Tailored Mixing Solutions for the Plastic Industry

More Insights into Plastics

Plastic powder, plastic ultra-fine powder, and resin powder are all synthetic polymer compounds. Also known as macromolecules or giant molecules, they are commonly referred to as plastics or resins. Their shapes and styles can be altered at will. They are a type of polymer formed through synthesis or condensation reactions, consisting of components like synthetic resin, fillers, plasticizers, stabilizers, lubricants, pigments, and other additives.

Production Process

The manufacturing of plastic products typically starts with formula design, aiming to prepare powders and pellets based on the specific performance requirements of the products. During the preparation stage, the polymer and various additives are first blended using mixing equipment to form a powder. Subsequently, this powder is plasticized with a plasticizer, and finally, plastic particles are produced through a pelletizer. In essence, this process involves thoroughly mixing various ingredients to achieve the highest possible level of uniformity. Generally, it requires equipment and processes such as mixing, kneading, and plasticizing, which are accomplished through diffusion, convection, and shearing mechanisms. The preparation of raw materials usually encompasses pretreatment, weighing, and transportation steps. It is often necessary to incorporate different proportions of stabilizers, fillers, pigments, or other additives into the masterbatch to endow the final product with the desired functions.

Applications

Rigid PVC processing

PVC material

PVAL material

Polyolefin PP/PE

EPS

Powder coating

Rubber

Powder injection molding materials

Adhesive solvent

Mixer Selection

Common Mixing

For standard mixing operations conducted at room temperature and pressure, S&L recommends the horizontal ribbon mixer (WLDH Series) and the Double-screw conical mixer (DSH-Series). These mixers offer relatively gentle mixing actions, making them suitable for handling simple mixing requirements. The WLDH Series is more convenient for maintenance and cleaning, while the DSH-Series, due to its vertical structure, can ensure complete discharge of the materials. For a more detailed understanding of their mixing principles and structures, please visit our website for the product introductions.

Mixing with Heating/Cooling

During the mixing process, certain materials like modified plastics and EVA require heating and cooling functions. S&L addresses this by installing heating or cooling jackets outside the mixer. The specially designed jackets enable uniform heating and prevent issues such as uneven temperature distribution between the upper and lower sections of the jacket or a too-small heat exchange area. The heating medium is usually hot water, hot oil, or steam, with a pressure range of 3-10 bar. The cooling medium is typically condensed water, operating at a pressure of 3-5 bar. It is necessary to preheat the mixer before adding and mixing the materials.

Liquid Spraying for Coating

Based on different formulas, many customers need to spray solvents onto the masterbatch to achieve uniform coating. In such cases, the high-speed designed plough mixer (LDH-Series) is a more suitable choice. The ploughs create a shearing effect, and perfect mixing is achieved during high-speed operation. Additionally, the high-speed chopper system on the mixer body helps break up any agglomerated materials.

Granule Mixing

When dealing with granular plastic materials, it is crucial to avoid reducing the particle size during the mixing process. The clearance between the agitator and the mixer body should not be too small, as otherwise, the plastic granules may get stuck in the gap and be damaged in terms of their physical shape due to friction. S&L recommends the conical screw mixer (DSH-Series) or the double shaft paddle mixer (WZ-Series). For large batch capacities, the DSH-Series is the ideal option, while for smaller capacities, the WZ-Series can achieve high mixing uniformity in a very short time.

Typical Users

3M Company

Evonik-Degussa

Arkema

Eastman

Toray

Sumitomo Bakelite

Teijin Chemicals

Forst Photovoltaic Materials

Zhejiang NHU Special Materials

FOREX Jiangsu Sunchem

Allnex-Eternal Resins