Thin-wall injection molding requirements for injection molding machines and molds(1)

- Apr 13, 2018-

Core Tip: Thin-wall injection molding has become the most demanding performance of injection molding machines in order to meet the requirements for producing small and light parts. According to the definition of portable electronic parts, thin-walled refers to a wall thickness of less than 1 mm; for large automotive parts, the thin-walled wall can be 2 mm. In short, thin-walled products require changes in the processing technology, higher pressures and speeds, shorter cooling times, changes in the ejection of parts and alignment of the gates. In order to meet the requirements for producing small and light parts, thin-wall injection molding has become the most needed performance of the injection molding machine. According to the definition of portable electronic parts, “thin wall” means that the wall thickness is less than 1 mm; and for large automobile parts, “thin wall” can be 2 mm. In short, thin-walled products require changes in the processing technology, higher pressures and speeds, shorter cooling times, changes in the ejection of parts and alignment of the gates. The change of processing technology at the same time promoted the development of the design of molds, machines and parts, and put forward higher requirements for injection molding machines and molds.

The performance of the current injection machine is much more than 10 years ago. Materials, gate technology, and design advances have further broadened the performance of standard injection molding machines for filling thin-walled parts. However, as the wall thickness continues to decrease, a more special injection machine with high speed and high pressure performance is required. At present, it is common for electronic parts with a thickness of less than 1 mm to have a filling time of less than 0.5 seconds and an injection pressure of more than 210 MPa. Hydraulic injection machine for thin-wall injection molding, designed with an accumulator, can frequently drive injection molding and mold clamping; all-electric injection machines and electric/night pressure injection machines with high speed and high pressure performance, in order to withstand For the new injection presses, the minimum value of the clamping force must be between 5 and 7 tons per square inch (projected area). In addition, when the wall thickness is reduced and the injection pressure increases, large stencils can help reduce bending. Tie rods for injection molding machines for thin-walled products require a 2:1 or lower ratio of stencil thickness. When producing thin-walled parts, closed-loop control of injection speed and pressure, as well as other processing parameters, helps control filling and holding pressure at high pressures and speeds.