Mastering the Core: Key Logic for Efficient Operation of Overflow Jet Fabric Dyeing Machines

Exceptional performance of overflow jet fabric dyeing machine is rooted in deep understanding and precise control of several core operational principles. This article aims to clarify these key points, providing clear guidance for dyeing technicians and offering professional perspective for equipment selection and evaluation.

Core 1: The Starting Point of Precision — Nozzle Selection

The nozzle is the "heart" of this fabric dyeing machine. Correct selection is fundamental for smooth start to the dyeing process.

Structure is the Foundation: High-quality overflow jet fabric dyeing equipment nozzle typically features multi-layer annular design. Inner ring gap creates high-speed dye liquor jet that provides the core traction, while the outer flow-guiding ring stabilizes the direction, minimizing fabric flutter and creasing risks. Flange connection design allows for easy disassembly and thorough cleaning, a practical feature that ensures long-term stability and prevents clogging.

Selection Follows Logic: The core principle for choosing the nozzle specification (inner diameter) is clear: it must be larger than the rope-folded diameter of the fabric in its wet state. This ensures the fabric passes smoothly through dye stream, avoiding permanent creases from squeezing or poor circulation from insufficient traction. A well-designed machine should offer a range of nozzle options with clear selection guidelines to accommodate fabrics from lightweight to heavy.

Core 2: The Soul of Synchronized Operation — Balancing Lifting Wheel and Nozzle Pressure

Soul of dyeing quality and efficiency lies in the synergy between cloth lifting wheel (mechanical traction) and the nozzle pressure (liquid traction). Achieving dynamic balance between them is the most crucial operational skill.

Consequences of Imbalance: If the lifting wheel runs too fast with insufficient dye jet traction, the fabric becomes overstretched, leading to deformation, weft skew or even breakage. Conversely, if the wheel is too slow, the fabric can pile up and fold under the jet impact, creating hard-to-remove "chicken paw" marks or uneven dyeing, potentially causing blockage.

Logic and Goal of Adjustment: Proper adjustment is a process of "observe, judge and coordinate." Operator must assess the fabric state (taut or piled) through the viewport and adjust accordingly, following the principle of "adjust the lifting wheel speed in the opposite direction, then coordinate nozzle pressure." For example, if the wheel is too fast, slow it down; if the fabric remains tense, slightly increase nozzle pressure by 0.2-0.5 bar to enhance the liquor's "lifting force." The ultimate goal is to achieve an ideal state where the fabric flows naturally suspended and smoothly inside the tube. For multi-tube machines, ensuring load difference not exceeding 10% between tubes is key to preventing "tube difference" and ensuring color consistency.

Note:

When using the double-end feeding process for lightweight fabric, setting lifting wheel speed to 500 meters per minute enables conventional two-tube fabric dyeing machine to process a batch of up to 4000 meters in single cycle. This approach significantly boosts production efficiency while maintaining high dyeing quality.

Key Operational Steps for Double-End Feeding:

1. Low-Speed Feeding & Tension Control: The feeding process must begin in a low-speed mode. It is crucial to maintain strictly consistent tension between the two fabric strands. This ensures smooth and even entry into fabric dyeing machine, preventing issues where one strand feeds faster, slower, tighter or looser than the other.

2. Stable Circulation Before Dyeing: After the fabric ends are joined (knotted or sewn), continue running the machine at a low speed for approximately 10 minutes. This critical step verifies that both fabric strands are circulating steadily and without tangles or pile-ups. Only after confirming this stable flow should you proceed with subsequent dyeing steps like heating, pressurizing and adding chemical.

Core 3: The Guarantee of Consistent Output — Process Details and Standardization

Beyond core balance, standardized control of detailed processes is the cornerstone of reproducible results batch after batch.

Process Refinement: Dyeing is not static. For instance, during the high-temperature phase (130-140°C) for polyester, nozzle pressure should be adjusted based on fabric weight: 0.3-0.5 bar for lightweight fabrics, 1.2-1.5 bar for heavy fabrics. Circulation and balance must be maintained during heating and cooling phases, and rapid cooling from high temperatures is strictly avoided to prevent thermal shock creases.

Operation Standardization: This includes unit consistency and maintenance discipline. Confusion between pressure units (bar, MPa, psi) is a major risk. Details like clear multi-unit markings on pressure gauges and unified units in process documents reflect the quality of professional modern fabric dyeing equipment. Furthermore, disassembling and cleaning the nozzle after each batch is the simplest yet most effective maintenance to preserve flow design and jet performance.

Conversion formula

1 bar = 14.5038 psi = 0.1 MPa

1 MPa = 10 bar = 145.038 psi

1 psi ≈ 0.06895 bar ≈ 0.006895 MPa

Future Perspective: Pathways to Enhanced Efficiency

Currently, overflow jet dyeing technology is evolving towards greater intelligence and sustainability. Real-time parameter monitoring via IoT sensors and process optimization using algorithms promise to increase dyeing reproducibility to over 98.5%. Meanwhile, adopting high-efficiency pumps, heat recovery systems, and low liquor ratio (as low as 1:5) designs can significantly reduce water, energy, and chemical consumption. These trends are becoming important factors in evaluating the long-term value of new-generation fabric dyeing equipment.

About Wuxi Shin Tong Yunn Machinery Technology Co., Ltd.

We specialize in the R&D and manufacturing overflow jet fabric dyeing equipment. We believe that excellent textile dyeing machine is the crystallization of superior mechanical design, ergonomic operational logic and profound understanding of dyeing process. We are committed to integrating the core operational principles mentioned above into every detail of our machine design, providing our customers with stable, efficient and manageable dyeing solutions. We look forward to exchanging ideas with industry peers on achieving superior dyeing quality and production efficiency through the perfect integration of equipment and process.