Styrofoam molding
DATE：2019/10/30 9:03:49 / READ： / SOURCE：This station
Styrofoam molding
(1) Pre-expansion
The use of EPS beads to produce PS foam plastics must first be pre-expanded. When preparing a higher density foam, the pre-foaming process can be carried out by infrared heating, hot air heating or hot water heating. Steam and vacuum pre-expansion can achieve a density of less than 0.012 g/cm2.
The steam pre-expander is composed of a stainless steel cylinder and a stirrer. The wall of the cylinder has small holes for heating steam for heating, and the EPS particles entering the cylinder using the screw feeder are continuously and evenly fed, heated, expanded and foamed. And discharged at the discharge port at the upper part of the cylinder. The heated water vapor pressure was 0.2 MPa. The pre-expanded EPS emerging from the discharge opening at the top of the cylinder enters the air drying and is cooled and discharged. The temperature inside the barrel is 90-105 ° C, and the heated water vapor is divided into four rows from bottom to top, and heated with water vapor having a gauge pressure of 0.05 to 0.1 MPa.
The vacuum pre-expansion machine is heated in a vacuum-coated cylindrical mixer vessel coated with polytetrafluoroethylene to a temperature of 71 to 82 ° C with a jacketed water vapor, and vacuumed to pre-expand the EPS particles.
The pre-expanded particles can be further molded after being placed at room temperature for a certain period of time, generally at room temperature for 8 to 10 hours.
(2) Extrusion molding
The equipment parameters used for extrusion molding were as follows: extruder screw diameter D = 65 mm, L/D: 18 or more, compression ratio 3, screw rotation speed 15 to 35 r/min. A flat foam PS can be produced using a T-die, a hanger-type handpiece, or a foamed paper can be produced using a circular head. The round nose has a ring gap of 70cm and the gap is adjustable from 1 to 2mm.
Barrel temperature: 100 ~ 120 ° C / 130 ~ 160 ° C / 110 ~ 130 ° C, the head mold temperature of 90 ~ 110 ° C. The liquid paraffin in the formulation has the ability to block the interaction of nucleating agents, and can also be replaced by silicone oil, DOP, starch or stearate. The thickness is 0.76 to 4.3 mm.
(1) Pre-expansion
The use of EPS beads to produce PS foam plastics must first be pre-expanded. When preparing a higher density foam, the pre-foaming process can be carried out by infrared heating, hot air heating or hot water heating. Steam and vacuum pre-expansion can achieve a density of less than 0.012 g/cm2.
The steam pre-expander is composed of a stainless steel cylinder and a stirrer. The wall of the cylinder has small holes for heating steam for heating, and the EPS particles entering the cylinder using the screw feeder are continuously and evenly fed, heated, expanded and foamed. And discharged at the discharge port at the upper part of the cylinder. The heated water vapor pressure was 0.2 MPa. The pre-expanded EPS emerging from the discharge opening at the top of the cylinder enters the air drying and is cooled and discharged. The temperature inside the barrel is 90-105 ° C, and the heated water vapor is divided into four rows from bottom to top, and heated with water vapor having a gauge pressure of 0.05 to 0.1 MPa.
The vacuum pre-expansion machine is heated in a vacuum-coated cylindrical mixer vessel coated with polytetrafluoroethylene to a temperature of 71 to 82 ° C with a jacketed water vapor, and vacuumed to pre-expand the EPS particles.
The pre-expanded particles can be further molded after being placed at room temperature for a certain period of time, generally at room temperature for 8 to 10 hours.
(2) Extrusion molding
The equipment parameters used for extrusion molding were as follows: extruder screw diameter D = 65 mm, L/D: 18 or more, compression ratio 3, screw rotation speed 15 to 35 r/min. A flat foam PS can be produced using a T-die, a hanger-type handpiece, or a foamed paper can be produced using a circular head. The round nose has a ring gap of 70cm and the gap is adjustable from 1 to 2mm.
Barrel temperature: 100 ~ 120 ° C / 130 ~ 160 ° C / 110 ~ 130 ° C, the head mold temperature of 90 ~ 110 ° C. The liquid paraffin in the formulation has the ability to block the interaction of nucleating agents, and can also be replaced by silicone oil, DOP, starch or stearate. The thickness is 0.76 to 4.3 mm.
Author：admin