CN1962085A - Method for spray coating of crackle lacquer - Google Patents

Abstract

A method for spraying crack paint, the method comprising the steps of: a. spraying a polypropylene primer diluted with a polypropylene solvent on the surface of a product made of a modified polypropylene material, the polypropylene primer can be gray primer, black Primer or off-white primer; b. After drying the sprayed polypropylene primer, spray an acrylic primer diluted with xylene solvent, and then cool it until the surface is dry; c. Spray a crack solvent on the acrylic primer Diluted polypropylene crack paint, then dry; d. Spray on the polypropylene crack paint and be diluted by polyurethane solvent, and add the polyurethane color paint of curing agent, dry then. The cracked paint sprayed by the method of the invention not only has good decorative effect of leather texture, but also has lower production cost.

Description

A method of spraying crack paint

technical field

The invention relates to a method for spraying the surface of workpieces, in particular to a method for spraying crack paint on the surface of workpieces so as to present skin texture effects.

Background technique

Spraying paint on the surface of workpieces is a common surface treatment method. Among them, spraying paint on the surface of metal workpieces is mainly to prevent corrosion of workpieces and play a decorative role. On the other hand, non-metal products, such as plastic or leather products, are painted to produce a decorative effect, mainly to produce a leather effect. This surface treatment is more common in automotive interior parts. At present, there are generally two ways to produce the surface grain of automobile interior parts: one is to use leather decoration, the other is to imitate leather grain, and the latter is to process and produce by making molds. The main defect of the above two ways is that the production cost is relatively high.

Contents of the invention

The present invention aims to solve the above problems, and provides a new method for spraying crack paint on polypropylene products, so as to achieve the purpose of not only having better leather texture decoration effect, but also having lower production cost.

To achieve the above object, the invention provides a method for spraying cracked paint, the method may further comprise the steps:

a. Spray a polypropylene primer diluted with a polypropylene solvent on the surface of a product made of a modified polypropylene material;

b. After drying the sprayed polypropylene primer, spray the acrylic primer diluted with xylene solvent, after baking, let it cool until the surface is dry;

c. Spray polypropylene crack paint diluted by solvent benzene solvent on the acrylic primer, and then bake;

d. Spray the polyurethane color paint diluted with polyurethane solvent and add polyurethane curing agent on the polypropylene crack paint, and then bake.

In step a, the polypropylene primer and the polypropylene solvent are prepared in a weight ratio of 1:0.8-0.9, and the dilution time is 12-13 seconds.

When the polypropylene primer is diluted with polypropylene solvent, it is necessary to choose slow-drying, medium-drying and fast-drying solvents according to the temperature and humidity of the spray booth. Solvent, under constant temperature and humidity conditions, use a medium-dry solvent.

If the proportion of polypropylene solvent is lower than 0.8, the viscosity of the primer may be thick and easy to orange peel, and the surface of the product may be sunken and wrinkled. If the proportion of polypropylene solvent is greater than 0.9, the spraying will hang and cannot be sprayed on the surface of the product, and there will be no coverage.

In step b, the baking temperature of the polypropylene primer is 65-70°C, and the baking time is 20-30 minutes; the acrylic primer and xylene solvent are prepared in a weight ratio of 1:1, and the dilution time is 14-16 Seconds, bake at 65-70°C for 15-20 minutes.

The primer needs to be baked after spraying, otherwise the surface hardness requirements and testing standards will not be met. If the baking temperature is lower than 65°C and the time is less than 20 minutes, the baking will not reach the required hardness for drying the paint film, and It will cause the topcoat to bite the bottom. If the temperature is higher than 70°C and the time is longer than 30 minutes, baking deformation will occur and the finished product will be scrapped.

If the solvent dilution time is less than 14 seconds, the paint is too thin and will sag. If the dilution time is greater than 16 seconds, if the paint is too thick, orange peel will occur, which will affect the appearance quality.

In step c, the polypropylene crack paint and the solvent benzene crack solvent are prepared in a ratio of 1:0.8-0.9 by weight, the dilution time is 14-16 seconds, and the temperature is baked at 65-70° C. for 10-20 minutes.

If the cracking solvent ratio is lower than 08, for example, the cracking effect will be small, resulting in high surface solubility after spraying, and drying too quickly will make the appearance dull and the texture unclear.

If the cracking solvent ratio is greater than 0.9, the cracks will be very rough, resulting in low surface solubility after spraying, making the appearance of the product too wet, dull and chaotic.

In step d, the polyurethane color paint and the polyurethane solvent adding the curing agent are prepared in a ratio of 1:1 by weight, and the dilution time is 13 to 15 seconds. The polyurethane solvent and the curing agent are prepared in a ratio of 7:1 by weight. Bake at ~70°C for 50-60 minutes.

If the ratio of the polyurethane solvent is less than 1, the surface hardness of the product will be low, not dry, and not wear-resistant.

If the ratio of polyurethane solvent is greater than 1, the surface of the product will turn yellow, resulting in serious color difference.

The contribution of the present invention is that the method can strengthen the adhesion of the sprayed cracked paint, and the effect of the skin pattern produced by spraying is the same as that of the mold impression, but reduces the production cost and reduces the expensive cost of mold opening caused by the mold impression . The method can produce different thickness lines according to actual requirements, can reduce mold opening time, improve production efficiency, and has simple operation and high practicability. The cracked film produced is uniform, has good adhesion, looks beautiful, and feels the same as skin texture.

Description of drawings

Fig. 1 is the schematic diagram of the coarse cracked paint made by the method of the present invention.

Fig. 2 is the schematic diagram of fine grain crack paint made by the method of the present invention.

Fig. 3 is the schematic diagram of the crackle paint that is made by general method.

Detailed ways

The following examples are further explanations and illustrations of the present invention, and do not constitute any limitation to the present invention.

The method for spraying crack paint of the present invention comprises the steps:

a. Dilute the PP gray polypropylene primer with PP (polypropylene) solvent at a ratio of 1:0.85 (parts by weight) for 12 minutes, control the viscosity of the paint by controlling the time, and then spray it on the product made of modified polypropylene material surface.

b. Dry the sprayed polypropylene primer at a temperature of 68°C for 20 minutes to volatilize the solvent, and dilute the 206 type acrylic black primer with X3 (xylene solvent) in a ratio of 1:1 (parts by weight) for 15 minutes. Seconds, dry at 70°C for 15 minutes and then spray on the dried polypropylene primer, then let it cool until the surface is dry.

This step is used to strengthen the intermediate coating interface, the joint between the bottom surface.

c. Dilute the polypropylene cracked paint with a benzene solvent in a ratio of 1:0.85 (parts by weight) for 15 seconds, spray it on the acrylic primer, and then dry it at 68°C for 15 minutes to evaporate the solvent.

This step is used to adjust the thickness of the cracks according to the required texture effect.

d. Mix PU (polyurethane solvent) and polyurethane curing agent in a ratio (parts by weight) of 7:1, then mix and dilute it with PU (polyurethane) paint in a ratio (parts by weight) of 1:1 for 14 seconds, spray on The cracked polypropylene paint is applied, and then dried at a temperature of 68°C for 60 minutes to evaporate the solvent.

In this step, the depth of the color can be adjusted according to different color requirements.

According to the above-mentioned method of the present invention, the leather pattern with the same effect as the pattern of the mold can be produced on the product made of the modified polypropylene material in the automobile trim.

Figure 1 and Figure 2 are two kinds of large and small grains made according to the above process. Control the spray gun paint flow at 200-250ml, and the air pressure at 0.5-0.6mpa, then form the coarse grain as shown in Figure 1. Control the paint flow rate of the spray gun at 100-200ml, and the air pressure at 0.2-0.35mpa, then the fine lines shown in Figure 2 will be formed. The cracks and lines in Figure 1 and Figure 2 are all cracked outside the coating, and the lines are continuous, so the surface has a concave-convex feeling, showing a skin-like effect. Fig. 3 is the crackle that is made by general spraying method, and the texture of its crackle has cracked on the substrate (substrate is white), and texture is discontinuous, and adhesion is relatively poor.

Claims (5)

1, a kind of method of spray coating of crackle lacquer is characterized in that, it comprises the steps:

The surface spraying of a, the product made at modified polypropylene material is by the polypropylene priming paint of polypropylene solvent dilution;

B, will be sprayed polypropylene priming paint oven dry back spraying by the acrylic primer of xylene solvent dilution, after the baking then cold put to the surface from doing;

C, the polypropylene crackle lacquer that spraying is diluted by the solvent benzol kind solvent on acrylic primer, baking then;

D, paint spraying by the polyurethane solvent dilution, and add the polyurethane colored paint of polyurethane curing agent, baking then at polypropylene crackle.

2, the method for spray coating of crackle lacquer as claimed in claim 1 is characterized in that, in the step (a), polypropylene priming paint and polypropylene solvent are prepared in 1: 0.8～0.9 weight portion ratio, and dilution time was 12～13 seconds.

3, the method for spray coating of crackle lacquer as claimed in claim 1 is characterized in that, in the step (b), the baking temperature of polypropylene priming paint is 65～70 ℃, and stoving time is 20～30 minutes; Acrylic primer and xylene solvent were prepared in 1: 1 weight portion ratio, and dilution time was 14～16 seconds, 65～70 ℃ of temperature bakings 15～20 minutes.

4, the method for spray coating of crackle lacquer as claimed in claim 1, it is characterized in that in the step (c), the polypropylene crackle lacquer is prepared in 1: 0.8～0.9 weight portion ratio with solvent benzol class crackle solvent, dilution time was 14～16 seconds, 65～70 ℃ of temperature bakings 10～20 minutes.

5, the method for spray coating of crackle lacquer as claimed in claim 1, it is characterized in that, in the step (d), polyurethane colored paint and the weight portion ratio preparation of the polyurethane solvent that adds curing agent in 1: 1, dilution time was 13～15 seconds, polyurethane solvent and curing agent were prepared in 7: 1 weight portion ratio, 65～70 ℃ of temperature bakings 50～60 minutes.