Lubes em Foco Magazine – issue 94
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Extrusion
A manufacturing method used to produce objects with a fixed cross-sectional profile by pushing material through a die head. It is widely used in plastics manufacturing industries. The process involves several key steps, starting with feeding raw material, such as thermoplastic resin pellets, into a screw conveyor, melting them in a barrel with heating chambers, and then forcing them through a die to shape the product. A detailed explanation of the extrusion method, step by step, is provided below.
Feeding raw material into the hopper
Acts as a reservoir, ensuring a consistent supply of material to the extrusion system. This step is essential to maintain a constant flow of material, which is essential to produce uniform products.
Heating and conveying screw
Material is conveyed into the heating chamber using a screw mechanism, often referred to as an extrusion screw, which rotates and pushes the material forward while mixing it to ensure homogeneity. This step ensures that the material is evenly distributed and prepared for the melting process.
Melting the material in the heating barrel
As the material passes through the heating barrel, it is subjected to high temperatures, causing it to melt and transform into a plastic state. The heating barrel is equipped with heating belts and temperature controls to maintain precise melting conditions. The melted material must reach a specific viscosity to ensure that it can flow smoothly through the head.
Forcing the molten material through the die head
After melting, the material is forced through a die, which is a special tool that shapes the molten material into the desired cross-sectional profile. The die sets the final dimensions and shape of the product. Pressure applied by the extruder screw ensures that the material flows correctly through the die.
Cooling and solidification of the extruded product
As the resin leaves the die head, it begins to cool and solidify, setting the shape determined by the die. Cooling is achieved by cooling water. Proper cooling is essential to prevent warping and ensure that the product maintains its structural integrity.
Finishing or trimming
Once the formed product has cooled and solidified, it is finished by trimming the trim or subjected to additional finishing processes. Finishing methods can include – printing / assembly / surface treatment – depending on the application. This step determines that the product meets the required specifications and is fit for use.
Conclusion
By fine-tuning each step of the process, extrusion enables the optimal production of a wide range of products with consistent precision and quality. The method is widely adaptable, making it suitable for a variety of applications and materials.
