The “7 types of plastics” usually refer to the Resin Identification Code system found on packaging and molded products. The number inside the familiar triangular symbol identifies the main resin family; it does not automatically indicate recyclability, safety, quality, or the number of times a product has been recycled.

The phrase seven types of plastic recycling usually refers to the seven resin identification codes found on plastic products—not seven separate recycling technologies.

The main types of plastic pelletizers are strand pelletizers, water-ring or die-face pelletizers, underwater pelletizers and air-cooled hot-cut systems.