Flash

Flash is excess thin sheet-like, spiky, or film-like waste material formed when material overflows the mold parting line or ejector locations during injection molding, die casting, forging, and similar processes. In foreign trade, flash is both a quality defect term and a key indicator for acceptance and claims. Usage scenarios include: 1) specifying in procurement contracts or technical agreements that 'products shall be free from flash affecting function or appearance'; 2) describing defects in inspection reports; 3) serving as evidence in customer complaints or claims. Notes: Flash and burr are often confused, but flash specifically refers to overflow at the mold parting surface, while burr mostly refers to fine protrusions after machining; flash and overflow are often synonymous in injection molding. Difference: Flash is a defect, while 'flash removal' is an allowed trimming process. Foreign trade practitioners need to clarify the allowable size, location, and trimming standards for flash to avoid returns or deductions due to ambiguous definitions. In addition, different industries have different acceptance levels for flash; for example, automotive and medical parts usually have zero tolerance.