Analysis of Several Critical Temperatures in Processing Plastic Bottles

(1) Melting temperature TM: For crystalline polymers, the temperature at which a three-dimensional remotely-ordered state of a macromolecular chain structure is converted to an unordered viscous state, also called the melting point. It is the lower limit of the molding processing temperature of the crystalline polymer.

(2) Glass transition temperature TG: refers to the transition temperature from the glassy state to the highly elastic state or from the latter to the amorphous state of the amorphous polymer (including the amorphous portion in the crystalline polymer). It is the lowest temperature for the free movement of the amorphous polymer macromolecular segment, and is also the upper limit of the working temperature of the product. > Aluminum spot welding machine

(3) No flow temperature: The highest temperature at which flow does not occur under a certain pressure. A certain amount of plastic is added to the upper end of the capillary rheometer die, heated to a certain temperature, constant temperature, so that the new 10MIN, the application of 50MPA constant pressure, if the material does not flow out from the die, after pressure relief will be material temperature Raise the difficulty by 10 degrees, and then apply a constant pressure of the same size after holding 10 minutes. This continues until the melt flows out from the die. Decreasing the temperature by 10 degrees is the non-flowing temperature of the material.

(4) Flow temperature TF: refers to the temperature at which an amorphous polymer changes from a highly elastic state to a viscous flow state. Is the lower limit of the amorphous plastic processing temperature.

(5) Decomposition temperature TD: refers to a polymer in a viscous flow state. When the temperature is further increased, the degradation of the molecular chain is exacerbated, and the temperature at which the polymer molecular chain is significantly degraded is the decomposition temperature.