How can polyester-specific dendritic internal lubricants reduce melt viscosity fluctuations and improve molding efficiency in PET injection molding?
Publish Time: 2026-05-28
In PET (polyethylene terephthalate) injection molding, melt flow properties directly affect product quality, production efficiency, and equipment operational stability. With the increasing demands for molding quality in electronic product casings, new energy vehicle components, and precision engineering plastic products, reducing melt viscosity fluctuations and improving processing stability have become crucial issues in PET material processing. Polyester-specific dendritic internal lubricants, with their unique molecular structure and excellent processing aid properties, can effectively improve the flow characteristics of the PET system, thereby increasing production efficiency and product quality.1. Improving molecular chain mobility and reducing melt flow resistanceIn the molten state, PET molecular chains exhibit strong entanglement, which increases melt flow resistance and leads to increased viscosity. Dendritic internal lubricants, with their unique multi-branched structure and functional groups, can distribute between polyester molecular chains, reducing inter-segment friction and increasing molecular freedom of movement. 1. Enhanced internal lubrication leads to smoother melt flow and effective control of viscosity fluctuations, thereby improving processing stability.2. Improved melt uniformity and reduced localized flow differences.During injection molding, uneven melt mixing can easily lead to localized viscosity differences, resulting in unstable mold filling, flow marks, or dimensional deviations. Dendritic internal lubricants can disperse uniformly in the PET system and promote coordinated internal melt flow, keeping the material more uniform during plasticizing and conveying. This not only reduces viscosity fluctuations but also improves melt filling consistency, ensuring high-quality molding.3. Enhanced thermal stability and reduced performance changes during processing.PET processing typically requires high temperatures, which can lead to material degradation or viscosity changes. Dendritic internal lubricants have excellent heat resistance, maintaining stability during processing and reducing melt performance fluctuations caused by temperature changes. Simultaneously, their unique structure helps alleviate localized overheating, allowing the material to maintain relatively stable rheological properties throughout the plasticizing process, thereby improving production continuity.4. Optimize Filler Dispersion and Improve Processing FlowabilityMany PET products incorporate functional fillers such as glass fiber, mineral powder, or flame retardants. Uneven filler dispersion increases melt flow resistance and causes viscosity fluctuations. Dendritic internal lubricants improve the interfacial state between the filler and resin, promoting uniform filler distribution. A uniform dispersion not only reduces processing resistance but also enhances overall material flow properties, making the injection molding process smoother and more efficient.5. Shorten Injection Cycle and Improve Production EfficiencyStable melt flow properties increase mold filling speed and molding efficiency. Reduced viscosity fluctuations allow the melt to fill complex mold cavities more quickly, reducing issues like short shots and incomplete filling. Simultaneously, improved flowability reduces injection pressure requirements, helping to shorten holding pressure and molding cycles. This not only improves equipment utilization but also lowers unit product production costs.6. Improve Product Surface Quality and Reduce Post-Processing NeedsStable melt flow makes it easier for a uniform and dense structure to form on the product surface, reducing defects such as flow marks, silver streaks, weld lines, and surface roughness. Dendritic internal lubricants can also enhance the surface gloss of products, making the finished product more aesthetically pleasing. High-quality surface finishes help reduce subsequent finishing processes, improving overall production efficiency and product added value.In PET injection molding, polyester-specific dendritic internal lubricants effectively reduce melt viscosity fluctuations by improving molecular chain movement, enhancing melt uniformity, increasing thermal stability, promoting filler dispersion, and optimizing flow properties. Simultaneously, they can shorten molding cycles, improve production efficiency, and enhance product appearance quality. With the widespread application of high-performance PET materials in new energy vehicles, electronics, and communication equipment, dendritic internal lubricants will play an increasingly important role in improving processing efficiency and product quality.
