Black spots in PVC granules are mainly caused by **unclean screws, raw material contamination, carbonization from overheating, or poor environmental conditions**. Solutions include regularly cleaning the screw and die head, controlling temperature and residence time, inspecting raw materials, maintaining a clean production environment, cleaning auxiliary equipment and filters, and checking the heating system. These measures help prevent black spots and improve the appearance and quality of PVC granules.

This article explores the blending modification of TPU and PVC to improve material performance and reduce costs. PVC/TPU blends show excellent oil resistance and enhanced flame retardancy, although higher TPU content can reduce solvent resistance. Adding chlorinated polyethylene (CPE) as a third component further improves tear strength, thermal stability, and processability while helping maintain TPU’s flexibility at low temperatures. The blending ratio significantly affects mechanical and shape memory properties, with ratios like TPU/PVC 90/10 offering optimal performance. Combining TPU, PVC, and copolyester (COP) can also produce melt-processable rubber that combines toughness, cost efficiency, and low-temperature flexibility.

This article explains how to choose suitable carrier resins for color masterbatches in TPE (thermoplastic elastomer) pelletizing based on application scenarios. It emphasizes key selection criteria such as compatibility, processing temperature, performance impact, and cost-efficiency. Specific carriers like LDPE, PP, PS, EVA, and SEBS are recommended for different TPE uses—ranging from toys and automotive parts to medical tubing and food-grade products. It also highlights considerations for pigment-carrier matching, masterbatch concentration, and processing optimization.

This article outlines four key considerations when selecting plastic additives. First, the compatibility between additives and polymers is crucial to ensure uniform mixing and long-term stability. Second, additives must withstand the processing conditions, especially high temperatures. Third, the synergy or antagonism between multiple additives can significantly impact performance. Finally, the intended use of the plastic product—such as food packaging or medical applications—places strict requirements on the toxicity and extractability of the additives.

This article explains the advantages of side vacuum exhaust systems in plastic extrusion. Unlike traditional top-mounted systems, side vacuum systems prevent material overflow by positioning the vacuum port laterally, improving process stability and reducing maintenance. It also clarifies that a stable negative pressure—not higher vacuum strength—is key to effective degassing. Factors such as temperature control, screw speed, and screw design also significantly impact performance. The side vacuum system is especially suitable for high-volatility materials where reliability is critical.

This article provides a comprehensive overview of screw maintenance for extruders. It covers key topics such as screw cleaning methods, including the use of purging compounds and HDPE as a cost-effective alternative, as well as the causes and effects of screw wear. It also explains the procedures for removing screws, the materials used in screw manufacturing, and how to select the right materials based on processing needs. Additionally, a Q&A section addresses common concerns, such as increasing production output, screw design, and wear prevention. This guide is valuable for anyone involved in plastic extrusion or recycling operations.

This article provides an overview of key factors influencing extruder screw performance, including the effects of screw length-to-diameter (L/D) ratio, screw diameter (thickness), and material selection. It also explains how shear forces generated by the screw impact material plasticization and overall extrusion efficiency. Understanding these elements is crucial for optimizing extruder design and ensuring stable, high-quality production.

This article explains the structure and function of extruder screws, which are divided into three main zones: the feeding zone, where solid resin is transported and preheated; the compression zone, where the resin melts through external heating and shear heat; and the metering zone, which ensures uniform extrusion. Additionally, the article discusses darmage(a mixing section), screw elements used in twin-screw extruders, the compression ratio affecting resin flow and pressure, and the barrel, which houses the screw and facilitates heat transfer. Proper screw design is essential for optimizing resin plasticization, mixing, and extrusion efficiency.

This article explores the structure, types, and functions of extruder screws, which are essential in resin processing. It distinguishes between single-screw and twin-screw extruders, highlighting their respective advantages in mixing and production efficiency. The document also discusses different screw designs, such as full-flight and mixing (darmage) screws, and their impact on resin blending and production output. The key takeaway is that selecting the right extruder screw depends on the specific application and desired balance between mixing efficiency and production capacity.

Poor discharge or blockage in a plastic pelletizer machine head may be caused by foreign materials, heater malfunctions, or improper temperature settings. Solutions include inspecting and replacing the heater, cleaning the extrusion system, and adjusting temperature settings as needed.