Example 37.—Find the useful particulars for a plated fabric composed of 2/20's worsted @ 8/6 per lb., 10's cotton @ 4/- per lb. The cotton yarn appears on the back and has 50 per cent. more take-up than the face.
| 10 × 840 | |
| = 15's worsted. | |
| 560 |
| 15 plus 50 % of 15 | = 22½ | ÷ 15 | = | 1½ | lb. @ 4/- | = 6/- |
| 15 plus 0 | = 15 | ÷ 10 | = | 1½ | lb. @ 8/6 | = 12/9 |
| 3 | lb. | = 18/9 |
15 ÷ 3 = 5's counts. 18/9 ÷ 3 = 6/3 per lb.
From the column of weights it is seen that this is divided equally between the two yarns; although the cotton is finer in diameter, yet the weights are made equal by extra take-up in loop formation.
Example 38.—A garment order is being executed from 2/42's yarn which runs short, 2/60's is in sufficient stock, and it is required to find what counts used with this will give the same weight of garment on the frame. Applying the difference rule—
| 2/60's | = 30's | 30 × 21 | 30 × 21 | |||
| = | = 70's. | |||||
| 2/42's | = 21's | 30 - 21 | 9 |
Example 39.—Given two counts 48's and 24's in stock, find the third yarn needed to twist with these to obtain a counts equivalent to 10's single. The first step is to fold the two yarns together by the addition rule—
| 48 × 24 | |
| = 16's. | |
| 48 + 24 |
Then by the difference rule—