DuPont Delrin® 111P POM
Executive Summary
DuPont Delrin® 111P is a high-viscosity polyoxymethylene (POM) homopolymer engineered for high-performance applications. Its distinction lies in its unique molecular structure, which, compared to traditional acetal copolymers, allows for a more organized crystalline network. This homopolymer advantage directly translates into superior mechanical properties, including higher tensile strength, greater stiffness, and significantly enhanced resistance to creep and fatigue. As a result, Delrin® 111P serves as a robust, dimensionally stable alternative to metals and a high-performance upgrade over standard engineering plastics like acetal copolymers and nylons. The material is optimized for injection molding, providing excellent precision, low warpage, and minimal void formation, making it a preferred choice for critical components in demanding applications across the automotive, industrial, and consumer goods sectors.
Introduction to DuPont Delrin® 111P
This section provides a foundational understanding of the material, its chemical identity, and its primary market position, setting the stage for the subsequent detailed analysis.
Material Identification and Chemistry
Delrin® 111P NC010 is a natural-colored, high-viscosity, high-molecular-weight polyoxymethylene (POM) provided in pellet form. Its chemical designation, according to ISO 1043-1, is POM. The material is notable for its pure homopolymer backbone, which distinguishes it from copolymers. While different product names such as Delrin® 111P, 111DP, and 111PA exist within this family, they refer to a very similar basic homopolymer grade, and their core performance and processing characteristics are highly consistent.
Core Attributes and Differentiating Advantages
The fundamental attributes of Delrin® 111P include high strength, high stiffness, good toughness, and exceptional dimensional stability. It represents a significant improvement over its predecessor, Delrin® 100P, with documented enhancements in tensile strength and modulus. Additionally, this grade is specifically modified for more precise injection molding, offering reduced warpage and minimizing the formation of voids. These collective improvements make it an ideal choice for applications requiring both high precision and mechanical robustness.
The Molecular Structure: The Homopolymer Advantage
The superior performance of Delrin® 111P is a direct result of its fundamental molecular architecture. The uniform homopolymer backbone allows for a more organized stacking of polymer chains as the material solidifies, creating larger, more ordered crystalline domains than those found in acetal copolymers. This highly regular crystalline structure forms an extensive and intricate network of entanglements, which restricts the relative movement of the polymer chains. This highly networked structure is the source of Delrin® 111P's excellent macroscopic mechanical properties. The restricted molecular mobility under sustained loads enables the material to better maintain its original shape, thereby providing superior creep resistance. Similarly, this network can absorb impact energy and help the structure return to its original configuration, significantly enhancing its impact strength. This structure also makes the material more resilient to repetitive stress cycles, offering exceptional fatigue endurance. This fundamental advantage of the homopolymer structure is the basis for the material's premium performance in demanding engineering applications.
Comprehensive Material Properties
Table 1: Key Technical Properties of DuPont Delrin® 111P
| Property | Value | Unit | Test Method |
|---|---|---|---|
| Mechanical Properties | |||
| Tensile Modulus | 3200 | MPa | ISO 527-1/-2 |
| Yield Stress | 72-73 | MPa | ISO 527-1/-2 |
| Yield Strain | 19-24 | % | ISO 527-1/-2 |
| Nominal Strain at Break | 35 | % | ISO 527-1/-2 |
| Flexural Modulus | 2900 | MPa | ISO 178 |
| Flexural Stress @ 3.5% strain | 80 | MPa | ISO 178 |
| Notched Charpy Impact @ 23°C | 11-12 | kJ/m² | ISO 179/1eA |
| Notched Charpy Impact @ −30°C | 8-9.5 | kJ/m² | ISO 179/1eA |
| Thermal Properties | |||
| Melting Temperature | 178 | °C | ISO 11357-1/-3 |
| Heat Deflection Temp @ 0.45 MPa | 165 | °C | ISO 75-1/-2 |
| Heat Deflection Temp @ 1.80 MPa | 98-100 | °C | ISO 75-1/-2 |
| Vicat Softening Temperature | 160 | °C | ISO 306 |
| Physical Properties | |||
| Density | 1420 | kg/m³ | ISO 1183 |
| Water Absorption @ Saturation | 1.0 | % | ISO 62 |
| Molding Shrinkage (Parallel) | 2.1 | % | ISO 294-4 |
| Molding Shrinkage (Normal) | 1.9 | % | ISO 294-4 |
| Melt Volume-Flow Rate (MVR) | 2.1 | cm³/10min | ISO 1133 |
| Electrical Properties | |||
| Comparative Tracking Index (CTI) | 600 | V | IEC 60112 |
Comparative Performance Analysis
This section places Delrin® 111P within the broader context of engineering materials, with data-backed arguments for its superiority over common alternatives.
Delrin® 111P vs. Standard Acetal Copolymer (POM-C)
Delrin® homopolymers, by design, outperform standard acetal copolymers in several critical areas. For example, typical copolymer grades like Hostaform® C 9021 and Celcon® M90 have tensile moduli of approximately 2760 to 2850 MPa, which is lower than Delrin® 111P's 3200 MPa. Similarly, the yield stress of Delrin® (72-73 MPa) is higher than the typical values for copolymers (64-65 MPa).
In terms of impact strength, Delrin® 111P’s notched Charpy impact strength at 23°C (11-12 kJ/m²) and at -30°C (8-9.5 kJ/m²) is significantly higher than that of typical copolymer grades (e.g., Celcon® M90's 6 kJ/m² or Hostaform® C 9021's 6.5 kJ/m²). This demonstrates the homopolymer's superior ability to absorb energy without fracturing. Although Delrin® 111P has a lower Melt Volume-Flow Rate (MVR) value (2.1-2.4 cm³/10min) compared to a grade like Hostaform® C 9021 (8 cm³/10min), it is noted for having "more favorable molding characteristics" and "better flow rates" in practice.
Table 2: Delrin® 111P vs. Typical Acetal Copolymer (POM-C)
| Property | Delrin® 111P | Typical POM-C | Unit |
|---|---|---|---|
| Tensile Modulus | 3200 | 2760-2850 | MPa |
| Yield Stress | 72-73 | 64-65 | MPa |
| Notched Charpy Impact | 11-12 | 6-6.5 | kJ/m² |
| Melting Point | 178 | 166 | °C |
| Melt Volume-Flow Rate (MVR) | 2.1 | 8 | cm³/10min |
| Density | 1420 | 1410 | kg/m³ |
Delrin® as a Metal Replacement
With its high strength, low friction, and wear resistance, Delrin® 111P is a viable alternative to metals such as steel, brass, and aluminum. A significant advantage is its light weight; it is roughly half the weight of aluminum and one-sixth the weight of steel, which is crucial for lightweighting initiatives in the automotive and aerospace industries to improve fuel efficiency and overall performance. Furthermore, Delrin®’s self-lubricating properties and low coefficient of friction make it ideal for maintenance-free sliding and moving parts. It also boasts excellent resistance to a wide range of chemicals, including gasoline, solvents, and neutral chemicals, making it suitable for environments where many metals would degrade.
Processing and Manufacturing Guidelines
This section serves as a practical guide for engineers, providing specific parameters and best practices for converting the raw material into a finished product.
Injection Molding Recommendations
To achieve optimal results with Delrin® 111P, the following processing parameters are recommended based on available data:
Table 3: Recommended Processing Parameters for Injection Molding
| Property | Range | Optimum | Unit |
|---|---|---|---|
| Melt Temperature | 210−220 | 215 | °C |
| Mold Temperature | 80−100 | 90 | °C |
| Hold Pressure | 90−110 | - | MPa |
| Drying Temperature | - | 80 | °C |
| Drying Time | 2−4 | - | hours |
Other Processing Methods
In addition to injection molding, Delrin® 111P is suitable for other fabrication techniques, including cast film, profile, and sheet extrusion. The material's "reliable machinability" allows it to be processed using standard machine shop equipment, including drilling, milling, turning, and sawing. Its high rigidity and dimensional stability ensure that it does not deform during machining, which facilitates achieving tight tolerances.
The Delrin® 111P Value Proposition
The value proposition of Delrin® 111P is rooted in its homopolymer structure, which provides a peerless combination of strength, toughness, durability, and dimensional stability. This fundamental molecular advantage allows it to outperform various engineering plastics, especially acetal copolymers, in key performance areas such as creep resistance, fatigue resistance, and impact strength. The material's light weight and self-lubricating properties also make it an excellent substitute for metals like aluminum and steel in applications requiring both weight reduction and reduced maintenance. For engineers seeking to design high-performance, long-lasting, and precise components for the most demanding applications, Delrin® 111P is a clear and reliable choice. Its superior mechanical properties, stable processing characteristics, and resistance to a variety of environments make it the material of choice when uncompromising performance and manufacturing precision are required.