Coating processes – Direct application of electrical – magnetic – wave – or... – Electrostatic charge – field – or force utilized
Patent
1999-03-08
2000-03-14
Parker, Fred J.
Coating processes
Direct application of electrical, magnetic, wave, or...
Electrostatic charge, field, or force utilized
427479, 427480, 427483, 427486, 118629, 118631, 118634, 361228, B05D 106, B05B 5025
Patent
active
060370122
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a process for applying water-based products, in particular water-based paints and/or varnishes, to the surface of glass articles. This process makes it possible to obtain various appearances such as an appearance of coloration in the bulk of the glass, a chemical satin-effect appearance or an enameled appearance. It is intended in particular for decorating jars, flasks, bottles or carafes of any type.
2. Discussion of the Related Art
The standard processes for applying varnish to glass articles consist in spraying the products onto their walls using a more or less complex array of pneumatic spray guns. However, the use of these processes involves many problems, and the results obtained are not satisfactory.
The deposition yields are generally less than 50%. These yields are proportionately lower the more complex the shape of the articles, this shape determining the number of spray guns required to obtain a homogeneous deposit on the surface of the articles. However, the larger the number of spray guns, the more complex it is to adjust the parameters relating to these spray guns in a manufacturing unit. In point of fact, these adjustments can last several hours, and it is necessary to remember not only the spatial position of each of the spray guns, but also their operating characteristics (air pressure for spraying, product pressure, nozzle diameter, horn pressure, type of cap, etc.) in order to ensure good reproducibility of the processes over time.
Despite the large number of spray guns which can be used and the tiresome adjustments which need to be carried out, the shape of certain articles is such that there are areas in which it is still difficult, or even impossible, for the sprayed product to reach.
Moreover, a homogeneous deposit of water-based paints and/or varnishes, containing very fine particles of resin in suspension in water, is particularly difficult to make. Water is in particular a solvent which is very difficult to spray, and pneumatic spray guns do not manage to disperse particles of homogeneous size. The particles ejected by the spray guns are, in point of fact, coarse in the axis of projection and increasingly fine on either side of this axis. This size disparity of the product particles has the consequence of giving rise to phenomena which interfere with the production of a high-quality deposit. Thus, the finest particles of varnish have a tendency to dry before reaching the glass substrate, or even of drying too quickly on this substrate, which gives rise to localized powdering, spattering and pitting effects on the surface of the treated articles. On the other hand, the coarsest particles of varnish are slow to dry after being sprayed on the surface of the articles, so much so that orange-peel effects, running and local excess thicknesses appear, which thus degrade the quality of the coating on the treated articles.
A first solution for overcoming all of these drawbacks consists in increasing the spraying air pressure excessively. However, this solution cannot be considered seriously since it does not allow the quality of the coating to be improved significantly and it also involves a considerable reduction in the spraying yield, which is, however, already very low.
OBJECTS AND SUMMARY OF THE INVENTION
The process according to the present invention makes it possible to solve all of these implementation problems and to obtain articles with a very high-quality coating. To do this, it includes: (i.e., negative or positive) polarity, and maintaining their surface at a temperature of between 15.degree. C. and 30.degree. C., resulting particles in a wide area so as to form a mist,
In this way, the particles are distributed homogeneously on the surfaces of the articles by means of an electric field resulting from these different polarities. Under the effect of the electrostatic attraction, charged particles reach the glass surface. It is observed that this surface brings itself, by means of a natural
REFERENCES:
patent: 4116904 (1978-09-01), Verma
patent: 5698269 (1997-12-01), Carlblom et al.
Parker Fred J.
Societe Autonome de Verreries SA
LandOfFree
Process for applying water-based products such as paints and var does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Process for applying water-based products such as paints and var, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Process for applying water-based products such as paints and var will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-166900