Help for smooth execution during absence of key position.
Reduce miscommunication/ malfunctioning facts to others
department. Others departments
can
communicate easily for any kind of emergence.
Sometimes this system can reduce hamper to Buyer’s/ Vendors/
service provider/ others in
terms
of various communication fact during absence of key position.
Sub-ordinates can’t be misguided during absence of key position.
Course : Research Methods Submit
by : September 07, 2012
1. Cite
practical examples of multistage sampling.
2. Janata
Bank Ltd. would like to select 200 depositors who opened accounts in the said
bank during the last two years. The depositors can be divided into four
strata according to their occupations with stratum sizes N1=6,000,
N2= 4,000, N3= 3,000,
N4=2,000. The respective standard deviations are: δ1=210,
δ2=130, δ3= 302, and δ4= 175. Further, the
sampling cost for each unit is Tk. 8. How a sample size of 200 should be
allocated to four strata with (a) proportional allotment; and (b) optimal
allotment.
Question: 3
Mention the appropriate scale as well as
logic for the following statements:
(a) The
coordinator of CEMBA/CEMPA programme, Dhaka RRC
has advised the students to make registration in order to select 10 students
as per first come first serve basis for appointing with vice chancellor at
BOU main campus.
(b) A six
member admission committee of CEMBA/CEMPA programme would be formed as per
seniority of the faculty members at the School of Business,
BOU.
Answer:
(a)
Statement: The coordinator of CEMBA/CEMPA programme,
Dhaka RRC has advised the students to make registration in order to select 10
students as per first come first serve basis for appointing with vice
chancellor at BOU main campus.
The above statement is falling
into Nominal scale.
The nominal scale simply allows
the categorization of the responses into mutually exclusive categories. There
is no relationship between categories, implying that there is no ranking or ordering.
The typical application of nominal scale is in classification of responses by
social class, “like” or “dislike”, “yes” or “no”, sex and so on. The
statistical operation possible for nominally scaled data is counting only.
From the above logic we can
sees the similarities with the statement. So we can say it is a nominal
scale.
(b)
Statement: A six member admission committee of
CEMBA/CEMPA programme would be formed as per seniority of the faculty members
at the School of Business, BOU
The above statement is falling
into ordinal scale.
The ordinal scale allows the
respondent to rank some alternatives by some common variables. Here it is
feasible for a user of the product/service to the best to worst. However the
amount of difference between ranks cannot be found but it is only possible to
compute positional statistical measures like median and mode for such data.
From the above logic we found
similarities with questioned statement. So we can say that it is an ordinal
scale.
To determine the durability of prints, pigments, flocks,
motifs and add-ons, for the lifetime of the garment.
PRINCIPLE
A finished garment or fabric specimen of specified minimum
size is subject to a prolonged wash in a Hoover side impeller or Durawash
washing machine. It is assessed against
an untreated specimen for deterioration in appearance.
APPARATUS
Hoover side impeller, top loading, non- automatic washing machine (single or twin tub), 40 litre capacity. or Durawash
ECE detergent/sodium perborate
Polyester makeweights (ballast) as specified in BS EN 26330
Grey Scales for assessing change in colour BS EN 20105 A02
Veri-Vide light cabinet (or equivalent) with lectern
Thermometer
Timer
Overlocking sewing machine
Balance
CONDITIONING & TESTING ATMOSPHERE
It is not necessary to condition the samples nor carry out
the assessment or testing in a standard atmosphere. Ordinary room conditions
are satisfactory so long as the correct procedure is followed.
TEST SPECIMENS
Cut at least one specimen for testing (minimum size 300mm x 300mm of fabric, or one complete garment plus duplicate for comparison). Complete garment to be tested where possible.
Overlock any raw edges of woven fabric to prevent fraying.
PROCEDURE
Fill the washing machine with 40 litres of clean water & heat to 40+/- 2 degrees C
Add 160g ECE detergent/40g Sodium Perborate and run the machine for two minutes to dissolve the powder.
Add the test specimens, made up to a total 1kg load with polyester makeweights (ballast)
Run the machine for 15 minutes, remove test specimens, rinse once in hand hot water and once in cold water to remove any surplus detergent, spin to extract excess water
Flat dry specimens in dry air not exceeding 60 degrees C
REPORT
Report the numerical grade recorded together with the reason
for any down grading. General deterioration in appearance, loss or change in
shade, delamination etc.
NOTE
Where all assessments are satisfactory the overall result of satisfactory is to be given. Polyester makeweights must be thoroughly cleansed between tests to ensure no contamination.
Defect Recognition and Consistency
At Auto Sportswear,
we strongly believe that one of the more effective ways to establish
consistency in classifying defects, is to hold frequent Major / Minor
exercises. These sessions are a review of selected garments with marginal
defects. Inspectors rate the defects privately and the QC Manager leads a recap
discussion with the group determining how each should be classified: major or
minor.
Group discussion should be encouraged and all QC Inspectors
should participate, including Piece Goods Inspectors. By sharing with and
observing from one another, Factory Inspectors will begin to think more
alike. Improving Inspector consistency
throughout the factory and becoming consistent with the Auto Inspectors, will save needless failures. This
in turn will save time and money.
This is a valuable and quick exercise that the factory
should hold routinely throughout the year.
Exercise Leader Instruction
Complete Major / Minor Session with factory example garments and inspectors completing the Defect Tally Sheet. Lead class discussion and get consensus on each garment.Have students participate and use the defect standards to
classify each defect.
Defect Standards Library
In addition to the Major / Minor Sessions, the factory QC
management should maintain a Defect Standards Library to train factory personnel
and to assist QC Inspectors in determining acceptability of challenging
problems. The library should be made up of major and minor defects that
primarily set the standard or limits for acceptability.
To assist in the establishment of this library, we’re providing you with a copy of a collection of fabric defects and common quality sewing problems. End of Impeller article
A prepared sample of fabric is subjected to a tumbling
action against a known abrasive pad. Pile loss is then assessed.
APPARATUS
AATCC “ATLAS” Accelerator, Model AB-7 fitted with 108mm S-Shaped rotor with specimen viewer
Ceramic abrasive lining ring
Rubber based adhesive
Method for removing loose fluff, I.e. vacuum cleaner or brush
Circular cutter 11.28cm in diameter giving a resultant sample area of approximately 100 sq cm.
PROCEDURE
Calibrate accelerotor
Cut two 300mm x 300mm samples
One sample to have appropriate cleaning treatment (as garment care label using appropriate method
Cut the following samples:
Original – four samples, three to test, one kept as original
After Cleaning – cut three samples for test
Glue outside of circle with rubber based adhesive. Fray loose shorter threads to a depth of 2-3 mm (woven fabrics).
Once the adhesive is dry, condition the samples for a minimum of 4 hours at 65 +/- 2% rh and a temperature of 20 +/- 2 degrees C. Testing must also take place in a conditioned environment.
Number and weigh accurately, both original and cleaned samples. This initial weight is now referred to as ‘X’.
Fold one sample in half, place it across the top rotor in the accelerotor and close the door.
Test specimen at appropriate time and speed, initially 3000rpm quickly reducing to 2000rpm after rotor has begun to spin and maintain that speed throughout the test cycle.
Examples as guide:
Velvet 3 mins @ 2000rpm
Corduroy 5 mins @ 2000rpm
Velour 5 mins @ 2000rpm
Remove specimens from accelerotor
Remove all loose fibre from both the sample and accelerotor using vacuum cleaner or brush.
Condition the sample for a further 4 hours, as previously.
Weigh accurately the tested sample. (This weight is now referred to as ‘Y’)
Repeat process e. to I. on both original and cleaned samples saving one original sample for comparison.
SAMPLE DISPLAY & GRADING
Use the following formula to calculate the percentage weight loss of each sample (both original and cleaned):
X – Y x 100 = Result X
X = Weight before testing
Y = Weight after testing
Visually assess each sample comparing with the initial appearance to the original untested sample and grade these samples according to the following assessment table:
Grade : Visual Assessment
NO CHANGE : No change in appearance
NEGLIGIBLE :No obvious loss of individual pile tufts and/ or slight negligible narrowing of the cord wale
SLIGHT :Limited small areas of pile loss and/ or slight narrowing of the cord wale
SIGNIFICANT: Considerable pile loss and/or significant narrowing of the cord wale
DISTINCT : Extreme pile loss causing half or more of the base cloth to be visible and/or distinct narrowing of the cord wales
Retain samples
REPORT
Average percentage weight loss for each set of both original
and cleaned samples, quoting ‘original’ or ‘cleaned’ as appropriate.
The test method describes methods for determination of strength of attachment of press-studs (poppers), jeans buttons, rivets and snap fasteners to garments.
PRINCIPLE
A
sample is taken from the garment, consisting of a sandwich of several fabric
layers, through which a press-stud (popper) has been applied. This is subjected
to a known load, applied in such a way that the two halves of the press-stud
component are pulled in opposing directions, thus tending to prise the two
halves apart. Male and female halves of the press-stud are tested separately.
APPARATUS
Tensile testing device of the constant rate of elongation type, capable of determining the applied load to +/- 5% accuracy at a rate of traverse 50+ mm/minute.
Preparation of test specimens and materials (removal from the garment): Cut a parallel strip of fabric from the garment that contains a single male or female press-stud so that the press stud component is positioned centrally on a fabric strip approximately 30mm wide by 150mm long.
TEST PROCEDURE
Condition for a minimum of 4 hours at 65+/- 2%rh and a temperature of 20+/- 2 degrees
Testing must take place in a conditioned environment.
Grip the specimen in the jaws of the tensile test device. Determine the force to remove the press stud component.
Test a minimum of ten male and ten female components.
REPORT
Report the average press-stud removal force (in Newtons) for the 10 male components separate from the 10 female components.
Report the minimum press-stud removal force (in Newtons) for the male and female components separately.
Report if the fabric has broken down and if so at what force, even if the press-stud has not been removed.
Incomplete Heat-Setting-
Definition and Causes
With synthetic knit and woven fabrics and with fabrics containing Spandex yarns, a complete Thermo-fixing process must take place.
This is done to ensure that after finishing a dimensionally stable fabric is produced and prevents the fabric to exhibit wrinkles and edge curling.
This is normally done by exposing the surface of the fabric to temperatures of 360-380 degrees Fahrenheit for a certain period of time (dwell time).
This dwell time will be dependant on type of fabric, percentage of the Spandex yarn and the size of the heating chambers.
In certain cases in order to prevent heat damage a small quantity of wetting/penetrant type of chemicals need to be added in the Pad tank.
Preventive Suggestions
All technical aspects of the heat-setting process must be
examined and appropriate steps need to be taken.
Corrective Measures:A refinishing at a higher than the original temperature will
be required.
Excessive Over-Feed and Under-Feed-
Definition and Causes
During the drying process the control and stabilizing fabric’s weight (Yield) is an important function.
This is, normally, done by devices known as Over-feed (or under-feed) rollers and wheels.
In knit fabrics to increase the weight, these devices are made to increase the density of the knitted courses across the width of the fabric in a uniform and precise way.
This is referred to as Over-feeding and its excessive use will cause severe crease lines on the selvedge of the fabric on both sides.
To decrease the weight, a reverse action takes place. Excessive use of this Under-feed action will cause the fabrics to develop severe creases, particularly, in the middle portion.
These problems do not appear in woven fabrics.
Preventive Suggestions:A correct and precise method of finishing, based on the type
of fabric must be used.
Corrective Measures:With cotton fabrics, a refinishing at a correct measure of under-feed or over-feed will correct the problem.
Conclusion
With synthetic fabrics, a rewashing of the fabric at pressurized conditions and at high temperatures will be necessary for Tensile Testing Device
Minimum
slot opening distance (MM) anti-knife (L * W * L * W)
250*70*250*70mm
Minimum
slot height
7*100mm
For
Board Thickness
0-10mm
Main
motor power
7.5KW
Total
power
16KW
Paper
kicking accuracy
Degree
of bending of the national standards, kicking paper error of plus or minus
1.5MM
Slotted
precision
Degree
of bending of the national standard, slotted error of plus or minus 2MM
Function and Feature: Our company has developed ZYM series of roller printing and die-cutting machines, , which is a new ideal production equipment in carton production industry in recent years.
Conclusion
The Die Cut Printing Machine is mainly the automatic document feeder board., printing, slotting, corner cutting, trimming, drilling (any shape), and other procedures forming a printing and die cutting equipment, the compact mechanical structure, simple operation, adjustment convenient, advanced performance, high efficiency, ensure that processing of high-grade cardboard carton production industry an ideal replacement machine. It is suitable for a variety of shaped cardboard boxes or cartons.
