Smoothing Agent Testing

Leveling agent inspection mainly conducts scientific testing and analysis on chemical composition qualitative and quantitative analysis, physical and chemical property testing, functional indicator evaluation, hazardous substance and impurity testing, ecotoxicology and environmental behaviour testing, and application process adaptability testing, objectively assessing the product quality grade and issuing a detailed test report, providing a basis for manufacturers' quality control and downstream users' product acceptance.

Testing Items

Chemical composition qualitative and quantitative analysis: Determines the main chemical components and contents of the leveling agent, such as the organosiloxanes, fatty alcohol polyoxyethylene ethers, fatty acid esters and mineral oils. This is the basis for evaluating its performance, safety and compliance, and is crucial for verifying the product formula, tracing the sources of the raw materials and investigating the unqualified components.

Physical and chemical property testing: Covering the indicators such as the viscosity, density, pH value, flash point, pour point, cloud point, surface tension and thermal stability. These data are directly related to the processing performance, use safety and storage stability of the leveling agent in the downstream applications such as the textile, plastics and papermaking industries.

Functional indicator evaluation: Evaluates its core functions for the specific application scenarios. For example, in the textile industry, the hand feel (softness and smoothness), whiteness change, friction coefficient, anti-static performance and the influence on the colour fastness of the fabric treated with the leveling agent need to be tested.

Hazardous substance and impurity testing: Screens and quantitatively analyses the possible hazardous substances, such as the formaldehyde, extractable heavy metals (lead, cadmium, mercury and arsenic), alkylphenol polyoxyethylene ethers (APEO), polycyclic aromatic hydrocarbons (PAHs) and short-chain chlorinated paraffins (SCCPs), ensuring that the product meets the environmental protection regulations and ecological standard requirements at home and abroad.

Ecotoxicology and environmental behaviour testing: Evaluates the biodegradability, ecotoxicity (such as the acute toxicity to the aquatic organisms) and the residue and migration characteristics in the water bodies and soil of the leveling agent. This is related to the green and environmental protection attributes of the product, and is the key basis for obtaining the ecological label certification.

Application process adaptability testing: Simulates the actual production conditions, testing the compatibility of the leveling agent with the other auxiliary agents, emulsion stability (resistance to acid, alkali, electrolyte and shear), no corrosiveness to the equipment, and the application effects at the different temperatures and concentrations, ensuring its stability and effectiveness in the actual production.

Testing Scope

Leveling agents for the textile dyeing and printing: Including the various leveling and softening finishing agents for the natural fibres (cotton, wool, silk and flax), chemical fibres (polyester, polyamide and acrylic) and their blended fabrics. The testing needs to cover the different processes such as the pre-treatment, dyeing and finishing, evaluating the comprehensive influence on the fabric style and physical indicators.

Leveling agents for the plastic and rubber processing: Mainly referring to the internal and external lubricants, such as the stearic acid and its salts, waxes and organosilicon compounds. The dispersion in the polymer processing, thermal stability, the influence on the mechanical properties (such as the tensile strength and impact strength) and surface gloss of the products, as well as whether the problems such as the blooming and migration are caused, are tested.

Leveling agents for the papermaking industry: The chemicals used to improve the surface smoothness, gloss and printability of the paper, such as the polyethylene wax emulsions and organosilicon. The testing focus includes the sizing effect, the influence on the paper strength, air permeability and ink absorption, as well as whether the relevant safety standards such as the food contact materials are met.

Leveling agents for the personal care and daily chemical products: The components applied in the products such as the shampoos, conditioners and skincare products to impart the smooth skin feel or hair feel, such as the polydimethylsiloxane (silicone oil) and cationic conditioning agents. The testing needs to pay attention to their purity, irritation, sensitization and whether the cosmetic safety technical specifications and other regulations are complied with.

Leveling agents for the leather processing: The smooth hand feel agents used in the leather fatliquoring and finishing processes. The testing items include the improvement effects on the leather softness, fullness, waterproofness and the fastness to dry and wet rubbing, as well as whether the prohibited substances (such as the hexavalent chromium and specific azo dyes) are contained.

New and special leveling agents: Covering the organofluorine leveling agents, bio-based leveling agents, nanomaterial leveling agents and reactive durable leveling agents. The testing scope extends to their special functions, such as the super-hydrophobic/oleophobic property, antibacterial property, durability (resistance to washing and dry cleaning), as well as the safety evaluation of the nanomaterials.

Testing Methods

Chromatographic analysis method (GC/GC-MS, HPLC/LC-MS): The gas chromatography/mass spectrometry and high-performance liquid chromatography/mass spectrometry are the core means for the qualitative and quantitative analysis of the organic components in the leveling agent. The GC is applicable to the volatile silicone oils and fatty acid esters; the HPLC/LC-MS is applicable to the analysis of the heat-unstable, high-molecular-weight or strongly polar surfactants and additives.

Spectroscopic analysis method (FT-IR, NMR, ICP-MS/OES): The Fourier transform infrared spectroscopy is used for the functional group identification and structure confirmation; the nuclear magnetic resonance spectroscopy provides the more precise molecular structure information. The inductively coupled plasma mass spectrometry/optical emission spectrometry is used to precisely determine the trace and ultra-trace heavy metal impurity contents.

Physical property standard testing method: Executed in accordance with the international, national or industry standards. Such as the viscosity determination (GB/T 265 and ASTM D445), pH value determination (GB/T 6368), flash point determination (GB/T 3536 and ASTM D93) and surface tension determination (GB/T 22237 and ISO 304), ensuring the comparability and accuracy of the data.

Application performance simulation testing method: Simulates the actual application conditions in the laboratory. For example, a fabric style tester and friction coefficient tester are used to evaluate the hand feel of the textile; a small extruder and rheometer are used to evaluate the processing performance of the plastic lubricants; and a paper smoothness tester and printability tester are used to test the effects of the papermaking leveling agents.

Ecological safety standard testing method: Referring to the standard methods such as the OECD, ISO and GB. Such as the biodegradability testing (OECD 301 series), fish acute toxicity testing (OECD 203) and algae growth inhibition testing (OECD 201), scientifically evaluating the environmental risks of the product.

Hazardous substance restricted use standard testing method: Strictly carried out in accordance with the specific methods required by the regulations. For example, the formaldehyde content is determined according to GB/T 2912.1, the extractable heavy metals are determined according to the GB/T 17593 series standards, and the APEO content is determined according to GB/T 23322, ensuring the market access compliance of the product.

Testing Standards

Domestic Standards:

1. GB/T 265, Petroleum products — Determination of kinematic viscosity and calculation of dynamic viscosity

2. GB/T 6368, Surface active agents — Determination of pH of aqueous solutions — Potentiometric method

3. GB/T 3536, Petroleum products — Determination of flash and fire points — Cleveland open cup method

4. GB/T 2912.1, Textiles — Determination of formaldehyde — Part 1: Free and hydrolysed formaldehyde (water extraction method)

5. GB/T 17593, Textiles — Determination of heavy metals

6. GB/T 23322, Textiles — Determination of surfactants — Alkylphenol ethoxylates

International Standards:

1. ISO 304, Surface active agents — Determination of surface tension by drawing up liquid films

2. OECD 301, Ready biodegradability

3. OECD 203, Fish, acute toxicity test

4. OECD 201, Freshwater alga and cyanobacteria, growth inhibition test

Note: The applicable standard can be selected according to the product use and customer trade requirements; standards agreed in the contract take precedence over general standards.

Testing Instruments and Equipment

Chromatography-mass spectrometry combined instrument: As the core equipment of the composition analysis, the gas chromatography-mass spectrometry and liquid chromatography-mass spectrometry can separate, identify and quantify the complex organic substances in the leveling agent. It is the indispensable high-end instrument for the traceability analysis, impurity screening and formula analysis.

Spectroscopic analysis instruments: The Fourier transform infrared spectrometer is used for the rapid identification of the substance categories; the inductively coupled plasma mass spectrometer is the "gold standard" for detecting the heavy metal elements, with the extremely high sensitivity; the nuclear magnetic resonance spectrometer is used for the in-depth analysis of the precise molecular structures of the unknown compounds.

Physical property testing instruments: Including the rotational viscometer, densitometer, pH meter, automatic flash point tester, surface tension meter, thermogravimetric analyser and differential scanning calorimeter, used for the comprehensive characterization of the various basic physical and chemical parameters and thermal behaviours of the leveling agent.

Material application performance testing systems: For the different industries, the dedicated equipment needs to be equipped. Such as the hand feel tester, universal material testing machine and rubbing fastness tester in the textile field; the torque rheometer and melt flow rate tester in the plastic field; and the smoothness tester and gloss meter in the papermaking field.

Environmental toxicology testing equipment: Including the biochemical oxygen demand determination system, chemical oxygen demand tester, and the fish/algae/daphnia culture and observation systems for the acute toxicity testing, used to evaluate the ecotoxicological effects and environmental fate of the product.

Pre-treatment and auxiliary equipment: The efficient sample pre-treatment is the key to ensuring the accurate detection, requiring the microwave digestion instrument, Soxhlet extractor, solid phase extraction device, ultrasonic cleaner, precision analytical balance and the various standard sieves, constant temperature and humidity chambers and other auxiliary equipment to support the complete testing process.