off. The designed equipment allows to study the influence due only to the foaming phenomenon, baked, cured that causes a certain level of adhesion between the solid and the coated surface.

For its industrial interest, two particular applications are described: the adhesion of polyurethane foam (PUR) and the adhesion of baking dough to non-stick coatings.

On the one hand, polyurethane foam (PUR) is a synthetic and hard-plastic material, highly crosslinked and non-fusible, and the industrial production of this type of foams covers a wide range of applications that are part of our life. Its use extends to all types of furniture in seats of sofas and chairs, padding padding, in automotive as the main element of dashboards, seats, in cars, mattresses and in many other items such as toys, clothing, sponges, footwear, pillows, cushions, containers and in general all types of padding or fillings. The objective, among others, of the proposed invention is to assess the efficiency of all types of coatings applied to aluminum molds with or without release agent for the release of PUR foams and / or any type of foam that has a tendency to stick to the walls of a mold. In parallel, it can also be used to assess the efficiency of release agents in the release of polyurethane foam. The equipment allows to discriminate the efficiency of the non-stick coatings from the point of view of the demolding of PUR foams.

On the other hand, the bakery industry develops all kinds of supports, trays, molds, pieces, and others, which are designed to prevent the baked dough from adhering to the metal substrates in the baking process. With this objective, coatings that prevent the adhesion of these masses to the substrates have been developed since the 1950s. Fluoropolymeric coatings, of the sol-gel type and some elastomers have been developed for this. These coatings are known as nonstick coatings. Well, in the same way that the utility of the invention for PUR foams has been described, a similar procedure is followed for use in bakery doughs. With the present invention, the real situation is simulated which allows the pressure and take-off work of all types of bread doughs poured on a mold and on which its cooking will take place and, therefore, that adheres to the specimens contained in the.

Likewise, with the present machine, a situation is simulated in which the adhesion to non-stick coated substrates for any type of solid or liquid with a tendency to adhesion that can be contained in a closed mold can be evaluated. It is known that in this industrial sector paint adhesion tests or coatings are applied on the substrates. Among the adhesion tests to the substrate are the lattice cutting tests, such as those described in UNE EN ISO 2409, ASTM D3359 and DIN 53151, which are test methods to assess the resistance offered by paint coatings to be separated from their substrates when a square network of incisions is made in the coating so that it reaches the substrate. The rules establish the procedure to make the incisions and the evaluation of the results. Other standards with similar objectives such as ASTM D2197 propose a method that, using a punch of known hardness and geometry, assess the effort required to produce a breakage of the coating. What is intended to regulate with said regulations is a very different objective from the one proposed in the present invention, given that by means of the machine object of the present invention, measurements are proposed in order to assess the adhesion of the product to the coating and not to the substrate.

Norms are also known for assessing the tensile strength of a metal specimen which, by means of an adhesive, is anchored to the coated substrate, for example, ASTM D 4541 or ISO 4624 standards. The test principle consists in adhering a traction or traction head to the coating to be tested, with an adhesive of adequate quality. Once the test area is isolated from the rest, by means of a blade, the sufferer is pulled perpendicular to the surface to be tested and the result of the adhesive force is obtained.

On the other hand, the capacity or non-stick property of coatings or coatings could be another way of assessing the adhesion of an organic coating. The problem is that this property, the non-stick, is not a property clearly established and difficult to quantify numerically. Different approaches have been developed to address an approach tailored to it. Among them is the patent ES2565566 which discloses a procedure and a device for obtaining useful data to quantitatively determine the non-stick capacity but which does not determine the adhesion force of the product on the coating, and the device differs totally from that set forth herein. The invention is based on a structure comprising a motor that connected to a shaft rotate the surface where the tests are performed.

It is also known what is disclosed in document US5041304 which describes the means necessary to calculate the non-stick capacity of a material, and which is based on analyzing the relationship between the angle of inclination and the non-stick capacity of a material covered by three materials. different nonstick. Finally, it is also known what is disclosed in document US4970893 where apparatus is described for measuring the non-stick capacity of a liquid that is based on the measurement of the angle of inclination of a drop of water that is positioned in a horizontal plane that rotates on a axis until the drop begins to slide The rotation is activated by a motor and the angle is measured by a counter that is not an inclinometer.

Taking these aspects into account, it can be observed that the problem of determining the adhesion in a product is something that is not solved, and additionally, a machine, system or device that manages to simulate the conditions to determine such adhesion either. The present invention solves this problem, and proposes a machine with which it is possible to solve the technical problem of simulating the real situation of a product to determine the adhesion on non-stick surfaces.

DESCRIPTION OF THE INVENTION

The present invention proposes a machine with which the adhesion force and the work on flat specimens coated with non-stick material that are put in contact with masses or foams can be measured, in conditions similar to those produced in the molds to manufacture these Products in the industry.

As previously advanced, there is no known document in the prior art that describes equipment or systems for measuring the strength or adhesion work of solids forming foams, doughs, pastes or gels, etc. However, and due to the need to evaluate the efficiency of non-stick coatings subjected to continuous cycles of use, the present invention is proposed with which it is possible to evaluate the efficiency of the coatings, in this case through force and take-off work necessary for the coated specimens to be separated from the masses or foams, which are produced inside the mold. Thus, the present invention proposes a novel and effective way of simulating the conditions necessary to analyze the take-off efficiency of a non-stick coating.

The machine consists of a mold or container with a rectangular prism shape, comprising a frame with three removable covers, one for the upper face, another for the lower face or base and another intermediate lid. In the intermediate cover, openings are enabled as windows to accommodate one or several flat plate specimens, one specimen for each opening. These specimens have a face coated with a non-stick coating. The intermediate lid fits the container frame in such a way that the Coated part is exposed by the inner part of the container. The intermediate cover is sealed with the specimens by screwing with the upper cover. A product is poured into the mold. Then the container is closed by the bottom lid. The closure of the assembly ensures the tightness of the mold. The product poured inside the machine case is in contact with the flat sheets coated with non-stick. The product is cured in the box or internal part of the machine. The machine is opened by the top cover and with a dynamometer the force and work to detach the non-stick coated plate specimens in contact with the product from the mold is determined.

Throughout the description and the claims the word "comprises" and its variants are not intended to exclude other technical characteristics, additives, components or steps. For those skilled in the art, other objects, advantages and features of the invention will be derived partly from the description and partly from the practice of the invention. The following examples and drawings are provided by way of illustration, and are not intended to be limiting of the present invention. In addition, the present invention covers all possible combinations of particular and preferred embodiments indicated herein.

For example, the present invention has the ability to regulate the temperature inside the mold. For this, electrical resistors are fixed to the frame walls by means of screws. The mold temperature is governed by a thermocouple connected to a temperature controller. The thermocouple is preferably fixed in the center of one of the device covers. The controller activates the operation of the resistors until the target temperature is reached. The activation of the electrical resistors can be arranged before or during the process of generating the foam or mass inside the mold.

Also, the present invention can generate a pressure inside the mold. Now in addition to the outer covers and the intermediate cover, there is a floating intermediate cover that can be moved vertically and resting on the inner walls of the mold frame, so that the tightness of the area under pressure is ensured . This floating cover performs the thrust effect on the foam or mass that is in the molding, for which there is a pressure regulating valve and a pressure gauge that allows to regulate the pressure between the lower closing lid and the floating lid.

Additionally, in order to complete the description and to help a better understanding of the features of the invention, a set of figures is presented, where the following is illustrated and not limited to: Figure 1 shows an exploded view of the machine object of the present invention, where the essential components of said machine are shown.

Figure 2 shows a free perspective view of the mounted machine, in which the upper cover is uncovered and the specimens are not located and fixed in the intermediate cover.

Figure 3.- shows the machine assembly, according to the previous figures, in which the machine is completely closed.

Figure 4 schematically shows a sequence of use of the machine to measure the force and take-off work on the specimens.

Figure 5.- shows an exploded view of the machine including an electrical resistance system with regulation and temperature control inside the mold.

Figure 6 shows a free perspective view of the machine with the electrical resistance system, according to the previous figure.

Figure 7.- shows an exploded view of the machine including a system to exert a pressure inside the mold, with the regulating devices.

Figure 8 shows a free perspective view of the machine with the system to exert pressure inside the mold, according to the previous figure.

DETAILED DESCRIPTION OF THE MODES OF EMBODIMENT

The present invention proposes a machine, as can be seen in Figure 1, comprising a frame (4), as a closed rectangular prism, and at least three covers, an upper cover (1) and a lower cover (2) , which perform the upper and lower closure of the frame (4), and an intermediate cover (3) configured to accommodate a plurality of specimens (1 1) with non-stick coating, the specimens being the ones to be subjected to the tests according to It is the object of the present invention.

As can be seen in these figures, the central body of the machine is formed by a frame (4) which in a particular manufacturing mode has a rectangular prism shape and has been manufactured by the screwed connection of four aluminum laminated plates. In the upper and lower surface of the frame, a recess has been carried out in such a way that it allows for the proper adjustment of the upper (1) and lower (2) closing caps, thereby achieving a tight seal thereof. Additionally, the frame has a step (5) on which the intermediate cover (3) rests. Also, as can be seen in these figures, on the horizontal surface of the step (5), threaded holes have been made that allow to accommodate headless screws (6) for alien wrench and threaded holes (7) that allow fixing by means of screws (8) the intermediate cover (3) of the assembly. The upper cover (1) and lower cover (2) are fixed to the frame (4) by means of headless screws (6) that are through to the intermediate cover (3), and by means of those headless screws (6) the lower cover (2) and upper cover

(I) together with nuts (9) allow the closing of the upper (1) and lower (2) covers on the frame (4). In a preferred embodiment of the invention, as can be seen in Figure 1, the preferred number of headless screws (6) is six, and the threaded holes (7) are six.

Figure 2 shows the partially assembled machine. Flat specimens

(I I) covered are positioned in openings or windows (10) made in the intermediate cover (3). These flat specimens (1 1) have a non-stick coated face, this face is exposed to the product that is inserted into the machine. These windows (10) have been machined generating a seat (100) on the intermediate cover (3) to allow the specimens (1 1) to be accommodated and fit them, so they have this seat (100) that allows to fit the specimens (11) coated. The height of the seat (100) is slightly less than the thickness of the plate of the test piece (1 1) and, therefore, it protrudes slightly over the intermediate cover (3) and thus is in turn fixed by the upper cover (1) by way of closure. In one embodiment of the invention, the number of windows (10) is four.

In figure 3 you can see the assembly completely closed and assembled. In a preferred embodiment of the invention, the machine for measuring force and take-off work of the flat specimens (1 1) with non-stick coating consisting of a series of elements comprising a beater (4), a lower cover (2), an upper cover 1) and an intermediate cover (3) with windows (10) on which the specimens (1 1) with their non-stick coated plates will be arranged.

The purpose of the device is to simulate the conditions of foaming, baking dough or any type of product that generates high adhesion in the mold that forms it. For this, the product is manufactured externally and poured into the internal area of the machine closed with a lid, preferably the upper one (1). Therefore, the frame (4) is initially available with the intermediate cover (3) and upper cover (1) mounted and with the specimens (1 1) housed in the intermediate cover (3). The product is then poured inside the machine. Immediately after the closure of the bottom cover (2).

Once the assembly is closed, the specimens (1 1) housed in the windows (10) of the intermediate cover (3) are exposed to the product that has been introduced into the machine. Once the product has been expanded or cured and after a set time has elapsed, the upper lid is opened (1). By means of a suitable device, the assembly is moved to a device equipped with a dynamometric head that determines the strength and work of take-off of the flat sheet specimens (1 1) covered with non-sticks arranged in the machine.

The sequence of work on the device is shown in the scheme in Figure 4. The sequence can be described in the following stages:

I) open and disassembled machine;

II) positioning of the intermediate cover (3) in the frame (4) and placement of the specimens (1 1), which in this case of a preferred embodiment are four;

III) closing of the top cover (1) of the machine;

IV) inversion of machine position and product discharge;

V) closing the lower cover (2) and waiting for the expansion and curing time;

VI) new inversion and opening of the upper cover (1) of the assembly and carrying out the test of take-off of the specimens (1 1).

In a specific embodiment, according to figures 1-4, the machine for measuring the force and take-off work is formed by a frame (4), constructed with 4 aluminum plates of the 5000 series from 10 to 20 mm thick by a height between 80 to 150 mm. The outer dimensions of the frame (4) are from 200 to 450 mm, both in length and width. On the frame (4) an intermediate cover (3) is fixed in which four windows (10) of 40x40 to 80x80 mm are practiced and which has a recess to accommodate coated specimens (1 1). The intermediate cover (3) with windows is made of 5000 series aluminum and has a thickness between 4 to 8 mm and dimensions between 190 to 440 mm. In this cover 6 6 8 mm through holes and 6 M6 threaded holes are practiced to be fixed to the frame. Similarly, both the upper cover (1) and the lower plate (2) are made of 5000 series aluminum and have a thickness between 4 to 8 mm and dimensions between 190 to 440 mm. In these covers there are 6 M6 threaded holes to fix the aforementioned plates to the frame (4) of the machine.

Figures 5 and 6 show another embodiment of the invention, comprising all previous elements, and where additionally it has the possibility of regulating the temperature inside the mold. For this, the machine additionally comprises a plurality of electrical resistors (12), preferably prismatic, fixed to the walls of the frame (4) by screws, joining together by means of fixing elements (120) such as clamps or clamps . The mold temperature is governed by a thermocouple (13) connected to a temperature controller (14). The thermocouple (13) is fixed in a through coupling (201) made in a central point of the lower cover (2), in which the through coupling is closed when it is free, and which is enabled to allow the thermocouple to fit ( 13). The temperature controller (14) activates the operation of the resistors (12) until the target temperature is reached. The activation of the electric resistors (12) can be organized before or during the process of generating the foam or mass inside the machine as required for each test.

Figures 7 and 8 show another embodiment of the invention in which it is allowed to generate a pressure inside the mold. In this embodiment, in addition to the lower closing cover (2) with the through coupling (201), there is a floating cover (15) located between the lower cover (2) and the intermediate cover (3). This floating cover (15) travels through the walls of the frame (4) of the mold, and is designed in such a way that it ensures the tightness of the area under pressure. This floating cover (15) performs the thrust effect on the foam or mass that is in the molding. The lower closing cover (2) is connected by means of the through coupling (201) to a pressure generating device (16) comprising a pressure regulating valve and a pressure gauge that allows to regulate the pressure between the lower cover (2) closure and floating cover (15).

Claims

1. Machine for testing specimens whose surface has a non-stick coating, in which the machine comprises a frame (4) as a closed rectangular prism, an upper cover (1) and a lower cover (2) that perform the closure upper and lower of the frame (4), for which in the upper and lower of the frame (4) there is a recess in such a way that the upper (1) and lower (2) covers fit the contour of the frame (4); and characterized in that it also comprises an intermediate cover (3) that has at least one window (10) practiced in its body and configured to house a flat sheet metal specimens (11) with non-stick coating; where the frame (4) internally has a step (5) on which the intermediate cover (3) rests; where on the horizontal surface of the step (5) a plurality of threaded holes (7) are made that allow to accommodate headless screws (6) which, through the intermediate cover (3), fix the upper cover (1) and the cover lower (2) to the frame (4), and where the threaded holes (7) allow fixing the intermediate cover (3) to the step (5) by means of screws (8).

2. Machine for testing specimens whose surface has a non-stick coating according to claim 1, characterized in that the intermediate lid (3) with the specimens (11) is sealed with the upper lid (1) by screwing (9). ).

3. Machine for testing specimens whose surface has a non-stick coating according to claim 1, characterized in that the windows (10) of the intermediate cover (3) are machined generating a seat (100) in which they are housed and adjust the specimens (11).

4. Machine for testing specimens whose surface has a non-stick coating according to claim 3, characterized in that the height of the seat (100) is less than the thickness of the plate of the specimen (11).

5. Machine for testing specimens whose surface has a non-stick coating according to claim 1, characterized in that it comprises a plurality of electrical resistors (12) fixed to the walls of the frame (4) by screws, joining together by means of fixing elements (120), and which are connected to a temperature controller (14).

6. Machine for testing specimens whose surface has a non-stick coating according to claim 1, characterized in that a through-coupling (201) is provided at a central point of the lower cover (2).

7. Machine for testing specimens whose surface has a non-stick coating according to claims 1, 5 and 6, characterized in that it comprises a thermocouple (13) that is fixed to the lower cover (2) by means of the through coupling (201) and in turn connects to a temperature controller (14).

8. Machine for testing specimens whose surface has a non-stick coating according to claims 1 and 6, characterized in that it internally has a floating lid (15) located between the lower lid (2) and the intermediate lid (3 ), and where a pressure generating device (16) is connected between the lower cover (2) and the floating cover (15) in the lower cover (2).

9. Machine for testing specimens whose surface has a non-stick coating according to claims 8, characterized in that the pressure generating device (16) comprises a pressure regulating valve and a pressure gauge.