The Electronic Needle Selection V-bed System Jimmy Lam Institute of Textiles & Clothing

The Electronic Needle SelectionThe Electronic Needle SelectionV-bed SystemV-bed System

Jimmy LamJimmy Lam

Institute of Textiles & ClothingInstitute of Textiles & Clothing

Learning ObjectivesLearning Objectives

Disadvantages of mechanical needle selectionDisadvantages of mechanical needle selection Advantages of electronic needle selectionAdvantages of electronic needle selection Comparison between mechanical and electronic V-Comparison between mechanical and electronic V-

bed machinebed machine

– Ref:Knitting Handbook Vol. 9, Jacquard Mechanism on V-bed Ref:Knitting Handbook Vol. 9, Jacquard Mechanism on V-bed

pp38, by K.H. Yuepp38, by K.H. Yue

Disadvantages of Mechanical Disadvantages of Mechanical KnittingKnitting

Can you name any limitation of mechanical Can you name any limitation of mechanical V-bed machine for jacquard fabric ?V-bed machine for jacquard fabric ?

DisadvantagesDisadvantages Restriction on pattern area, and freedom of Restriction on pattern area, and freedom of

designdesign Pattern time and cost is directly proportional to Pattern time and cost is directly proportional to

the pattern sizethe pattern size Machine with more than double systems is Machine with more than double systems is

almost impossiblealmost impossible Prolonged time is required in pattern correction Prolonged time is required in pattern correction

and modificationand modification

Electronic Needle SelectionElectronic Needle Selection

V-bed machine with electronic needle selection is V-bed machine with electronic needle selection is known as electronic V-bed knitting machineknown as electronic V-bed knitting machine

It builds with computer system to control all It builds with computer system to control all machine operations according to the knitting machine operations according to the knitting instruction.instruction.

Needle selection is only part of the programme for Needle selection is only part of the programme for jacquard knittingjacquard knitting

Can you name any other operations for electronic Can you name any other operations for electronic jacquard selectionjacquard selection ? ?

Advantages of electronic needle Advantages of electronic needle selectionselection

1)1) Huge pattern sizeHuge pattern size– The electronic V-bed machine can have pattern The electronic V-bed machine can have pattern

areas of 125 X125 stitches, 256 X 256 stitches; 512 areas of 125 X125 stitches, 256 X 256 stitches; 512 X 512 stitches and 1024 X 1024 stitches. In fact, the X 512 stitches and 1024 X 1024 stitches. In fact, the pattern areas are governed by machine memory and pattern areas are governed by machine memory and is expandable.is expandable.

AdvantagesAdvantages

2) Fast and low pattern cost2) Fast and low pattern cost– Patterning for electronic V-bed machine has to be done Patterning for electronic V-bed machine has to be done

on specific Computer Aided Design (CAD) System. To on specific Computer Aided Design (CAD) System. To produce a jacquard pattern on CAD system is fast and produce a jacquard pattern on CAD system is fast and simple. The pattern can be input to system by keyboard, simple. The pattern can be input to system by keyboard, free-hand drawing on the graphic tablet or through free-hand drawing on the graphic tablet or through scanner. Together with the instruction in specific scanner. Together with the instruction in specific computer language.computer language.


– The jacquard pattern is then transferred to a data carrier The jacquard pattern is then transferred to a data carrier for knitting machine to read and store. If overhead of the for knitting machine to read and store. If overhead of the CAD system is not involved, the patterning cost is data CAD system is not involved, the patterning cost is data carrier cost (tape or floppy disk) plus the few hours labor carrier cost (tape or floppy disk) plus the few hours labor cost.cost.

– In addition, for mechanical V-bed machine, the In addition, for mechanical V-bed machine, the patterning cost is multiplied by number of machine patterning cost is multiplied by number of machine involved. For electronic V-bed, this cost id divided by the involved. For electronic V-bed, this cost id divided by the number of machines of the same model, gauge and widthnumber of machines of the same model, gauge and width . .

One CAD Design Centre can serve a number of computerized knitting machine


(3) Multi-System machine. – Modern electronic V-bed m/cs are built-with compact

cam to reduce weight and width of cam carriage. This allows more knitting systems to be installed and higher production rate.

– However, increasing the number of knitting systems will increase the weight of carriage which will cause difficulty on repairing when it is getting to heavy. In addition, it will increase the costs of knitting machine.


(4) Pattern correction and modification

– All modern V-bed m/c has built-in computer and monitor as standard equipment. The input data (pattern/design) from independent design system can be adjusted or modified right on each individual m/c. These correction and modification only require work on the m/c keyboard and store on computer.

A simplified CAD/CAMprocess for computerizedknitting machine

Comparison between Mechanical and Electronic V- Bed machines

A German StollDesign Workstation

Note that the input processcan be done via keyboard,graphic tablet and digital camera

A German Universal Design Workstation •Tape is used as •a storage device

ComparisonComparison

(1) Knitting Speed – With the exception of machine down time for

pattern change, .both systems have similar machine speed. However, the electronic V-bed m/c has stroke reduction for narrow panel. In addition, the pattern change for e-m/c is about 15 mins., about 30% of the mechanical machines with jacquard steels.


(2) Overheads – The overhead for electronic V-bed machine is a lot

higher- than mechanical one. In addition, a design centre (CAD) must be used with the electronic machine. Therefore, this high capital costs limits the manufacturers to produce high profit knitwear only.


(3) Pattern preparation time & cost – The electronic machine with design centre is superb

in this area. Both the preparation time and cost of design is less than mechanical one. See Figure

(4) Freedom of Design – The modern electronic V-bed with extra functions

like stitch presser, comb take down, intarsia yarn carriers allows the machine to knit far more complicated pattern with huge pattern data.

Knitting cost increases withnumber of mechanical machines. But it remains the samefor computerized machines

Pattern time increases with number of mechanical machinesbut decreases with computerizedmachines


(5) Training of new hands – All modern machines are design with one common goal,

to build a machine easy to use and difficult to go wrong. Therefore, training of new hands is lot easier for new machine.

(6) Technician and machine operator – No problems on human resource for electronic V-bed -

industries as all young people prefer to work on modern hi- -tech industries with better working condition and higher paid than the mechanical one.


(7) Maintenance – The modern practice on maintaining the electronic

parts. is to replace instead of repair when malfunction occurred; thus it is lots easier but the costs is higher.

DiscussionDiscussion

What are the major advantages of electronic What are the major advantages of electronic needle selection knitting machine ? needle selection knitting machine ?

What are the limitation of electronic needle What are the limitation of electronic needle selection knitting machine?selection knitting machine?

Documents

The Electronic Needle Selection V-bed System Jimmy Lam Institute of Textiles & Clothing