IE20000042A1

IE20000042A1 - A method and system for painting

Info

Publication number: IE20000042A1
Application number: IE20000042A
Authority: IE
Inventors: Patrick Woods; James O'gorman
Original assignee: Nypro Res And Developments Ltd
Priority date: 1999-01-20
Filing date: 2000-01-20
Publication date: 2000-10-04
Also published as: IES20000043A2; IES20000044A2; GB2346098A; IES20000045A2; GB2346098B; IE990044A1; GB0001255D0

Abstract

A plurality of mobile telephone mouldings (21) are mounted to a frame (20) by releasable mounting clips (28). The frames (20) are releasably mounted to a trolley (3). The trolley (3) is used to deliver the frames (20) through an accessway to a treatment area (5) maintained under positive pressure to exclude contaminants. The frames (20) are removed from the trolley (3) and delivered to a pretreatment unit (6) in which the mouldings (21) are brushed with brushes (75), heated using infra red heaters (76) and high velocity de-ionised air is then applied through nozzles (77). The frames (20) of pretreated mouldings (20) are then delivered to spray paining booths (7,8,9). After painting, the mouldings (21) are cured and delivered from the treatment area (5) on a trolley (3).

Description

Introduction The invention relates to a method for spray painting a plurality of individual articles such as for painting housings for mobile telephones and the like. The invention also relates to a system for use in the method of the invention.

Spray painting of articles on an industrial scale is especially difficult because of the hazardous nature of the chemicals used and the consequent health and safety issues that arise. To overcome these difficulties enclosed spray booths are used. However, problems arise in preparing articles to be painted. These problems are especially difficult in the case of a plurality of relatively small articles to be painted.

There is therefore a need for a spray painting method and a system for use in the method which will alleviate at least some of these problems.

Statements of Invention According to the invention there is provided a method for spray painting a plurality of individual articles comprising the steps of:releasably mounting a number of articles to be spray painted on a frame; delivering the frame with the articles in position to a pre-treatment unit; pretreating the articles on the frame in the pre-treatment unit by;heating the articles on the frame; and Il JU rilgaWB. ; 1 WJMWAJJXAlMJ-UtMiarMWIMBFX'Wm. .'Ml OPEN TO PUBLIC INSPECTION INT CL7>3]^ · $/2 1$ζΧ> UNDER SECTION 28 AND RULE 23 IE 000042 NYFR04/C/IE -2 directing a stream of de-ionised air against the heated articles on the frame to remove contaminants, removing the frame with the pre-treated articles from the pre-treatment unit; mounting the frame with the pre-treated articles in position on a spray painting delivery system; spray painting the pre-treated articles on the frame; curing the spray painted articles on the frame; and removing the spray painted articles from the frame.

In one embodiment of the invention the articles are pre-treated by:brushing at least the major surfaces to the articles; heating the brushed articles, preferably by infra red heating; directing a stream of de-ionised air against the heated brushed articles; and drawing contaminants removed from the articles during pre-treatment away from the articles.

Preferably the removed contaminants are drawn away from the articles by an extraction process. Ideally the extraction process includes the steps of:drawing air containing contaminants through a filter; filtering the contaminants from the contaminated de-ionised air; and NYFR04/C/IE -3recycling the filtered air for direction of a stream of filtered air against following articles in the pre-treatment unit.

In a preferred embodiment wherein the method includes the steps of:mounting a plurality of frames, each containing a number of articles on a trolley; delivering the trolley to the pre-treatment unit; removing a frame containing a number of articles from the trolley; placing the removed frame on the pre-treatment unit; after pre-treatment, removing the frame containing a numbeT of pre-treated articles from the pre-treatment unit and mounting the frame on a trolley; removing a frame containing pre-treated articles to be painted from the trolley; placing the frame containing the pre-treated articles on a feed to a spray painting station; spray painting the articles on the frame; and placing the frame having the spray painted articles on a trolley.

Preferably the method includes the step of spray painting the articles with a number of coats of paint at a number of spray painting stations and mounting the frame containing the spray painted articles on a trolley to partially cure the painted articles between applied coats of paint.

IE 000042 NYFR04/C/IE -4In a preferred embodiment the method includes the steps of: mounting the articles to be treated on the frame at a preparation station; pre-treating the articles in a pre-treatment area in a positive pressure environment; and leading the articles to the pre-treatment area through a controlled accessway to maintain the positive pressure in the pre-treatment area.

In another aspect of the invention provides a system for painting articles by a method of the invention comprising: a plurality of frames, each for mounting a plurality of articles to be painted; a pre-treatment unit for pre-treating the articles on the frame, the pretreatment unit comprising:heating means for heating the articles on the frame; and an air system for directing a stream of air against the heated articles on the frame to remove contaminants; a spray painting booth for receiving a frame containing pre-treated articles for painting; and curing means for curing the spray painted articles.

Preferably the pre-treatment unit comprises:brush means for brushing at least the major surfaces of the articles; IE 000042 NYFRO4/C/IE -5heating means for heating the brushed articles; and an air system having means for directing a stream of air at the heated articles, suction means for drawing air containing contaminants removed from the articles to a filter which filters the air and an air recycle line for recycling filtered air to be applied to following heated articles.

In one embodiment the pre-treatment unit includes a conveyor on which a frame containing a plurality of articles to be pre-treated are hung for leading through the brush means, heating means, and the air stream.

Preferably the spray painting booth includes a robotic handler for receiving a frame of pre-treated articles, for directing the frame for painting of the articles, and for directing the frame containing the painted articles for removal.

Ideally the system includes a plurality of releasable mounting means for releasably mounting articles to be painted to the frame. Preferably the releasable mounting means comprises at least two portions, one portion for engaging a first article and a second for engaging a second article in spaced-apart relation to the first article.

In this case preferably the article to be painted is a mobile telephone moulding and the first portion of the mounting means engages a charger port of one moulding and the second portion of the mounting means engages an aerial part of an adjacent moulding.

In one embodiment the frame is generally rectilinear having a pair of side frame members interconnected by upper and lower frame members, the frame having a plurality of cross members extending between the side frame members, at least the cross frame members being adapted to receive a releasable mounting means. Preferably at least the cross frame members have mountings therein or thereon to receive the mounting means at predetermined desired locations on the frame.

IE 000042 NYPRO4/C/IE -6The invention also provides a system including a trolley for mounting a plurality of the frames. Preferably the trolley includes spacer means for maintaining the frames in spaced-apart relation to one another. Ideally the spacer means is movable from a release position for mounting and de-mounting the frames to and from the trolley to a locked position to maintain the mounted frames in spacedapart relation.

In a preferred embodiment the trolley includes a framework to receive a plurality of frames and the spacer means is mounted to and movable relative to the framework.

Preferably the trolley includes a wheeled chassis for movement of the trolley to and from the pre-treatment unit and to and from the painting booth.

In a preferred embodiment the system includes a loading area for loading frames containing articles to be painted, a pre-treatment area in which a pre-treatment unit is located, means for maintaining a positive pressure in the pre-treatment area and access means for controlled access between the preparation area and the pretreatment area to maintain the positive pressure in the pre-treatment area to exclude contaminants.

Brief Description of the Drawings The invention will be more clearly understood from the following description thereof given by way of example only, in which: Fig. 1 is a schematic view of a system for painting articles according to the invention; Fig. 2 is a perspective view of a mounting frame used in the system of the invention; IE 000042 NYFR04/C/IE -7Fig. 3 is a perspective view of a mounting detail of the frame; Fig. 4 is a cross sectional view of the mounting detail of the frame; Fig. 5 is a perspective view from the front of one portion of the mounting; Fig. 6 is a perspective view from the rear of the mounting portion of Fig. 5; Fig. 7 is a perspective view of another portion of the mounting; Fig. 8 is a perspective view of an article to be painted; Fig. 9 is an enlarged front view of a number of the articles mounted on a frame; Fig. 10 is a front view of a frame having a plurality of articles mounted thereto; Fig. 11 is a perspective view of a trolley for receiving a plurality of the frames; Fig. 12 is a front view of a detail of the trolley on an enlarged scale; Fig. 13 is a front view of the trolley with frames in position; Fig. 14 is a perspective view of a corner detail of the loaded trolley; Fig. 15 is a view of another detail of the trolley; Fig. 16 is a cross sectional view of a handle detail of the trolley; IE 000042 NYFR04/C/IE -8Fig. 17 is a perspective view of the handle of Fig. 16; Fig. 18 is a perspective view of a pretreatment unit used in the method and system of the invention; Fig. 19 is a side view of the unit of Fig. 18; and Fig 20 is a plan view of the unit of Fig. 18.

Detailed Description Referring to the drawings and initially to Fig. 1 there is illustrated a method and system for spray painting a plurality of individual articles such as mouldings for mobile phones. In the invention a plurality of articles are releasable mounted on support frames at loading stations 1,2. The frames with articles in place are then loaded onto a trolley 3 which is delivered through an accessway into a treatment area 5 which is maintained under positive pressure to exclude contaminants. A trolley 3 with the frames in place is then delivered to a pretreatment unit 6. The frames are unloaded, passed through the pretreatment unit 6 and, after pretreatment the frames with the pretreated articles are re-loaded unto a trolley 3. The trolleys 3 with the frames containing pretreated articles are then delivered to one of three spray painting booths 7, 8, 9. At each booth a frame is taken from a trolley 3 and mounted on a robotic handler which takes the frame into the booth for painting of the articles. In some cases the different booths 7, 8, 9 may be used to apply different coats of paint. For example, a primer coat may be applied in booths 7 or 9 and a finishing coat applied in booth 8. After painting, frames containing the painted articles are loaded onto a trolley 3 and delivered to a curing oven 10. After curing, the trolley 3 with frames containing the cured articles are delivered from the positive pressure sterile area 5 through an accessway. The frames containing the painted articles are removed from the trolley, and the painted articles are de-mounted from the frames, ready for assembly.

IE 000042 NYFRO4/C/IE -9Referring to Figs. 2 to 10 there is illustrated one frame 20 for mounting a plurality of articles, in this case mobile telephone mouldings 21, to be processed as described above. The frame 20 is of generally rectilinear shape having a pair of side frame members 22, 23 and a plurality of spaced-apart cross members 25 interconnecting the side members 22, 23. Each of the cross members 25 has a plurality of spaced-apart pre-drilled locating holes 27 to each of which a releasable mounting clip 28 is attached. The releasable mounting means is a plastics component having a pair of spaced-apart rearwardly projecting clip portions 29 which clip onto the cross member 25 as illustrated. A spud 30 of the mounting clip 28 engages in the locator hole 27, on mounting to the cross member 25. The releasable mounting clip 28 has two main engagement portions for engaging adjacent articles mounted to the frame. An upper engagement portion 32 of the mounting clip 28 is engagable in a battery charger port of the moulding 21 as illustrated in Fig. 9. A separate mounting pin 35 is retained by a curved holding arm 36 extending from the mounting clip 28. The pin 35 engages an aerial port 38 of an adjacent housing 21 as illustrated particularly in Fig. 9. Further removable clip portions 41, 42 hold two parts of the casing 21 together and cover parts which are note to be painted.

The frame 20 also includes two T-shaped lugs 47 for mounting to a trolley 3.

Referring now to Figs. 11 to 17 there is illustrated a trolley 3 which is used for releasably mounting the frames 20. The trolley 3 in this case has a chassis 50 with wheels 51 for ease of moving the trolley 3 as described above. The trolley 3 has an upper tier 52A for receiving an upper bank of frames 20 and a lower tier 52B for receiving a lower bank of frames 20. Each of the tiers 52A, 52B has two downwardly opening rails 54 for receiving the mounting lugs 47 of the frames 20. Each tier receives a plurality of rails 54 loaded with articles to be painted. Spacer means for retaining adjacent frames 20 in a tier in spaced-apart relation is in this case provided by spacers 60 which are hingedly mounted to the trolley frame for movement between a swung-in spacing configuration as illustrated in Fig. 14 to a swung out release position.

IE 000042 NYFRO4/C/IE - 10End retaining means for retaining the outermost frames 20 in position on the trolley 3 are provided by side arms 65 which are pivotally movable from the retaining position illustrated in Fig. 14 to a release position illustrated in Fig. 12. The free ends of the rails 34 are also closed by stops 67 which are pivotally movable from a release position shown in Figs. 11 and 12 to a locking position illustrated in Fig. 13.

Releasable handles 68 are used to lift the frame of wet painted components from the spray booth to the trolley. The handle 68 has clip portions 69 which releasably engage adjacent frame cross members 25 as illustrated in Fig. 16.

Referring to Figs. 18 to 20 there is illustrated a pretreatment or preparation unit 6 for pretreating the articles prior to painting. The unit 6 includes a base 70 with trolley wheels 71 and upstanding supports 72 which support an overhead conveyor 73 with hooks 74 on which frames 20 containing articles to be pretreated are hung. The pretreatment unit 6 has brushes 75 for initially cleaning the articles on the frame 20 followed by a heating means in the form of banks of infra red heaters 76 which heat the brushed articles. Nozzles 77 direct a high velocity stream of deionised air against the heated brushed articles to remove contaminants. The contaminants are drawn away from the unit 6 by a suction duct 78. The suction air containing the contaminants is drawn through a filter 79 in which the contaminants are filtered from the air and purified air is recycled by a pump 80 which directs a stream of the filtered air against a following frame having a plurality of brushed and heated articles. The brushes, heaters and nozzles may all be adjusted to accommodate various article and treatment conditions.

The invention provides an integrated system for highly efficient handling, pretreating and spray painting of a plurality of relatively small articles such as housings for mobile telephones.

Claims

1. A method for spray painting a plurality of individual articles comprising the steps of:releasably mounting a number of articles to be spray painted on a frame; delivering the frame with the articles in position to a pre-treatment unit; pretreating the articles on the frame in the pre-treatment unit by:heating the articles on the frame; and directing a stream of air against the heated articles on the frame to remove contaminants, removing the frame with the pre-treated articles from the pretreatment unit; mounting the frame with the pre-treated articles in position on a spray painting delivery system; spray painting the pre-treated articles on the frame; curing the spray painted articles on the frame; and removing the spray painted articles from the frame. IE 000042 NYPR04/C/IE - 13

2. A method as claimed in claim 1 wherein the articles are pre-treated by:brushing at least the major surfaces to the articles; heating the brushed articles; directing a stream of air against the heated brushed articles; and drawing contaminants removed from the articles during pretreatment away from the articles.

3. A method as claimed in claim 2 wherein the removed contaminants are drawn away from the articles by an extraction process.

4. A method as claimed in claim 3 wherein the extraction process includes the steps ofidrawing air containing contaminants through a filter; filtering the contaminants from the contaminated air; and recycling the filtered air for direction of a stream of filtered air against following articles in the pre-treatment unit.

5. A method as claimed in any preceding claim including the steps of:mounting a plurality of frames, each containing a number of articles on a trolley; delivering the trolley to the pre-treatment unit; removing a frame containing a number of articles from the trolley; IE 000042 NYFR04/C/IE -14placing the removed frame on the pre-treatment unit; after pre-treatment, removing the frame containing a number of pretreated articles from the pre-treatment unit and mounting the frame on a trolley; removing a frame containing pre-treated articles to be painted from the trolley; placing the frame containing the pre-treated articles on a feed to a spray painting station; spray painting the articles on the frame; and placing the frame having the spray painted articles on a trolley.

6. A method as claimed in claim 5 including the step of spray painting the articles with a number of coats of paint at a number of spray painting stations and mounting the frame containing the spray painted articles on a trolley to partially cure the painted articles between applied coats of paint.

7. A method as claimed in any preceding claim including the steps of: mounting the articles to be treated on the frame at a preparation station; pre-treating the articles in a pre-treatment area in a positive pressure environment; and IE 000042 NYPR04/C/IE -15leading the articles to the pre-treatment area through a controlled accessway to maintain the positive pressure in the pre-treatment area.

8. A method of painting a plurality of articles substantially as hereinbefore described with reference to the accompanying drawings.

9. A system for painting articles by a method as claimed in any preceding claim comprising: a plurality of frames, each for mounting a plurality of articles to be painted; a pre-treatment unit for pre-treating the articles on the frame, the pre-treatment unit comprising:heating means for heating the articles on the frame; and an air system for directing a stream of air against the heated articles on the frame to remove contaminants; a spray painting booth for receiving a frame containing pre-treated articles for painting; and curing means for curing the spray painted articles.

10. A system as claimed in claim 9 wherein the pre-treatment unit comprises:brush means for brushing at least the major surfaces of the articles; heating means for heating the brushed articles; IE 000042 NYFR04/C/IE - lean air system having means for directing a stream of air at the heated articles, suction means for drawing air containing contaminants removed from the articles to a filter which filters the air and an air recycle line for recycling filtered air to be applied to following heated articles.

11. A system as claimed in claim 10 wherein the pre-treatment unit includes a conveyor on which a frame containing a plurality of articles to be pretreated are hung for leading through the brush means, heating means, and the air stream.

12. A system as claimed in any of claims 9 to 11 wherein the spray painting booth includes a robotic handler for receiving a frame of pre-treated articles, for directing the frame for painting of the articles, and for directing the frame containing the painted articles for removal.

13. A system as claimed in any of claims 9 to 12 including a plurality of releasable mounting means for releasably mounting articles to be painted to the frame.

14. A system as claimed in claim 13 wherein the releasable mounting means comprises at least two portions, one portion for engaging a first article and a second for engaging a second article in spaced-apart relation to the first article.

15. A system as claimed in claim 14 wherein the article to be painted is a mobile telephone moulding and the first portion of the mounting means engages a charger port of one moulding and the second portion of the mounting means engages an aerial part of an adjacent moulding.

16. A system as claimed in claim 14 or 15 wherein the frame is generally rectilinear having a pair of side frame members interconnected by upper IE 000042 NYPRO4/C/IE - 17and lower frame members, the frame having a plurality of cross members extending between the side frame members, at least the cross frame members being adapted to receive a releasable mounting means.

17. A system as claimed in claim 16 wherein at least the cross frame members have mountings therein or thereon to receive the mounting means at predetermined desired locations on the frame.

18. A system as claimed in any of claims 9 to 17 including a trolley for mounting a plurality of the frames.

19. A system as claimed in claim 18 wherein the trolley includes spacer means for maintaining the frames in spaced-apart relation to one another.

20. A system as claimed in claim 19 wherein the spacer means is movable from a release position for mounting and de-mounting the frames to and from the trolley to a locked position to maintain the mounted frames in spaced-apart relation.

21. A system as claimed in claim 19 to 20 wherein the trolley includes a framework to receive a plurality of frames and the spacer means is mounted to and movable relative to the framework.

22. A system as claimed in any of claims 19 to 21 wherein the trolley includes a wheeled chassis for movement of the trolley to and from the pretreatment unit and to and from the painting booth,

23. A system as claimed in any of claims 9 to 22 including a loading area for loading frames containing articles to be painted, a pre-treatment area in which a pre-treatment unit is located, means for maintaining a positive pressure in the pre-treatment area and access means for controlled access IE 000042 NYPRO4/C/IE -18between the preparation area and the pre-treatment area to maintain the positive pressure in the pre-treatment area to exclude contaminants.

24. A system for painting articles substantially as hereinbefore described with 5 reference to the accompanying drawings.

25. Articles whenever painted by a method as claimed in any of claims 1 to 8 and/or using a system as claimed in any of claims 9 to 24.