Textiles Part 25

=Experiment 1--Construction of Cloth=

Apparatus: Pick gla.s.s, dissecting pin,[21] foot-rule.

Materials: 4 square inches of burlap.

References: _Textiles._ See page 54, Weaving; page 1, Fibers.

_Directions_

1. Look at the cloth under the pick gla.s.s and describe the appearance and structure of its interlacing threads, called weave.

2. With a pin separate the interlacing threads of the cloth which are called _warp_ and _filling_. _Warp_ is composed of yarn running in the direction of the length of the cloth. _Filling_ is composed of yarn running at right angles to the warp.

_a._ What are the interlacing threads of cloth called?

_b._ Of what is warp composed and in what direction do the warp threads extend? filling?

3. Notice the appearance of the individual threads (called _yarn_) of the warp and filling. Test the strength of the yarn by trying to break it.

4. Untwist one of the warp threads and one of the filling threads.

Notice whether the yarn becomes stronger or weaker as it is untwisted.

What effect has twist on the yarn?

5. After untwisting one of the threads what remains? Measure the length of several of these ends called _fibers_. Describe the appearance of the fiber as to curl, feel, fineness, etc.

_Questions_

1. Of what does yarn consist?

2. What causes the fibers to cling together?

3. What is the process called by which two sets of threads interlace?

4. When two sets of threads interlace or are woven what is produced?

=Experiment 2--Plain or Homespun Weave=

Apparatus: Hand loom,[22] two pencils, scissors.

Material: Yarn of two colors.

Reference: _Textiles_, page 58.

_Directions_

1. Make a warp on the hand loom with green yarn by having parallel threads running the longest way of the loom to the notches.

2. A _harness_ is a framework on a loom used for raising certain warp threads. Use a pencil as a harness and raise the 1st, 3d, and 5th warp threads. A _shed_ will in this way be formed through which the shuttle carrying the filling thread will pa.s.s. Use the red yarn for filling and attach it at one end before pa.s.sing it through the shed.

3. With a second pencil to act as a second harness raise the 2d, 4th, and 6th warp threads. Pa.s.s the filling through the shed thus formed.

4. Repeat twice Directions 2 and 3.

5. Tie all ends, cut the woven sample away from the loom, and mount in note-book.

_Questions_

1. What part of a loom is the harness?

2. What is meant by a shed?

3. What carries the filling thread through the shed on a loom?

4. What is the principle of plain weaving?

5. Name some fabrics produced by plain weaving? See _Textiles_, page 58.

=Experiment 3--Twill Weave=

Apparatus: Hand loom, four pencils, scissors.

Materials: White cotton warp, colored yarn filling.

Reference: _Textiles_, page 58.

_Directions_

1. On the hand loom make a warp by threading four white warp threads to a notch until there are six sets of warp threads.

2. Using a pencil as a harness (See Exp. 2) raise the first thread of each set of warp threads and pa.s.s the filling thread through the shed thus formed.

3. With another pencil as a second harness raise the second thread of each set of warp threads and pa.s.s the filling.

4. With a third pencil raise the third thread of each set of warp threads and pa.s.s the filling.

5. With still another pencil to act as a fourth harness raise the fourth thread of each set and again pa.s.s the filling.

6. Repeat the above directions (2 to 5) several times. Notice that the moving of the filling thread, one warp thread to the left, each time it is woven is causing a diagonal line or rib to form, called _twill_.

7. Cut the woven sample away from the loom and mount.

_Questions_

1. Why is this weave called a twill weave?

2. How is the diagonal line or twill formed?