DE3347600A1 - Preparatory treatment electrode - Google Patents

Abstract

As part of a corona preparatory treatment station which is used for the preparatory surface treatment of plastic films in order to increase the surface adhesion capability. The electrode consists of individual, non-insulated elements which have a capacitive connection to the voltage source so that a stabilised electric discharge is possible without insulation of the opposite electrode, for example a drum-type electrode.

Description

TITLE: PRE-TREATMENT ELECTRODE APPLICATION: For electrical Corona pre-treatment devices and systems for the surface treatment of plastic, paper and other foils.

PURPOSE Granting or increasing the surface adhesion STAND OF TECHNOLOGY Known @ I exist in the case of film pretreatment stations between the opposing rollers and electrodes are evenly spaced. space from approx. 2 mm (Fig 1).

An alternating voltage is applied to these two electrodes and of such magnitude that there is an electrical discharge in the space comes. In order for a stabilized discharge to occur, one of the two electrodes be isolated.

Appropriately, one of the electrodes is a roller (Fig. @ P1) the other a metal rod (Fig. @ The film runs over the roller (Fig. @ P3) so that it passes through the stabilized electrical discharge is pretreated on that side of the film, facing the metal (Fig. @ P2).

REFERENCES: P 17 65 369.9 REVIEW: If the roller is insulated, then comes Damage often leads to breakdown of the insulation. This causes the stabilized one to fall Discharge from or is concentrated selectively at these damaged areas is also the case when the metal rod is isolle and the folic is over the uninsulated Roll läu @@ An even greater disadvantage is that the pretreatment effect is essential is smaller if the electrical discharge is from an insulator instead of a metal.

TASK: To give a pretreatment electrode, which the criticized Does not have disadvantages, which is structurally simpler and therefore still considerable Shows advantages over the known electrodes described above.

SOLUTION Fig. 2 shows such a VBH electrode in section.

Fig.3 shows it in front view.

The film (Fig 2 + 3 P1) runs over a roller (Fig 2 + i) parallel to the A metal electrode stands at a distance of approx. 2 mm above the film on the roller axis. consisting of several elements placed next to each other (Fig. 2 + 3 P3).

These elements are electrically isolated from each other and have a capacitive connection (Fig. 2 + 3 P4) to the PLUS pole of the high voltage source (Fig. 2 + 3 P5).

The MINUS pole of the high voltage source is connected to the roller (Fig. 2 + 3 P6).

When the high voltage is applied to both electrodes it happens to a discharge between the elements (Fig.2 + 3 P3) and the roller (Fig.2 + 3 P2).

Where the film runs, under the elements, there is a stabilized one Discharge. A concentrated discharge takes place at the points where no film is running, which has only a limited power consumption depending on its capacity, so that a short circuit in the high voltage is excluded and the others standing above the film Elements can function undisturbed. The capacities (Fig. 2 + 3 P4) are dimensioned in such a way that that a pretreatment is sufficient and, on the other hand, only small currents flow so that the elements can be touched safely.

If the individual elements of the metal electrode are removed, it remains At this point, the discharge is off, creating the possibility for partial pretreatment given is.

For such an arrangement one needs a voltage lower Order of magnitude as described in Fig. 1.

In addition, the VßH effect is much better with the same performance, because the discharge takes place directly between two uninsulated electrodes.

Claims (1)

CLAIM 1) Pretreatment Elsktrode (Fig. 2 + 3) consisting of one uninsulated metal roller (Fig. 2 + 3 P2) and an opposite uninsulated one Metal electrode made of individual uninsulated elements (Fig. 2 + 3 P3). CLAIM 2) VBH electrode according to claim 1) characterized by, that the individual uninsulated metal elements (Fig.2 + 3 P3) are each capacitive (Fig. 2 + 3 are electrically coupled to the high voltage source P4). (Fig. 2 + 3 P5) CLAIM 3) VBH electrode according to claim 1 + 2 characterized in that the kapatitivc Connection between the elements and the high voltage source only of this size is that small currents do not pose a risk to the operating personnel when touched. Thus, this arrangement is TOUCHPROOF. CLAIM 4) VBH electrode according to claim 1, 2, 3 characterized by that the individual elements can be removed for the establishment of a partial Pretreatment.