Your Answer : (Not Answered)

Correct Answer : A

Correct answer: Both A and R are true, and R is the correct explanation of A

Both are true and the reason is the necessity. A tolerance of one unit means something quite different under CIELAB than under CMC, since the latter varies its weighting with the position of the colour. Specifying a limit without the formula therefore specifies nothing enforceable, which is why supply contracts state both, along with the illuminant and observer.

Your Answer : (Not Answered)

Correct Answer : C

Pressure decides pick-up and therefore add-on, so a gradient in one gives a gradient in the other. Checking the mangle across the width is a routine part of setting up a run. The fault shows as a gradient across the piece.

Your Answer : (Not Answered)

Correct Answer : A

Correct answer: 2 - 4 - 1 - 3

The order is fixed by the chemistry. The fabric is padded with the liquor and squeezed to a controlled pick-up, dried to remove the water without curing, then cured at high temperature so the finish reacts and fixes, and finally washed if unfixed material or reaction by-products must be removed. Curing before drying would trap water and give an uneven result.

Your Answer : (Not Answered)

Correct Answer : A

The phosphorus promotes charring rather than flaming combustion and survives repeated laundering. Borax systems work but wash out, so they suit only disposable or rarely washed articles. Durability is what the phosphorus systems add.

Your Answer : (Not Answered)

Correct Answer : D

Correct answer: 1 and 2 only

Statements 1 and 2 are correct: fluorochemicals repel both liquids, and the long chain C8 types have been restricted because their perfluorooctanoic degradation products are persistent and bioaccumulative, driving the shift to C6 chemistry and to non-fluorinated alternatives. Statement 3 is wrong - silicones repel water well and oil hardly at all.

Your Answer : (Not Answered)

Correct Answer : C

Correct answer: All of them

All three are correct. The thickener and any unreacted dye must be removed, or the fabric is left stiff and the loose dye rubs off, so poor washing off shows as both a harsh handle and poor rub fastness. And transfer printing genuinely needs no washing off, because the dye sublimes directly into the fibre with no thickener and no unfixed residue on the surface - one of that process’s main attractions.

Your Answer : (Not Answered)

Correct Answer : A

The repeat cannot exceed the circumference, since the design must join seamlessly as the cylinder turns. Standard circumferences are chosen so that common repeat lengths divide into them exactly. Longer designs need a flat screen instead.

Your Answer : (Not Answered)

Correct Answer : D

Digital printing places the ink directly from a print head with no image carrier at all. The other three all need an engraved or exposed image, which is where their setup cost lies. Setup cost is what decides the economics.

Your Answer : (Not Answered)

Correct Answer : D

Correct answer: A-2, B-4, C-1, D-3

Four machines and four presentations of the goods. A winch moves fabric in rope form over an overhead reel. A jigger passes fabric open width from one roll to the other through a shallow trough. A package machine dyes yarn wound on perforated cones or cheeses. A beam machine dyes fabric wound on a perforated beam. The form of the substrate is what decides the machine, as the last item in this topic says.

Your Answer : (Not Answered)

Correct Answer : D

Correct answer: True

Hot mercerising swells the fibre less, so the effect on lustre is smaller, but the hot caustic penetrates a fabric far faster and more evenly - particularly a heavy or tightly constructed one, and one that has not been fully prepared. Where uniformity matters more than maximum lustre, and where the range must run quickly, the trade is worth making.

Your Answer : (Not Answered)

Correct Answer : B

Correct answer: A-2, B-4, C-1, D-3

Four benefits from three structural changes. The convoluted, flattened cotton fibre swells into a round smooth cylinder that reflects light directionally, which gives the lustre. The swollen cellulose is more accessible to dye, which raises the uptake. The chains become better aligned along the fibre axis, which raises the strength. And the shrinkage is taken up under tension during the process, so the finished fabric is dimensionally stable afterwards.

Your Answer : (Not Answered)

Correct Answer : C

It moderates the release of active oxygen and also sequesters some metal ions. Its drawback is silicate deposits on machinery and fabric, which is why organic stabilisers have been developed. Silicate scale is a maintenance burden.

Your Answer : (Not Answered)

Correct Answer : B

Correct answer: 1 and 2 only

Statements 1 and 2 are correct: the perhydroxyl ion is the bleaching species, and a stabiliser is needed because peroxide otherwise decomposes faster than it bleaches. Statement 3 is wrong in the way it is put - raising the pH increases the perhydroxyl concentration but also accelerates decomposition, so there is an optimum band around pH 10.5 to 11, above which the peroxide is spent uselessly and the fibre is attacked.

Your Answer : (Not Answered)

Correct Answer : C

Correct answer: True

Because the loss corresponds to the impurities removed, and cotton’s natural impurity content is fairly consistent, weighing the fabric before and after gives a direct check on whether the scour has gone far enough - or too far. A figure well below the expected range means an incomplete scour, and one well above it means the cellulose is being degraded.

Your Answer : (Not Answered)

Correct Answer : A

Correct answer: Both A and R are true, and R is the correct explanation of A

Both are true and the reason gives the necessity. Desizing is a solubilisation rather than a removal - nothing leaves the cloth until it is washed out. Poor washing is a common source of unlevel dyeing, since the residual dextrins remain on the fibre and interfere with the dye reaching it.

Your Answer : (Not Answered)

Correct Answer : B

The oxidant attacks size of any kind, which suits a commission finisher receiving cloth of unknown history. The risk is that it can attack the cellulose too if the conditions are not controlled. Commission finishers meet this situation often.

Your Answer : (Not Answered)

Correct Answer : A

Correct answer: True

Hardness, iron, alkalinity and dissolved solids all affect how a dye behaves - the exhaustion, the shade and the fastness - so the same recipe in different water gives a different result. That is why a mill measures its water and treats it to a specification rather than accepting whatever the supply delivers, and why a change of borehole or season can shift shades unaccountably.

Your Answer : (Not Answered)

Correct Answer : C

Correct answer: raising the temperature of the bath

Heating makes hardness worse rather than better: temporary hardness precipitates as scale as the bicarbonate decomposes, which is exactly the deposit to be avoided. The other three are genuine remedies - sequestering holds the ions in solution, lime soda precipitates them, and ion exchange removes them onto a resin.

Your Answer : (Not Answered)

Correct Answer : D

The first two are correct. The third is exactly the trap, since French, German and English degrees are all different and a bare number can be wrong by a factor of two. Every specification should name its scale explicitly.

Your Answer : (Not Answered)

Correct Answer : C

Both are true and the reason gives the mechanism: the scale forms exactly where the heat transfer occurs, so it insulates the surface and can lead to overheating of the metal. Feed water treatment is the standard defence.