PVC SG8 Resin K59-55 For Sale

PVC SG8 is a high polymerization, rigid polyvinyl chloride (PVC) resin produced by suspension polymerization, with an average degree of polymerization of 650-750 and a K value of 55-59. Compared with the general-purpose PVC SG5, SG8 has a higher molecular weight and melt strength, resulting in superior mechanical properties, internal pressure resistance, and forming hardness. It is particularly suitable for the production of rigid extruded and injection-molded products.

Currently, the main manufacturers of PVC SG8 include Zhongtai Chemical, Xinjiang Tianye, Shaanxi Beiyuan, Sanyou Chemical, Beiyuan Chemical, and Inner Mongolia Yihua, all of which use the calcium carbide-based suspension polymerization process.

Item		PVC SG8
Viscosity No. ml/g		86-73
K value		59-55
Polymerizing Index		740-650
Number of impurity particles		20max
Volatile Matter, %		0.4max
Apparent Density, g/ml		0.50min
Number of Fish Eye (/400 cm2)		30max
Plasticizer absorption of 100g resin, g		12min
VCM Residue, ppm		5max
Whiteness(160°C,10min), %		75min
Particle size	≥0.25mm	2.0max
	≥0.063mm	95min

Performance Features of PVC SG8

(1) Excellent Mechanical Properties. With a relatively high molecular weight, PVC SG8 provides superior impact resistance and mechanical strength. Its high degree of polymerization offers excellent internal pressure resistance, making it suitable for manufacturing pressure-bearing pipes.

(2) Good Processing Adaptability. SG8 PVC resin can be processed by extrusion, injection molding, and compression molding. It has good compatibility with processing aids and thermal stabilizer systems.

(3) Strong Chemical Resistance. It offers good resistance to acids, alkalis, and most salts, and is not affected by oils or alcohol-based solvents.

(4) Outstanding Electrical Insulation. With high volume resistivity and low dielectric loss, PVC resin SG8 is well suited for electrical insulation applications such as cable sheathing and electrical conduit pipes.

(5) Cost-Effective. PVC material is known for its stable price, low production cost, and strong substitutability. Although PVC resin SG8 is slightly more expensive than SG5, it offers excellent economic value in applications requiring higher mechanical strength.

Primary Uses

Pipe and Fitting Systems. PVC resin SG8 performs well in rigid PVC pipe systems such as uPVC water supply pipes, agricultural irrigation pipes, and pressure transmission pipelines. Manufacturers also use this grade for injection-molded pipe fittings, including elbows, tees, and various connectors, where it delivers stable dimensions and reliable mechanical strength.
Profiles. The resin suits the extrusion of building door and window profiles, decorative trim profiles, and a wide range of industrial profiles. Products made from this grade maintain good rigidity, smooth surface appearance, and long-term service performance.
Electrical Products. Producers commonly apply PVC SG8 in wire and cable protective conduits, electrical conduit pipes, and cable trunking systems with matching accessories. These products provide effective electrical insulation and dependable flame-retardant performance.
Sheets and Plates. This material supports the production of rigid PVC sheets and plates used in furniture panels and chemical corrosion-resistant boards. The material offers good stiffness, chemical resistance, and easy secondary processing.
Other Industrial Products. It also serves in PVC corrugated roofing sheets, transparent PVC products with added UV stabilizers, and drip irrigation tape substrates, meeting requirements for weather resistance, transparency, and processing stability.

Environmental and Safety Key Points

Although processing temperatures are relatively low, adequate ventilation is still required to prevent the accumulation of residual VCM (vinyl chloride monomer). It is recommended to equip facilities with activated carbon adsorption systems.
Preferably, use calcium-zinc composite stabilizers to produce RoHS-compliant electronic and electrical components, with heavy metal content ≤10 ppm.
Waste PVC SG8 products can be mechanically recycled. Recycled material can be used to manufacture items such as building cover panels and industrial pallets. Due to the lower initial mechanical strength, it is recommended that recycled material is not reused more than twice to ensure product performance.