Overview
ISO 9947:2005 - "Textile machinery and accessories - Two-for-one twisters - Vocabulary" defines standardized terminology for two-for-one (TFO) twisters used in the textile industry. This International Standard provides clear English and French terms and definitions (with equivalent German terms included for reference) to ensure consistent communication across design, production, procurement and maintenance of TFO twisting machines.
Key topics
- Scope and purpose
- Establishes a vocabulary of terms and definitions specifically for two-for-one twisters (TFO twisters).
- Ensures uniform use of terms across manufacturers, users and regulators.
- Core definition
- A two-for-one twister is a twisting machine that inserts twist at a 1:2 ratio: for one revolution of the spindle the yarn receives two turns of twist.
- Important operational notes: yarn is unwound from a stationary feed package, guided through the rotating spindle, twisted and wound onto a take-up package; the yarn balloon rotates around the stationary feed package and yarn progression inside the rotor is opposite to balloon rotation.
- Twist calculation
- Amount of twist (in turns per metre) is given by the formula:
- Twist = 2 × (spindle revolutions per min) / (yarn speed in m/min)
- Machine dimensions and layout terms
- Definitions for machine length, width, height, maximum/minimum operating heights and section length (centre-to-centre of intermediate frames), with references to illustration figures.
- Components vocabulary
- Standard terms for components such as drive unit, control units and elements for power transmission, and other construction elements used in TFO machines.
- Supporting materials
- Symbols list and alphabetical indexes (English, French, German) to aid lookup and translation.
Applications and users
ISO 9947:2005 is useful for:
- Machine manufacturers and designers - consistent terminology in specifications, drawings and user manuals.
- Procurement and quality teams - accurate product descriptions, contract language and acceptance criteria.
- Maintenance and operations personnel - clear component names and operating-height definitions for safe handling and servicing.
- Technical authors and trainers - producing manuals, instruction booklets and training materials (reproduction of terms/definitions for educational use is permitted under conditions stated in the standard).
- Standards committees and testing labs - harmonized vocabulary for test reports, conformity assessment and international collaboration.
Related standards
- Prepared by ISO/TC 72 (Textile machinery), Subcommittee SC 1 (spinning, twisting and winding). Refer to other ISO textile machinery standards for technical specifications, safety, testing and performance where detailed machine requirements are needed.
Keywords: ISO 9947, two-for-one twister, TFO twister, textile machinery vocabulary, twist calculation, machine dimensions, drive unit.