Explore our industrial portfolio designed for optimal inline production reliability and dynamic automation.
BAOD EXTRUSION (Jiangsu Baodie Automation Equipment Co., Ltd.) founded in 2002, dedicated to designing, manufacturing and sales of plastic extrusion equipment. Based on 18 years experience of designing and fabricating high quality machines in Taiwan, the original parent company (KINGSWEL GROUP) invested in establishing extrusion machines manufacturing base in Shanghai in 1999.
25 years experience of plastic extrusion designing and manufacturing. Long-term focus on research and development for:
Years of Manufacturing Experiences
Modern Industrial Factory Area
Dedicated Engineering Employees
In the modern plastic extrusion landscape, micro-extrusion has transitioned from a niche processing capability to a mainstream manufacturing requirement. At the center of this paradigm shift is the SJ35 Single Screw Extruder. Characterized by a nominal screw diameter of 35mm, the SJ35 platform is uniquely engineered to handle low-volume, ultra-precise melt streams. It acts as the backbone for manufacturing high-integrity micro-tubing, thin-walled precision profiles, and co-extruded structural layers where output stability and volumetric accuracy are paramount.
Unlike larger scale systems that prioritize mass throughput, the design architecture of a premium SJ35 extruder focuses on uniform shear stress distribution, minimal thermal variation, and ultra-short residence times. In precision applications—such as medical catheter manufacturing, multi-layer fuel line co-extrusion, and fluorine-plastic sleeve development—slight fluctuations in melt temperature or head pressure translate directly to wall-thickness variations, rendering final products non-compliant. High-performance custom SJ35 extruders address this by utilizing highly tailored screw profiles, servo-motor control topologies, and closed-loop pressure feedback mechanisms.
To eliminate high-frequency flow pulsations and dynamic thermal variations within the polymer melt path, enabling continuous production tolerances within ±0.02 mm.
The ultimate performance of any SJ35 extruder is governed by its screw design, which must match the rheological footprint of the processed polymer. Our engineering team customizes the L/D (Length-to-Diameter) ratio—typically ranging from 25:1 for standard polyolefins to 30:1 or even 32:1 for high-performance engineering plastics like PA12, TPV, or fluoropolymers. The physical design of the screw is segmented into three critical zones:
The feed zone utilizes an optimized helical flight depth to ensure steady solid feeding. Transitioning to the compression section, the flight depth decreases progressively. The compression ratio (usually between 2.2:1 and 3.2:1) is selected based on the polymer’s melting behavior. For semi-crystalline materials, a rapid compression gradient prevents unmolten particles from moving downstream, while amorphous polymers require a gradual gradient to minimize local shear heat generation.
To achieve absolute thermal homogeneity without degrading the polymer chains, custom Maddock mixing sections, pineapple mixers, or distributive mixing pins are integrated into the metering zone. These elements subject the melt to controlled shear stress, breaking down pigment agglomerates and eliminating thermal gradients across the channel.
Furthermore, the barrel configuration features wear-resistant bimetallic liners made from tungsten carbide alloys, providing superior chemical protection against corrosive outgassing from polymers like PVC or Fluoroplastic compounds (FEP/PFA). Ceramic heating bands paired with air-cooling fans ensure thermal control stability within ±1°C in each zone, preventing thermal overshoot.
The modular nature of the SJ35 extruder allows for seamless integration into diverse localized industrial applications around the globe.
In medical cleanrooms, custom SJ35 extruders process PU, PEBAX, and FEP to manufacture multi-lumen pediatric catheters and IV lines. By integrating melt pumps and outer-diameter laser gauges, the system dynamically alters screw speed based on real-time feedback, preserving tight concentricity and dimensional stability.
Modern automotive assemblies rely on micro-tubes for windshield washing systems, pneumatic controls, and electrical wire insulation. The SJ35 extrusion line is designed to process TPV and PVC profiles at high line speeds, ensuring excellent surface finish and physical durability against grease, heat, and moisture.
For industrial heat exchangers and aerospace wire protection, fluorinated ethylene propylene (FEP) is extruded directly onto steel wire or composite cores. The high-temperature heating zones (up to 400°C) of the SJ35 fluoroplastic-configured extruder prevent melt-fracture and optimize adhesion.
Engineered for high performance, dynamic precision, and maximum longevity across demanding industrial settings.
Designed for ultra-precise micro-tubing applications where wall tolerances must meet strict standards.
Enables co-extrusion of multi-layer polyamide tubes for automotive fuel and emissions applications.
Engineered to operate in cleanroom facilities with high throughput speeds and medical-grade compliance.
Delivers high-output corrugated forming with rapid vacuum calibration and profile consistency.
Combines fiber-reinforced knitting technology with durable polymer extrusion layers.
Optimized for processing multi-durometer sealing strips with excellent structural elasticity.
When purchasing bespoke processing lines like the custom SJ35 extruder, manufacturing agility and component trace-ability are key. Operating out of the Jiangsu and Shanghai manufacturing hubs, BAOD EXTRUSION utilizes a highly integrated industrial ecosystem. China's dense industrial cluster allows us to source premium materials—such as high-grade 38CrMoAlA nitrided steel, Siemens motors, ABB variable frequency drives, and Omron temperature controllers—efficiently and cost-effectively.
Our manufacturing processes integrate CNC machining centers for precise screw-flight milling, vacuum heat-treatment furnaces to control steel hardness, and mechanical assembly setups. This vertical integration reduces production lead times by 30% to 45% compared to Western counterparts, without compromising mechanical quality. More importantly, this localized supply chain structure offers clients customized machinery configurations at a lower cost-of-ownership, providing a rapid return on investment (ROI).
The future of precision plastic extrusion is built on automation and intelligent process control. Modern iterations of the SJ35 extruder incorporate advanced PLC interfaces (such as Siemens S7-1200 or S7-1500 architectures) that serve as the central brain of the production line. By continuously monitoring parameters—including melt temperature, melt pressure, motor torque, and puller speed—the system maintains real-time control over the entire production cycle.
We are actively integrating AI-driven closed-loop adjustments into our systems. For example, if a downstream laser gauge detects a minute deviation in the outer diameter of a medical tube, the PLC automatically calculates the necessary speed compensation for either the screw or the puller. This instant correction reduces start-up waste and ensures consistent product quality during long manufacturing runs.
Our control platforms support secure cloud connectivity, enabling remote diagnostic checks, system updates, and predictive notifications for component wear, ensuring minimal downtime for global manufacturing sites.
Stay up to date with the latest advancements in extrusion technology, exhibitions, and technical analysis from BAOD.
At the National Exhibition and Convention Center (Shanghai), BAOD showcased its latest R&D achievements, presenting "Smart Extrusion · High-Efficiency Innovation" solutions.
Delivering high-reliability micro-tube processing lines for highly demanding demolition, infrastructure, and mining operations worldwide.
A technical comparison analyzing the mechanical tolerances, manufacturing standards, and cost-efficiency ratios between China and European manufacturers.
An in-depth look at how BAOD meets international manufacturing standards, ensuring safety, traceability, and high precision for critical automotive fuel and cooling lines.
Get answers to common technical queries about the design, integration, operation, and maintenance of SJ35 single screw systems.
A: The SJ35 extruder is highly versatile and can process a wide range of thermoplastics, including PE, PP, PVC, PU, TPU, TPV, PA (Polyamide), and high-temperature fluoroplastics like FEP and PFA. Achieving optimal processing performance depends on configuring the screw's L/D ratio, compression profile, heating capacity, and wear resistance to match the specific thermal and rheological properties of your target material.
A: We maintain high dimensional accuracy through a combination of engineering solutions: high-precision AC servo-motor drives, closed-loop melt pumps that eliminate melt flow pulsations, highly sensitive PID heating zones with dual cooling fans, and downstream laser measurement systems that send real-time feedback to the main PLC control panel.
A: For fluoroplastics (such as FEP or PFA), we recommend a customized L/D ratio of 30:1 or 32:1. The screw must be made from high-nickel alloys (such as Hastelloy) or bimetallic steel to withstand the corrosive hydrofluoric gases emitted during processing. In contrast, standard polyolefins generally require an L/D ratio of 25:1 or 28:1.
A: A melt pump acts as a positive displacement device that isolates the extrusion die from pressure variations upstream in the extruder barrel. It delivers a consistent volume of polymer melt, allowing for faster production runs and significantly reduced wall-thickness variation in delicate profiles and micro-tubing.
A: Absolutely. Due to its compact footprint and precise output control, the SJ35 is an ideal co-extruder for adding functional outer coatings, thin inner liners, or color stripes to multi-layer automotive hoses, medical catheters, or corrugated pipes.
A: Sourcing from Jiangsu provides access to a highly integrated industrial supply chain, advanced manufacturing facilities, and cost-efficient production processes. This allows BAOD to offer rapid customization, shorter lead times, and competitive pricing while meeting international quality standards like CE and ISO 9001.
Complete your production line with our specialized down-stream units, calibrators, and high-speed cutters.
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