What molecular change helps cotton resist permanent creasing after durable press treatment?
A Dissolves the whole fabric
B Restrains cellulose chain movement
C Adds mechanical knit loops
D Increases warp flotation
Answer: B. Restrains cellulose chain movement. Crosslinks reduce molecular rearrangement in cellulose and aid crease recovery.
On a roll-and-shoe compactor, why may the delivery roll run slower than the feed roll?
A Promote lengthwise compression
B Increase web elongation
C Shift colour module alignment
D Remove the full pile
Answer: A. Promote lengthwise compression. A lower delivery rate lets fabric shorten in the compaction zone under controlled conditions.
What makes a waterproof breathable fabric different from an impermeable sheet?
A It is always wool
B It absorbs all rain
C It transmits water vapour
D It blocks all vapour
Answer: C. It transmits water vapour. Suitable membranes or coatings can resist liquid water while allowing some water vapour transfer.
Which tradeoff can arise when crease resistance improves after strong cellulose crosslinking?
A Lower tear strength
B Zero laundering loss always
C Completely unchanged hand
D Guaranteed higher tensile strength
Answer: A. Lower tear strength. Crosslinking can restrict molecular movement and reduce some strength properties. The effect depends on recipe and treatment.
What does a low-liquor application method usually reduce compared with a high pickup route?
A Amount of dye fixed necessarily
B Production width by definition
C Starting dry textile mass
D Water carried to drying
Answer: D. Water carried to drying. Lower liquid pickup leaves less water to evaporate if finish delivery is maintained.
When stenter feed speed exceeds chain speed, what is the setting called?
A Overfeed
B Underdraft
C Shearing
D Dewatering
Answer: A. Overfeed. Overfeed delivers extra fabric length to the chain, allowing controlled relaxation or contraction.
Why may a hydrophobic softener impair towel performance?
A It always breaks loops
B It increases water solubility
C It can slow wetting
D It converts pile to yarn
Answer: C. It can slow wetting. A water-repellent surface treatment can slow water uptake, which conflicts with a towel’s purpose.
Schreiner calendering uses a roll with what surface?
A Very fine engraved lines
B Large cutting knives
C Open yarn package slots
D A loose cloth pile
Answer: A. Very fine engraved lines. Fine engraved lines modify how the textile reflects light, giving a characteristic lustrous appearance.
For a stain-release trial, when is the result assessed?
A Only after removing fibres
B Only at initial dyeing
C After controlled laundering
D Before applying any soil
Answer: C. After controlled laundering. Soil release is evaluated by how readily an applied stain is removed under defined wash conditions.
For an antistatic finish, which electrical property can indicate improved charge dissipation?
A Higher yarn twist
B Lower surface resistance
C Lower water pressure
D Greater fabric reflectance
Answer: B. Lower surface resistance. Lower resistance can provide paths for electrostatic charge to dissipate across a treated surface.
How can a relaxed dryer help a knit retain dimensions?
A Applies a new warp size
B Increases fabric stretch
C Adds a crosslinking catalyst
D Limits lengthwise tension
Answer: D. Limits lengthwise tension. Low-tension drying lets loops adjust without keeping the fabric elongated.
After a vertical flame source is removed, what duration may be reported?
A Yarn winding time
B Afterflame time
C Fabric traverse rate
D Prewash cycle length
Answer: B. Afterflame time. Afterflame time records how long flaming persists after removal of the ignition source.
Coating can improve liquid water resistance by creating what?
A Open every inter-yarn pore
B Create a continuous barrier
C Add a raised nap
D Increase moisture uptake always
Answer: B. Create a continuous barrier. A suitable coating can close many liquid paths by forming a largely continuous barrier.
Treated fabric beads water but lets it through under applied pressure. What does beading demonstrate?
A Surface water repellency
B Guaranteed full waterproofing
C Flame retardancy
D Molecular fibre strength
Answer: A. Surface water repellency. Beading indicates low surface wetting. Penetration under pressure is a separate barrier property.
In friction calendering, what difference between contacting rolls helps develop a polished surface?
A Different finished yarn counts
B One roll never rotates
C Different surface speeds
D Identical zero pressure
Answer: C. Different surface speeds. Relative motion between rolls and fabric under pressure contributes to a polishing action.
What is a key reason to control pH and temperature in cotton biopolishing?
A Make enzymes replace yarn
B Convert cotton to keratin
C Maintain enzyme activity
D Prevent all water evaporation
Answer: C. Maintain enzyme activity. Cellulase performance depends on application conditions. Uncontrolled activity can either under-treat or damage the textile.
Heat setting without controlling width may solve length instability but cause which issue?
A Higher yarn twist always
B Automatic antistatic action
C No colour remains
D Incorrect finished width
Answer: D. Incorrect finished width. Thermoplastic fabric can stabilise at an undesired width if the width is not controlled during setting.
Identify the test that increases liquid pressure on fabric and checks for penetration.
A Elmendorf tear test
B Pilling box test
C Hydrostatic pressure test
D Wrap reel test
Answer: C. Hydrostatic pressure test. The hydrostatic method measures resistance to water penetration under applied pressure.
Silicone softening can reduce inter-fibre friction. Which change can a user usually notice?
A Fibre identity conversion
B More actual warp ends
C Higher dye bath pH
D Smoother fabric feel
Answer: D. Smoother fabric feel. Lower friction can make the fabric feel smoother and more supple.
Which garment finishing approach cures the resin after garment assembly and shape pressing?
A Precut warp sizing
B Hank dyeing
C Wet stock blending
D Postcure durable press
Answer: D. Postcure durable press. Postcure holds the sewn garment in its desired shape during pressing and then cures the finish.
Excessive compression in a compactor can cause which surface fault?
A Sharper colour registration
B More balanced dyes
C Corrugated appearance
D Complete fibre dissolution
Answer: C. Corrugated appearance. Excess lengthwise compression can make the fabric buckle and give visible corrugation.
Chemical shrink resistance for wool aims to reduce which fibre-surface effect?
A Directional scale-related friction
B Whole yarn crosslink count
C Fibre water temperature
D Yarn package density
Answer: A. Directional scale-related friction. Wool scales contribute to directional friction, fibre migration and felting shrinkage. Treatments can alter their effect.
In foam finishing, what replaces some of the liquid volume in the carrier?
A Solid warp yarn
B Air
C Free liquid dye
D Industrial starch granules
Answer: B. Air. A foamed carrier contains air bubbles, allowing application with less liquid under suitable conditions.
In a resin finishing bath, why is a catalyst sometimes added?
A Replace all washing steps
B Increase fabric width mechanically
C Pick more warp ends
D Promote crosslinking reaction
Answer: D. Promote crosslinking reaction. A catalyst helps the curing reaction proceed under the selected processing conditions.
Which issue can arise if biopolishing proceeds too far?
A Permanent new pile growth
B Excess fabric mass loss
C Increase in yarn count indefinitely
D Full recovery of lost fibres
Answer: B. Excess fabric mass loss. Excessive hydrolysis can remove too much surface material and weaken the fabric.