CN101670332A

CN101670332A - Oil paint coating line-based process for coating water paint in two layers on automotive plastic exterior trimming part

Info

Publication number: CN101670332A
Application number: CN200810013154A
Authority: CN
Inventors: 董鸣
Original assignee: Shenyang Minghua Mould Plastic Science & Technology Co Ltd
Current assignee: Shenyang Minghua Mould Plastic Science & Technology Co Ltd
Priority date: 2008-09-10
Filing date: 2008-09-10
Publication date: 2010-03-17

Abstract

The invention discloses an oil paint coating line-based process for coating water paint in two layers on an automotive plastic exterior trimming part. In the process, to implement two-layer coating technology, an oil/water-based insulation combined system of a robot is imporved and the temperature of a base paint oven in an oil-based production line is regulated by process control of a pretreatment step and by using stable industrial propane (with a purity of more than 95 percent) as a flame treatment fuel and executing base material flame treatment experimental design, base paint spraying isavoided, water-based color paint is directly sprayed on a plastic base material, and a varnish is an oil-based varnish. After equipment improvement is completed, original oil-based paint can still beused in normal production.

Description

Automobile plastic exterior trimming parts water paint two paint coating technologies based on the oil paint paint line

Technical field

Present technique is applicable to car plastics exterior trimming parts, such as bumper, threshold, wheel cover etc., the especially coating decoration of car bumper.

Background technology

Both at home and abroad automobile factory as general, benz, BMW, masses, Huachen, modernly different quality standards is arranged for the colored exterior trimming parts of car, mainly there are some differences in these standards aspect aspect of performance such as colored paint film adhesion, anti-corrosion, weatherability, alternating hot and cold, humidity, stone impact and the outward appearances such as aberration, gloss.For satisfying the quality standard of automobile factory, the paint line of present domestic car exterior trimming parts producer all adopts three coating oil paint coating process to produce all kinds of colored bumpers, oil paint is meant with solvent to be the coating of main carrier, and some is a Control During Paint Spraying by Robot, and some then is a hand spray.Three coatings are meant carries out priming paint, three times sprayings of paint and varnish on the plastic basis material of moulding, as shown in Figure 1.It is the adhesive force that guarantees between plastic basis material and the paint that priming paint mainly acts on, and colored paint then is to form the color that automobile factory requires, and varnish is used to satisfy the every performance and the outward appearance of paint film.Usually the oil paint coating process is divided into low temperature and high temperature two individual system again, and it is dry to adopt high temperature (more than 120 degrees centigrade) or low temperature (between 80 degrees centigrade to 90 degrees centigrade) to toast according to last one varnish baking link.Divide according to toasting number of times, can be divided into three sprays, two bakings and two kinds of construction technologies of three sprays, one baking (promptly wetting, it is wet to bump) again.The wherein wet technology that wets of bumping will be saved energy resource consumption because of having economized one priming paint baking; And low temperature system higher temperatures system is saved the energy.Although to the low temperature system, drying by the fire to three sprays, one baking systems from three sprays two has had some progressive from high temperature, yet fundamentally do not solve the construct problem of hazardous emission of energy resource consumption and oil paint.Aspect energy resource consumption mainly from two aspects, the one, the consumption of the energy in the production process, as the baking etc.The 2nd, handle the energy resource consumption (waste gas uses combustion system usually) of noxious emission.

Abroad, be to reduce noxious gas emission, most of car exterior trimming parts producer from the nineties in last century just on priming paint and colored paint the use lacquer replace solvent and paint, varnish is because of the quality requirement of its special purposes and automobile factory, then use oil paint, technological process is illustrated as Fig. 2 always; Be identical purpose, the powder-type of use coating is also arranged, the other technologies progress is carried out on this basis.Be devoted to develop the paint that is fit to two coatings nearly 2 years some paint producers, promptly cancel priming paint, only spray aqueous finish paint and oil varnish, and reach the quality standard of automobile factory, as shown in Figure 3, this The Application of Technology is still in the trial stage.

In the face of urgent day by day environmental protection and energy-conservation requirement, water paint is an inexorable trend in the application in car plastics coating field.Yet the construction technology condition of water paint and oil paint has very big difference, and the automatic painting line of a volume production is moving tens million of even more than one hundred million, and the time that colored bumper application industry develops at home is still short, and the update of production line also needs long time.

Bypass the difference of water paint and oil paint construction environment and each process section control of product characteristic, only from Fig. 2 and Fig. 1 as can be seen, the present domestic international ripe water paint construction technology of ripe oil paint construction technology of using has been lacked colored paint drying link.As being transplanted to external water paint construction technology domestic, must on existing basis, increase the colored paint baking oven, this transformation destroys the original system balance because of it, need transform from process environments and whole automatic conveying system, the investment that has a big risk is high, time is long, and the production line that has come into operation can't interrupt transforming over tens days usually.Secondly, after the transformation, will break the execution conditions of original oil paint system, the quality risk height, oiliness is constructed with water-based can't conllinear production.

Summary of the invention

For addressing the above problem, the present invention introduces two coating aqueous systems on the oiliness production line.By transformation to base material flame treatment operation, coating decoration instrument (robot under the spraying situation automatically) and paint supply systems, implement two coating water-based construction technologies, solve at one stroke water paint and substitute the optimization that oil paint and three is coated with course two coatings, and need not to re-construct the new production line, save great amount of investment, product meets world-famous battle wagon factory quality standard on outward appearance and performance, simultaneously after transformation, oil paint and water paint can be realized conllinear production, do not influence existing oiliness system.

Description of drawings

Fig. 1 is three sprays, two baking oil paint coating process schematic flow sheets, is typical oil paint spraying coating process, domestic generally use;

Fig. 2 is three sprays, three baking water paint coating process schematic flow sheets, for typical water paint spraying coating process, generally uses in countries such as Europe;

Fig. 3 is two sprays, two baking water paint coating process schematic flow sheets, is two coating new technologies;

The specific embodiment

From the technological angle analysis, need to solve following technological difficulties:

1) pretreatment of base material 2) aqueous finish paint and oiliness colored paint isolation technology 3) the colored paint drying varniss

One, pretreatment of base material

Comprise washing and drying and flame treatment, three steps of electrostatic precipitation; The purpose of washing is to remove pollutants such as grease that substrate surface impacts the performance and the outward appearance of paint film, rubbish, particle, and oil paint is consistent with water paint in this.In high temperature oil paint system, generally do not need flame treatment, but the processing of low temperature system moderate heat flame is necessary operation, thereby shows that in order to improve base material energy increases paint film adhesion.For reaching quality requirement, there is surface energy parameter request in different coating producers to flame treatment, and is high more usually good more.Compare oil paint and three coating water paints, two-layer water paint technology requires harsher to the clean-up performance of substrate surface, and different flame treatment technology exerts a decisive influence to base material adhesive force, the experiment proved that the surface high processing of energy can not obtain the paint film adhesion of expection on two-layer aqueous coating technology.Therefore, the washing and drying link can realize that the latter then needs by scrap build and experimental verification by taking suitable chemicals and strict process control.

The flame treatment operation at first is the stable of burning gases, need commercial propane is replaced by with natural gas energy resource in common city, purity is more than 95%, calorific value, the often change of composition ratio because of common gas, impure more, will cause flame treatment effect instability or bring particle contamination.Guarantee on different substrate materials, to carry out the flame treatment experimental design under the stable prerequisite of fuel, according to the quality standard of automobile factory, test paint performance, the comparative experiments result, the definite flame parameters that can be transplanted to product is optimized the flame treatment path on product.

Two, the thorough isolation of water paint and oil paint

On the robot automatic spraying production line, can use following comparatively economic method:

1) water-based oiliness spraying motion parts uses same robot

2) spraying control section, independent fully.Comprise paint feeding system, pipeline, spraying control system, spray gun.

At present, ABB AB has this technology, can realize function, and oiliness, aqueous systems can onlinely be switched simultaneously.

Three, the drying of colored paint paint film

General aqueous systems construction needs colored paint paint film levelling at a certain temperature, to reach drying varniss, avoids varnish spraying back that shrinkage cavity takes place.Yet oil paint is to wet to bump wet trade between paint and varnish, does not have the dry link of colored paint, and this makes general water paint to construct in the oil paint system.After adopting two-layer construction technology, can utilize priming paint oven drying colored paint paint film, temperature is reduced to 60 degree from normal priming paint 90 degree bakings, can guarantee the colored paint drying varniss, and water content is less than 10%, satisfies the requirement of road, back varnish spraying.

Four, brief summary

By above-mentioned measure, can be implemented in and implement water colour paint oil varnish construction technology on the oiliness automatic spraying production line, total investment for trnasforming urban land is little, risk is little, can carry out fundamentally energy-conserving and environment-protective more off time in production.

Claims

1 one kinds of automobile plastic exterior trimming parts coating construction process, on the oil paint paint line, by (1) washing and drying link technology controlling and process, (2) adopt stable technical grade propane (95% above purity) as flame treatment fuel, and carry out the experimental design of base material flame treatment, and (3) are carried out oiliness/water-based to robot and are isolated the sharing system transformation, and (4) are adjusted the oven temperature of oiliness production line, realize two paint coating technology, but former oil paint ordinary production still simultaneously.

2 according to the described coating construction process of claim 1, it is characterized by (1) no priming paint (2) water colour paint drying (4) varnish that directly construction (3) utilizes the priming paint baking oven of oil paint to carry out water colour paint on plastic basis material and still adopts oil paint technology.