Lecture 13

Single Knit Machines (plain)

Main Products

Single Jersey Pique Locast Honey comb Pique fleece Two thread fleece Feed stripes

Single Knit Machine Working

Single bed of needle Only cylinders Needles and sinkers High speed Wider width Most common Easy to handle

Double Knit Machines

Cylinder and Dial Two bed of needles No sinker Double side knitting

Sub types

Interlock Rib Double jersey (interchangeable)

Interlock

Highly flexible fabric Can adopt any body shape Used for under garments Soft hand feel

Lecture 13 Knitting Accessories Compressed air Lubricants Air conditioned Yarn storage Fabric Storage

Compressed Air

For Cleaning Oiling Fluff removing

Parameters of Compressed Air Cool Dry Required pressure Required quantity

Sources

Compressors Piston based Screw Base

Cooling Process

Refrigerator technology Cooling towers

Best is refrigerator technology

Lubricants

Main purpose is lubrication to reduce friction between parts of machines, particular between needles and cams

Parameters of Lubricants

High lubrication Easy wash during wet processing No smell No stain

Normally called white oilSupplied by all big companies Some chemical manufacturers add some auxiliaries in

it

Air Conditioning of the hall

Main objectives: Low temperature to keep machines cool Control of fluff Healthy environment Strength consistency of yarn Smooth running of machines Less wear and tear of machine High speed of machines Less breakage of needle and sinkers

Storage

To avoid mixing Better look after Less wastage in transportation Easy to locate Controlled inventory

Lect 14 Knitting Calculations

Lecture 15 Fleece Fabric

A fabric made by sheep wool, soft warm A fabric soft , warm bulky Generally used to: Protection from cold Sweat absorption (sweat shirt) Baby clothes

Fleece ---

A fabric knitted with two types of yarn. Fine yarn is on front side and course yarn on back side. In most of cases fine yarn is 100% cotton while course yarn is P/C 50:50

Normal combination and fiber ratio: 30/16, 20/10, 26/12 etc PC/C, C/PC

Types of Fleece

Two thread fleece Three Thread Fleece

Two thread Fleece

Very rare Was popular when three thread fleece were

not common Generally not liked due to impassion of

course yarn on front side Low quality product

Conti---

Made on single jersey machines Maximum medium weight, since very course

yarn difficult to use Long loop is difficult

Cam Arrangement

On Fleece fabric.docthree needle track machine:

CHARACTERISTICS OF TWO THEAD FLEECE Light to medium weight Double impact on front side, particularly in

case of different fibers No good brushing possible due to short

length of loop

Three Thread Fleece

Made on fleece machines

High grammage is possible( 500 GSM) High brushing due to long loop on back side Maximum course yarn is possible ( up to 10 count)

on back side Very common in use Fleece machine guage is 16 or 18

Yarn

C/PC PC/C

30/16, 22/12/ 20/10

Cam Arrangement

Fiber Percentage

Calculation Method

Example: Front yarn 30s 100% cotton Back yarn 16 s 50:50 P/C Consumption ratio

Front Two kgs Back one kg

Conti---

Total consumption three kgs Calculation: front yarn 2 kgs 100 % cotton Back yarn 1 kg ( ½ Kg polyester and ½ kg cotton Total Cotton consumed 2 + 0.5 =2.5 Kgs Total polyester consumed ½ kg Ratio: cotton= 2.5/3*100= 83.33% Polyester= 0.53*100=16.66% Such ratio is normally called 80:20 Fleece

Main characteristics of Three Thread Fleece Highly absorbent High weight is possible Can use entirely different yarn on both

sides( even dyed yarn) Pattern is possible ( diagonal stripes etc) Very common in use

Fleece problems and their remedies Uneven loop – control yarn supply Loop stretch– control cam tension Needle line on front side Wales thickness variation on front side due to

fluff contamination between the needles, needs regular cleaning, more cleaning is required due to course yarn

C--

Poor brushing–due to high TPI yarn– use low TPI

Dyeing variation due to different percentage of yarn… calculate exact % by using Skelton test

Steak problem after dyeing due to heavy weight fabric--- use anti creasing agents in dyeing

C---

High shrinkage --- use compactor or tumble dryers

Other types of fleece

Sherpa fleece --- brushed and washed to get balls

Polar fleece ---- loops on both sides also brushed on both side

Loop knits

Terry fabric to knitted terry towel

Good luck, May Almighty bless you

Knitting Costing

Objectives of the session:To make participants familiar with the basic terms of costingTo create an understanding about the costing methodsTo develop a skill to do costing in a

Knitting department

Basic Cost Terms and Concepts Different Costs for Different Purposes Fixed and Variable cost Cost Drivers Direct and Indirect Cost Controlled and Uncontrolled cost Direct material Direct Labour

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Manufacturing Overhead Indirect material Indirect labour Other Manufacturing Cost Service department Overtime Premium Idle Time Conversion Cost

Cost Flow in a Manufacturing Company

Direct Material Direct Labour Manufacturing Overhead

Economic Characteristics of Cost Opportunity Cost Out of Pocket Cost Sunk Cost Differential Cost Incremental Cost Margin Cost Average Cost

Cost and Benefit Information

Job Oriented Cost System

Product Costing

Types of Product Costing

Job-Order Costing System Process Costing System

Activity Based Costing (ABC)

Stage One Overhead Costs are assigned to activities

Overhead Cost are assigned to production job

Knitting Cost

Process Cost Job-Order Cost

Process Cost

Material Labour

Material

Direct Yarn Lubricants Machine Accessories Needles Energy

Continue…

Indirect Engineering Department Other Service department

Labour

Direct labour Worker Technical people Managers Accounts

Indirect labour

Marketing people Accounts People Finance People Others

Overhead

Administration Financial Cost Marketing Cost

Knitting Department

Costing is based on Process and as well as on Job Order

Process Based Costing Knitting is main process

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Material Main Cost is of yarn Yarn Consumption Yarn wastages Yarn Running Properties Yarn Package sizes

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Other material Machine Accessories Needle s--- Breakage depends upon yarn

quality Lubrication depends upon yarn quality

Labour

Different Production for Different yarn and fabric qualities

Different production for different customers Different Production in different seasons Requirement of number of workers is

different

One Practical Example

Labour Cost Department of 20 machines Staff One Knitting Manager and one assistant

along with three shift in charges Three Shift production 5000 kgs per day @ 145 per kg

Continue…

Salary Bill KM 30000 Assistant 15000 Shift In charges 30000 Labour 180000 Other Staff 25000 Total 270000

Material Consumption

Yarn 5600 Kgs Yarn price 125 per kg Needles 100 per day Needles 40000 per six month Sinker 40000 per six month Machine oil 10 kg per day Parts 200,000 per annum

Prices Needles Rs. 35 per needle Sinker Rs. 20 per needle Oil Rs 120 per kg Machine Price Rs. 2.5 million per

machine Depreciation 10 % straight Financial cost 7.5 % per annum Total project cost 85 Million

Calculate:

Cost per kg with the current data Fixed and variable cost Break Even point in Rs and in Kgs Project pay back period BE( pcs) F/P-V BE $ F/1-V/P

Time Cost Concept

Per hour factory cost Per month factory cost

Cost improvement strategy

Minimum fixed cost Less wastage High efficiency Low idle time Maximum utilisation of machines

Role of Knitting in Dimensional stability of Knitted Fabrics

Dimensional Stability

Resistance to change in area

Change in the Area

May be negative

or positive

Reason:

Textile Raw Material

Spinning

Knitting

Wet Processing

Stitching

Change

Wanted? Unwanted? Wanted in case of bandages

Some time in fitted garments Unwanted in case of garments

Can We Have Zero Shrinkage Garments Yes…but with many ifs and buts Normally Cannot Have to live with tolerance

Tolerance Limits:

Depends upon: Textile raw material Yarn Count Knitting Structure

Mechanisms of Shrinkage

Swelling of fibers If there is no swelling then there is no

shrinkage ??????? Elongation of fibers No elongation no shrinkage????? Recoverable Elongation High Recoverable Elongation no shrinkage ?????

Shrinkage Concept needs some clarification --- due to swelling--- needs more lengthy path

to travel ---kept in stretched form ---needs to be in

natural form ---kept in pressed form ---needs to be in

natural form

Other Factors---

---space between loops and wales to move ---high tension during feeding --- residual energy ---mixture of fine and course yarns

How knitting department can help in shrink controlling? Yarn Twist Yarn Tension Knitting structure--- is not in the control of knitter, it

depends upon designer Proper combination of yarn count and machine

guage Uniform yarn feeder tension Uniform and appropriate fabric take up tension

Total Productivity Management What is productivity?

Doing more with less

Productivity is an approach, a mindset, and a way of thinking to do more with less

Why productivity?

 Increase output increase productivity  Profit and productivity are synonymous Cutting cost improve productivity Profit today and tomorrow are possible Partial productivity improvement is

worthwhile Productivity only applies to production

When Productivity?

    High competition, survival is based upon the right balance between price quality and delivery

    Manufacturing industry has been redistributed to include the third world.

    The economic and social well being of people, and in turn the peace of the world, depends organisation of all kinds making effective use of the limited resources.

    There is a huge need of funds for education, health and other services. It is the duty of the business organisations to mange their productivity more effectively to fulfil these needs.

The undesirable effects of inflation can be reduced by the efficient production

Conti…

Productivity becomes a crucial issue when there is a scarcity of resources.

TPM and Knitting

Resource utilization Minimum wastage Maximum output Invention in methods Controlling and preventions Improve contributing factors

Inputs in knitting

Yarn Machines Machine spare parts Machine accessories Labour hours Financial cost Department per hour cost

Outputs:

Knitted fabric Revenue from knitted fabric Profit= Rev-cost

TMP CYCLE

Measure Evaluate Plan Implement

How it is measured?

Documentation Calculation Monitoring

How it is evaluated?

Compare With? Competitors Industry Sellers claims Previous records

How to plan it?

SWOT analysis Trend analysis By regression analysis Think new ways Involve every one Group responsibility Incentives Celebrate the minor success plot on graphs

Implement?

With full confidence of positive results

Achievements

High production Low knitting faults Low consumption of accessories Low wear and tear cost Less down time In time deliveries more profit More employment

Benefits of High productivity

Only one way of survival

Quality control in knitting

Before Knitting

Yarn Machine Needles Sinkers Oil

Yarn

Before knitting Count Weight Winding Cone shapes Packing

After Making samples

Yarn variation Patta (Barrenness) Thick and thin places Dead cotton Knots Strength Cotton color

Machine

Gauge Working condition Automation Safety measures Spare parts

Needles and sinkers

Quantity Quality Spare Working conditions

Quality of knitted fabric

Knitting is a irreversible phenomenon

Checking can only intimate and no repair is possible

Only it can help in prevention

Checking Method

100% checking of knitted fabric Report is made Report is presented to managers Action is taken Pass fail decisions are made

Point system

Four point system is used, which is not useful Rather checking should be on number of

faults Strong coordination is required between

quality and production people