Views: 0 Author: Jason Hong Publish Time: 2026-09-19 Origin: Site
When a knitting factory evaluates a circular knitting machine, one of the first questions is often: “How many kilograms can this machine produce per day?”
The answer cannot be determined from RPM alone. Two machines running at the same speed may deliver very different output because production is also affected by machine diameter, needle count, active feeders, stitch length, yarn count, fabric structure and actual operating efficiency.
A useful calculation should therefore separate theoretical production from real factory production. This article explains a practical method for estimating both.
Before calculating production, confirm the following information:
Actual needle count
Number of active feeders
Machine speed in RPM
Average stitch length in millimetres
Yarn linear density in tex
Percentage of needles actually knitting
Expected operating efficiency
Diameter and gauge are often used to estimate the number of needles:
Estimated needle count = π × machine diameter in inches × gauge
However, the actual cylinder needle count supplied by the machine manufacturer should always be used when available.
For a plain single jersey structure in which all needles knit at every active feeder, yarn consumption can be estimated in two stages.
Yarn length (m/min) = Needles × active feeders × RPM × stitch length (mm) ÷ 1,000
Theoretical production (kg/hour) = Yarn length (m/min) × yarn tex × 60 ÷ 1,000,000
Then apply the expected machine efficiency:
Estimated actual production = Theoretical production × operating efficiency
For cotton yarn expressed in English cotton count, an approximate conversion is:
Tex = 590.5 ÷ Ne
For example, 30 Ne cotton yarn is approximately 19.7 tex.
Consider a plain single jersey machine with the following proposed production conditions:
Parameter | Example value |
|---|---|
Machine diameter | 34 inches |
Machine gauge | 28G |
Estimated needle count | 2,991 needles |
Active feeders | 102 |
Machine speed | 25 RPM |
Stitch length | 2.8 mm |
Yarn count | 30 Ne cotton |
Yarn linear density | Approximately 19.7 tex |
Assumed operating efficiency | 85% |
First, calculate the yarn length consumed per minute:
2,991 × 102 × 25 × 2.8 ÷ 1,000 = approximately 21,356 m/min
The theoretical fabric weight is:
21,356 × 19.7 × 60 ÷ 1,000,000 = approximately 25.2 kg/hour
After applying the assumed 85% operating efficiency:
25.2 × 85% = approximately 21.4 kg/hour
For 24-hour production:
21.4 × 24 = approximately 514 kg/day
This result is an estimate for the stated conditions—not a guaranteed output. If the yarn, stitch length, machine speed, fabric structure or efficiency changes, the result will also change.
The theoretical formula assumes continuous knitting under fixed conditions. A real knitting floor includes both planned and unplanned stops.
Time is lost during yarn replacement, fabric roll changes, cleaning, style changes, quality inspection, maintenance and fault handling. A factory should use its own historical efficiency data whenever possible instead of relying on an optimistic percentage.
Plain single jersey is relatively straightforward because all needles can knit at every feeder. Piqué, mesh, jacquard and transfer structures contain tuck, miss or transfer actions. The effective number of knitted loops may therefore be lower than the maximum assumed by the basic formula.
A high set RPM does not guarantee high daily production. Frequent yarn breaks, unstable yarn tension or excessive machine stops can make a slower but more stable setting more productive over 24 hours.
A longer stitch consumes more yarn per loop and generally increases output by weight, but it also changes the fabric construction, GSM, appearance and dimensional behaviour. Stitch length must be selected for the required fabric—not increased simply to obtain a higher kilogram figure.
Gross knitted weight is not the same as saleable fabric weight. Start-up fabric, defective sections, inspection cuts and other losses should be deducted when the factory calculates usable output and production cost.
The basic formula is most suitable for plain structures using one main yarn system. More complex fabrics should be calculated yarn system by yarn system.
The ground yarn and Lycra have different linear densities and feeding conditions. Calculate their consumption separately, then add the two weights.
Face yarn, binding yarn and fleece yarn may have different counts, stitch lengths and feeding arrangements. Each yarn system should be calculated separately. A single average yarn count can create a misleading result.
Not every selected needle forms a loop at every feeder. Pattern design, miss stitches, tuck stitches and loop transfer all affect yarn consumption. The best estimate should be based on the actual pattern and a confirmed fabric trial.
Cylinder and dial needles must both be considered. The knitting sequence and active needle arrangement should be confirmed before applying a production formula.
A fair comparison must use the same production conditions. Ask each supplier to calculate output using the same:
Machine diameter and gauge
Actual needle count
Active feeder quantity
Yarn count and composition
Stitch length
Target GSM
Fabric structure
RPM
Operating efficiency
Number of production hours
If one quotation uses theoretical maximum speed while another uses realistic factory efficiency, their kilogram figures cannot be compared directly.
The most useful production estimate should explain both the assumed conditions and the calculation method. A single “kg per day” number without these details is not enough for an investment decision.
For a more reliable calculation, provide the machine supplier with:
A physical fabric sample or clear fabric photo
Fabric composition
Yarn count for every yarn system
Required GSM
Finished fabric width
Machine diameter and gauge
Required fabric structure
Expected daily working hours
Target production capacity
Any Lycra, plating, jacquard or transfer requirements
Machine output should always be evaluated together with fabric quality, operating stability and usable production. The highest RPM or the highest theoretical kilogram figure is not necessarily the most profitable choice.
HENGYE Machinery recommends confirming the target fabric first and calculating production from the actual machine configuration. If you send us your fabric sample or specifications—including yarn count, GSM, width and required capacity—our technical team can recommend a suitable circular knitting machine and provide a production estimate based on clearly stated conditions.
Explore our Single Jersey Circular Knitting Machines, Double Jersey Circular Knitting Machines and Computerized Jacquard Knitting Machines, or contact HENGYE Machinery for a configuration recommendation.
