In modern manufacturing, molds, as the basic tools of industrial production, undertake the important task of molding raw materials into various complex parts. With the deepening of the concept of green manufacturing and energy saving and consumption reduction, plastic steel mold has gradually become a new choice in the mold market due to its advantages of light weight, environmental protection and low cost.
First of all, we need to understand what plastic steel mold is. As the name suggests, plastic steel mold is a type of mold system made of plastic and steel composite or modified engineering plastics (such as PPS, PA+GF, etc.). Compared with traditional all-metal molds, it uses lightweight materials to replace part or all of the steel structure, thereby reducing the overall weight, shortening the production cycle, and reducing manufacturing and maintenance costs. Especially in the field of trial molds, small batches or non-metallic material molding, plastic steel mold has been widely used.
However, in the injection molding process, the mold needs to work under high temperature (usually above 200°C) and high pressure (up to hundreds of MPa). This puts extremely high demands on the heat resistance, strength, rigidity and thermal expansion stability of the mold. Traditional steel molds (such as P20, H13, etc.) perform well in this regard, while plastic steel molds have low heat deformation temperature and poor thermal conductivity. Therefore, whether they can be used in high temperature and high pressure environments depends mainly on their material selection and structural design.
Currently, high-performance plastic steel molds on the market mostly use glass fiber reinforced engineering plastics or metal powder filled composite materials, such as PA66+30%GF, PPS+GF, polyetheretherketone (PEEK), etc. The heat deformation temperature of these materials can reach above 230°C and can withstand certain temperatures and pressures in a short period of time. At the same time, the mold design will enhance the overall rigidity by adding rib structures, metal insert supports, and split splicing methods to ensure that no deformation or breakage occurs under the action of injection pressure. Under certain injection molding parameter control, this type of plastic steel mold can be used for medium and low pressure, short cycle injection molding tests or small batch production.
However, it is worth noting that the long-term high temperature resistance and fatigue resistance of plastic steel molds are still significantly inferior to those of steel molds. In continuous high-pressure injection molding, complex plastic parts molding or high-precision demand scenarios, plastic steel mold is prone to changes in fit clearance, surface wear or structural cracking due to thermal expansion and contraction. In addition, its low thermal conductivity reduces cooling efficiency, indirectly affecting the production cycle and product dimensional stability. Therefore, plastic steel mold is more suitable for application environments with relatively low process temperature, simple structure and low number of repetitions.
From a cost-effectiveness perspective, plastic steel mold has obvious advantages for product lines with short development cycles and frequent updates, such as plastic packaging, advertising logos, small daily necessities and other industries. It can complete mold development and sample manufacturing at a lower cost and faster speed, saving time and money for enterprises. For industrial parts that require extremely high strength and high frequency of use, such as automobile shells, electronic product shells and other fields, it is still recommended to give priority to high-strength metal molds.
With the support of specific design and materials, plastic steel mold can withstand medium-temperature and high-pressure injection molding environments to a certain extent, but its performance upper limit is subject to the thermal properties and structural rigidity of the raw materials, and it is still difficult to completely replace traditional steel molds. In the application, scientific selection should be combined with specific process requirements, production batches and precision requirements. With the development of new composite materials and mold structure innovation, plastic steel mold is expected to show greater potential in more high-performance injection molding scenarios in the future.
