Dear Jenny
How embarassing. This test has normally worked fine for me, though I have
seen linen twist anti-clockwise before it twists clockwise as it wets out and
swells if I haven't wetted it enough. The other problems usually are having a
large enough sample in good enough condition. I have a couple of other
references:
"Textile Laboratory Manual", Walter Garner, National Trade Press, 1951,
2nd edition. (very useful book) No description of method but "TWIST ON DRYING.
None: Indian kapok; variable: cotton; clockwise:
flax, ramie, Java kapok, coir; anti-clockwise: true hemp, jute, sisal,
manilla, New Zealand hemp, Mauritius hemp."
"The Identification of Flax, Hemp, Jute and Ramie in Textile Artefacts"
MSc thesis by Joan A Marshall, University of Alberta, 1992 references
"Microscopic structure of fibers" in American Dyestuff Reporter, 31, pp 334-41,
by CW Hock, 1942 and "Helical fibrillar arrangements in jute" in Nature, 1964,
pp 670, by MK Sen and RN De, 1949, as well as 4 other references and says that
there is confusion about which way to look at them, fibres had to be
immersed more than once to get a reaction, and that different test fibre samples
reacted at different speeds. With any luck Joan Marshall will pick up this
posting and give more details.
Vivien Chapman
Head of Organics Conservation
National
Museums Liverpool
0151 478 4841
vivien.chapman@xxxxxxxxxxxxxxxxxxxxxxx
From: Jennifer BARNETT
[mailto:jcbarnett@xxxxxxx]
Sent: 26 February 2007 22:12
To: TEXCONS@xxxxxxxxxxxxxxxxxx
Subject: drying twist test in fibre identification
Dear colleagues,
Sent: 26 February 2007 22:12
To: TEXCONS@xxxxxxxxxxxxxxxxxx
Subject: drying twist test in fibre identification
Today a group of students and I went about carrying out the drying twist
test on linen and hemp fibres, following the method described in "Identification of textile fibres", The Textile
Institute, 1985, 7th edition
Make a fibre thoroughly wet then remove excess water
with a tissue. Grasp one end with the tweezers and hold the free end over
the heat source (in this case, a hot plate). Observe the movement of the
fibre by pointing the free end directly towards you.
results
• clockwise
- linen, ramie and nettle
• anticlockwise
- hemp and most other fibres
• alternating clockwise and anticlockwise
- cotton
Our results: two different linen samples repeatedly
twisted anti-clockwise while the one hemp sample (identified by the Neocarmine W
stain test) twisted clockwise. Cotton performed as to be expected. So many
contrary reactions (particularly with the linen) would seem to cause doubts as
to the accuracy of the described expected result. Could this book possibly be
wrong? Could there be other factors at play? Any other thoughts?
Not having any other references to hand in which this
method is mentioned, I hope someone has another source for this test to check
the expected direction of twist for linen and hemp.
With thanks,
Jennifer Barnett
Regina Textilia
historic textiles conservation, research and consultancy
Route de Dancé
FR - 42260 Bully
tel/fax * 33 (0)4 77 65 20 11
Vivien Chapman
Head of Organics Conservation
National Museums Liverpool
Tel: 0151 478 4841
Fax: 0151 478 4990
Visit the family exhibition 'Shipwrecked - can you escape the island?' at the Merseyside Maritime Museum until 20 May 2007.
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