Back to results
US 9,920,177 B2Granted
Continuous method for producing solid, hollow or open profiles
AssigneeNmc S.A.
InventorsVincent Navez, Robert Frere, Jean-Pierre Mayeres, Emmanuel Noel
Life of this patent
Estimating the term…
Abstract
Disclosed herein is a method for producing a polystyrene foam. The polystyrene is dosed with a gas and the polystyrene and gas are mixed in an extruder in order to obtain a homogenous mixture. The homogeneous mixture is cooled as it travels through the extruder and is then extruded from the die at a pressure of less than 7 MPa to form a foam with a smooth skin.
Claims12
A method for producing solid, hollow or open profiles, based on polystyrene, comprising:
- dosing polymers comprising polystyrene,
- plasticizing the components in an extruder in order to obtain a homogenous mixture,
- injecting a pressurized gas via an injection port in an amount from 0.2 to 0.4% by weight based on the polymers comprising polystyrene,
- kneading and pressurizing said homogeneous mixture and gas until complete dissolution of the gas in order to obtain a mixture in a single phase,
- gradually cooling said mixture while maintaining the pressure required for solubilizing the gas, to a temperature above 135° C.,
- having said mixture in a single phase, pass from a die into ambient conditions to form a foam, where the mixture passes onto the die at a rate of 50 to 120 kilograms of polystyrene per hour;
- and where the pressure at the shaping tool is 3 MPa to 7 MPa;
- and
- drawing the foam with a motor to produce a calibrated foam having a density of 290 to 350 kilograms per cubic meter and having a cell size of 25 to 100 micrometers.
6 more elements
A method for producing solid, hollow or open profiles, the method comprising:
- dosing a polymer including polystyrene;
- plasticizing the polymer including the polystyrene in an extruder to obtain a homogenous mixture;
- injecting a pressurized gas into the extruder in an amount from 0.2 to 0.4% by weight of the homogenous mixture;
- kneading and pressurizing said homogeneous mixture and gas until dissolution of the gas to obtain a mixture in a single phase;
- cooling the mixture to a temperature in excess of 135° C. while maintaining the pressure required for solubilizing the gas;
- passing the mixture from a die at a rate of 50 to 120 kilograms of polystyrene per hour;
- to form a foam;
- where the foaming occurs outside the die and where the pressure at the die is 3 MPa to 7 MPa pounds per square inch;
- and
- drawing the foam with a motor to produce a calibrated foam having a density of 290 to 350 kilograms per cubic meter and having a cell size of 25 to 100 micrometers.
7 more elements
Dependencies are inferred from the claim text.