CCP BP-05S

The core of polyvinyl alcohol (PVA) performance lies in its degree of hydrolysis. The 88 Series PVA, which is partially hydrolyzed (usually around 87.0 to 89.0 mol%), differs from the fully hydrolyzed 99 Series in that it provides better flexibility, interfacial activity, and water solubility that can be adjusted. When PVA is partially hydrolyzed, about 11% to 13% of vinyl acetate groups (-OAc) are kept in the molecular chain. Because of these hydrophobic groups, the 88 Series PVA acts as an amphiphilic substance with high interfacial activity, unlike the 99 Series. Because of this, it works well as a protective colloid in emulsion polymerization and as a flexible base for strong adhesives and coatings with specific functions.     1. Molecular Structure Determines Function: Amphiphilicity and Protective Colloid Mechanism 1.1  Amphiphilicity Due to Hydrophobic-Hydrophilic Balance Partially hydrolyzed 88 series PVA molecular chains possess two functional groups with vastly different polarities: Hydrophilic groups: A large number of hydroxyl groups (-OH). Hydrophobic groups: A small number of evenly distributed vinyl acetate groups (-OAc). This structure makes PVA a highly effective high-molecular-weight surfactant or protective colloid. When dissolved in water, the molecular chains adsorb at the water-oil (monomer) interface, with the hydrophobic groups tending to embed into the oil phase, while the hydrophilic groups extend toward the water phase. This unique arrangement forms a stable, high-molecular-weight physical barrier (i.e., a protective steric barrier) around the oil phase particles, effectively preventing aggregation of emulsion particles during polymerization, storage, or mechanical shear, and is the core mechanism for ensuring emulsion stability. 1.2 Reduced Crystallinity and Improved Water Solubility Unlike the highly regular structure of the 99 series, the irregular distribution of vinyl acetate groups on the molecular chain disrupts the regular packing of PVA molecules, resulting in: Reduced crystallinity: The proportion of crystalline regions decreases, weakening the hydrogen bond network. Improved cold-water solubility: Lower crystallinity allows water molecules to more easily penetrate and disrupt the amorphous region structure. Therefore, 88 series PVA can dissolve quickly or even completely at lower temperatures (typically 40°C to 60°C), greatly simplifying dissolution operations during formulation and production.   2. Effect of Degree of Polymerization on Rheological Properties and Stability Given a consistent level of partial hydrolysis, the key differences between different PVA grades are mainly in their average degree of polymerization (DP) or molecular weight (MW). The DP has a direct impact on the viscosity of the PVA solution, the thickness of the steric barrier layer, and how the emulsion ultimately performs. The refined positioning of ElephChem's 88 series grades: ElephChem PVA Average degree of polymerization Average molecular weight Core application positioning 2688 / 2488 2400~2650 118000~130000 High molecular weight: Provides the strongest steric protection and is used in emulsion polymerizations requiring the highest stability (such as high-performance VAE emulsions). 2088 / 1788 1700~2100 84000~104000 General purpose: Balances viscosity and protection for general-purpose PVAc and VAE emulsions and adhesives. 1792 1700~1800 54000~60000 Medium-low molecular weight: Suitable for specialty water-soluble fibers and viscosity-sensitive coating systems. 0588 / 0488 420~650 21000~32000 Ultra-low molecular weight: Minimal effect on solution viscosity, suitable for inks, inkjet coatings, or as a co-stabilizer in emulsions. High degree of polymerization (Polyvinyl Alcohol 2688 / Polyvinyl Alcohol 2488): Long molecular chains provide a stronger steric hindrance. In emulsion polymerization, long chains help distribute and stabilize monomer droplets and polymer particles, which is needed for high-solids, high-viscosity emulsions. Ultra-low degree of polymerization (Polyvinyl Alcohol 0488 / Polyvinyl Alcohol 0588): These stabilizers function similarly to small-molecule emulsifiers, but provide improved polymer adhesion. Their low viscosity allows them to be used in high-solids coatings and slurry systems without affecting the rheological properties of the final product.   3. Analysis of Key Industrial Applications of Partially Hydrolyzed 88 Series PVA The interfacial activity and controllable water solubility of the 88 series PVAs give them core competitiveness in the fine chemicals, adhesives, and specialty materials sectors: 3.1 Emulsion Polymerization Industry: Stabilizers and Protective Colloids This is the core and irreplaceable application of the 88 series PVAs. It is widely used in the polymerization of monomers such as vinyl acetate (VAc), acrylates, and styrene-acrylates, and is a key additive in the manufacture of PVAc, VAE, and acrylate emulsions. Mechanism: 88 Series PVA acts as a protective colloid, not only stabilizing the emulsion during the initial polymerization phase but, more importantly, determining the freeze-thaw resistance, mechanical shear stability, and rewettability of the final emulsion. Applications: Architectural coating emulsions (such as interior wall latex paint), wood adhesives (white latex), textile nonwoven adhesives, carpet adhesives, etc. 3.2 Water-Solubility and Functional Films/Fibers The low crystallinity of partially hydrolyzed PVA makes it easier to dissolve quickly in cold water, making it a preferred environmentally friendly packaging material. Water-Soluble Packaging Film: Used for quantitative packaging of products such as pesticides, dyes, detergents, and laundry detergent beads. Upon application of water, the film quickly dissolves, releasing the contents, providing both convenience and environmental friendliness. Water-Soluble Fiber: Used in the textile industry as temporary support yarn or "sacrificial" yarn. After the fabric is finished, the PVA fibers dissolve in warm water, leaving behind a fabric with a special openwork or structural effect. 3.3 Adhesive and Coating Systems Adhesives: Due to the retention of hydrophobic groups in the molecular chain, 88-series PVA has better affinity and adhesion to certain hydrophobic surfaces and organic materials than 99-series PVA. It is widely used in specialty paper adhesives and rewettable adhesives (such as postage stamp adhesives). Specialty Coatings: Ultra-low molecular weight grades (such as 0488) can be used as ink-receiving coating additives for inkjet printing paper, providing excellent pigment binding and fast drying properties without significantly increasing coating viscosity. 3.4 Other Fine Chemical Applications Suspension Polymerization Dispersant: Used in the suspension polymerization of PVC resins, it helps control the size, porosity, and density of PVC particles, which is crucial to the processing properties of PVC resins. Ceramic Binder: Used as a temporary binder for bonding ceramics before molding and sintering. After sintering, it can be completely burned and vaporized, leaving no residue.   4. Conclusion: Continuous Innovation in Partially Hydrolyzed 88 Series PVA ElephChem partially hydrolyzed 88 Series PVA takes full advantage of both hydrophilic and hydrophobic elements in its molecular structure. This allows for careful control during emulsion polymerization and affects how well it sticks and dissolves in water. If the 99 Series is the "rebar" of structural materials, then the 88 Series is the "stabilizer" and "flexibility controller" of fine chemical systems. Partially hydrolyzed 88 Series PVA is still critical to the growth of modern fine chemicals and sustainable materials. This is due to the continued expansion of markets, like those for green water-based coatings, good emulsions, and biodegradable packaging, along with PVA's special interfacial chemistry and grade system.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com

Polyvinyl alcohol (PVA) is an essential polymer material in numerous applications, including dry-mix mortar, adhesives, and textile sizing. When selecting PVA products, users often focus on their degree of polymerization, alcoholysis degree, and mesh size to ensure core properties such as solubility, viscosity, and bond strength. However, dust content is a crucial, often overlooked indicator that directly impacts production safety, operator health, and material loss. The mesh size of PVA (e.g., 20, 120, 200 mesh) determines its particle size, and particle size is the primary factor determining dust content.    1.Why does PVA generate dust? The dust content of PVA powder is primarily affected by its particle fineness (mesh size) and morphology: Finer particles generate higher dust content. Products with larger mesh sizes (e.g., 200 mesh) have a higher proportion of fine particles and a greater ability to remain suspended in air, resulting in greater dust generation. Static electricity: Dry PVA powder is prone to static electricity during friction and conveying, which can exacerbate the suspension and dispersion of fine particles.   2. Definition and Significance of Dust Content "Dust content" refers to the degree of fine dust suspended in the air during the handling of powder products due to their extremely fine particles. These fine particles (typically less than 10 μm or even 5 μm) not only cause material loss but, more importantly, impact operational safety, environmental cleanliness, and worker health. Dust analysis of PVA products with different mesh sizes: Mesh Size 20 mesh (PVA 088-05) 120 mesh (PVA 088-50S) 200 mesh (PVA-217S) Particle Size Range Approximately 800-900 μm Approximately 100-150 μm Approximately 50-80 μm Particle Surface Area Very Low Moderate Moderate Very High Dust Level (Relative) Low Medium-Low High Photo Aerodynamic Characteristics Heavy particles with high inertia settle easily and are difficult to suspend. 120 mesh (CCP BP-24S) settle quickly, but will still fly at the moment of feeding. Light particles are easily carried by air currents and remain suspended for a long time, forming a dust cloud. Occupational Health Risks Lowest risk. Dust is mostly non-inhalable and has minimal respiratory irritation. Risk is manageable. General local exhaust ventilation and protective equipment are required. Highest risk. Fine dust poses a high risk of lung entry and requires strict protection. Dust Explosion Risk Large particle size makes dust cloud formation difficult, resulting in a low risk. Possesses some potential for dust cloud formation, resulting in a medium risk. Dust cloud density easily reaches the lower explosion limit, resulting in the highest risk. Production and feeding requirements General ventilation is sufficient. Local exhaust or dust hoods are required. Efficient, enclosed feeding and specialized dust collection systems are essential. Cost Factors No additional dust suppression treatment is required. Anti-caking agents (or granulation) may be required to reduce dust. High costs must be invested in crushing, fine grading, and safety protection systems. Properly controlling PVA dust levels is not only a safety requirement but also directly impacts production efficiency and product quality: Excessive dust concentrations can cause material loss and metering errors; Suspended particles entering the reaction system can lead to unstable emulsion polymerization or uneven film thickness; Dust deposition can accelerate equipment wear and affect long-term operational reliability.   Regardless of mesh size, all PVA powder handling practices should adhere to the following basic principles: Avoid vigorous handling: Pour the material into the container slowly and steadily, avoiding pouring from a height to minimize interparticle friction and air turbulence. This is the simplest and most effective way to reduce dust generation. Maintain ventilation in the work area: Local exhaust or exhaust systems must be installed near all feed ports and mixing equipment to capture generated dust at the source. Adhere to chemical management practices: Although PVA has low toxicity, the storage, handling, and emergency response instructions in the Material Safety Data Sheet (SDS) should still be reviewed and followed. Environmental cleanliness: Regularly clean accumulated dust from equipment and floors with an industrial vacuum cleaner. Never use compressed air to blow dust, as this will re-inflate accumulated dust, increasing the risk of explosion and inhalation.   3. Conclusion In the production and use of PVA powder, dust management is the intersection of process control and safety assurance. Different mesh sizes require appropriate feeding methods and protective measures. Especially for fine powders above 120 mesh (CCP BP-20S), engineering approaches to dust control should be prioritized, rather than relying solely on personal protection. Through scientific particle size selection, process design, and environmental control, PVA product performance and production stability can be maximized while ensuring safety.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com  

Polyvinyl alcohol (PVA), an indispensable water-soluble polymer material, is used in a wide range of fields, including construction, textiles, papermaking, and chemicals. Among the many PVA specifications, mesh size, or particle fineness, is a key factor in determining processing efficiency and final product quality.   1. Mesh Size Basics: A Measurement of Particle Size Mesh size is a unit of measurement for powder particle fineness. It refers to the number of holes in a sieve per inch. The smaller the mesh size, the larger (coarser) the particles. Mesh size and dissolution rate: The dissolution process of a powder begins with the wetting and penetration of the particle surface by water molecules. The finer the particle size (the larger the mesh size), the greater its specific surface area. A larger specific surface area means that water molecules can contact more PVA molecular chains, significantly accelerating wetting, swelling, and disentanglement, ultimately increasing dissolution rate. Mesh size and dispersion uniformity: Fine particles are more easily dispersed in liquid or solid mixtures. When coarse particles (such as 20 mesh) are added to water, they are more likely to settle or clump due to density differences, forming "fish eyes" that are difficult to dissolve. Mesh Size and Dust Density: The finer the particle size, the lower the critical velocity at which it becomes suspended in air, resulting in higher dust levels. 20 mesh PVA produces low dust, while 200 mesh PVA requires strict dust control measures.   2. Introduction and Application of PVA Specifications of Different Mesh Sizes Mesh Size  20 mesh(Polyvinyl Alcohol 0588) 120 mesh (PVA 088-05S) 200 mesh (POVAL 22-88 S2) Photo Bulk Density Relatively high Medium Relatively low (fluffy powder) Key Features The largest particles have the lowest surface area. This dissolution process is the slowest, but dust generation during operation is minimal; it is also known as a "low-dust" or "dust-free" grade. This medium-sized particle size is the most commonly used grade in industry. It strikes a good balance between dissolution efficiency, ease of operation, and cost. The extremely fine particles and maximum surface area ensure the fastest dissolution and the best dispersibility. Applications Dry-mix mortar for construction: Coarse-grained PVA, as a binder, is less likely to form high-viscosity clumps during initial mixing, allowing for better dispersion in other components (such as cement and sand). It also produces minimal dust, improving the on-site construction environment.   Specialized slow-release adhesives: In certain specialized construction mortars or adhesives, PVA needs to dissolve slowly to provide lasting adhesion.   Preventing rapid thickening: Suitable for formulations that require prolonged mixing and where rapid thickening of the solution is undesirable. Conventional adhesives: Used in the manufacture of common water-based adhesives such as wood glue and paper glue.   Textile sizing agents: Prepare sizings at standard temperatures and times to meet the sizing requirements of most textiles.   Emulsion polymerization protective colloids: Serves as stabilizers and protective colloids in the polymerization of emulsions (such as VAE and acrylic emulsions). They provide a sufficiently rapid dissolution rate without excessively increasing system viscosity, ensuring stability and particle size distribution during emulsion polymerization. High-end water-based coatings: Suitable for high-end paints and putty powders that require extremely high dispersibility and a minimum of residual particles.   Fast Preparation/Low-Temperature Dissolution: Fine powder ensures rapid and thorough dissolution of PVA at low temperatures or under limited stirring capacity.   Water-Soluble Film: Used in the production of water-soluble packaging films requiring high transparency and good solubility, such as laundry bags and pesticide packaging.   Pharmaceutical/Cosmetic Excipients: Used in certain fine chemical applications requiring high precision.   3. How to Make the Best Choice? Choosing the right mesh size for PVA is essentially a trade-off between production efficiency, environmental safety, and product performance: For those seeking dissolution speed and product fineness (e.g., coatings and films): 200 mesh is preferred. For those seeking versatility, balanced performance, and moderate cost (e.g., conventional adhesives): 120 mesh is preferred(PVA 088-50S). For those emphasizing operational safety, low dust generation (e.g., large-volume batching), or specific sustained-release requirements: 20 mesh is preferred(Poval 217).   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com