Project Description
Thermal and Hydrolysis Resistant PET Resin
High-IV & Low-CEG Solutions for Polyester Spiral Link Dryer Fabric
Product Overview
In extreme industrial environments such as papermaking and industrial filtration, standard polyester (PET) fibers quickly degrade due to high temperature and moisture. To solve this challenge, our High-IV (Intrinsic Viscosity) & Low-CEG (Carboxyl End Group) PET Resin is engineered specifically for high-performance industrial monofilament extrusion. High IV & Low CEG PET Resin is also called Thermal- and Hydrolysis-Resistant PET Resin.
High-IV (IV≥0.90 dl/g): Represents ultra-long molecular chains, imparting exceptional mechanical strength, superb modulus, and outstanding creep resistance to the end product.
Low-CEG (≤ 12 mol/t): Minimizes reactive carboxyl end groups, thereby shifting the chemical equilibrium to prevent hydrolytic cleavage in harsh environments.
Advanced Manufacturing Process
Our specialty resin is produced via a rigorous, state-of-the-art two-step polymerization technique:
1. Melt Polycondensation: Pure Terephthalic Acid (PTA) and Ethylene Glycol (EG) undergo conventional melt polymerization to form base amorphous PET chips with a standard viscosity (IV ≈ 0.64-0.68dl/g).
2. Solid-State Polycondensation (SSP): The base chips are pre-crystallized and transferred into a high-vacuum, nitrogen-purged SSP reactor tower. When maintained at temperatures just below the melting point (200–220°C) for extended periods, the polymer chains continue to elongate in the solid state. This process achieves the target high-IV while successfully capping and reducing the remaining carboxyl groups to under 12 mol/t (or even below 10 mol/t)
Technical Specifications
| Property | Unit | Standards | Test Result | |
| Intrinsic Viscosity | dl/g | 0.93±0.010 | 0.93 | |
| Melting Point | ℃ | 260±2 | 259 | |
| Color Value | b | 5.0±1.5 | 5.2 | |
| L | ≥84 | 89 | ||
| End Carboxyl | mol/t | ≤10 | 10 | |
| Moisture Content | % | ≤0.4 | 0.1 | |
| DEG Content | % | 1.05±0.15 | 0.94 | |
| Ash Content | % | ≤0.05 | 0 | |
| Fe Content | mg/kg | ≤2 | 1 | |
| Irregular Chip | % | ≤0.3 | 0 | |
| Powder Content | mg/kg | ≤100 | 0 | |
| TiO2 Content | % | 0.31±0.03 | 0.31 | |
Unique Performance Advantages
Inhibition of “Autocatalytic” Hydrolysis: Standard PET degrades in wet, hot conditions when water molecules attack its ester bonds. This cleavage generates more acidic carboxyl groups (-COOH), which then act as an autocatalyst to accelerate further degradation. By drastically reducing the initial CEG, our resin eliminates the source of autocatalysis, extending the mesh fabric’s service life by 2 to 4 times.
Superior Dimensional Stability: The high-IV structure guarantees that extruded monofilaments exhibit high crystallinity and orientation. The resulting fabrics resist stretching, shrinking, or creeping under prolonged high mechanical tension.
Excellent Surface Wear Resistance: The robust macro-molecular weight enhances intermolecular cohesion, ensuring the mesh surface withstands persistent metal-to-yarn and yarn-to-yarn mechanical friction without fraying or filament breakage.
Downstream Applications
Our high-IV, low-CEG resin is primarily extruded into heavy-duty Industrial Monofilaments (typically ranging from 0.1mm to 1.0mm or larger in diameter) for weaving technical textiles:
Polyester Spiral Link Dryer Fabrics: The primary application. Used in the dryer section of paper machines where monofilaments are formed into spiral loops or woven screens. They transport paper sheets through steam-heated cylinders at 100–160°C under severe humid-heat exposure.
Sludge Dewatering Belts & Filter Press Meshes: Applied in municipal wastewater treatment and industrial environmental filtration, where resistance to chemical attack and high tension is mandatory.
Industrial Conveyor Belts: Used in food dehydration lines (e.g., tea and food drying), textile printing/dyeing dryers, and solid-liquid separation nets in the chemical sector.
Critical Industry Pain Points Solved
Eliminating Unscheduled Downtime from “Mesh Bursting”: Traditional dryer fabrics embrittle rapidly due to steam hydrolysis, leading to sudden mesh rupture. Our resin mitigates this risk, ensuring predictable maintenance cycles.
Preventing Paper Wrinkling and Off-Tracking: Under excessive tension and heat, standard monofilaments creep, leading to belt distortion. The exceptional dimensional stability of our resin maintains an absolutely flat fabric line and precise paper tracking.
Cost-Effective Alternative to High-End Engineering Plastics: Rather than forcing manufacturers to upgrade to prohibitively expensive specialty polymers such as PPS, PFA, or PEEK, our advanced PET offers a high-ROI alternative that delivers the required hydrolysis resistance at a fraction of the cost.
