Ninghai: The Technological Power Behind Lightweight Mold Cars
A lighter car itself contributes more to energy conservation and emission reduction, which is one of the main directions for innovative development in the automotive industry under the background of “dual carbon”. Research shows that for every 100 kilograms of weight lost in a car, fuel consumption per 100 kilometers is reduced by 0%.3 to 0.6 liters. With the increasing requirements of the country for fuel and environmental indicators, as well as the prominent issue of electric vehicle endurance, the lightweight of automobiles has become an industry trend.
Automobile lightweight refers to minimizing the curb weight of a vehicle while ensuring its strength and safety performance. So, how to make cars lose weight? Ninghai County First Injection Mold Co., Ltd., a 40 year old automotive parts mold enterprise, has been “betting” on the research and development and manufacturing of microcellular foam injection molds.
The cross-sectional structure of microcellular foam injection molded products is like a ‘sandwich’, with two smooth surfaces appearing honeycomb like in the middle, densely covered with ten to tens of micrometers of closed micropores. Air occupies the space of the plastic material, reducing its own plastic content, and being able to achieve both strength and weight reduction. “Ding Bo, the deputy general manager of the company, explained that mold manufacturing is crucial to achieve the effect of a ‘sandwich’.
The first injection mold has been developing large-scale component molds for well-known domestic and foreign automotive companies such as BMW, Mercedes Benz, FAW Volkswagen, and Shanghai General Motors. Since 2013, First Injection has started researching, developing, and manufacturing microcellular foam injection molds. The initial use was physical microcellular foaming technology, which mixed nitrogen gas into the material through stirring to form foam pores. The products made were mainly used in automotive interior components, “Dingbo said.
In recent years, microcellular foaming technology has expanded to automotive exterior components, with higher requirements for product size and contour accuracy. The first injection mold switching path has begun to develop chemical microcellular foaming injection molds. The process of chemical foaming is to add a chemical foaming agent during the injection molding process, which generates a chemical reaction and releases carbon dioxide to form bubbles. Due to the greater difficulty of control, enterprises have overcome many difficulties in the process of technological research and development.
In the past, ordinary automotive injection molds did not have particularly strict requirements for temperature, speed, and back pressure. It is normal for each part of the same mold to have a cooling temperature difference of five or six degrees, “Ding Bo said. However, microcellular foaming relies on precise control of temperature, pressure, and other aspects. The long process and large temperature difference mean uneven foaming, which can cause problems such as bulging, silver threads, orange peel, and large color difference on the surface of the product.
To this end, the R&D team conducted countless explorations and experiments in the number of mold gates, position arrangement, temperature control system, and other aspects, and quickly mastered key technologies in just six months. Ding Bo gave an example: “In foaming, excessive temperature can cause bulging, so we added an exhaust port and evenly arranged the cooling system to control the temperature difference of the entire mold within two degrees
At present, the chemical microcellular foam molds developed and produced by enterprises can reduce the weight of plastic components by 30%. In 2020, once the mold was launched, it won 8 orders. In March of this year, a car company placed a large order of 10 million yuan directly.
Our microcellular foaming technology can be widely applied to instrument panels, door panels.The market for interior and exterior decorations such as pillar guards, central passages, chair backboards, ventilation ducts, and motor brackets is very broad. This year, it is expected that our mold production value will reach 2%.500 million yuan Ding Bo is full of confidence in the future of the enterprise.
(Source: Ninghai County Science and Technology Bureau)