Surface blurriness in injection molded products refers to the unclear areas formed on the product's surface due to poor mold interior surfaces or excessive use of mold release agents.

In the process of injection molding, a subtle and barely noticeable line occasionally appears on the surface of plastic products—water marks, also known as weld lines. These hairline seams originate from the interface where molten plastic flows and merges within the injection mold cavity, hence they are vividly termed as flow marks.

In the injection molding process, plastic deformation failure is an issue that cannot be ignored. This phenomenon refers to the situation where localized plastic deformation occurs in the mold cavity under the action of molding pressure and temperature, rendering the mold unusable or even scrapped.