| 摘要 |
The web curtain coating system has a jet applicator (10) with a valve (20) in the jet chamber (16), which is opened against spring pressure. The jet chamber is divided into an ante-chamber (22) and a main chamber (24). The coating feed (18) opens into the ante-chamber, and the outflow opening (26) is at the end of the main chamber away from the valve. The web curtain coating applicator jet has an outlet opening formed by a valve, opened against spring pressure. The jet chamber valve body is formed by a spring leaf (28), preferably of stainless spring steel or a plastics with a reinforcement of glass or carbon fibers. The spring leaf has a thickness (d) of 0.2-30.0 mm and preferably 1.0 mm. The spring leaf projects over the edge (32) of the ante-chamber, with its free end (28b), by a length of 3-15 mm for the valve function. When the valve leaf is opened, it frees a gap (34) with a width (s) of 0.05-3.0 mm. An additional valve can be in the main chamber, to divide it into a pressure chamber and a dosing chamber. The pressure chamber is at the ante-chamber, while the outlet opening is at the end of the dosing chamber away from the valve. The dosing chamber has a flow length of 50-100 mm. The additional valve is a leaf spring, opened against the spring pressure, with the same dimensions and of the same materials as the main valve leaf spring. The additional valve can be a choke valve, with a profiled valve body as a rod with a rotary symmetrical axis or a profiled bar. The valve spring leaf extends as far as the outlet opening, so that the main or dosing chamber forms the curtain applicator only when the valve spring leaf is opened to lie against a wall of the applicator body. A setting unit acts on the valve spring leaf, on the side which is not in contact with the coating medium. The main or pressure chamber has an air bleed line (36). The outlet opening has a width of 0.2-4.0 mm.
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