Apparatus and method for coating elongated strip articles

• US 4,675,230 A
• Filed: 11/12/1985
• Issued: 06/23/1987
• Est. Priority Date: 11/12/1985
• Status: Expired due to Term

• Current Assignee: Alcan Incorporated (Rio Tinto Limited)
• Original Assignee: Alcan Incorporated (Rio Tinto Limited)
• Inventors: Innes, Robert A.
• Primary Examiner(s): Lusignan, Michael R.
• Application Number:
  US06/796,920
• Time in Patent Office: 588 Days
• Field of Search: 118/411, 118/419, 118/107, 118/416, 427/286, 427/280, 427/369, 427/355
• US Class Current: 427/280
• CPC Class Codes: B05C 5/0254 Coating heads with slot-shaped outlet B05C5/0283 takes precedence
• CPC Class Codes: B05C 5/0295 Floating coating heads or nozzles
• CPC Class Codes: B05D 1/26 performed by applying the liquid or other fluent material from an outlet device in contact with, or almost in contact with, the surface

Abstract

Apparatus and procedure for applying a paint or like coating to an elongated strip article using a coating head having an open-sided slot to which coating material is supplied under pressure, and a support such as a roll around which the strip is advanced past the head for receiving from the slot a layer of paint metered between the head and the strip, wherein a load is continuously exerted on the head during operation for urging the head against the applied paint layer on the strip so as to maintain a uniform metering gap between the head and the coated strip surface. The load may be exerted by devices such as air cylinders acting on the head and capable of adjustment to vary the magnitude of the load for different coating operations.

Claims

1. Apparatus for coating a major surface of an elongated strip article, comprising:

(a) a rigid coating head defining an elongated, open-sided slot and having an extended surface immediately adjacent the open side of the slot;

(b) means for supplying liquid coating material under pressure to the slot;

(c) means for supporting the head while permitting translational movement of the head relative to the supporting means in a direction perpendicular to the long dimension of the slot;

(d) means for continuously longitudinally advancing a strip article successively past the slot open side and the extended surface of the head in a direction transverse to the long dimension of the slot while maintaining a major surface of the article in facing proximate relation to the slot so as to constitute a moving wall substantially closing said open side, such that during operation with the article advancing past the slot and liquid coating material supplied to the slot, the last-mentioned article major surface drags a layer of the coating material from the slot, said advancing means supporting the strip, opposite the slot, at a fixed distance from the head-supporting means; and

(e) mean, acting between the head-supporting means and the head, for continuously exerting a load on the head to urge the head toward the last-mentioned article major surface such that, during operation as aforesaid, said head is pressed by said load-exerting means against the deposited layer of coating material to maintain said layer at a predetermined constant thickness while said layer alone holds the head entirely away from contact with the last-mentioned article major surface.

2. Apparatus as defined in claim 1, wherein said load-exerting means is adjustable to vary the magnitude of said load.

3. Apparatus as defined in claim 1, wherein said load-exerting means comprises at least one air cylinder.

4. Apparatus as defined in claim 3, wherein said load-exerting means comprises a plurality of air cylinders acting on said head at spaced locations along the length of the slot.

5. Apparatus as defined in claim 1, wherein said advancing means includes a roll having an axis parallel to the long dimension of the slot and fixed in relation to the head-supporting means, said roll further having a cylindrical surface positioned closely adjacent the slot open side;

and wherein said extended surface of said head is shaped and positioned to approach progressively nearer to said cylindrical surface in the direction of advance of the article.

6. Apparatus as defined in claim 5, wherein said extended surface has an upstream extremity at said slot, and a downstream extremity which is between 5 and 150 microns closer to said roll surface than is said upstream extremity.

7. A method of coating a major surface of an elongated strip article, comprising:

(a) supplying liquid coating material under pressure to an elongated, open-sided slot defined in a rigid coating head having an extended surface immediately adjacent the open side of the slot, said head being supported for translational movement in a direction perpendicular to the long dimension of the slot, while

(b) continuously longitudinally advancing a strip article successively past the slot open side and the extended surface of the head in a direction transverse to the long dimension of the slot with a major surface of the article maintained in facing proximate relation to the slot so as to constitute a moving wall substantially closing said open side, such that the last-mentioned article major surface drags a layer of the coating material from the slot, and while

(c) continuously exerting a load on the head to urge the head toward the last-mentioned article major surface such that the head is pressed by the load-exerting means against the deposited layer of coating material and maintains said layer at a predetermined constant thickness while said layer alone holds the head entirely away from contact with the last-mentioned article major surface.