Plasma Surface Pretreatment Technology Implemented

May 5, 2025, Dongguan – In spray coating production, poor adhesion leading to peeling, flaking, or salt spray failure is the second most common quality issue after appearance defects. Especially for low surface energy plastics such as PP, PE, POM, as well as glass, ceramics, and some oxidized metals, conventional coating struggles to achieve sufficient bonding strength. Traditional solutions include primer application or flame treatment, but they involve complex processes, high pollution, and inconsistent results. Dongguan Mansheng Automation Equipment Co., Ltd. announces the successful integration of an inline atmospheric plasma surface treatment module into its 6th generation 360° high speed rotating automatic spray system. This enables an all in one “cleaning + activation + coating” process, boosting coating adhesion by 3–5 times for hard to bond materials, providing a new solution for automotive interiors, 3C electronics, toys, medical devices, and other industries.

Wettability and adhesion depend on surface energy. Plastics like PP and PE have only 29–32 dyn/cm, while typical coatings have 35–40 dyn/cm. When coating surface tension exceeds substrate surface energy, the paint cannot wet evenly—like water on a lotus leaf—resulting in weak adhesion. Flame treatment and corona treatment are common but limited:

• Flame treatment poses fire risks and uneven coverage on complex shapes.
• Corona treatment works poorly on 3D parts.
• Primers add cost and VOC emissions.

Plasma pretreatment is widely recognized as the most effective solution: High voltage ionization generates reactive plasma that bombards the surface, introducing polar groups ( OH, COOH) and raising surface energy above 72 dyn/cm. It also removes oils and dust, creating an ideal pre coating surface.

Mansheng did not simply purchase off the shelf plasma generators; it achieved deep integration:

Plasma nozzles are mounted directly on the robot arm or reciprocator beam, treating the surface just before spraying. Nozzle width: 10–50 mm Processing speed: 250–500 mm/s (matched to coating speed) No extra cycle time.

Plasma power, gas flow, distance, and passes are stored with spray recipes. When a part model is selected, plasma parameters load automatically for batch consistency.

Integrated contact angle measurement module checks water contact angle immediately after treatment.

• Pass: < 30°
• Fail: automatic re treatment or alarm

Data is uploaded to the cloud for full quality traceability.

• Compressed air (low cost, moderate effect)
• Nitrogen / argon (superior performance for high end parts)

One click switching via valve manifold. “Previously, customers had to buy separate plasma treaters and design integration themselves. We provide a turnkey treatment + coating solution,” said the Technical Director of Mansheng Automation.

A Jiangsu auto parts factory supplies PP instrument panel trims to Geely and BYD, requiring soft touch matte coating with cross hatch adhesion ≥ 4B (ISO 2409). Previously used primer:

• Added 2 processes
• Cost: ¥15 per part
• Long drying time hurt takt time

After adopting Mansheng’s integrated plasma + coating line (primer eliminated):

• Adhesion: 5B (max grade), better than primer’s 4B
• Takt time: Reduced by 40 seconds per piece
• Cost saving: ~¥12 per piece
• Defect rate: From 3.5% to 0.4%

“The plasma performance exceeded expectations. All in one line, simple operation, no separate primer control,” said the Production Director.

3D print resin highlight: Residual release agent causes severe adhesion failure. A Guangdong 3D print service provider improved adhesion from severe flaking to 4B and won industrial orders.

Mansheng plasma module: ~¥30,000–50,000 per set (nozzle, power, gas control, inspection). High ROI for mass production with adhesion pain points.

Beyond adhesion improvement, plasma removes micron level oils, release agents, and dust more reliably than manual wiping. The system automatically adjusts intensity based on soil level, serving both cleaning and activation. Critical for medical devices, optical lenses, and high cleanliness applications.

A Zhejiang toy factory producing ABS/PP toy cars eliminated adhesion complaints. “Blind aging test: treated samples stable for 200 hours; untreated peeled at 48 hours. Plasma is now mandatory,” said the Quality Manager. A sanitary ware company used Mansheng’s line to spray antibacterial glaze on ceramic toilets, passing 500 steel wool scrubs and securing a long term European contract.

As coating quality demands rise, plasma pretreatment is shifting from high end option to production standard, especially for plastics, glass, and composites. “We have pre installed plasma interfaces and algorithms in our 6th generation controllers for easy upgrades,” said Mansheng’s General Manager. “Coating is not just spraying—it requires perfect surface preparation.” Mansheng’s integrated plasma spray systems are available for order. Customers can bring hard to bond materials to the Dongguan showroom for free trials.

Dongguan Mansheng Automation Equipment Co., Ltd. is a national high tech enterprise with 13 invention patents. It has integrated inline atmospheric plasma surface treatment to solve adhesion challenges for PP, PE, glass, ceramic, and other low surface energy substrates. Release Date: May 5, 2025 Word Count: ~2,080 words