Method and device for spraying mixtures obtained from the reaction of polymer materials
AssigneeStemma Srl
InventorEttore Bordin
Life of this patent
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Abstract
The invention relates to a method and a device for producing a thin article or a thin coating on a previously manufactured solid body. At least two reactive polymer materials (A, B) are mixed together thoroughly and die resultant mixture (M) is discharged via a nozzle (216) in the form of a thin tube (250). This thin tube is pulverized or atomized by means of the introduction of a controlled flow of pressurized air with the result that die pulverized mixture (Z) may be sprayed onto an open mould (300) or onto a surface (350) or onto a previously manufactured solid body which is to be coated.
Claims6
Method for producing a thin article or a thin coating on a previously manufactured solid body, comprising the steps of:
- introducing at least two basic components (A, B) of reactive polymer materials in a fluid state into at least one chamber (212, 214;
- 215) provided inside a casing (210;
- 211) having a nozzle (216) at one end;
- obtaining a mixture (M) from the reaction of said basic components by means of a helical screw (218;
- 219) which is able to rotate about its axis (X) and to move linearly along it inside said casing (210;
- 211);
- discharging the mixture (M) through the nozzle (216),
- characterized in that
- in the zone of said chamber which is closer to the nozzle the mixture (M) is imparted the form of a thin tube (250);
- a controlled flow of pressurized air is introduced at the end of the nozzle (216) to obtain a pulverization or atomisation of said thin tube with the result that the mixture (M) can be sprayed;
- the pulverized mixture (Z) is sprayed onto an open mould (300) or a surface (350) or said solid body (400).
Spraying device comprising:
- a casing (210;
- 211) enclosing at least one chamber (212, 214;
- 215) having a nozzle (216) at one end,
- radial openings or channels (221, 223) for feeding reactive basic components (A, B) in a fluid state of a polymer mixture (M), said openings or channels being provided on the surface (213) of one chamber or of the chamber (212;
- 215), whereby the said basic components may contain additives depending on the application or use of the mixture,
- a mixing screw (218;
- 219) with a helical profile extending along the axis (X) of said at least one chamber,
- means (220, 222) for operating the mixing screw so as to cause it to rotate about said axis (X) and move linearly along it,
- characterized in that
- the end diameter of the mixing screw (218) in front of the nozzle (216) is the same as the diameter of the nozzle itself,
- a ring (240) comprising a free head (246) encircles with a calibrated radial clearance (242) the end portion of the casing (210, 211) and has a position adjustable along the axis of rotation (X) of the mixing screw (218;
- 219), the said ring being provided with openings (244) for introducing pressurized air onto the mixture (M) discharged by the nozzle (216) through a front clearance (245), also calibrated, so as to pulverize or atomize the mixture so that it can be sprayed.
Dependencies are inferred from the claim text.