Performance and Characteristics of Plastic Cap Molds

Performance and characteristics of plastic bottle cap molds

1. Wear resistance of plastic mold steel material

When the mold blank undergoes plastic deformation in the plastic mold cavity, it flows and slides along the surface of the cavity, causing severe friction between the cavity surface and the mold blank, resulting in the failure of the plastic mold due to wear and tear. So the wear resistance of plastic mold steel is one of the most basic and important properties. Hardness is the main factor affecting wear resistance. In general, the higher the hardness of plastic bottle cap mold components, the smaller the wear and tear, and the better the wear resistance. In addition, wear resistance is also related to the type, quantity, morphology, size, and distribution of carbides in plastic mold steel.

2. Strength and toughness of plastic mold steel materials

The working conditions of plastic molds are mostly very harsh, and some often bear large impact loads, leading to brittle fracture. To prevent sudden brittle fracture of plastic mold components during operation, plastic molds should have high strength and toughness. The toughness of plastic molds mainly depends on the carbon content, grain size, and microstructure of the material.

3. Fatigue fracture resistance of plastic mold steel material

During the working process of plastic molds, long-term cyclic stress often leads to fatigue fracture. Its forms include low-energy multiple impact fatigue fracture, tensile fatigue fracture, contact fatigue fracture, and bending fatigue fracture. The fatigue fracture performance of plastic molds mainly depends on their strength, toughness, hardness, and the content of inclusions in the material.

4. High temperature resistance of plastic mold steel materials

When the working temperature of plastic molds is high, it will cause a decrease in hardness and strength, leading to early wear or plastic deformation and failure of the plastic molds. Therefore, plastic mold steel materials should have high resistance to tempering stability to ensure that plastic molds have high hardness and strength at working temperatures.

5. Cold and hot fatigue resistance of plastic mold steel materials

Some plastic molds are in a state of repeated heating and cooling during the working process, causing the surface of the mold cavity to be subjected to tensile and compressive stress, resulting in surface cracking and peeling, increasing friction, hindering plastic deformation, reducing dimensional accuracy, and ultimately leading to the failure of the plastic mold. Cold and hot fatigue is one of the main forms of failure in thermally activated plastic molds, which should have high resistance to cold and hot fatigue.

6. Corrosion resistance of plastic mold steel materials

Some plastic bottle cap molds, due to the presence of chlorine, fluorine and other elements in the plastic raw materials during injection molding, decompose and release highly corrosive gases such as HCI and HF after heating, which corrode the surface of the plastic mold cavity, increase its surface roughness, and exacerbate wear and failure.