会社のニュース The Difference Between General Plastics and Engineering Plastics

  Plastics are broadly categorized into general-purpose plastics and engineering plastics, based on their performance characteristics and typical applications. Definition: General-purpose plastics are characterized by their high production volume, wide range of uses, excellent formability, and low cost. They are the workhorses of the plastics industry. Engineering plastics, conversely, are a class of polymers engineered specifically for use as industrial components or structural housing materials. They are defined by their superior mechanical strength, impact resistance, heat resistance, hardness, and long-term aging stability. Key Differences: The most common general-purpose plastics are the "big five": Polyethylene (PE), Polypropylene (PP), Polyvinyl Chloride (PVC), Polystyrene (PS), and ABS. All are thermoplastics. Engineering plastics encompass materials like Polycarbonate (PC), Polyamide (PA/Nylon), Polyacetal (POM), Modified Polyphenylene Ether (PPO), Polyester (PBT, PET), Polyphenylene Sulfide (PPS), and Polyarylate. This category also includes high-performance thermosets like unsaturated polyester, phenolic plastics, and epoxy resins. Application: This is the primary differentiating factor. General-purpose plastics are typically used for non-structural applications in high-volume consumer goods, packaging, and everyday items (e.g., bottles, films, containers, disposable products). Engineering plastics are selected for technical applications where they must withstand mechanical stress, heat, and harsh environmental conditions, often replacing traditional materials like metal, glass, or wood in automotive parts, electronic enclosures, gears, and bearings.