LAB EXPERIMENT 03

To determine starch contents in the Greigh fabric

PERFORMANCE ABJECTIVE

Upon the successful completion of this experiment student will be able to:

i. Understand purpose of different sizes applied on yarns ii. Understand the way to evaluate size contents in the fabriciii. Understand the calculating size content

MACHINES/MATERIAL REQUIRED

Greigh fabrics Iodine / tagwa solution Violet scale

CHEMICAL REQUIRED

Potassium iodide (100%) Ethanol Water

DISCUSSION Sizes are chemicals applied on the warp yarns prior to weaving so that the yarn can with stand wear and tear and different tensions during weaving process .There are there types of sizes that are conventionally applied on the warp yarns

i. Natural Sizes (eg. Starch)ii. Santhitic sizes (eg.PVC)iii. Natural polymer based sizes (eg.CMC)

The amount of size used is mentioned by the greigh department so as to decide the extent of desizing to be carried out

PROCEDUREPrepration of KI solution

Dissolve 10 grams of KI ( potassium iodide ) in 100 ml demineralized water Sir until it is completely dissolve Make the volume up to 800 ml with water Finally add ethanol to make the volume up to 1000 ml

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Name: _____________________________________________ ID No. ____________________

Signature of the lab tutor________________________ Date:_____________________

Precautions for Ki Solution

Don’t expose the sun light Store in the brown bottle and used within 3 months

ASSESMENT OF SIZE CONTENTS

Pour few drops the Ki solution of the fabric to be tasted Rub the cloth gently Compare color change with violet scale and no rating

NOTE:1. Fabric must be brought to room temperature before conducting the test

2. Before conduction of test the fabric PH should be neutralized

Evaluation

Color change Quantity of starch

No change No of starch is present

Pale blue Trace of starch

Bluish brown Appreciable amount of starch

Brown Modified starch PVA

Test results:

Violet Scale rating _____________________________

%age of size content in the fabric _________________

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REVIEW QUESTION

Q 1.?

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Q 2.?

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Q 3. ?

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FINAL CHECK LIST

1. Clean your machinery equipment’s /materials and workbench before you leave 2. Ensure the replacement of all equipment’s to their specified storage area 3. Submit your answer to question together with your data. Calculation and result before

the next laboratory /experiment

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