Premium PVC Resins SG3, SG5, SG7: Tailored Engineering for End - to - End Industrial Solutions

Molecular Design & Physical Attributes

SG3 (High - Flexibility Grade)
Engineered with a polymerization degree of 1300 - 1500 and K - value of 70 - 72, this grade features long molecular chains that enhance plasticizer entrapment.  Its 60 - 250μm particle distribution ensures uniform dispersion in soft compound formulations, allowing 25 - 35g of plasticizer absorption per 100g resin.  The resulting amorphous structure grants exceptional elongation at break, making it ideal for products requiring repeated flexing without cracking.

SG5 (Versatile Medium - Grade)
Balancing a polymerization degree of 1000 - 1100 with a K - value of 65 - 67, SG5 offers a dynamic middle ground.  Its optimized particle density (0.45 - 0.58g/mL) facilitates smooth melt flow in both extrusion and injection molding, while moderate plasticizer absorption (20 - 28g/100g) enables transition from semi - rigid cable sheaths to low - flexibility profiles.  The molecular chain regularity minimizes processing defects, ensuring consistent wall thickness in pipe extrusion.

SG7 (Rigid Engineering Grade)
With a polymerization degree of 700 - 850 and K - value of 60 - 62, SG7 prioritizes molecular packing efficiency for rigidity.  Its compact 40 - 180μm particle structure (density 0.50 - 0.62g/mL) reduces voids in molded parts, enhancing impact resistance in building profiles.  The low plasticizer absorption (15 - 22g/100g) allows for fully rigid formulations, while residual vinyl monomer ≤3μg/g meets food - contact safety standards for packaging applications.

Application Ecosystem

SG3: The Flexibility Specialist
In agricultural sectors, SG3 - based films with 40 - 50 phr plasticizer additions form UV - stabilized greenhouse covers, balancing light transmission with tear resistance strength.  For medical applications, its low monomer content enables soft tubing for dialysis machines, while in footwear, it creates elastic soles that retain shape across temperature fluctuations.

SG5: The Industrial Workhorse
Cable manufacturers leverage SG5’s 10 - 20 phr plasticizer range to produce flame - retardant insulation sheaths for power grids, combining electrical insulation with mechanical durability.  In construction, it extrudes into weatherproof sealing strips for windows, where its moderate hardness resists ozone degradation.  Injection - molded automotive components, such as door trims, benefit from its impact - strength - to - weight ratio.

SG7: The Rigidity Champion
Industrial piping systems rely on SG7’s high modulus for chemical - resistant sewer pipes and pressure - rated water mains.  Extruded window profiles, when blended with titanium dioxide, exhibit exceptional colorfastness in outdoor environments.  Electronics manufacturers use it for injection - molded appliance housings, capitalizing on its dimensional stability during high - temperature assembly.

Process Optimization Guide

Thermal Management Nuances
SG3 demands strict temperature control (160 - 180°C) to prevent premature decomposition;  even a 10°C overshoot can cause hydrochloric acid release, leading to yellowing.  In contrast, SG7 tolerates 180 - 200°C processing, allowing faster extrusion rates for large - diameter pipes, though exceeding 210°C risks molecular chain scission.

Additive System Design
Stabilization: SG3 requires 1 - 2 phr of calcium - zinc composite stabilizers to counteract thermal degradation during high - plasticizer processing, while SG7 needs only 0.5 - 1 phr due to reduced plasticizer - induced stress.
Lubrication: All grades benefit from 0.2 - 0.5 phr of polyethylene wax, but SG3 may require higher dosages to mitigate internal friction in soft compounds.
Functional Additives: Antioxidants in SG7 formulations extend outdoor service life, while impact modifiers in SG5 enhance notch resistance for cold - climate applications.

Engineering Excellence in Resin Design

By integrating precise molecular engineering with application - driven testing, our SG3, SG5, SG7 portfolio empowers manufacturers to transcend traditional PVC limitations. From the flexibility required for medical disposables to the structural integrity demanded by high - rise construction, these resins embody the fusion of scientific rigor and industrial practicality—setting new benchmarks for performance - driven polymer solutions.

Specifications

Quality Control Sheet