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D4507-93 – Standard Test Method Technical Guide
ASTM D4507-93a defines the specification for thermoplastic polyester (TPES) materials used in molding and extrusion. It establishes a standardized approach to identifying material compositions through a series of referenced test methods, serving as a vital tool for manufacturers and quality assurance. The standard emphasizes that this specification is for calling out materials in end-use parts and not as a primary guide for material selection.
📐 Material Specifications and Classification
This specification covers TPES materials suitable for molding or extrusion. It includes properties required to identify compositions, with additional requirements agreed between user and supplier via suffixes in Section 5. Values are in SI units per Practice E380. Note that this standard is similar to ISO 7792/1-1985 but has significant technical differences.
⚙️ Test Methods and Performance Criteria
The standard references several ASTM test methods to evaluate material properties. These tests cover mechanical, thermal, physical, and flammability characteristics. Proper conditioning as per D618 is critical for reproducibility.
| 🟦 Test Method | 📏 Standard | ⚡ Property Measured |
|---|---|---|
| Tensile Properties | D638 | Strength and elongation |
| Deflection Temperature | D648 | Heat resistance under load |
| Flexural Properties | D790 | Flexural strength and modulus |
| Impact Resistance | D256 | Izod impact strength |
| Melt Flow Rate | D1238 | Viscosity and flow characteristics |
| Specific Gravity | D792 | Density |
| Transition Temperatures | D3418 | Thermal transitions |
| Inherent Viscosity | D4603 | Polymer viscosity for PET |
Conditioning of specimens according to Practice D618 is essential to ensure consistent and comparable test results across different materials and labs.
📊 Key Properties and Applications
The properties evaluated through these methods are critical for material identification. For example, tensile testing (D638) provides mechanical strength data, while deflection temperature (D648) indicates thermal performance. Flammability tests are included for risk assessment, but the standard cautions against using results for actual fire hazard evaluation.
| 🧪 Flammability Test | 📏 Standard | 🎯 Purpose |
|---|---|---|
| Horizontal Burning | D635 | Rate and extent of burning |
| Vertical Burning | D3801 | Extinguishing characteristics |
| Smoke Density | D2843 | Smoke generation from burning |
| Ignition Properties | D1929 | Ignition temperature and behavior |
| Oxygen Index | D2863 | Minimum oxygen for combustion |
Per Section 1.5, this standard measures properties under controlled lab conditions only and must not be used to appraise fire hazard under real fire conditions. Results may contribute to fire risk assessment when combined with other factors.
❓ Frequently Asked Questions
🔍 What is the scope of ASTM D4507?
It covers thermoplastic polyester materials for molding or extrusion, providing a means to call out materials for end-use parts, not for material selection.
💡 How should materials be selected according to this standard?
Material selection requires expertise in plastics, considering design, performance, environment, fabrication, and economics. This specification is for calling out materials only.
⚡ What test methods are referenced in D4507?
Key methods include D638 for tensile, D648 for deflection temperature, D256 for impact, D1238 for flow rate, and flammability tests like D635 and D2863.
📌 How does D4507 relate to ISO 7792/1?
While similar in scope, the technical content of this standard differs significantly from ISO 7792/1-1985, as noted in the standard.