Application of VINNAPAS Resin in Composite Materials
VINNAPAS resins are used in fiber-reinforced plastic composites as low-profile additives, which can reduce the shrinkage rate to below 0.05% and achieve Class A surface finish. Series C can be thickened with oxides, while Series B and UW are suitable for mild thickening conditions. These resins are easily soluble in styrene and can be prepared into solutions for SMC, BMC and other processes.
In fiber reinforced plastic (FRP) composites, solid VINNAPAS® resins are used as low-profile additives to achieve zero shrinkage, Class A surface quality, complete viscosity control and design flexibility.
VINNAPAS® resins are highly efficient thermoplastic shrinkage-resistant (low-profile) additives suitable for high-temperature molded unsaturated polyester resin composites. Besides zero shrinkage, high-temperature unsaturated polyester applications like Sheet Molding Compound (SMC) and Bulk Molding Compound (BMC) require effective thickening to ensure easy processing of composites and even distribution of glass fibers during compression molding flow. The carboxylated VINNAPAS® C series combined with magnesium oxide or calcium oxide forms an ideal thickening system for unsaturated resin composites. Used with thickeners, it can reach stable high viscosity. After maturation, this combination effectively prevents thermoplastic resin bleeding.
Carboxyl-free VINNAPAS® B and UW homopolymer series are only used for unsaturated polyester resin composites requiring mild thickening or no thickening.
Add VINNAPAS® resin into styrene and stir fully to prevent lump formation in the dissolving process. The operation is usually conducted at room temperature. A slight temperature rise during dissolution is normal, which is caused by shear friction. The prepared solution shall be protected from direct sunlight during storage, and excessive heat will speed up dissolution.
It is essential to maintain solution stability since styrene monomers are prone to self-polymerization. The solid content of VINNAPAS® LPA solution is generally 40%, and this proportion may change according to the molecular weight of different VINNAPAS® series and composite material formulas.
VINNAPAS® resins are highly efficient thermoplastic shrinkage-resistant (low-profile) additives suitable for high-temperature molded unsaturated polyester resin composites. Besides zero shrinkage, high-temperature unsaturated polyester applications like Sheet Molding Compound (SMC) and Bulk Molding Compound (BMC) require effective thickening to ensure easy processing of composites and even distribution of glass fibers during compression molding flow. The carboxylated VINNAPAS® C series combined with magnesium oxide or calcium oxide forms an ideal thickening system for unsaturated resin composites. Used with thickeners, it can reach stable high viscosity. After maturation, this combination effectively prevents thermoplastic resin bleeding.
Carboxyl-free VINNAPAS® B and UW homopolymer series are only used for unsaturated polyester resin composites requiring mild thickening or no thickening.
Composite parts will suffer severe shrinkage without low-profile additives. Adding VINNAPAS® resins can lower the shrinkage rate below 0.05% to obtain extremely smooth and uniform surfaces.
VINNAPAS® low-profile additives (LPA) are almost fully soluble in styrene. Solid VINNAPAS® polyvinyl acetate resins dissolve easily in styrene, allowing you to prepare VINNAPAS® styrene solutions as needed.
Add VINNAPAS® resin into styrene and stir fully to prevent lump formation in the dissolving process. The operation is usually conducted at room temperature. A slight temperature rise during dissolution is normal, which is caused by shear friction. The prepared solution shall be protected from direct sunlight during storage, and excessive heat will speed up dissolution.
It is essential to maintain solution stability since styrene monomers are prone to self-polymerization. The solid content of VINNAPAS® LPA solution is generally 40%, and this proportion may change according to the molecular weight of different VINNAPAS® series and composite material formulas.
The average content of VINNAPAS® low-profile additives in styrene is listed below:VINNAPAS® C Series: 40%VINNAPAS® B Series: 40 – 45%VINNAPAS® UW Series: 30 – 40%
