Tricot Machine Technology Quiz

Tricot Machine Technology

• Tricot machines are used in knitting technology
• The machine has several key components
• Key components include warp beams, sley bars, tension bars, knitting elements, fabric take-up rollers, and a batch roller.
• The warp beam carries the warp threads
• The sley bars space the warp threads
• The tension bars maintain tension in individual warp threads
• Knitting elements includes warp guides, sinkers, needles, and a presser bar.
• Fabric take-up rollers take fabric from rollers at a constant rate
• The batch roller winds up the fabric onto large rolls
• The crank shaft drive, within a case, powers the knitting components

Main Parts of a Tricot Machine

• Warp beams, carrying the warp threads
• Sley bars, spacing the warp threads
• Tension bars, keeping tension on warp threads
• Knitting elements: warp guides, sinkers, needles, and presser bar.
• Fabric take-up rollers, handling the fabric at a constant rate
• Batch roller, where the fabric is wound onto large rolls
• Crank shaft drive, powering the knitting components within a housing

Knitting Elements

• Guides: thin, flat wires; 25mm wide
• Attached vertically to guide bar assemblies
• Usually at least 2 guide bars per tricot machine, though 3 or 4 are also common
• Have two movement types: one forward and backward from a cam shaft; and lateral (shogging) motion from the pattern wheel.
• Needles: mounted in leads and vertically inserted into the needle bar.
• The needle bar gets motion from the main cam shaft
• Machine gauge, normally varying between 20-36
• Needle bar length determines machine width, typically 210cm to 420cm
• Sinkers: also made of thin, punched steel sheets; number of sinkers per 25mm determines the gauge; hold fabric in the throat as the needles move; prevent needles from going through existing loops to aid knock over.
• Sinkers are mounted on a movable sinker bar, also driven by the main cam shaft
• Presser: a strip of fibrous or plastic material attached to the presser bar along the entire needle bed; closes the beard of the needle during loop formation

Knitting Cycle

• Rest position (a): needles rise to 2/3 full height, beards face machine's back, presser withdrawn

• Forward swing & overlap (b, c): Guides move forward with sinkers overlapping old loops, positioning at correct height on needle stems.

• Return swing & second rise (c, d): Guides swing to front, needles rise to full height, new loops slip off beards onto stems above old overlaps, minimizing guide bar swing.

• Pressing (e): Needle bar descends, open beards cover new overlaps, presser advances/closes beards

• Landing (f): Sinkers withdraw, upward curve of their bellies lands old loops onto closed beards;

• Knock-over & underlap shog (g): Presser withdrawn, needle bar descends, causing the old overlaps to be knocked over; underlap shog can occur anytime between pressing and knock-over usually occurs in opposite directions on the two guide bars.

• Sinkers move (h): Sinkers move forward, holding down fabric loops; pushing them away from rising needles.

• The knitting cycle reduces necessary guide bar swing and time required.