Inflation molding device
An inflation molding device includes a viscosity estimation unit that estimates a viscosity of a bubble discharged in a substantially cylindrical shape from a die, a temperature identification unit that identifies a temperature of the bubble, and a parameter estimation unit that estimates a viscosity parameter of the bubble based on the viscosity of the bubble estimated by the viscosity estimation unit and the temperature of the bubble identified by the temperature identification unit.
1 . An inflation molding device comprising:
a temperature sensor configured to measure a temperature of a bubble discharged from a die;
a camera configured to capture an image of the bubble; and
a processor configured to execute
acquiring bubble shape data from the image of the bubble captured by the camera,
calculating a strain (ϵ) and a strain rate ({dot over (ϵ)}) of the bubble based on the acquired bubble shape data,
estimating one or more viscosity parameters of the bubble based on the calculated strain (ϵ), the calculated strain rate ({dot over (ϵ)}), and the measured temperature,
receiving an input of a molding condition, and
performing a simulation to calculate a shape or a stress of the bubble using the input molding condition and the estimated viscosity parameters,
wherein the viscosity parameters are coefficients of a viscosity model equation representing a viscosity (η) of the bubble as a function of the strain (ϵ), the temperature, and the strain rate ({dot over (ϵ)}), and
the viscosity parameters are the coefficients used as a multiplier, a divisor, or an exponent for the strain (ϵ), the temperature, or the strain rate ({dot over (ϵ)}) in the equation representing the viscosity (η).
2 . The inflation molding device according to claim 1 ,
wherein the camera is an infrared camera that acquires a bubble temperature distribution image, and
the processor is configured to execute
estimating the viscosity (η) of the bubble using a shape of the bubble identified based on the bubble temperature distribution image acquired by the infrared camera, and
identifying the temperature of the bubble based on the bubble temperature distribution image acquired by the infrared camera.
3 . The inflation molding device according to claim 1 ,
wherein the processor is configured to execute performing a simulation to calculate a stress distribution of the bubble by using the estimated viscosity parameters.
4 . The inflation molding device according to claim 3 ,
wherein the processor is configured to execute
estimating the stress distribution of the bubble, and
estimating a viscosity distribution of the bubble based on the estimated stress distribution of the bubble.