First, the plastic mixture is put into molds (Figure II.2-1a)
Gas not immediately pumped into that after a lapse of time (very short, a few seconds) to be inserted (Figure II. 2-1.b). This delay in order to establish solid outer layer of material product called the crust. Coating thickness depends on the time delay, short time delay makes the crust thinner thickness desired. The thickness of the coating also depends on the volume of the liquid mixture in the cavity. The mission of the crust is penetrated air pressure prevents product.
Air pressure gradually increased (Figure II.2-1c), airflow tend to go to places with low resistance (the edges of the mold) optimization process for composite filling made of blown away plastic to the mold, the crust is formed with the thickness increased.
Finally, keeping phase (Figure II.2-1d), mixed filling into the mold under pressure of the gas, the gas prevents the formation of dimples on the surface of the product and the thickness of the crust reaches the end, it comes with the cooling process.
đang được dịch, vui lòng đợi..
