Home Automatic Screen Changer Calculation: 1050cm² SK300 750cm² SK230XL 570cm² SK230 Types

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Production

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The representation on the side shows a principle sketch of the automatic screen changer. The extruder feeds the plastic melt through the filter zone, which is hermetic closed by two seal pistons. The contamination closes the screen area and effects an increase in pressure. When the adjusted pressure limit is reached, the valve closes the melt channel and both of the seal pistons open so that the screen belt can be moved along. During this time the extruder can operate continuously and the accumulator piston is pressed down. When there’s a new screen belt in the filter zone the seal pistons close and the filter zone is hermetic closed again. Now the valve opens and the accumulator piston slowly moves upwards and empties the accumulator. As soon as the accumulator piston has reached its uppermost position the screen changing procedure is completed.

 

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BritAS automatical screen-changer amortizes himself usually within one year.

"Melt filtration in the recycling of plastics"

The increasing competition for markets for recycled material commits the operators of processing equipments to reduce the production costs by simoultaneously improving their product quality. Within the bounds of a recycling line, the melt by filtration is one of the decisive factors for the later use of recycled material and the marketing success that goes along with it. Besides, it counts to minimize the frequently intense filtration costs.

For the recycling enterprise of today it counts to procure a leading role in the market in comparison with other competitors through advanced technologies. With the selectively suitable technologies a high stand of automation, low costs of operation, high availability in addition to an adequate performance are in the foreground.

Within the recycling of secondary plastics with a following regranulation, especially with the processing of mid to strong soiled synthetics, the significance of the melt filtration is growing. Thus, in the almost last separation step of the recycling process the quality of the recycled material influences decisively the area of use of the regranulated material as well as the obtention of the targeted market price.

The company Britas GmbH, resident in Hanau, is a manufacturer of an automatic screen changer system which, for several years now, is being successfully used in the melt filtration. The strength of this screen changer system lies in the filtration of mid to strong contaminated plastics, such as within the recycling of construction and agrarian films up to household plastics waste. Based on the existing high contents of different kinds of impurities, the special technoligical concept of this screen changing system simply is predestinated for such a use. The Britas system, based on the application of a fresh screen with each screening process, on one hand secures, that after each screen change the complete free filtration area is at disposal.

The practice has shown, that the filtrating area itself, with impurities such as aluminium, wood, adhesive labels, inorganic fibers, etc. cannot be restored through a cleaning of the means of screening so that an exchange will become necessary.

On the other hand, it is guaranteed, that in connection with a possible, extremely quick screen changing time of less than 2 minutes, the desired constant high throughput, also with short-time fitting increased impurity charges, can be reached at any time. Besides, the experience has shown, that with the use of the Britas screen changer with already existing systems a clear increase of the throughput was possible.

Fears in the company to calculate with higher screen costs have been unindorsed in practice. Clear advantages show up against it with the deucedly small material loss which occures during the discharge of impurities, since with the Britas system only the sticking impurities combined with plastic on the screen will be discharged. Just with regard to increasing disposal-costs of the residues this is surely a further positive aspect.

The showpiece of the equipment however, is its fully automatic function. Due to the free programmable control, the Britas screen changer operates practically without personnel. Depending on the soiling, only for the aprox. one times daily necessary change of the screen roll (aprox. 50m screen belt), just 10 minutes of "manpower" are estimated.

An additional online-service of Britas GmbH by a modem connection to the operator of the equipment enables a failure diagnosis as quick as lightning, so that a high availability can be guaranteed.