Jason Cheung
Skype: prototype6003
Fax: (852)-2544 5670
Room E160, 3rd Floor,
Wing Tat Commercial Building,
97 Bon Strahamnd,Sheung Wan, Hong Kong
Current position:  Home > Technical >

Spray Coating Technology of Plastic Prototype

Time:2018-01-02 14:52 source: Leecheer Author: Leecheer Click:

Spray Coating Technology of Plastic Prototype

Spray coating characteristics:

Currently, air spraying is comparatively extensive spraying technology 

in coating craft project. Air spraying makes use of compressed air 

which form negative pressure when flow spray gun. The paint vehicle

 is absorbed form sucker by negative pressure, and is sprayed out by 

spray gun as coating mists. When spraying, coating mists become 

even film on the surface of prototype. Air spraying can paint even film,

and smear layers are very smooth. It can spray the hidden parts such

as gaps and unevenness. The utilization rate of dope is low in this way,

which is about 50 to 60 percent. There are some effect after coating 

on plastic prototype.

1.  Spray coating can cover the deficiency of prototype surface.

2. The plastic itself is difficult to color. Spray coating can paint many

kinds of color on plastic.

3. Spray coating improves the electrostatic properties of plastic, 

which can reduce dusty-adsorption.

4. Spray coating strengthens hardness and mar-resistance of plastic.

5. Spray coating improves weather resistance of plastic.

6. Spray coating can adjust the gloss of plastic surface.

7. Some special lacker such as sand paint, fluff paint can achieve 

effect of good appearance and hand feeling.

 Moreover , the surface confition after plastic formed has great impact 

to appearance quality. 

The technological process of plastic spray painting technology

1. Annealing : It is easy to form internal stress when plastic molding 

and processing, so after coating, the stress concentration position 

is easy to crack. Therefore , the annealing treatment or post nital 

treatment can be adopted to relieve stress. Annealing treatment is to 

heat ABS formed parts to heat below distortion temperature, that is 60 

and heat preservation for 2 hours. However, those technology need 

lot of equipment investment. For this reason, post nital treatment 

can be adopted, that is to deploy liquor which can relieve plastic stress, 

and immerse the plastic parts into liquor for 1520minn to anneal.

2. Degreasing : plastic parts often stick with greasy dirt, hand 

perspiration and release agent, which make coating adhesion worse 

and the coating would crack, blister and fall off. It need to degrease 

before apply coating. For plastic parts, gasoline or alcohol is often be 

used , and then alkaline degreasing. After clean out alkali liquor, 

the pure water should be used to clean up at last. 

3. Static electricity removal and dust removal: Plastic parts are 

nonconductor and  its surface resistance is about 1013Ω which is easy

to produce static electricity. It is easy adsorb tiny dust and attached 

appearance when it electrify. The dust attached surface because of static 

electricity is very difficult to wipe out. High pressure ionization air flow 

has very good effect to Static electricity removal and dust removal.

4. Spraying coating:The thickness of plastic coating is 15~20μm and 

it need to spray 2 or 3 times to finish.One time spray spraying coating 

need to dry for 15miniutes and the do the second spraying coating. 

If the surface need to be glossy , the surface must spray transparent 

coating. The spraying coating have nofluence to flame retardant property.

5. StovingAfter spray coating, plastic parts can be dried under 

natural condition and they can also be baked under 60 temperature 

for 30 minutes.

Keywords: plastic, spray coating, technology. CNC prototype  
Copyright © 2012-2016  HongKong Leecheer Prototype Manufacturing Limited  www.chinaprototyping.com
skype:prototype6003 Email:leecheer@chinaprototyping.com 
Keywords: prototype manufacturers,china prototyping,prototype companies,sla prototype,cnc prototype china,sls prototype,vacuum casting proess,short run production,rapid sheet metal.functional prototype,appearance prototype,Transparent prototype,Aluminum prototype