What is the difference between cast plastic and extruded plastic?

1, Process principle
Cast plastic: Cast plastic usually refers to a product obtained by pouring liquid plastic into a mold and then cooling and solidifying it to obtain the desired shape and properties. This process is similar to metal casting, but the material is replaced with plastic. The key to casting plastic lies in the fluidity of liquid plastic and the design of the mold to ensure that the plastic can fully fill the complex structure in the mold and maintain the desired shape and size after cooling. Casting plastic technology is widely used in the manufacturing of large and complex plastic products, such as automotive components, home appliance casings, etc.
Squeezing plastic: Squeezing plastic is the process of using an extruder to extrude heated plastic material from a mold, forming a continuous plastic profile. During the extrusion process, the plastic material is subjected to high pressure and shear force inside the mold, resulting in plastic deformation and solidification. The key to extruding plastic lies in the design of the mold and the performance of the extruder, to ensure that the extruded plastic profile has a uniform cross-section and smooth surface. Extrusion plastic technology is widely used in the manufacturing of pipes, panels, door and window profiles, etc.
2, Material characteristics
Casting plastics: Casting plastics usually use plastic materials with high thermal stability, low shrinkage rate, and good flowability. These materials can maintain a longer flow time in liquid state, making it easier to fully fill the mold. At the same time, cast plastics also need to have good curing properties and dimensional stability to ensure the accuracy and performance of the final product. Common casting plastic materials include epoxy resin, polyurethane, etc.
Squeezing plastics: Squeezing plastics are usually made of plastic materials with high strength, high toughness, and good extrusion performance. These materials can maintain stable extrusion speed and pressure during the extrusion process, ensuring that the extruded plastic profiles have a uniform cross-section and smooth surface. At the same time, extruded plastics also need to have good weather resistance and corrosion resistance to meet the needs of different fields of use. Common extruded plastic materials include polyethylene, polyvinyl chloride, etc.
3, Product Form and Application Scope
Casting plastics: Casting plastics come in various forms, including simple flat plates, shells, and complex three-dimensional structures. Due to its ability to manufacture large and complex plastic products, cast plastics are widely used in fields such as automobiles, home appliances, aerospace, etc. For example, components such as car bumpers and instrument panels are typically manufactured using cast plastic technology. In addition, cast plastics are also used to manufacture consumer goods such as toys and artworks.
Extruded plastic: The product form of extruded plastic is mainly continuous profiles, such as pipes, boards, door and window profiles, etc. These profiles have uniform cross-sections and smooth surfaces, making them easy for subsequent processing and installation. Squeezing plastic technology is widely used in fields such as construction, agriculture, and transportation. For example, water supply and drainage pipes, wire and cable sheaths, etc. in buildings are usually manufactured using extruded plastic technology. In addition, extruded plastic is also used to manufacture consumer goods such as packaging materials and agricultural films.
4, Technological advantages and limitations
Casting plastics: The advantage of casting plastics technology lies in the ability to manufacture large, complex structured plastic products with high precision and performance. However, there are also certain limitations to casting plastics, such as high mold costs and long production cycles. In addition, casting plastic technology requires high flowability and curing performance of materials, so material selection is relatively limited.
Extruded plastics: The advantages of extruded plastics technology lie in high production efficiency, high material utilization rate, and low product cost. Squeezing plastic can continuously produce large-sized profiles with uniform cross-sections and smooth surfaces. However, extruded plastics also have certain limitations, such as product shape and size being limited by molds, and material extrusion performance affecting product quality. In addition, extrusion plastic technology requires high strength and toughness of materials to meet the needs of different fields.