What is Sintering?

Sintering is a thermal process used to consolidate powdered materials into solid parts by applying heat—and sometimes pressure—without fully melting the material. In plastics, plastic sintering enables the production of complex components from fine polymer powders, offering a practical solution for manufacturing technical parts with controlled porosity, tailored geometry, and reliable mechanical performance.

Unlike injection or extrusion molding, which fully melt the polymer, plastic sintering involves heating the powder to a temperature below its melting point, allowing particles to bond through molecular diffusion. This principle is used in traditional compression molding techniques and advanced methods such as selective laser sintering (SLS), widely applied in additive manufacturing and 3D printing.

One of the key advantages of sintering is the ability to produce parts with porous structures or specific densities. This makes it ideal for applications like filters, medical components, self-lubricating bearings, or fluid control systems. It is also useful for processing materials that are difficult to mold conventionally, such as high-performance thermoplastics or reinforced plastics.

Polymer consolidation processes by sintering require precise control over temperature, heating time, and ambient atmosphere to avoid material degradation and ensure uniform fusion between particles. Powder characteristics—such as particle size, shape, and distribution—are also critical, influencing final part density, mechanical strength, and surface finish.

In selective laser sintering, a high-energy laser selectively fuses thin layers of polymer powder, building the part layer by layer from a CAD model. This process offers great design flexibility, eliminates the need for molds, and is ideal for functional prototypes, small series, or customized components. Common materials for this process include PA12, TPU, and PEEK, due to their thermal stability and mechanical performance.

Plastic sintering is also used in industrial compression molding of sintered plastics, where powder is pressed and heated inside closed molds to create highly resistant, dimensionally stable parts. This method is widely applied in the production of gears, bushings, valve components, and technical items that demand tight tolerances and robust performance.

At companies like Plásticos Lezo, where customized plastic solutions are developed, knowledge of polymer consolidation processes through sintering is essential to offer innovative alternatives. Whether in additive manufacturing or functional part development using advanced materials, plastic sintering provides a high-value technical option.

In summary, plastic sintering is a sophisticated powder-fusion manufacturing process that allows for the production of precise, durable, and functional components from polymers. With its adaptability to different shapes, materials, and production volumes, sintering stands out as a key technology in plastic transformation processes.