US3623950A - Enzymatic dehairing process - Google Patents

Enzymatic dehairing process Download PDF

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Publication number
US3623950A
US3623950A US815236A US3623950DA US3623950A US 3623950 A US3623950 A US 3623950A US 815236 A US815236 A US 815236A US 3623950D A US3623950D A US 3623950DA US 3623950 A US3623950 A US 3623950A
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US
United States
Prior art keywords
percent
skins
dehairing
enzyme
hides
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US815236A
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English (en)
Inventor
Rolf Monsheimer
Ernst Pfleiderer
Helmut Uhlig
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Roehm GmbH Darmstadt
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Roehm GmbH Darmstadt
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from DE19681769160 external-priority patent/DE1769160C3/de
Application filed by Roehm GmbH Darmstadt filed Critical Roehm GmbH Darmstadt
Application granted granted Critical
Publication of US3623950A publication Critical patent/US3623950A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

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Classifications

    • C—CHEMISTRY; METALLURGY
    • C14—SKINS; HIDES; PELTS; LEATHER
    • C14C—CHEMICAL TREATMENT OF HIDES, SKINS OR LEATHER, e.g. TANNING, IMPREGNATING, FINISHING; APPARATUS THEREFOR; COMPOSITIONS FOR TANNING
    • C14C1/00—Chemical treatment prior to tanning
    • C14C1/06—Facilitating unhairing, e.g. by painting, by liming
    • C14C1/065—Enzymatic unhairing

Definitions

  • ExaminerGary M. Nath AltorneyCurtis, Morris & Safford ABSTRACT Process for dehairing skins and hides by treatment thereof, at a pH less than 5, with a mold-fungus protease showing its optimum effect at a pH below 5, with pepsin, with papain, or with a combination of these enzymes.
  • the present invention relates to processes for the enzymatic dehairing of skins and hides.
  • the enzymatic dehairing of skins and hides has up till now been carried out in a weakly acid to weakly alkaline region with proteolytic enzymes which exert their optimum effect within this region.
  • proteolytic enzymes include the majority of enzymes obtained from mold fungi or bacterial cultures, as well as pancreatic enzymes.
  • the known dehairing processes have the disadvantage that the undesired growth of bacteria and fungi in the dehairing bath must be hindered by preservatives. This precaution is critically necessary, particularly in tropical countries, and leads to a corresponding increase in the cost of the process.
  • a process for dehairing using proteolytic enzymes has now been found according to which skins and hides are treated under nonswelling conditions at pH values below 5 with proteolytic enzymes exhibiting their optimum effect at pH values below 5, and/or with pepsin, and/or with papain. The hair is subsequently removed.
  • pepsin and papain are of particular importance. They can be used alone or together, optionally also in combination with other kinds of enzymes.
  • the most favorable working region is between pH 3 and 5, and the optimum efficacy for the process of theinvention is observed at about pH 4.
  • Papain is preferred in the pH region 4.0 to 5.0.
  • the enzyme bath should contain, for example, from 0.1 to 0.5 percent, calculated on the softened weight of the hides, of an enzyme product having an enzyme activity of 55,000-60,000 EZA. At a working temperature of 40 C., hair can be removed in from 24 to 48 hours.
  • EZA Enzyme activity, is determined using hemoglobin as a substrate.
  • the substrate is prepared by suspending 4.6 grams of hemoglobin in 143.4 ml. of water. After hours standing at 5 C., 80 grams of urea are added to the mixture, which is heated to 25 C. and combined with 32 ml. of 0.5 N aqueous NaOH and 20 ml. of a 1 N aqueous KH P O, solution. The final mixture has a pH of 7.5.
  • the process can be practiced in such a manner that the hides and skins are immersed in a nonswelling enzyme bath.
  • a nonswelling enzyme bath it is also possible first to treat the hides and skins in an enzyme-free, acid, nonswelling bath adjusted to a pH below 5, and then to take them out of the bath and to treat them from the flesh side with an enzyme preparation in powder or paste form.
  • a further advantage of the process is that it leads to a complete destruction of pigmentation while extensively preserving the skin substance.
  • the process of the invention can advantageously be combined with oxidative dehairing, which also takes place in an acid region.
  • oxidative dehairing For the dehairing of calf and goat skins, cowhide, pigskin and the like, a small residuum of hair often remains. This can be completely removed using about one third of the amount of sodium chlorite usually employed in the art for oxidative dehairing, whereby the grain is not attacked. [Oxidative dehairing processes are discussed in the article by K. Rosenbusch on pages 1 19-121 of Das Leder" 1964).]
  • the weights of treating agent are expressed in percent by weight of the hides treated.
  • the EZA values for the pepsin used in examples 1, 5, and 7 were determined at a pH of 4; the EZA of the commercial enzyme product of example 6 was determined at pH 5.
  • the procedure used was as described earlier, but employed a buffer system other than NaOHlKH Po EXAMPLE 1
  • the initial pH value of the bath was 3.0-3.3.
  • the treatment time in the dehairing bath was 24 hours. After this period, the bath had a pH of 4.0-4.3.
  • the skins were subsequently dehaired in the usual fashion.
  • the treatment time amounted to 24 hours. During this time, the hides were paddled 3 or 4 times for S-minute periods. Dehairing was subsequently accomplished in the usual way.
  • the bacterial protease comprised 15,000 Loehlein- Volhard units [cf. Gerschenemisches Taschenbuch, by A. Kuentzel, Verlag Th. Steinkopff, Dresden and Leipzig 1955 86.]86.
  • a process as in clai r n l wh rei n said enzyme is papain.

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  • Chemical & Material Sciences (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • General Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Treatment And Processing Of Natural Fur Or Leather (AREA)
  • Cosmetics (AREA)
US815236A 1968-04-13 1969-04-10 Enzymatic dehairing process Expired - Lifetime US3623950A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE19681769160 DE1769160C3 (de) 1968-04-13 Enzymatisches Enthaarungsverfahren für Häute und Felle

Publications (1)

Publication Number Publication Date
US3623950A true US3623950A (en) 1971-11-30

Family

ID=5700019

Family Applications (1)

Application Number Title Priority Date Filing Date
US815236A Expired - Lifetime US3623950A (en) 1968-04-13 1969-04-10 Enzymatic dehairing process

Country Status (6)

Country Link
US (1) US3623950A (da)
CA (1) CA919606A (da)
CH (1) CH515994A (da)
DK (1) DK126861B (da)
FR (1) FR2006170A1 (da)
GB (1) GB1235422A (da)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4293647A (en) * 1977-03-02 1981-10-06 Rohm Gmbh Method of dissolving collagen-containing tissues
DE3429047A1 (de) * 1984-08-07 1986-02-20 Röhm GmbH, 6100 Darmstadt Enzymatisches enthaarungsverfahren
US5102422A (en) * 1987-02-13 1992-04-07 Rohm Gmbh Methods for leather processing including liquid enzyme formulation
US5324642A (en) * 1987-12-28 1994-06-28 Psychemedics Corporation Ligand assays of enzymatic hair digests
US5910419A (en) * 1997-05-06 1999-06-08 Johnson; Ted Donald Method for forensically screening hair samples for the presence of cannabinoids
US5981204A (en) * 1997-05-06 1999-11-09 Johnson; Ted Donald Method for forensically screening hair samples for the presence of cannabinoids
US6375948B1 (en) * 1999-07-12 2002-04-23 Kao Corporation Treating method for suppressing hair growth

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2289937A (en) * 1937-08-12 1942-07-14 American Arch Co Locomotive firebox equipment
US2363646A (en) * 1941-05-08 1944-11-28 Armour & Co Hide treatment
US2480761A (en) * 1945-09-14 1949-08-30 Hatters Fur Exchange Inc Process of recovering fur, hair, or wool from hide scraps and skins

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2289937A (en) * 1937-08-12 1942-07-14 American Arch Co Locomotive firebox equipment
US2363646A (en) * 1941-05-08 1944-11-28 Armour & Co Hide treatment
US2480761A (en) * 1945-09-14 1949-08-30 Hatters Fur Exchange Inc Process of recovering fur, hair, or wool from hide scraps and skins

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4293647A (en) * 1977-03-02 1981-10-06 Rohm Gmbh Method of dissolving collagen-containing tissues
DE3429047A1 (de) * 1984-08-07 1986-02-20 Röhm GmbH, 6100 Darmstadt Enzymatisches enthaarungsverfahren
US5102422A (en) * 1987-02-13 1992-04-07 Rohm Gmbh Methods for leather processing including liquid enzyme formulation
US5324642A (en) * 1987-12-28 1994-06-28 Psychemedics Corporation Ligand assays of enzymatic hair digests
US5910419A (en) * 1997-05-06 1999-06-08 Johnson; Ted Donald Method for forensically screening hair samples for the presence of cannabinoids
US5981204A (en) * 1997-05-06 1999-11-09 Johnson; Ted Donald Method for forensically screening hair samples for the presence of cannabinoids
US6375948B1 (en) * 1999-07-12 2002-04-23 Kao Corporation Treating method for suppressing hair growth
US7056499B2 (en) 1999-07-12 2006-06-06 Kao Corporation Treating method for suppressing hair growth
US7211278B2 (en) 1999-07-12 2007-05-01 Kao Corporation Treating method for suppressing hair growth

Also Published As

Publication number Publication date
GB1235422A (en) 1971-06-16
CH515994A (de) 1971-11-30
FR2006170A1 (da) 1969-12-19
DE1769160A1 (de) 1971-07-08
DE1769160B2 (de) 1976-03-18
DK126861B (da) 1973-08-27
CA919606A (en) 1973-01-23

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