ISO 4683-1-1998 Raw sheep skins - Part 1 Description of defects《绵羊原料皮 第1部分 缺陷的描述》.pdf

1、INTERNATIONAL STANDARD IS0 4683-l First edition 1998-03-01 Raw sheep skins - Part 1: Descriptions of defects Peaux brutes de moutons - Partie I: Descriptions des dkfauts Reference number IS0 4683-l :I 998(E) IS0 4683-l :1998(E) Foreword IS0 (the International Organization for Standardization) is a w

2、orldwide federation of national standards bodies (IS0 member bodies). The work of preparing International Standards is normally carried out through IS0 technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented

3、on that committee. International organizations, governmental and non- governmental, in liaison with ISO, also take part in the work. IS0 collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. Draft International Standards ado

4、pted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. International Standard IS0 4683-l was prepared by Technical Committee ISOmC 120, Leather, Subcommittee SC

5、1, Raw hides and skins, including pickled pelts. IS0 4683 consists of the following parts, under the general title Raw sheep skins: - Part I: Descriptions of defects - Part 2: Designation and presentation 0 IS0 1998 All rights reserved. Unless otherwise specified, no part of this publication may be

6、reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying and microfilm, without permission in writing from the publisher. International Organization for Standardization Case postale 56 l CH-1211 Geneve 20 l Switzerland Internet central iso.ch x.400 c=ch; a

7、400net; p=iso; o=isocs; s=central Printed in Switzerland ii INTERNATIONAL STANDARD o iso IS0 4683=1:1998(E) Raw sheep skins - Part 1: Descriptions of defects 1 Scope This part of IS0 4683 describes the defects which may occur on raw sheep skins (see note I). It is applicable to fresh and cured (air

8、 dried, wet salted or dry salted) sheep skins. NOTE 1 Those defects which may appear only during or after tanning, without there being any indication of their presence on the raw skins, have also been listed in this part of IS0 4-683. 2 Defects The defects listed in this part of IS0 4683 are divided

9、 into the following three categories: a) Ante-mortem defects, b) Post-mortem defects, and c) Preserving defects. 2.1 Ante-mortem defects 2.X 1 Abscesses; cysts Either tearing or hardening of the dermis caused by the presence of raised lumps on wooled sheep- skins. 2.1.2 Defects peculiar to wool-on s

10、kin a) Fibre diameter and fibre growth irregularities that lead to fibre weakness and breakage; and b) Wool/hair slips (tendency towards loss of wool/hair, as a result of illness). 2.1.3 Canary yellow wool Canary yellow wool is wool with a bright yellow unscourable stain within the wool staple. It i

11、s caused by micro-organisms that grow in the fleece when it is damp and warm, e.g. in wet, humid summers. The condition can cause weakening of the wool fibres. IS0 4683-l :1998(E) 0 IS0 1 2.1.4 Dermatophilosis (lumpy wool) The defect is visible as a crusty or scaby encrustation in the wool. It resul

12、ts from the exudate that arises from DermatophiIus congolen a ” 7: When laterite dust is settled on the epidermis, in large extensive patches, it gives rise to “ink stains” due to the presence of iron after the skins are vegetable tanned. . I- 2 , G, ; ., / 5 2.1.6 Ecchymosis ” r ” Spot on the flesh

13、 side of the skin, varying from dark red to brown, caused by sub-cutaneous bleeding, especially if the animal has been struck by a blunt object or if parts of the fleece have been roughly plucked before slaughter. This defect! is commonly known as bruising. . . 2.1.7 Fire mark Sheep skins deteriorat

14、e in quality due to fire-mark. This is a man made defect Fire mark is generally inflicted in different parts of the body with a view to cure some ailments. In raw skin, the defect is readily seen on the flesh side and is also prominently visible on the grain finished leather. ,. 2.1.8 Greasy skin Sk

15、in in which the histological structure of the dermis is abnormally loose due to . L the penetration of grease. This state is revealed after tanning by an empty or a I . hollow skin, and can give rise to an alteration in the mass/surface ratio. Delamina- ” ” tion may also occur in the greasy skins. 2

16、1.9 Heat sores Small scabs, varying from light to dark yellow, visible at the base of the wool fibres and on the flesh side. They give rise to a defect in the grain, often called “mite sores”. 2 IS0 46839 1:1998(E) 2.1 .lO Hyper-pigmentation Black hair female sheep skins are found to be affected on

17、 the grain on both sides of the back-bone (particularly in the butt area) due to hyper-pigmentation. Hair loosening may be noted in the affected areas. Physical properties of the leather in the affected area are poor associated with grain erosion and sometimes resulting in perforation. 2.1.11 Marks

18、on the fleece Damage caused by paint, tar, wax crayon, aniline dyes, which devalues the wool, leading even to matting of the hair. 2.1.12 Moire Long wrinkles in the direction of the spine, running parallel and symmetrical in relation to the spine. (They are a sign of a lack of density in the dermis

19、and, depending on the finishing, often remain very clearly on the grain or flesh or on the wool). 2.1.13 Pin hole When two or more wool follicles merge or kemp emerges from the follicles, it is known as pin holes in many countries. This is a genetic trait related to fine wool breed. This is invisibl

20、e in raw sheep skins (also refer to 2.1.15.5 for pin holes of Ectoparasite origin). 2.1.14 Poor wool crimp definition A wool staple is a natural grouping of wool fibres into discrete bundles. Crimp is the bold waves. folds or corrugations of wool fibres within the wool staple. Poor wool crimp defini

21、tion is the loss of these corrugations and the straightening of the wool fibre to more resemble hair. This condition has been associated with age and nutritional deficiencies. Poor crimp definition can lead to increased felting of the wool during wet processing of wool-on sheepskins. 2.1 .I5 Problem

22、 arising from plant sources 2.1.15.1 Bushy or seedy skin Skin with the dermis puncxred by thorns or seeds which. when imcianted, make a small hole or become embedded obiiqueiy in the thickness cf the skin and IS0 4683-l :1998(E) IS0 which, in spite of the perforation, are difficult to remove during

23、the process of transforming the skin into leather. 2.1 .I 5.2 Burr Prickles from certain plants and grasses may cause defect in sheep skins. These penetrated burr stick to the skin even after finishing into leather. 2.1 .I 5.3 Thistle-laden skin Skin with the fleece laden with thorny plant debris wh

24、ich mats together the fibres of wool. 2.1.16 Rib marks Defects of genetic origin caused by already perceptible folds on the skins of certain lambs leading to persistant marks, formed in long parallel furrows, at right angles to the back-bone. Rib marks are of two types, Blind rib and Lap rib. While

25、blind rib is visible on the skins only and can not be identified on wooled sheep skins, lap rib is more severe form of skin defect. Lap ribs can be seen in the raw wooled skins as patterns of wool growth. It is most obviously reflected in the merino stock. 2.1.17 Skins infested with Ectoparasites 2.

26、1 .17.1 Bobble This is considered to be a viral disease prevalent in sheep skins. In raw skin, the lesions are generally visible on the flesh side as round spots but after unhairing they become more prominent on the grain side. Bobble lesions have per- manent stains on both chrome and vegetable tann

27、ed leathers and render them unsuitable for quality leathers. 2.1.17.2 Demodex Skins on which it is possible to see, on the flesh side, nodules of varying size (several mm to more than 5 cm). The small nodules are not altered by beamhouse operations and show up on the tanned skin by a hardening of th

28、e tissue. On the other hand, if they measure more than 1 cm,they can form a pit by splitting th%e grain, or even a hole. This defect is caused by Demodectice mange (Follicular mange) mites. These mites may appear in: IS0 IS0 4683-l : 1998(E) . 9 nodular forms, . . 9 squamous forms, and . . . III) ac

29、ute forms. 2.1.17.3 By lice Because of the irritation caused by the biting or sucking type of lice, the animals scratch the affected parts of the body which leads to wounds and bruises. Lice species belonging to the genera Linognathus are found in sheep skins. Sheep skins infested with lice (Linogna

30、thus ovinus, Order Anoplura)., are identified by visible transparency of the skins at the infected places. 2.1.17.4 By mites Skins showing already advanced hardening of the tissue and a consequent . thickening of the dermis, together with scabs of greater or lesser thickness, and often stripping of

31、the wool, caused by mites and leading to alterations in the structure and grain. 2.1 .I 7.5 Pin-hole A defect of fine-wooled sheep skins consisting of prominent small holes penetrat- ing the skins to a considerable depth but not through it. These holes are the results of skin disease called Dermatlt

32、is micotica due to a bacteria which develops in the epidermic layer (also refer to 2.1 .I2 for pin holes). 2.1 A7.6 Pox marks Hard circular lesion based defects leaving scar marks on the grain. 2.1.17.7 By Psoroptic mange Psoroptes ovjs is responsible for the disease Sheep-scab in both woolly and ha

33、iry sheep skins. Sheep-scab affects the quality of wool as well as the grain side of the skin. The lesions appear as small hard pustular nodes and are covered by long hair. After liming, the nodes are removed leaving a depression on the grain particularly on both sides of back-bone. In finished leat

34、her the defect appears on the grain as innumerable pin prick marks on both sides of the back-bone. 5 IS0 4683-l :1998(E) 2.1.17.8 By Sarcoptic mange IS0 Sarcoptic mange (Sarcoptes scabiei) mites burrow into the substance of the sheep skins causing galleries. Marked thickening and wrinkling of the sk

35、in takes place associated with the formation of scab as well as bald patches. Grain surface of the leather becomes rough showing cris-cross tunnels. 2.1 .I 7.9 Cockle A defect on sheep skins appearing as small, firm nodules in lines running at right angles to the back-bone to flanks, due to infestat

36、ion by ked (Meliphagus ovinus) which causes modification of collagen. 2.1 .I 7.10 Tick marks Skins showing considerable hardening of the tissue caused by bites of parasites called ticks and subsequently leading, on tanned skins, to defects of structure and grain specific to this parasite. While tick

37、s are visible on raw wooled sheep skins their effects are not. Ticks affect skin quality to a considerable extent. Ticks responsible for tick damage though belong to various genera like Ixodus, Haemophysalis, Der- macentor, Hyalomma, Boophilus and Rhipicephalus, the most common live- stock ticks res

38、ponsible for damages in sheep skins belong to the general Hyalomma and Boophilus. They leave scar mark on the grain side of finished leather. 2.1.18 Sunlight yellowed wool Discoloured yellow-brown wooltips on Australian woolskins, most severe along and near the back-bone line. The tipping is caused.

39、 by UV radiation in summer sunlight and is exacerbated by moisture. The wool tips are chemically damaged and may dye unevenly. Additionally, the tips can bind chromium tanning agents further resulting in uneven dyeing. 2.1 J 9 Thin skin Skin in which the quality of the fibres constituting the tissue

40、 is rendered defective by an abnormal thinning due to illness or malnutrition in the weeks preceding slaughter of the animal. After tanning, it produces an empty or a hollow skin. IS0 IS0 4683-l : 1998(E) 2.1.20 Urine damage Urine stain which damages the wool, scorches it or causes an alteration in

41、the colouration of the f%r%, liable to cause a change in the grain. Generally a reddish, yellow colour, it is not found on the same areas as the dermatopM/osis, but more particularly areas near the thighs. 2.2 Post-mortem defects 2.2.1 Butcher score A score produced in the dermis caused by the knife

42、 or skinning too complete perforation. It is also known as flay damages. without 2.2.2 Butcher strain This terms applies .to. grain cracking arising from poor abattoir practices. It is quite different to grain crack arising from folding or pressure baling air dried skins. It is also known, as strain

43、 grain. 2.2.3 Grain crack Grain cracks are of following two types: (a) Tearing or cracking of grain during skinning, drying or during storage. It is generally situated on the butt or belly. (b) Breaking of the grain caused by folding or unfolding of a skin that has been over-dried. Usually found in

44、the dorsal area. These .are caused if b the skins are baled incorrectly and these are commonly known as folding cracks. . 2.2.4 Holes and shearer cuts Accident in skinning resulting from the fact that the knife or skinning tool has completely pierced the skins or cuts arising out of shearing of wool

45、 7 IS0 4683-l :1998(E) 2.2.5 Patches of fat or flesh IS0 Small pieces of fat or flesh remain attached to the skin and cause arain defect, by bacterial decomposition as these pieces pievent correct dehydration of the skin. 2.2,6 Poor pattern (Deformation) Presentation which gives the skin a processi

46、ng. It includes over cutting and results in a loss.of surface area. defective shape and causes tears during of the neck or feet which deforms the skin 2.3 Preserving defects Raw sheep skins can be preserved method used, they can be presented state(raw dried skins) or in the salted using various meth

47、ods. Depending on the in the form of skins preserved in the raw dry state (wet salted skins) or the dry state (dry salted skins). Each. of these states have their corresponding characteristic defects. This seems to be a suitable point to classify below the preserving defects taking into consideratio

48、n each of these states in addition to the general case. 2.3.1 Dried salted state 2.3.1.1 Defects caused by mineral salts Colouration of the grain side of the skin and alteration of the structure of the dermis caused by the combined action of mineral salts, in particular those derived from iron, and

49、the humidity in the ambient air. (These defects are noted in particular on skins stored for a long time). 2.3.2 Dry state 2.3.2.1 Blood stains Presence of congealed blood visible on the flesh side of the skin, causing a stain on the grain after tanning. IS0 4683-l : 1998(E) 2.3.2.2 Break-outs (from drying) Long irregular wrinkles on the flesh side of the skin, dark maroon in colour and at right angles to the back-bone. They can stain the grain after tanning and sometimes even cause a deterioration of the dermis comparable to vitrification. 2.3.2.3 Damage caused by derme