RU2802013C1 - Method for applying thermoplastic powder paint to metal workpieces - Google Patents

Abstract

FIELD: painting methods.

SUBSTANCE: painting metal parts. A method for applying thermoplastic powder paint to metal workpieces by dipping. The method includes placing the furnace 3 on the rail track 11, along which the frame 13 moves with the fluidization tank 1 with thermoplastic powder paint. The workpieces are installed on the traverses 12, placed on the external hooks 14 of the fluidization tank 1. The frame 13 with the fluidization tank 1 and the workpieces are moved along the rail track 11 to the center of the furnace window, after which the workpieces are lifted into the furnace 3 and the workpiece is preheated. The heated workpieces are lowered into the fluidization tank 1, into which compressed air is supplied. Powder paint particles come into contact with heated workpieces and stick to their surface. Then the workpieces are again lifted into furnace 3, where thermoplastic powder paint is baked, as a result of which it melts and spreads over the workpiece, forming a durable anti-corrosion coating. Traverses 12 with painted workpieces are lowered back onto the external hooks of the tank 14.

EFFECT: increasing the productivity and quality of painting works, reducing the loss of powder coating material.

3 cl, 4 dwg

Description

The field of technology to which the invention belongs .

The invention relates to the field of mechanical engineering, in particular to methods for applying thermoplastic powder paint to metal blanks by dipping, in which the blanks are preheated, lowered into a boiling fluidized bed, and the thermoplastic powder paint is baked.

The level of technology.

A method is known for applying thermoplastic powder paint to metal workpieces by dipping, in which the workpiece is preheated, lowered into a fluidized bed, and the thermoplastic powder paint is baked, see the description of the patent application for the invention US 20230013140, published on January 19, 2023. This method is the closest in technical essence and achieved technical result and is chosen as a prototype of the proposed invention as a method.

The main disadvantage of this method is the low productivity. Another disadvantage is that the equipment takes up a lot of space.

Disclosure of the invention.

The present invention mainly aims to provide a method of dip coating thermoplastic powder paint based on polyethylene on metal workpieces, which allows to increase productivity and quality in the process, as well as reduce the loss of material of the coating itself, which is the set object.

To achieve this goal,

• place the furnace above the rail track, along which the frame with the fluidization tank with thermoplastic powder paint can move,

• install the workpieces to be painted on the traverses, which are placed on the external hooks of the fluidization tank, which is mounted on the frame,

• move the specified frame with the fluidization tank and the workpieces along the rails until the traverse with the workpieces is exactly in the center of the furnace window,

• lift the traverse with blanks using a conveyor and place them in the furnace,

• carry out preliminary heating of blanks in the furnace and at the same time place the fluidization tank in the center of the furnace window, moving the frame along the rail track for this,

• heated workpieces are lowered by means of a conveyor into a fluidization tank with thermoplastic powder paint,

• compressed air is supplied to the thermoplastic powder paint, which is supplied from a centrifugal air pump through a membrane located in the bottom of the fluidization tank, as a result of which a boiling fluidized bed is formed, the particles of thermoplastic powder paint come into contact with heated workpieces and stick to their surface,

• remove dust from thermoplastic powder paint using a filter-absorber connected to the tank through a sleeve,

• billets with thermoplastic powder paint adhering to the metal of the billet are again lifted by a conveyor into the furnace, where the thermoplastic powder paint is baked, during which it melts and spreads over the billet and forms a durable anti-corrosion coating,

• position the frame with the fluidization tank in such a way that the traverse with painted blanks is lowered by means of a conveyor onto the external hooks of the fluidization tank, where it was originally located.

Thanks to these advantageous characteristics, it becomes possible that all processes for painting blanks are carried out in a vertical plane, which leads to a reduction in the time spent on a complete painting cycle. This improves the overall performance of the painting process.

There is a variant of the invention, in which, while the painted blanks are cooling down, on the other side of the fluidization tank frame, a new batch of blanks for painting is hung on the second traverse.

Thanks to these advantageous characteristics, it becomes possible to ensure the continuity of the painting process.

There is also such a variant of the invention, in which the pre-heating of the workpieces in the furnace is carried out in the time interval from 20 to 150 seconds and the temperature range from 250°C to 400°C

Thanks to these favorable characteristics, it becomes possible to specify the parameters for preheating the workpieces.

Brief description of the drawings.

Other distinctive features and advantages of the invention clearly follow from the description given below for illustration and not being restrictive, with reference to the accompanying drawings, in which (figures 1-4) shows a device that implements the method.

Figure 1 shows a front view of a painting device according to the invention,

Figure 2 shows a side view of a painting device according to the invention,

Figure 3 shows a top view of a painting device according to the invention,

Figure 4 shows an isometric view of a painting device according to the invention.

The device is an installation for painting metal products. The device is a semi-automatic line for applying thermoplastic powder paint based on polyethylene by dipping.

The figures indicate:

1 - fluidization tank

11 - rail track

12 - traverse

13 - frame

14 - tank hooks

2 - control cabinet

3 - polymerization oven

4 - conveyor

5 - filter absorber

Implementation of the invention.

The method of applying thermoplastic powder paint to metal workpieces can be implemented in this way.

Metal blanks (parts) are installed on the hooks 14 of one of the traverses 12 of the fluidization tank 1. The traverses 12 with the hooks 14 for the blanks are located at different ends of the frame 13. The fluidization tank 1 is also fixed on the frame 13. The frame 13 has a movement mechanism on the rail track 11. Not shown. Rail track 11 is attached directly to the floor.

After installing all the blanks on the traverse 12, the frame of the tank 13, together with the hung blanks, moves along the rail track 11 until the traverse 12 is exactly in the center of the furnace window 3. Then the furnace conveyor 4 picks up the traverse 12 with the blanks and lifts them into the furnace 3. Temperature The oven is adjustable from 250 to 400 degrees Celsius. Depending on the thickness of the metal and the air temperature in the furnace, the blanks are in the furnace from 20 to 150 seconds for preheating. During the heating of the blanks, the frame with the tank 1 is positioned by moving along the rail track 11 so that the fluidization tank 1 is in the center of the furnace window. Then the heated blanks are lowered with the help of a conveyor 4 into the fluidization tank 1 with powder paint.

Polymeric thermoplastic paint is located in the fluidization tank 1, which is a hopper with a special bottom. The very bottom of the tank 1 has an air-permeable membrane through which a stream of compressed air is supplied to the powder paint from a centrifugal air pump. The membrane passes air through itself and the powder is suspended in the air, while the powder itself boils and moves randomly. It is this method that allows powder paint to form the so-called fluidized (fluidized) layer.

Immersion of preheated workpieces for a short time in a fluidized layer of thermoplastic paint is carried out by lowering the traverse with a conveyor 4 equipped with a servo drive. Particles of polymer paint come into contact with heated workpieces and stick to its surface, i.e. the heat of the workpiece itself slightly melts the powder, but only in advance so that the powder adheres to the workpiece. To remove the resulting dust from powder paint, a filter-absorber 5 is connected to the tank 1 through a sleeve, equipped inside with cylindrical filters and an exhaust fan.

Next, the workpieces with powder adhering to the metal are again raised by conveyor 4 to furnace 3 where the thermoplastic powder is baked. The powder melts and spreads over the workpiece (polymerizes) and forms a durable anti-corrosion coating.

Control cabinet 2 has a program that allows you to position the frame of the tank 1 along the rails in automatic mode. The residence time of the blanks in the furnace 3, the speed of lifting and lowering the conveyor 4, the residence time of the blanks in the tank 1 with fluidized powder paint - all this is also set by the control program.

After baking the thermoplastic powder in the polymerization oven 3, the traverse 12 with the workpieces is again lowered onto the frame of the tank 13, while the frame must be positioned so that the lowered traverse 12 hits the hooks 14 on the edge of the frame 13, where it was originally located. Next, the frame with the traverse and painted blanks returns to its original position. While the painted workpieces are cooling down, on the other side of the frame of tank 1, a new batch of workpieces for painting is hung on the second traverse. The cooled blanks are removed from the traverse 12.

Paint cycle completed.

Industrial applicability.

The method of applying thermoplastic powder paint to metal blanks can be carried out by a specialist in practice and, when implemented, ensures the implementation of the stated purpose, which allows us to conclude that the invention meets the criterion of "industrial applicability".

In accordance with the proposed invention, a prototype installation was made to test the method of applying thermoplastic powder paint based on polyethylene to metal workpieces by dipping.

Installation tests have shown that the proposed method has a number of advantages:

1) painting and baking blocks are on top of each other.

2) Key painting operations occur in the vertical plane.

3) Reducing the occupied working area.

4) Reducing the time spent on the complete painting cycle.

5) Economical advantage due to fast transfer between painting and baking units.

6) The quality of painting products is increasing.

Thus, due to the fact that the blank baking chamber is located above the fluidization tank with powder paint, and the suspended blank is located in the center between them, so all cycles take place in a vertical plane, which saves time for moving blanks, and the stated technical result, namely: increase in productivity and quality in the process of work, as well as reduction in the loss of the material of the coating itself.

Claims (13)

1. A method for applying thermoplastic powder paint to metal blanks by dipping, in which the blanks are preheated, lowered into a boiling fluidized bed, and the thermoplastic powder paint is baked, characterized in that the furnace is located above the rail track, along which the frame with the fluidization tank with thermoplastic powder paint can move, install the workpieces to be painted on the traverses, which are placed on the external hooks of the fluidization tank, which is mounted on the frame, move the specified frame with the fluidization tank and with the workpieces along the rails until the traverse with the workpieces is exactly in the center of the furnace window, raise the traverse with blanks using a conveyor and place them in the oven, carry out pre-heating of the workpieces in the furnace and at the same time position the fluidization tank in the center of the furnace window, moving the frame along the rail track for this, heated blanks are lowered by means of a conveyor into a fluidization tank with thermoplastic powder paint, compressed air is supplied to the thermoplastic powder paint, which is supplied from a centrifugal air pump through a membrane located in the bottom of the fluidization tank, as a result of which a boiling fluidized bed is formed, the particles of thermoplastic powder paint come into contact with heated workpieces and stick to their surface, remove dust from thermoplastic powder paint using an absorbent filter connected to the tank through a sleeve, workpieces with thermoplastic powder paint adhering to the workpiece metal are again lifted into the furnace by means of a conveyor, where the thermoplastic powder paint is baked, during which it melts and spreads over the workpiece and forms a durable anti-corrosion coating, position the frame with the fluidization tank in such a way that the traverse with painted blanks is lowered by a conveyor onto the external hooks of the fluidization tank, where it was originally located. 2. The method according to claim 1, characterized in that, while the painted blanks are cooling, on the other side of the fluidization tank frame, a new batch of blanks for painting is hung on the second traverse. 3. The method according to claim 1, characterized in that pre-heating of the blanks in the furnace is carried out in the time interval from 20 to 150 seconds and in the temperature range from 250 to 400°C.