JPH0283167A - Removing method for coating film of used aluminum can - Google Patents

Abstract

PURPOSE:To almost completely remove the metal contained in a paint as well by removing a coating film with its errosion by projecting and colliding a metal grain with an aluminum small piece. CONSTITUTION:A used aluminum can is made in small pieces by cutting it in 5-40mm and the metal again in 0.2-0.8mm grain size is projected at >=55m/sec projection speed with stirring the adequate quantity of the small pieces. Thus, the coating film printed on the small piece surface is removed with errosion. As a result, the metal contained in the paint can be removed almost completely as well, defective aluminum cans can drastically be reduced and also the paint removal can be performed in a short time.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a method for removing a coating film printed on the surface of a used aluminum can for juice or beer.

(Prior art and problems) Generally, the paint printed on the surface of aluminum juice or beer cans contains some metals, and if the paint is melted and recycled, metals and metals may be mixed in as impurities. , there is a problem that the mechanical properties are deteriorated and the elongation of the material disappears, making it difficult to draw.

For this reason, conventional methods have been to break aluminum cans into small pieces, apply heat to the pieces to burn off the printed coating, and then stir and rub the pieces together to remove the coating. However, the special metals contained in the paint cannot be completely removed even by baking, and there is a problem in that the cans cannot be squeezed out when recycled, resulting in defective recycled cans.

Another problem was that it took a long time to stir and remove the coating after baking the aluminum pieces.

(Objective) In view of the above circumstances, the present invention was completed with the aim of providing a method for reliably and efficiently removing a coating film printed on the surface of an aluminum can.

(Means for Solving the Problems) The present invention involves cutting a used aluminum can into small pieces with a diameter of 5 to 40 mm, and stirring an appropriate amount of the small pieces to obtain particles with a particle size of 0.2 mm.
The method is characterized in that metal particles of ~0.8 mm are projected at a projection speed of 557 seconds or more, thereby removing the coating film printed on the surface of the small piece.

(Function) By adopting the solution described above, the present invention prevents the surface of small pieces of aluminum cans from being eroded by being exposed to high-speed projection of metal particles (for example, steel particles, zinc particles, aluminum particles) while being stirred. Then, the paint film is removed.

It should be noted that when the metal particles have a particle diameter of less than 0.2 mm, they scatter during projection due to their light weight, making high-speed projection difficult. It has also been found that when the metal particles have a particle size of 1.0 mm or more, the aluminum particles will bend when they collide with the aluminum particles, making it impossible to completely remove the paint film at deep positions.

(Example) Next, examples of the present invention will be shown.

Used aluminum cans are cut into pieces of 5 to 40m/■O, and about 15kg of small pieces are put into a stirring drum with a drum capacity of 0.08", and the stirring drum is slowly rotated to stir the small pieces of aluminum. Metal particles with a particle size of 0.2 to 0.811 are projected onto a small piece of aluminum using a rotating wheel at a speed of 45 to 6.
Table 1 shows the results of projection for 15 minutes at a speed of 51/sec and a projection amount of 100 kg/min.

In addition, the metal particles projected in this process and the pieces of the paint film removed are collected by falling through the pores drilled in the body of the stirring drum, and only the metal particles are separated for reuse. .

From the above results, metal particles with a particle size of 0.2 to 0.8 mm were projected onto a small piece of aluminum under stirring at a speed of 554 m/sec or higher, and the projected amount was 100 Kg/min. The coating film could be completely removed by spraying for a minute.

Incidentally, as a result of melting the aluminum pieces treated in Experiment N [L7 and examining the chemical components, it was found that although a trace amount of titanium was detected, the mechanical properties were hardly deteriorated.

Therefore, the speed at which the metal particles are projected toward the aluminum piece is 5
It turns out that it is better to set the speed to 5 m/sec or more.

In addition, another experiment revealed that the time required to completely remove the coating film varies depending on the size of the stirring drum, the amount of aluminum pieces thrown in, the amount of metal particles thrown, etc.

(Effects) As is clear from the above explanation, the present invention removes the paint film by projecting and colliding metal particles against small pieces of aluminum, and therefore almost completely removes the metal contained in the paint. This method has excellent effects such as significantly reducing the number of defects in recycled aluminum cans and removing paint in a short period of time.

Claims (1)

[Claims] A used aluminum can is cut into small pieces of 5 to 40 m/m□, and an appropriate amount of the small pieces is mixed with a particle size of 0.2 to 0.8.
A method for removing a coating film from a used aluminum can, which comprises projecting metal particles with a diameter of m/m at a projection speed of 55 m/sec or more, thereby removing a coating film printed on the surface of the small piece.