1. Jimmy K.C. Lam The Hong Kong Polytechnic University
CAD/CAM in Knitting (I) Advanced development in flat bed knitting machine
Jimmy K.C. Lam
The Hong Kong Polytechnic University

2. 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

3. Development in computerized V-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)

4. Development in computerized V-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)

5. Can you name any modern CAM development in this picture

6. 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.

7. 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.

8. 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

9. Whole Garment Flat Knitting Machine

10. 4-Needle beds Whole Garment Knitting
Top Needle bed
Front Needle bed

11. 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.

12. 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

13. 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.

14. 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

15. 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).

16. Exercises What is Knitran system for modern knitting
What is Whole Garment Knitting
Name the function of digital stitch control system