The German Witte Automotive Group launched a factory in 2016 in Ostroff, Northern Bohemia, specializing in the production of automotive door handles and lock modules with diverse shapes, colors and functions.
According to the customer's special requirements, the factory has produced 3 different types of door handles, including:
1. Door handles with sensors and appropriate electronic components, which require smooth interior wall mounting space, so that in production, the mechanical sliders in the mold are rolled out to create the necessary space.
2. A door handle consisting of two or more shells, which are fastened together through buckles and bolts.
3. There is no door handle for integrated sensor electronic components, which is a monolithic hollow part produced by gas-assisted injection molding technology.
These door handles are made of 30% glass fiber reinforced PA6, the shell is made of a pc/abs mixture, and the structural components behind are made of 30% glass fiber reinforced pp.
At present, the annual output of the Ostroff plant is about 3.5 million, with 14 clamping force 1800~ 5500kN of the mighty Barton Phil injection unit, which integrates the mighty linear manipulator and the peripheral equipment used to automate the downstream processing of the injection molded door handles. Hybrid of the mighty Barton Phil Macropower E 500/2100 Injection molding machine, equipped with a fully electric injection unit and a servo-hydraulic two-plate clamping unit, with the best energy efficiency molding quality consistent high-quality products, thus fully meet the customer's requirements.
Of the products produced, about 1 million door handles are hollow parts manufactured using the airmould® gas-assisted injection molding technology of the mighty Barton Phil.
As one of the most effective ways to reduce the wall thickness of plastic parts, gas-assisted injection molding also shortens the necessary cooling time, reduces material consumption, and eliminates the need for complex structures within the mold.
The process seems simple, but in order to achieve the best results, it requires highly sophisticated process control: The first step is to completely fill the cavity, through the cavity wall cooling and the outer layer is solidified. Then, the nitrogen, which is controlled by the dose, is blown into the plastic melt through the injection nozzle at a pressure of up to 300bar, where the pressurized gas acts like a piston, enabling the liquid plastic melt to move from the core to the overflow cavity through a mechanically opened channel. According to the type of door handle, the amount of plastic melt that is introduced is about 30% of the total amount of 25%~. The air pressure inside the hollow part then offsets the shrinkage caused by the cooling, thereby eliminating potential indentation defects on the outer surface. At the end of the cooling process, the molded parts and the contents of the overflow chamber are removed. The contents of the overflow cavity are removed and recycled to be reused with the native material.
According to the type of door handle, the cycle time is approximately shortened to 45~ 50s, so it is roughly equivalent to the production cycle time using the slider. Gas-assisted injection molding perfect car door handle