In the operation of hollow bottle blowing machine for processing, we must pay attention to some temperature control to ensure the production of suitable plastic bottles.

1.Melting temperature Tm: for crystalline polymer, it refers to the temperature at which the three-dimensional long-range ordered state of macromolecular chain structure transforms into disordered viscous flow state, also known as melting point. It is the lower limit of processing temperature for crystalline polymer.

2.Glass transition temperature (TG): refers to the transition temperature of amorphous polymer (including amorphous part of crystalline polymer) from glassy state to high elastic state or from the latter to the former. It is the lowest free motion temperature of the macromolecular segment of the amorphous polymer and the upper limit of the working temperature of the product.

3.No flow temperature: the highest temperature at which no flow occurs under a certain pressure. The automatic bottle blowing machine is to add a certain amount of plastic into the material barrel at the upper end of the die of the capillary rheometer, heat it to a certain temperature, keep the constant temperature for 10min, and then apply 50MPa constant pressure. If the material does not flow out of the die, increase the material temperature by 10 degrees after pressure relief, and then apply the same constant pressure after holding for 10min, so as to continue until the melt flows out of the die, and reduce the temperature 10 ℃ is the non flowing temperature of the material.

4.Flow temperature TF: refers to the transition temperature of amorphous polymer from high elastic state to viscous flow state. It is the lower limit of processing temperature for amorphous plastics.

5.Decomposition temperature Td: refers to the polymer in the viscous flow state. When the temperature rises further, the degradation of the molecular chain will be intensified. When the temperature rises to the point where the polymer molecular chain is obviously degraded, it is the decomposition temperature.

The above five points are the summary of how to pay attention to the temperature of the hollow bottle blowing machine in production, but generally speaking, it is not only these five points, which requires us to constantly sum up experience in our daily work, in order to find its problems.