Processing plastic bottles with blow molding machines i […]
Processing plastic bottles with blow molding machines is a common processing item in plastic processing, so where are the areas to be paid attention to in this processing? What I want to tell you is the temperature. The control of temperature is very important for processing plastic bottles. When operating a hollow blow molding machine for processing, some temperature control must be paid attention to to ensure that a suitable plastic bottle is manufactured.
No-flow temperature: The highest temperature at which no flow occurs under a certain pressure. It is to add a certain amount of plastic into the barrel at the upper end of the capillary rheometer die, and heat it to a certain temperature. After the constant temperature is known to be 10min, apply a constant pressure of 50MPA. If the material does not flow out of the die, the temperature of the material is released Increase the difficulty by 10 degrees, apply the same constant pressure after holding for 10min, and continue to do so until the melt flows out of the die. Decrease this temperature by 10 degrees to be the non-flowing temperature of the material. Flow temperature TF: refers to the temperature at which the amorphous polymer changes from a highly elastic state to a viscous flow state. It is the lower limit of the processing temperature of amorphous plastics.
Decomposition temperature TD: When the temperature of a polymer in a viscous fluid state is further increased, the degradation of the molecular chain will be aggravated, and the temperature at which the molecular chain of the polymer is significantly degraded is the decomposition temperature. Melting temperature TM: For crystalline polymers, it refers to the temperature at which the three-dimensional remote ordered state of the macromolecular chain structure transforms into a disordered viscous fluid state, also known as the melting point. It is the lower limit of the crystalline polymer molding processing temperature. Glass transition temperature TG: refers to the transition temperature of an amorphous polymer (including the non-crystalline part in a crystalline polymer) from a glass state to a high elastic state or from the latter to the former. It is the lowest temperature at which the macromolecular segment of the amorphous polymer can move freely, and it is also the upper limit of the working temperature of the product.