The process of injection molding is (plasticizing) to (flow) to (forming) to (crystallization).
Namely, glass state, high elastic state (rubber state), viscous flow state (plasticizing state), decomposition state, as shown in the picture:
Glass state: 0 ~ T1, the molecules are frozen, hard and brittle, and easy to break under pressure.
Viscous flow state (plasticized state) : T2 ~ T3, can be processed at will.
Decomposition state: T3, the plastic begins to crack, the gas decomposition, even the charred state.