CAD/CAM in Knitting (I)Advanced development in flat bed knitting machine Jimmy K.C. Lam The Hong Kong Polytechnic University
Learning Objectives • Development of modern Computer-controlled Flat Knitting Machine • Advanced knitting CAM systems • Gauge conversion and gaugeless knitting • Whole Garment Knitting – multiple needle beds knitting • Knitting needles and presser foot development • Digital stitch control system for quality control • Machine setup and take down device control
Development in computerizedV-bed machine (1) • The modern V-bed machine has gone through a number of developments to achieve flexible and integrated knitting in short cycle. • The development can be grouped into the following: • Development in CAM (knit/tuck/miss) system so as to increase knitted pattern flexibility • Development in Gauge system (to tailor for fashion market) • Development of new knitting concept (says from panel knitting, fully fashion knitting, integral and whole garment knitting)
Development in computerizedV-bed machine (2) • Special needles development (compound needle and slide needle) to facilitate pattern flexibility and production efficiency • Special transfer jack and stitch presser development to knit complicated design and fabric • Development of new take down tension device for sequential knitting • Digital control loop length device to control fabric quality (so loop length will be the same for different panel)
Modern Knitting CAM development Knitting Width Offer a wide range of machine width, from 48 inches to 100 Inches for different product Knitran System Knitting CAM systems with knit, tuck, miss and transfer. Knitting systems with single, double, triple, four- and six- configurations Ultra Lightweight carriage It allows for lower moment of inertia, increases stability and Higher production.
Modern Knitting Gauge development Gauge Range To increase product flexibility, and offer knitwear for all Seasons, gauge range from E3,4,5,6, 8, 10, 12, 14, 16, 18, 20 Gauge Conversion Gauge conversion incrases the capacity ofa single knitting Machine to support production in different gauge It is achieved by exchanging the needle bed with associated items. Gaugeless knitting Using the concept of slide needle, different “gauge” sizes are Possible to knit in a single garment.
Modern Knitting New knitting concept Whole Garment Knitting 3-dimensional knitting allows front body, back body and Sleeves to be knitted together in one piece. 4-bed configuration (2X knitting + 2X transfer) The additional of two transfer beds placed directly over a Conventional V-bed machine results in greater transfer and Patterning capacilities. 4-bed configuration (4X knitting) For whole garment design with 4-bed configuration with – Four independent needle beds for knitting
4-Needle beds Whole Garment Knitting Top Needle bed Front Needle bed
Modern Knitting Needle Development Compound Needles Compared with conventional latch needles, the compound design offers significant reductions in stroke, a thinner open/ close profile and higher operational stability for uniform production quality. Slide Needle Using a two piece slide mechanism instead of conventional transfer slip, the slide needle offer complex transfer capability in knitwear design.
Modern Knitting Jack and Presser Transfer Jack This transfer jack is specifically designed with slide needle to improve transfer technology. Stitch Presser The motor driven stitch pressers hold down the yarn gently and permit easy knockover for flexible product variety. Warp Insertion A hybrid warp/weft machine features a special plating cam and lace bars for performing warp knitting in combination with conventional flat knitting
Modern Knitting Stitch quality, racking Digital Stitch Control System Digital control offers consistency in loop length for integral knitting and whole garment production. Yarn cutter unit A single unit cutting system consists with two yarn grippers and a cutter. Double Racking Double racking is performed by simultaneous movement of the front and back beds in both direction effectively increasing the racking range for more flexibility in patterning without unwanted in total racking movement.
Modern Knitting Take down mechanism Setup device The setup device employs a row of fully active setup needles for even takedown. Complete separation of knitted parts are made possible sequential knitting. Take down roller The fabric take down system features two sets of independently adjustable rollers. The main rollers provide smooth and even fabric takedown, while the su rollers are located in close to the needle bed for optimal control
Modern Knitting Other devices Dust Cleaner A blower-operated dust cleaner continuously removes and prevents daily buildup of yarn dust and lint. Schedule knitting Schedule knitting allows an entire set of fully fashioned pieces to be knitted sequentially, for one garment at a time, support quick response in multiple variety small lot production Pattern memory Pattern memory capacity is available up to 192MB (12,582,913 bits or 1,024 wales by 4,096 courses).
Exercises • What is Knitran system for modern knitting • What is Whole Garment Knitting • Name the function of digital stitch control system