Language
- Chinese

language

Tel

Tel

+8618142863185
Follow us

Official Accounts

Official Accounts
Top

News

Testing Items for UV Vacuum Plating Performance (Part II)

Release time:

2026-05-22 17:05

Testing Items for UV Vacuum Plating Performance (Part II)

The chemical properties of UV vacuum‑plated coating systems determine their stability and durability under a wide range of environmental conditions. Unlike physical‑property testing, which focuses on surface appearance and mechanical strength, chemical‑property evaluation places greater emphasis on the molecular‑level structural characteristics of the coating material and its responsiveness to external chemical environments. From resistance to chemical corrosion and aging degradation to assessing the degree of coating cure and interfacial chemical stability, these chemical parameters serve as critical criteria for evaluating product quality and predicting service life. This paper outlines the principal chemical‑property test items and methodologies for UV vacuum plating, examining four key aspects: chemical resistance, weathering resistance, degree of cure, and surface chemical characteristics.

I. Chemical Resistance Testing

Chemical resistance testing evaluates the ability of a coated surface to withstand attack by various chemicals, serving as an important indicator of a product’s stability under everyday use and in specific environmental conditions.

1. Solvent Resistance Test

Solvent resistance testing evaluates a coating’s ability to withstand attack by organic solvents. The solvent‑wipe method involves repeatedly wiping the coating surface with a cotton swab soaked in a specified solvent—such as ethanol, methyl ethyl ketone, or toluene—and observing whether the coating exhibits softening, swelling, discoloration, or delamination. The test grade is assigned based on the number of wipes or the condition of the surface after wiping. This assessment provides valuable insight into the coating’s crosslink density and degree of cure.

2. Acid and Alkali Resistance Test

Acid–alkali resistance testing evaluates a coating’s ability to withstand corrosion by acidic and alkaline substances. The test is conducted using either the spot‑test method or the immersion method: a diluted acid or alkali solution is applied to the coating surface, or filter paper soaked in the acid/alkali solution is placed on it. After a specified exposure period, the coating’s surface is examined for changes, including blistering, discoloration, loss of gloss, softening, or delamination. This test is particularly important for products in bathrooms, kitchens, and other environments where cleaning agents may come into contact with the surface.

3. Cosmetics Resistance Test

The cosmetics resistance test is primarily intended for applications in the cosmetics packaging sector. Cosmetics such as lipstick, liquid foundation, and perfume are directly applied or dropped onto the coated surface; after being left under specified temperature and humidity conditions for a set period, the coating is examined for signs of corrosion, discoloration, softening, or reduced adhesion. This test simulates the chemical exposure that cosmetic packaging may encounter during actual use.

4. Sweat Resistance Test

The sweat‑resistance test evaluates the ability of a coating to withstand corrosion caused by human sweat. Filter paper soaked in artificial sweat— a test solution that mimics the composition of human sweat—is placed on the coated surface, and the sample is left under constant temperature conditions for a specified period before assessing any changes to the surface. This test provides valuable reference data for products that are in prolonged contact with skin, such as mobile phone housings, wearable devices, and eyeglass frames.

5. Detergent Resistance Test

The detergent resistance test evaluates a coating’s ability to withstand the corrosive effects of cleaning agents. A diluted detergent solution is either applied dropwise or used to soak the coated surface; after a specified exposure period, the coating is inspected for signs of blistering, discoloration, or reduced adhesion. This test is applicable to coated products used in everyday cleaning scenarios, such as in bathrooms and kitchens.

II. Weathering Performance Testing

Weathering performance testing evaluates the ability of coated films to resist aging and degradation under outdoor environmental conditions.

1. UV Aging Test

UV aging testing is an essential method for evaluating the light‑stability of coatings. Coated test panels are placed in a UV aging chamber and subjected to accelerated aging under specified UV irradiance levels and temperature–humidity conditions. The panels are periodically removed to assess whether the coating exhibits yellowing, loss of gloss, chalking, cracking, or other degradation phenomena. This evaluation is particularly important for products intended for outdoor use or prolonged exposure to sunlight, such as automotive components and exterior decorative parts.

2. Damp-Heat Aging Test

The damp‑heat aging test evaluates the stability of coatings under high‑temperature, high‑humidity conditions. Coated specimens are placed in a constant‑temperature, constant‑humidity chamber and exposed to these conditions for a specified period, after which the coating is inspected for signs of blistering, whitening, loss of gloss, softening, or reduced adhesion. This test provides valuable guidance for products—such as those used in bathrooms and kitchens—that are subjected to prolonged exposure to humid environments.

3. Salt Spray Test

Salt spray testing evaluates the corrosion resistance of coatings in salt‑containing environments. Coated test specimens are placed in a salt spray chamber and exposed to a specified salt‑spray environment for a defined period, after which the coating is inspected for failure modes such as pitting, discoloration, blistering, or peeling. This test is particularly critical for products intended for use in coastal or marine settings.

III. Coating Curing Degree Testing

The degree of coating cure directly affects the coating’s chemical and mechanical properties and is a critical parameter in quality control.

1. Curing Degree Testing

Cure‑degree testing evaluates the extent to which the polymerization reaction has been completed in a coating. The solvent‑wipe method involves repeatedly wiping the coating surface with a cotton swab soaked in a strong solvent; complete cure is determined by whether the coating softens, dissolves, or exhibits color transfer. Incompletely cured coatings will exhibit tackiness, dissolution, or noticeable residue after solvent wiping.

2. Infrared Spectroscopic Analysis

The chemical structure of the coating was analyzed using a Fourier-transform infrared spectrometer. By detecting the characteristic absorption peaks of unreacted functional groups, the degree of curing can be quantitatively assessed. This method provides molecular‑level information on the curing process and is more precise than the solvent‑wipe test.

3. Thermogravimetric Analysis

Thermogravimetric analysis evaluates the thermal stability and compositional makeup of a coating by measuring its mass changes during heating. By analyzing the thermogravimetric curve, it is possible to determine whether unreacted monomers or low-molecular-weight substances remain in the coating.

IV. Surface Chemical Property Analysis

Surface chemical properties influence the coating’s anti-fouling performance, wettability, and compatibility with other materials.

1. Surface Energy Measurement

Surface energy is determined by measuring the contact angle to evaluate the wettability of a coating’s surface. A specific test liquid is placed on the coating, and the contact angle of the droplet is measured. A smaller contact angle indicates higher surface energy and better wettability, while a larger contact angle corresponds to lower surface energy and enhanced hydrophobicity and oleophobicity. This measurement is crucial for assessing a coating’s resistance to fingerprints and its ease of cleaning.

2. Surface Elemental Analysis

X-ray photoelectron spectroscopy or energy-dispersive spectroscopy is employed to perform qualitative and quantitative analyses of the chemical elemental composition on the coating surface. This approach enables the detection of the distribution of low‑surface‑energy elements such as fluorine and silicon, thereby assessing the enrichment effect of anti‑fouling additives at the surface.

3. Adhesion Interface Analysis

The interfacial morphology between the coating and the substrate was examined using scanning electron microscopy to evaluate the bonding condition at the interface. Combined with energy-dispersive spectroscopy, elemental distribution at the interface can be analyzed to determine whether interfacial contamination or poor adhesion is present.

V. Testing of Specific Chemical Properties

For different application areas, UV vacuum-plated products must also undergo specific chemical‑performance testing.

1. Specialized Testing for Automotive Components

Automotive interior and exterior coated components must meet specific chemical performance requirements of the automotive industry, including resistance to gasoline, engine oil, and windshield washer fluid. The coating is immersed in the respective test fluids, and after a specified period, surface changes and adhesion retention are evaluated.

2. Specialized Testing for Electronic Products

The coating layer on electronic device housings must withstand the corrosive effects of everyday contact substances, such as hand sweat, sunscreen, and cleaning wipes. Appropriate test media are used for spot‑testing or wipe‑testing to evaluate the coating’s resistance.

3. Migration Testing of Packaging Materials

Coated products used for cosmetic and food packaging must undergo migration testing to assess whether low-molecular-weight substances from the coating can migrate into the packaged contents. Migration levels in simulated media are determined using gas chromatography–mass spectrometry to ensure compliance with applicable safety standards.

VI. Conclusion

Chemical‑performance testing for UV vacuum plating encompasses multiple aspects, including chemical resistance, weathering resistance, coating cure degree, and surface chemical characteristics. Tests such as solvent resistance, acid–alkali resistance, resistance to cosmetics, sweat, and detergents evaluate the coating’s ability to withstand chemical corrosion; UV aging, damp‑heat aging, and salt‑spray tests assess its long-term stability; cure‑degree measurements and spectroscopic analysis ensure that the coating achieves the intended level of crosslinking; and surface‑energy determination and elemental analysis evaluate the coating’s surface functional properties. Taken together, these tests form a comprehensive system for assessing chemical performance. By adhering to standardized testing procedures, the chemical stability of UV vacuum‑plated products can be effectively evaluated, providing quality assurance for their reliable application in fields such as cosmetic packaging, automotive components, and consumer electronics.

Disclaimer: The above content has been compiled from publicly available sources and is provided for reference only. If any infringement occurs, please contact us, and we will address it promptly.

Bosheng’s Recommended Products – Vacuum Plating
Primer
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-113	Bisphenol A epoxy acrylate	High hardness, high gloss, high fullness, contains 20% TPGDA.
B-151	Modified epoxy acrylate	Low halogen, yellowing-resistant, excellent plating performance, and strong adhesion.
B-160D	Modified epoxy acrylate	Good flexibility, yellowing resistance, and excellent adhesion.
B-163	Modified epoxy acrylate	Good flexibility, excellent pigment wetting, and strong adhesion.
B-165	Modified epoxy acrylate	Good flexibility and strong adhesion
B-212A	Aromatic polyurethane acrylate	High cost-performance, excellent plating adhesion, good toughness, and resistant to boiling water.
B-221	Aliphatic polyurethane acrylate	Fast curing, resistant to boiling water
B-268M	Aliphatic polyurethane acrylate	Good flexibility, excellent adhesion, superior plating performance, and strong hiding power.
B-574C	Polyester acrylate	Low viscosity, low odor, excellent wettability, suitable for LED UV.
B-619W	Aliphatic polyurethane acrylate	Fast curing, high hardness, excellent toughness, wear resistance, and chemical resistance.
Intermediate coat
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-374	Aliphatic polyurethane acrylate	Excellent flexibility, good leveling, resistant to abrasion and chemicals, and resistant to yellowing.
B-601	Aromatic polyurethane acrylate	High hardness, scratch resistance, chemical resistance, and excellent cost-effectiveness.
B-6020	Special functional group acrylate	Resistant to boiling water, excellent color development, and strong interlayer adhesion.
Topcoat
Product Model/English Abbreviation	Product Name/Product Type	Product Features
B-221	Aliphatic polyurethane acrylate	Fast curing, resistant to boiling water
B-301	Aromatic polyurethane acrylate	Fast curing, excellent toughness, and good sandability.
B-302	Aromatic polyurethane acrylate	Fast curing, high strength, excellent toughness, and good grindability.
B-368	Aliphatic polyurethane acrylate	Good toughness, excellent leveling, excellent bend resistance, and excellent heat resistance.
B-374	Aliphatic polyurethane acrylate	Excellent flexibility, good leveling, resistant to abrasion and chemicals, and resistant to yellowing.
B-574C	Polyester acrylate	Low viscosity, low odor, excellent wettability, suitable for LED UV.
B-601	Aromatic polyurethane acrylate	High hardness, scratch resistance, chemical resistance, and excellent cost-effectiveness.
B-6016C	Special functional group acrylate	Easy to apply, resistant to yellowing and boiling water, and improves the appearance of the paint film.
B-6019	Special functional group acrylate	Good leveling, excellent wetting, resistant to boiling water, and superior color dispersion.
B-609	Aliphatic polyurethane acrylate	Fast curing, high hardness, scratch resistance, and chemical resistance.
B-615A	Aliphatic polyurethane acrylate	Fast curing, excellent toughness, wear resistance, and chemical resistance.
B-619W	Aliphatic polyurethane acrylate	Fast curing, high hardness, excellent toughness, wear resistance, and chemical resistance.
B-6210	Aliphatic polyurethane acrylate	Low viscosity, chemical resistance, environmental resistance, and dual photothermal curing.
B-6211	Aliphatic polyurethane acrylate	Fast curing, high hardness, scratch-resistant, and free of organotin.
B-919B	Aliphatic polyurethane acrylate	Fast curing, high hardness, excellent toughness, and superior chemical and wear resistance.
Monomer Recommendation
Product Model/English Abbreviation	Product Name/Product Type	Product Features
BM2223 (TPGDA)	Di(propylene glycol) diacrylate	Good flexibility and low volatility
BM3231 (TMPTA)	Trimethylolpropane triacrylate	High crosslink density, high hardness, high gloss, and excellent wear resistance.
BM3235 (PET3A)	Pentaerythritol triacrylate	Fast curing, high crosslink density, high hardness, and excellent chemical resistance.
BM3380 (3EO-TMPTA)	Pentaerythritol triacrylate	More flexible and less irritating than TMPTA.
BM6261 (DPHA-80)	Dipentaerythritol hexaacrylate	High crosslink density, high hardness, chemical and wear resistance, and water resistance.
BM6263 (DPHA-90)	Dipentaerythritol hexaacrylate	High crosslink density, high hardness, chemical and wear resistance, and water resistance.

Share to:

Analysis of the Core Components of UV Vacuum Plating

Test Items for UV Vacuum Plating Performance (I)