Sheep & Wool

Slipe wools

Slipe wools are removed from the skins of slaughtered sheep at meat processing plants. A chemical depilatory (a lime/sodium sulphide preparation) is allied to the flesh side of the skins to release the wool, which is removed mechanically.

Most slipe wools come from prime lambs that have been managed at high levels of nutrition over the whole period of wool growth. Therefore, they are particularly sound, and because they will not have been exposed to the full season's climate, they are also of good, even colour.

As slipe wools have been pulled from the skin, they have a more consistent length compared with shorn wool from lambs of similar age and growth. This means there will be less wastage during processing. In addition, slipes are generally higher yielding (80-90%) because much of the dirt and suint is washed out during processing.

Slipe wool performs as well as shorn wool in spinning. However, care is required when dyeing wool textiles containing 20-80% slipes, as residual pH effects from the depilatory may affect the rate of dye uptake and lead to unevenness in colour.

Slipe wools are available in large lines of similar specifications (i.e. even length, micron and style grades), which are repeatable from season to season. This makes slipes most suitable for large-scale production of standardised yarns, and they are used in carpets, blankets, sliver knits, hand and machine knitting yarns, and woollen and worsted fabrics.

Lamb slipes contribute bulk and resilience to a blend, while sheep slipes have a slightly harsher handle than their equivalent shorn fleece and are therefore a useful carpet blend component.

From October-March the bulk of slipe wool produced is best suited to woollen spinning. Lesser quantities of combing length slipe for worsted processing is available from April to July.

Although generally available in reasonable quantities throughout the season, slipe wool varies in length according to the time of the year it is produced.

There are three broad categories of slipe wool: woolly lamb, shorn lamb and sheep.

Woolly lamb

Accounts for about 45-50% of all slipe, comes from previously unshorn, three to five month old lambs, and is generally finer than slipe taken from lambs later in the season. It is available in reasonable quantities from November through to May.

Shorn lamb

Accounts for about 30-35% of all slipe, comes from lambs which have already been shorn at three to four months (the wool being sold as greasy lambswool), and is therefore very short. It is available mainly from March to May.

Sheep

Accounts for about 15-20% of all slipe, comes from mature animals of two to six years of age, and is available in a wide variety of lengths. It is available mainly November-March, peaking in December-February.

Standard slipe grading

Within these categories, slipes are further differentiated according to a standard grading system that has been adopted by most meat processors. Where it is used, the wool from each skin is sorted into the following grades:

First slipes

Made up of body wool and are sound, uniformly grown, and largely free of vegetable matter and stains. They are graded for fineness, length, colour and vegetable matter contamination. Mostly free of depilatory residues.

Second slipes

Made up of skirtings and belly wool. Graded for fineness, length and vegetable matter contamination. They still carry some depilatory, and are often yellow-stained.

Third slipes

Made up of oddments, and are variable in length and heavily contaminated with lime.

Slipemaster

Wool that has been mechanically removed from untreated skin pieces. It is normally of poor colour and may contain small skin pieces.

Miscellaneous grades

Includes britch (crutchings), pelts (less than 25 mm), cotts and coloured wool.