Open Width vs Tubular Knitting Machine: Comparison

Author: Mike Chen, Production Director at  Leadsfon  | 11 Years Industry Experience

Introduction

The fundamental output format of a Circular Knitting machine - whether the fabric exits the machine as an open-width sheet or a continuous tubular cylinder - has ramifications that ripple through every downstream process in a textile mill. From slitting and de-twisting requirements to finishing line compatibility and fabric utilization rates, the open width versus tubular decision influences capital investment, operating costs, and final product quality.

For decades, tubular take-down was the default configuration for single jersey circular knitting machines, and it remains dominant in commodity knit production across South Asia and Central Asia. However, the rise of high-speed open width machines has steadily shifted the landscape, particularly in markets serving European and North American buyers who demand consistent, slit-ready fabric with minimal post-knitting processing.

This comparison examines the technical, operational, and economic factors that textile mill decision-makers must weigh when choosing between open width and tubular knitting machine configurations. The analysis draws on industry benchmarks across machine speed, fabric quality, finishing requirements, and total cost of ownership.

Technical Overview: How Each System Works

In a tubular knitting configuration, the circular knitting machine produces fabric in a continuous tube - essentially a seamless cylinder. The fabric is drawn downward through the needle zone by take-down rollers and accumulated in roll form. Since a tubular machine forms a closed loop of fabric, the resulting roll has two fabric layers (front and back) connected at both edges. This fabric must subsequently pass through a slitting machine to convert it into open-width form, unless the final product is designed for tubular processing (such as T-shirt body blanks, underwear, or certain sportswear applications).

An open width knitting machine incorporates a fabric cutting and spreading mechanism directly at the take-down point. As the tubular fabric descends from the knitting zone, a circular slitting blade cuts one side of the tube, and spreading rollers open the fabric into a single-layer sheet before it reaches the winding station. The result is fabric that exits the machine already in open-width format, ready for direct feeding into continuous finishing lines.

This integration eliminates the separate slitting step entirely. At 30 inches cylinder diameter, the fabric opening width is approximately 2.1-2.3 meters depending on stitch structure and yarn tension - well-suited to standard textile finishing equipment designed for 2.0-2.5 meter working widths.

Table 1: Technical Comparison - Open Width vs Tubular Systems

Production Speed and Output Comparison

Production speed is an area where tubular machines maintain a clear advantage. A 30-inch diameter, 24-gauge tubular single jersey machine can reliably operate at 28-32 RPM, yielding daily output of approximately 280-350 kg depending on yarn count and stitch settings. The open width equivalent, constrained by the mechanical resistance of the slitter-spreader assembly and the need for more precise fabric control during opening, typically operates at 22-28 RPM, producing roughly 230-300 kg per day under comparable conditions.

This 15-25% speed differential must be evaluated against the time saved by eliminating the separate slitting process. A typical tubular fabric roll requires 2-4 hours for slitting on a dedicated slitting line (for a 25 kg roll at 80-100 m/min slitting speed), plus material handling and queue time. Across a medium-sized mill running 20 machines, the elimination of this step through open width integration can recover 40-80 machine-hours per week.

Mills processing lightweight fabrics (below 130 g/m2) report that the speed gap narrows because lightweight tubular fabric is more prone to twisting and distortion during high-speed take-down, forcing operators to reduce RPM. At sub-130 g/m2 weights, both configurations often converge to the 22-26 RPM range, making the speed argument for tubular less compelling.

Fabric Quality: Open Width Advantages

The most significant advantage of open width knitting machines lies not in speed or cost, but in fabric quality. When tubular fabric sits in roll form awaiting slitting, the center crease - the fold line where the two fabric layers meet - develops over time, especially under the compressive force of roll winding. For fabrics destined for visible garment panels, this center crease is a persistent quality problem that often requires additional steaming, relaxing, or even re-processing to remove.

Open width machines, by opening the fabric immediately after knitting, prevent this crease from forming entirely. The fabric enters the roll as a flat, single-layer sheet with no fold lines. This is particularly valuable for solid-colored fabrics where crease marks can cause visible dye uptake irregularities - a defect that dyehouse managers consistently rank among their top five quality complaints.

Spirality - the inherent twist tendency of single jersey knits - is also better managed in open width configurations. Because the fabric is opened and spread under controlled tension at the point of knitting, the relaxation path is more uniform than tubular fabric that undergoes slitting days or hours after knitting, by which point the yarn has partially set in its tubular configuration. Independent testing by textile research institutes has documented spirality reductions of 15-25% in open width versus tubular processing for comparable single jersey cotton constructions.

Table 2: Finishing Process Comparison

Cost Analysis: Capital, Operating, and Total Ownership

The capital cost equation favors tubular machines: an open width single jersey machine typically commands a 10-25% price premium over an equivalent tubular model from the same manufacturer. For a new factory setting up 30 machines, this premium translates to a substantial six-figure USD capital differential. However, the total cost of ownership (TCO) picture is more nuanced.

An open width installation eliminates the need for one or more dedicated slitting lines. A single automated slitting line capable of processing the output of 10-15 tubular machines costs approximately USD 25,000-50,000, plus annual maintenance of USD 2,000-4,000 and dedicated operator labor (1-2 operators per shift). Open width machines also consume roughly 15-20% less floor space when the slitting line is factored out, reducing factory construction or rental costs.

Five-Year TCO Snapshot (20-Machine Factory):

• Open Width Fleet: Higher machine capital (+USD 200,000-400,000), no slitting line cost, lower labor cost (-1 to 2 operators per shift), lower fabric wastage (saving 0.5-1.0% of annual fabric output, worth approximately USD 30,000-60,000 per year at mid-scale production)

• Tubular Fleet: Lower machine capital, additional slitting line investment (+USD 75,000-150,000 for 2-3 lines), higher ongoing labor cost, higher fabric wastage (0.5-1.5% of output), higher quality risk from crease defects and re-processing

The breakeven point typically occurs at 18-24 months for mills producing medium-to-high-value fabrics where slitting wastage and quality rejections carry real financial consequences. For low-margin commodity production, the tubular cost advantage may persist throughout the machine lifecycle.

Application Suitability and Market Alignment

Open width machines are strongly favored in several specific application scenarios. Mills supplying cut-and-sew garment manufacturers prefer open width because the fabric arrives slit, relaxed, and ready for spreading and cutting tables without additional processing. European and North American buyers increasingly specify open-width-processed fabric in their quality manuals to minimize crease-related claims. Manufacturers of printed fabrics, where any crease or distortion compromises print registration, almost exclusively use open width configurations.

Tubular machines remain the practical choice for several established market segments. T-shirt body blank manufacturers value the tubular format because the garment side seams are eliminated - the tubular fabric becomes a seamless body. Underwear and intimate apparel production similarly benefits from tubular construction. Commodity knit fabric for developing markets, where price is the dominant competitive factor, continues to be produced predominantly on tubular machines.

The case of LEADSFON is instructive: the company offers both open width and tubular configurations across its single jersey machine series, and sales data shows that demand for open width models has grown from approximately 30% of single jersey orders in 2018 to nearly 55% in 2024, reflecting the broader industry shift toward value-added fabric production.

Decision Framework for Machine Selection

Choose open width machines when:

• Your primary customers require slit, relaxed, crease-free fabric delivered in open width format.
• Your product mix is heavy on solid-colored fabrics where crease marks are a high-risk defect.
• Your factory layout has limited space for additional slitting and material handling equipment.
• Your target markets are Europe, North America, or premium domestic brands with strict quality specifications.
• You process fabrics below 130 g/m2 where tubular speed advantage narrows significantly.

Choose tubular machines when:

• Price is the dominant competitive factor and product margins are thin (below 15% gross margin).
• Your product line includes significant T-shirt body blank, underwear, or tubular-processed product volumes.
• You process heavier fabrics (above 200 g/m2) where the tubular speed advantage is most pronounced.
• Your technical team prefers the simplicity of tubular systems with fewer mechanical components to maintain.
• Your markets accept tubular-delivered fabric with in-house or third-party slitting arrangements.

Hybrid strategy: Many mid-to-large mills operate a mixed fleet - approximately 40% open width for premium customers and 60% tubular for commodity production - optimizing both quality positioning and cost competitiveness across their product portfolio.

Frequently Asked Questions

Q: Can a tubular machine be retrofitted to open width configuration?

Retrofitting is technically possible but rarely cost-effective. Adding an after-market slitter-spreader assembly to a tubular machine requires significant mechanical modification, including new take-down frames, spreader rollers, and winding systems. The retrofit cost typically reaches 40-60% of the price difference between a tubular and factory-built open width machine, without achieving the same integration quality, fabric control, or component warranty coverage.

Q: Does open width knitting affect machine gauge options?

Open width configurations are available across the full gauge range from 18G to 40G for single jersey machines, with no inherent gauge limitations. However, at very fine gauges (above 32G), the additional mechanical load of the slitter-spreader assembly can reduce maximum operating speed by an extra 2-4 RPM beyond the typical open width speed differential. This factor should be considered when calculating ROI for fine-gauge open width installations.

Q: What is the fabric utilization difference between open width and tubular processing?

Fabric utilization - the percentage of knitted fabric that ends up in saleable finished goods - is typically 1-3% higher with open width processing. The key contributors are: elimination of slitting damage and edge wastage (0.5-1.5% savings), reduction in crease-related quality downgrades (0.3-0.8% savings), and improved cutting table yield from consistent-width fabric delivery (0.2-0.5% savings). For a mid-scale mill producing 2,000 tons annually, these percentages translate to 20-60 tons of additional saleable product.

Q: How do open width and tubular machines compare in terms of energy consumption?

Open width machines consume approximately 8-12% more electricity per machine due to the additional drive motors for the slitter, spreader, and take-up assemblies. However, when the electrical consumption of a separate slitting line is allocated to tubular machine output, the total energy per kilogram of finished open-width fabric is roughly comparable - within ±5% between the two approaches. From a total factory energy perspective, the difference is not a primary decision driver.

Q: Which configuration is easier to maintain and operate?

Tubular machines have a simpler mechanical design with fewer moving parts in the take-down zone, making them easier to maintain and train operators on. The learning curve for an operator transitioning from tubular to open width is typically 2-4 weeks, primarily focused on slitter blade alignment, spreader tension adjustment, and fabric tracking control. Experienced technicians can service both types, but spare parts inventory for open width machines is 20-30% larger due to the additional components.

Conclusion

The open width versus tubular knitting machine decision is fundamentally about a mill's position in the value chain. Mills competing on price in commodity knit markets will find tubular machines more cost-effective. Mills targeting premium and export markets, where fabric quality, consistency, and crease-free delivery are purchase order requirements, will increasingly find open width machines to be the necessary configuration.

The global trend is unmistakable: open width adoption is rising as textile supply chains consolidate around value-added production. Mills evaluating new capacity should model both the five-year TCO and the market positioning implications of each configuration before committing capital. The right answer depends not on which machine is 'better' in the abstract, but on which machine better serves the specific customers a mill intends to win.

For detailed specifications and configuration options across both machine types, visit the LEADSFON single jersey product pages or schedule a technical consultation with the application engineering team.