SUMMARY

The design of a line in the form of “U”, for the production of rectangular bottoms, makes possible the placement of the packing point near the press warehouse. This leads to a reduction in labor, since the same person who feeds the press, can pack the funds. So with a single operator, you can work at rates higher than 250 tapas / mi ..

BACKGROUND

In a modern facility for the manufacture of funds, today it is possible to work using a series of automations and unions, so that practically no direct labor is needed from the “scroll” shear to the packing station, including the press and rest of equipment. However, the cost of this type of facility is high, and is only justified for high productions, such as round bottoms for preserves, or covers for beverage cans.

There is always a series of formats of reduced runs, as are usually certain rectangular containers, which by their volume of business does not justify a high investment. Thinking about them, some type of facilities for the manufacture of rectangular bottoms have been assembled for a long time, which we describe in this work.

DESCRIPTION OF THE “U” LINE

We start with an automatic press that works with simple die, fed by strips. This press must have a warehouse of strips of sufficient capacity, so that once the same loaded, the operator has a certain time of autonomy, to engage in the packing of the finished funds. Said press is equipped with a double disk crimper, which turns the curl of the larger sides of the bottom when passing through it.

Once crimped, the bottoms fall to an elevator formed with two augers or spindles – analogous to that used in the stackers of lids -. Towards the end of this elevator, the rear guide – on which the ends of the bottoms rest – is interrupted. Consequently, they fall through a guide of curved shape, depositing in a horizontal conveyor belt, located at low height and running under the press towards the front of it. From it, the caps are delivered to a magnetic lift that goes back to the storage of the gumming machine.

See figure # 1 to better understand the flow of the line.

Figure nº 1

On the elevator of augers, you can place a previous guide equipped with an electromagnet. If we want to derive curly funds and without gumming, it will be enough to activate the electromagnet manually and it will prevent the bottoms from falling on the curved guide, continuing its ascent by the augers, forming a pile at the elevator finar. It is necessary to place a pneumatic finger, which acts when the pile has a certain height, separating the bottoms of the augers, in order to eliminate friction that would damage the interior varnish of the same.

The gumming machine is usually the neck of the installation, limiting its speed to the rest of operations. The bottoms already gummed down by a fall of gravity towards the bottom of the drying oven. It is equipped with a pair of augers. Later we will describe the same

The already dried bottoms, at the exit of the furnace are pushed by the augers towards a magnetic pulley, which takes the same ones and drives them through guides, transporting them towards the packing station. The same operator of the press, returning periodically to the point of packaging, will perform the operation of packaging them, in rolls of paper or cardboard boxes. For which it will be necessary to have in this place the necessary means. It is not convenient to use plastic wrap, since it prevents the total elimination of residual moisture that keeps the rubber from the bottoms.

DESCRIPTION OF THE RUBBER DRYING OVEN

This furnace occupies little space on the floor and consists of the following parts:

–          Two spindles in parallel and inclined, that receive the bottoms from a fall by gravity, and raise them slowly throughout the furnace.

–          A chain that supports the funds. This chain is located parallel to the spindles and behind them. It moves at the same linear speed as the ascension of the funds transported by the spindles. Its function is to keep the same parallel to each other, in order to avoid jams in the augers, also allows a good circulation of hot air to keep the funds separated from each other.

–          A metal casing that wraps around the whole: spindles, chain, etc.

–          A heating equipment, comprising an approved gas burner and a fan. The latter to ensure the recirculation of part of the hot gases. The direction of recirculation of the hot gases is opposite to the elevation of the bottoms, that is, the hottest zone is the outlet.

See these details in figure # 2

Figure nº 2

The implementation of the U-line is also possible if you have a grommet equipped with a vertical furnace on the same bench. In this case, the required surface is smaller, although the overall vision for the operator of the installation is not as good.