The 65‑series silicone extruder is a core piece of equipment for the mass production of silicone tubing, sealing strips, and custom‑shaped silicone products. With its ability to handle small and medium‑sized parts, consistent extrusion output, and flexible adjustment settings, it is widely used in the silicone‑product manufacturing industry. During high‑volume production, issues such as variations in tube diameter, uneven wall thickness, and significant dimensional tolerances frequently arise, leading to increased scrap rates and reduced production‑delivery efficiency. These dimensional deviations are not solely attributable to operator error; they stem primarily from three key factors—equipment condition, process parameters, and the intrinsic properties of the silicone raw material—making them critical challenges in routine production tuning and quality control.

Abnormal equipment operating conditions are the primary cause of dimensional instability. After prolonged operation, the screw and barrel of a 65‑silicone extruder experience slight wear, leading to increased clearance between mating parts. This degrades the accuracy of silicone material conveyance and metering, causing periodic fluctuations in extrusion flow rate, which in turn results in inconsistent product thickness and wall‑thickness deviations that exceed specifications. Meanwhile, malfunctions in the equipment’s traction system have a particularly pronounced impact: uneven tension in the traction belts, unstable servo speed control, and non‑uniform traction pressure can distort silicone products, leading to stretching and dimensional variations. In addition, long‑term use of the die head can cause wear, die‑orifice deformation, and misalignment during mold installation; coupled with imbalanced take‑up tension control and frame vibrations, these issues further exacerbate dimensional deviations in the finished products.

Improper adjustment of process parameters is the primary cause. Silicone rubber is far more temperature‑sensitive than conventional rubber, making precise temperature control in each zone of a 65‑grade silicone extruder especially critical. When the barrel and die temperatures are too low, the silicone fails to plasticize adequately, resulting in poor flowability, increased extrusion resistance, and a product that is hard and overly narrow; the dimensions are undersized, and the surface appears rigid. Conversely, excessively high temperatures can lead to premature vulcanization, disrupted rheological behavior, and abnormal expansion of the extrudate, causing oversized tube diameters and uncontrolled dimensional deviations. In addition, an improper balance between extrusion speed and take‑up speed, along with fluctuating extrusion pressure, are significant contributors to uneven wall thickness and dimensional variability in the final product.

Improper raw-material handling can exacerbate dimensional‑control issues. Inconsistent mixing of silicone rubber compounds, uneven hardness, and non‑standard regrind‑to‑virgin ratios can lead to unstable material flow. Additionally, if the silicone rubber is exposed to moisture or contains water‑borne impurities, its rheological properties will change during extrusion, compromising molding dimensional accuracy and giving rise to subsequent surface defects, thereby significantly reducing the yield of conforming parts.
To address dimensional deviations in 65‑mm silicone extruders, a mature and viable industry‑standardized optimization plan has been developed. Prior to production, it is essential to regularly inspect the wear of the screw, barrel, and extrusion die, promptly replace worn components, and calibrate die‑mounting accuracy to ensure uniform and stable output. During operation, precisely match extrusion speed with traction speed, fine‑tune servo‑system parameters, and adjust the pressure and tension of the traction belts to maintain synchronized line operation and consistent tension. Depending on the specific silicone formulation, carefully segment and set barrel and die temperatures to ensure thorough and uniform plasticization. In addition, standardize the raw‑material mixing, drying, and filtration processes to achieve consistent material properties, thereby addressing dimensional instability at its source.