Fabrics for the twenty-first century - The Courtauld Institute of Art

Young and Jardine Fabrics for the twenty-first century
12
Figure 8 (A) Graph comparing hysteresis ratio to crimp ratio
for the tested fabrics. (B) Graph comparing stress relaxation
ratio to crimp ratio for the tested fabrics.
between the initial tension before wetting and the final
tension after drying out, ΔTwarp and ΔTweft (see annotations
in Fig. 9A).
Two main types of responses are observed on
wetting. For the Ulster linen 3151, 12 oz cotton
duck, Kevlar ® Scenic and Peektex 17-220/56, an
increase in tension occurs. Figs. 9A and B show the
response curves for 12 oz cotton duck and Peektex
17-220/56. The cotton duck exhibits a fast increase
Table 7 Calculated wetting and relative humidity response
Fabric
Wetting response
Tmax (N) warp
(1 N/second) in tension from 50 N in the weft and
warp, to 177.24 N in the weft and 192.1 N in the
warp, respectively. Once the fabric has dried out
the final tension is 22.3 N in the weft and 13.8 N in
the warp. This response is consistent with previously
published data for cotton and linen (Collins, 1939;
Young, 1999). Peetex 17-220/56 (Fig. 9B) exhibits a
very small change in load in the weft of 1.4 N which
remains on drying out. Of all fabrics tested Peektex
17-220/56 (which has a partially crystalline molecular
structure) was the least responsive to moisture. Even
though Kevlar ® has a highly crystalline molecular
structure, RH has a significant effect on the rate of
moisture absorption in the fibre. Its equilibrium moisture
content is linear with RH. At 95% RH its moisture
regain from a dry state is 6.2% (Kevlar ® Technical
Guide, 2008). This is consistent with the response of
the Kevlar ® Scenic fabric. Presumably the yarns are
swelling with increased moisture, and thus the fabric
responses in a similar way to linen and cotton, increasing
in tension when restrained, but with less
magnitude.
All the polyester fabrics (with the exception of the
P110 and Carbotex fabrics) showed an initial fast
decrease in tension on wetting followed by a partial
recovery in tension on drying. Figs. 10A and B show
the response curves for the Carbotex 03_82 and
Polyflax 1008. Carbotex 03_82 loses the most tension
down to 2.7 and 1.7 N in the weft and warp, respectively.
It has a permanent decrease in tension of 11.6
and 16.9 N in the weft and warp. Polyflax 1008
(Fig. 10B) loses tension down to 38.7 and 39.0 N, in
the weft and warp, respectively, recovering with a permanent
decrease of 2.2 and 4.3 N. Polyflax 1008 and
T max (N)
weft ΔTwarp (N) ΔTweft (N)
RH response rate
warp (N/%RH)
Rate weft
(N/%RH)
Sailcloth 00169 33.1 37.4 −8.0 8.3 −0.24 −0.15
9.1 oz Clipper 45.2 40.6 −1.8 −2.6 −0.21 −0.22
Monofilament 55/31 †
41.6 43.6 −5.0 −4.6 −0.11 −0.12
P110 2004 2.9 5.9 −47.0 −44.3 Non-linear Non-linear
P110 2008 35.7 32.7 −17.1 −16.9 Non-linear Non-linear
Fredrix ® Polyflax 1008 39.0 38.7 −4.3 −2.2 −0.16 −0.13
Fredrix ® Polyflax 1008
Acrylic Primed
36.0 33.1 −10.7 −13.9 −0.16 −0.11
Stern 16207 38.8 37.2 −7.4 −1.2 −0.20 −0.20
Stern 16221 48.2 39.5 −2.1 −10.4 −0.30 −0.31
Carbotex 03_82 CF 1.7 2.7 −16.9 −11.6 Non-linear Non-linear
Carbotex 03_120 CF 2.1 4.6 4.5 9.3 Non-linear Non-linear
Peektex 17-220/56 50.2 51.2 0.0 1.4 −0.03 −0.01
Kevlar ® Scenic 76.5 122.5 −31.7 −25.6 Non-linear Non-linear
12 oz Cotton Duck 192.1 177.2 −36.9 −27.6 0.62 0.62
Fine Ulster Linen 3151 135.0 150.0 −42.0 −34.0 * *
Fine Belgium Linen Not measured Not measured Not measured Not measured Not measured Not measured
Superfine Belgium
Linen
Not measured Not measured Not measured Not measured Not measured Not measured
*See Tan et al., 1997.
† 55/31 denotes 55 μm filament diameter and 31 denotes 31% open area (OA).
Studies in Conservation 2012 VOL. 0 NO. 0