Process and system for producing waterborne coating layer in high temperature and low humidity climate

Patent metadata

Field	Value
Publication number	US-9731320-B2
Application number	US-201214234715-A
Country	US
Kind code	B2
Filing date	Jul 24, 2012
Priority date	Jul 27, 2011
Publication date	Aug 15, 2017
Grant date	Aug 15, 2017

Abstract

The present disclosure is directed to a process for applying a waterborne coating composition in a spray booth and a system thereof. The disclosure is particularly directed to a process for introducing water into incoming air for the spray booth to produce a conditioned spray booth having appropriate humidity levels. The process of this disclosure is particularly useful for applying a waterborne coating composition having effect pigments in a low humidity and high temperature climate.

First claim

What is claimed is:

1. A process for applying a waterborne coating composition over a substrate to form a coating layer, said process comprising the steps of:
a) obtaining temperature and humidity level of an incoming air for a spray booth;
b) determining a water introduction rate based on the temperature and humidity level of the incoming air, an air flow rate of said incoming air, and a target range of humidity level of said spray booth, wherein the water introduction rate is determined in the absence of input relating to humidity level of air within the spray booth;
c) producing a conditioned incoming air by introducing water into said incoming air at said air flow rate and at said water introduction rate; and
d) providing said conditioned incoming air to said spray booth to produce a conditioned spray booth.

2. The process of claim 1 further comprising the steps of:
e) applying said waterborne coating composition over said substrate in said conditioned spray booth to produce said coating layer.

3. The process of claim 1 , wherein said water introduction rate is determined by a water rate process comprising the steps of:
b1) determining specific humidity of the incoming air based on the temperature and humidity level of the incoming air;
b2) determining a target specific humidity based on a target range of humidity level of the spray booth;
b3) producing a specific humidity difference based on said specific humidity of the incoming air and said target specific humidity; and
b4) determining the water introduction rate based on the air flow rate of the incoming air and said specific humidity difference.

4. The process of claim 1 , wherein said water introduction rate is determined based on the temperature and humidity level of the incoming air, the air flow rate of said incoming air, the target range of humidity level of said spray booth, and a humidity correlation function that correlates individual water introduction rates with temperatures and humidity levels of the incoming air, target ranges of the humidity levels of the spray booth, and air flow rates of the incoming air.

5. The process of claim 1 , wherein said waterborne coating composition comprises one or more metallic effect pigments.

6. The process of claim 5 , wherein said substrate has an existing coating layer having an existing visual coating effect produced from one or more existing metallic effect pigments, and said coating layer produced thereof having a visual effect matching said existing visual effect.

7. The process of claim 1 , wherein said temperature and humidity level of said incoming air are in a range of from 80° F. to 120° F. and in a range of from 1% relative humidity (RH) to 25% RH, respectively.

8. The process of claim 1 , wherein said conditioned spray booth has an air temperature and a humidity level in a range of from 60° F. to 100° F. and in a range of from 30% RH to 60% RH, respectively.

9. The process of claim 8 , wherein said humidity level is in a range of from 30% RH to 50% RH.

10. The process of claim 1 , wherein said waterborne coating composition comprises a range of from 10% to 90% of water, percentage based on the total weight of said waterborne coating composition.

11. The process of claim 1 , wherein in step c), said water is introduced by spraying into said incoming air.

12. The process of claim 1 , wherein said substrate is a vehicle, vehicle body, or a vehicle part.

13. A process for producing a predicted temperature and humidity level of a spray booth, said process comprising the steps of:
1) obtaining a target water introduction rate, an air flow rate of an incoming air for the spray booth, and temperature and humidity level of the incoming air; and
2) producing said predicted temperature and humidity level based on said target water introduction rate, said air flow rate, and said temperature and humidity level of the incoming air, wherein the predicted humidity level is produced in the absence of input relating to humidity level of air within the spray booth.

14. The process of claim 13 , wherein said target water introduction rate is determined by a water rate process comprising the steps of:
b1) determining specific humidity of the incoming air based on temperature and humidity level of the incoming air;
b2) determining target specific humidity based on a target range of humidity level of the spray booth;
b3) producing a specific humidity difference based on said specific humidity of the incoming air and said target specific humidity; and
b4) determining the water introduction rate based on the air flow rate of the incoming air and said specific humidity difference.

15. The process of claim 13 , wherein said water introduction rate is determined based on the temperature and humidity level of the incoming air, the air flow rate of said incoming air, the target range of humidity level of said spray booth, and a humidity correlation function that correlates individual water introduction rates with temperatures and humidity levels of the incoming air, target ranges of the humidity levels of the spray booth, and air flow rates of the incoming air.

16. The process of claim 1 , wherein water is introduced into said incoming air at a location that provides maximum air velocity in the spray booth.

17. The process of claim 1 , wherein the humidity level of the incoming air is obtained from current local weather station posting on relative humidity or dew point, weather station forecast on relative humidity or dew point for a specific time frame, online weather condition posting, or a combination thereof.

18. The process of claim 1 , further comprising drying the coating layer in the spray booth in the absence of conditioned incoming air.

Assignees

• Larson John Charles
• Moore John R
• Axalta Coating Systems Ip Co

Inventors

• Larson John Charles
• Moore John R

Classifications

• B05D3/0486 Primary

  Operating the coating or treatment in a controlled atmosphere · CPC title

• B05B12/12

  responsive to conditions of ambient medium or target, e.g. humidity, temperature {position or movement of the target relative to the spray apparatus (B05B12/082, B05B12/084 take precedence)} · CPC title

• B05D1/02

  performed by spraying · CPC title

• B05B15/1222

  Operations & Transport · mapped topic

• B05D7/14

  to metal, e.g. car bodies (involving a chemical reaction between the metal and the coating C23) · CPC title