Difference between revisions of "PH value"

Latest revision as of 21:21, 6 December 2021

The pH-value of leather

The pH of a substance means, at ten-logarithmic intervals, how acidic or basic this substance is. Distilled water is defined as having a pH of 7, so that a substance with a pH of 8 (such as seawater) is ten times more basic and a substance with a pH of 5 (such as coffee) is one hundred times more acidic. Coca Cola has a pH of 2 and is therefore one hundred thousand times more acidic than distilled water.

In the production of leather and leather care, the pH value is important as leather is produced with a pH of about 4.5 to 5.5. This pH ensures that the fat and tannins bound in the leather remain.

With the ageing of the leather, the acid-base ratio shifts to the alkaline (above pH 7), which makes the leather unstable. The leather darkens, becomes hard and brittle. The shift is due to age, humidity, sun, but also perspiration (skin, hair contact with car and furniture leather, sweat from feet in shoes (daily between 100-200 ml), hands in gloves or sweated collars of leather jackets).

Typical damage due to skin and hair contact in furniture (head and armrests).

Steering wheels also react to skin contact with time. Due to the pH shift, the leather is also more susceptible to mould.

Skin-damaged car armrests and a shift knob.

Another reason is alkaline cleaners. Most household cleaners are alkaline, because they have a good cleaning effect. However, leather cleaners should not be alkaline, which is technically possible, but not considered by all manufacturers.

The leather care should also restore or maintain the acidic condition. Particularly, when old leather is contaminated with mould, acetic acid as a pH regulator is particularly suitable for removal and prevention. Also in the case of a restoration of leather, regulating the pH-value is just as important as the re-greasing to make the leather more resistant to environmental influences.

However, there is also a limit to how much acid a leather is capable of. Therefore, when regulating the pH, always be very careful not to damage the leather. A characteristic feature of book bindings, which can be observed in libraries, is red decay, when sulphur dioxide reacts with the air in the leather to become sulphuric acid, which irreparably erodes book covers. Sulphuric acid is one of the strongest acids and is far below the minimum pH-value of 3.5 for leather.

**Average pH values**
(Source: Wikipedia, License: GFDL)
Substance	pH-value	Type
battery acid	<0	↓
stomach acid (sober stomach)	1,0–1,5	acid
lemon juice	2,4
Coca Cola	2–3
fruit juice of the shadow morello	2,7
vinegar	2,9
orange and apple juice	3,5
wine	4,0
sour milk	4,5
beer	4,5–5,0
acid rain	< 5,0
coffee	5,0
tea	5,5
rain (natural rainfall)	5,6
mineral water	6,0
milk	6,5
water (depending on hardness)	6,0–8,5
NEUTRAL	7,0
human saliva	6,5–7,4
blood	7,4	basic
sea water	7,5–8,4
pancreas juice (intestinal juice)	8,3
soap	9,0–10,0
household ammonia	11,5
bleach	12,5
cement	12,6
sodium hydroxide solution (caustic soda)	13,5–15

Additional information

WE UNDERSTAND LEATHER - WWW.COLOURLOCK.COM

@@ Line 4: / Line 4: @@
-==Der pH-Wert von Leder==
+==The pH-value of leather==
-Der '''pH-Wert''' ''(lat.: potentia Hydrogenii, "Kraft des Wasserstoffs")'' eines Stoffes bezeichnet in zehnerlogarithmischen Abständen, wie sauer bzw. basisch dieser Stoff ist. Destilliertes Wasser ist mit einem pH-Wert von 7 definiert, so dass - im Vergleich - ein Stoff mit pH-Wert 8 (wie Meerwasser) zehnmal basischer ist und ein Stoff mit pH-Wert 5 (z. B. Kaffee) einhundertmal saurer ist. Cola hat einen pH-Wert von 2 und ist damit hunderttausendmal saurer als destilliertes Wasser.
+The '' pH '' of a substance means, at ten-logarithmic intervals, how acidic or basic this substance is. Distilled water is defined as having a pH of 7, so that a substance with a pH of 8 (such as seawater) is ten times more basic and a substance with a pH of 5 (such as coffee) is one hundred times more acidic. Coca Cola has a pH of 2 and is therefore one hundred thousand times more acidic than distilled water.
-In der [[Lederherstellung]] und [[Lederpflege]] ist der pH-Wert dahingehend von Bedeutung, dass durch die [[Gerbung]] im Leder grundsätzlich ein saures Milieu mit einem pH-Wert von ca. 4,5 bis 5,5 erzeugt wird. Dieser pH-Wert sorgt mitunter dafür, dass die im Leder gebundenen Fett- und Gerbstoffe gehalten werden.
+In the [[leather production|production of leather]] and [[leather care]], the pH value is important as leather is produced with a pH of about 4.5 to 5.5. This pH ensures that the fat and tannins bound in the leather remain.
-Mit der Alterung des Leders verschiebt sich das Säure-Basen-Verhältnis allerdings ins Alkalische (über pH 7), was das Leder instabil macht. Das Leder dunkelt, wird hart und brüchig. Die Verschiebung erfolgt durch Alter, Luftfeuchtigkeit und Sonne, aber auch durch Schweiß (Haut-, Haarkontakt bei [[Autoleder|Autos]] und Möbeln, Schweiß durch Füße in Schuhen (täglich zwischen 100-200 ml), Hände in Handschuhen oder "Speckkragen" bei Jacken).
+With the [[leather damages|ageing of the leather]], the acid-base ratio shifts to the alkaline (above pH 7), which makes the leather unstable. The leather darkens, becomes hard and brittle. The shift is due to age, humidity, sun, but also  perspiration (skin, hair contact with [[car leather|car]] and [[leather furniture|furniture leather]], sweat from feet in [[leather shoes|shoes]] (daily between 100-200 ml), hands in [[Leather gloves|gloves]] or sweated collars of [[leather clothing|leather jackets]]).
@@ Line 20: / Line 20: @@
 </p>
 <p align=center>
-''Typische Schäden durch Haut- und Haarkontakt bei [[Möbelleder]]n (Kopfteile und Armlehnen)''<br></p>
+''Typical damage due to skin and hair contact in [[leather furniture|furniture]] (head and armrests).''<br></p>
 <p>&nbsp;</p>
@@ Line 31: / Line 31: @@
 </p>
 <p align=center>
-''Auch Lenkräder reagieren mit der Zeit auf Handschweiß. Durch die pH-Verschiebung wird das Leder auch anfälliger für [[Schimmel]]befall''<br></p>
+''[[Leather steering wheel|Steering wheels]] also react to skin contact with time. Due to the pH shift, the leather is also more susceptible to [[Moldy leather - Mouldy leather|mould]].''<br></p>
 <p>&nbsp;</p>
@@ Line 43: / Line 43: @@
 </p>
 <p align=center>
-''Durch Hautkontakt geschädigte Auto-Armlehnen und ein Schaltknauf''<br></p>
+''Skin-damaged car armrests and a shift knob.''<br></p>
 <p>&nbsp;</p>
+Another reason is alkaline [[leather cleaner|cleaners]]. Most household cleaners are alkaline, because they have a good cleaning effect. However, leather cleaners should not be alkaline, which is technically possible, but not considered by all manufacturers.
-Ein weiterer Grund sind alkalische Reiniger. Die meisten Haushaltsreiniger sind alkalisch, weil dann problemlos eine gute Reinigungswirkung entsteht. Lederreiniger sollten aber nicht alkalisch sein, was technisch auch möglich ist, aber nicht von allen Herstellern beachtet wird.
+The [[leather care]] should also restore or maintain the acidic condition. Particularly, when old leather is contaminated with mould, acetic acid as a pH regulator is particularly suitable for removal and prevention. Also in the case of a restoration of leather, regulating the pH-value is just as important as the [[Oils & fats in the leather industry|re-greasing]] to make the leather more resistant to environmental influences.
-Auch die Pflegemittel sollten idealerweise den sauren Zustand wiederherstellen bzw. aufrechterhalten. Gerade bei [[Schimmel]]befall an Altledern eignet sich beispielsweise Essigessenz als pH-Regulator zur Entfernung und Vorbeugung vorzüglich. Auch bei der generellen Altlederrestauration ist eine Rücksäuerung ebenso wichtig wie eine [[Lickern|Rückfettung]], um das Leder wieder resistenter gegen Umwelteinflüsse zu machen.
+However, there is also a limit to how much acid a leather is capable of. Therefore, when regulating the pH, always be very careful not to damage the leather. A characteristic feature of book bindings, which can be observed in libraries, is [[red decay]], when sulphur dioxide reacts with the air in the leather to become sulphuric acid, which irreparably erodes [[Leather book cover|book covers]]. Sulphuric acid is one of the strongest acids and is far below the minimum pH-value of 3.5 for leather.
-Gleichwohl gibt es natürlich auch eine Grenze, wieviel Säure ein Leder verträgt. Ein gelegentlich in Bibliotheken zu beobachtender, charakteristischer Säureschaden an [[Bucheinband|Bucheinbänden]] ist etwa der [[Roter Zerfall|Rote Zerfall]], wenn Schwefeldioxid aus der Luft im Leder zu Schwefelsäure reagiert, die den Einband irreparabel zerfrisst. Schwefelsäure ist allerdings auch eine der stärksten Säuren und untertrifft den für Leder maximal verträglichen pH-Wert von 3,5 bei weitem.
@@ Line 57: / Line 56: @@
 {| class="prettytable right"
-|+'''Durchschnittliche pH-Beispielwerte'''<br>
+|+'''Average pH values'''<br>
-(Quelle: [http://de.wikipedia.org/wiki/PH-Wert Wikipedia], Lizenz: [http://de.wikipedia.org/wiki/Wikipedia:GNU_Free_Documentation_License GFDL])'''
+(Source: [http://de.wikipedia.org/wiki/PH-Wert Wikipedia], License: [http://de.wikipedia.org/wiki/Wikipedia:GNU_Free_Documentation_License GFDL])'''
-!bgcolor="#cccccc" | Substanz || bgcolor="#cccccc" | pH-Wert || bgcolor="#cccccc" | Art
+!bgcolor="#cccccc" | Substance || bgcolor="#cccccc" | pH-value || bgcolor="#cccccc" | Type
 |-
-| Batteriesäure
+| battery acid
 |style="background-color: #CC0000; text-align: center"| <0
 |style="text-align: center" rowspan="1"| ↓
 |-
-| Magensäure (nüchterner Magen)
+| stomach acid (sober stomach)
 |style="background-color: #EE0000; text-align: center"| 1,0–1,5
-|style="text-align: center" rowspan="16"| sauer
+|style="text-align: center" rowspan="16"| acid
 |-
-| Zitronensaft
+| lemon juice
 |style="background-color: #FF3300; text-align: center"| 2,4
 |-
-| Cola
+| Coca Cola
 |style="background-color: #FF6600; text-align: center"| 2–3
 |-
-| Fruchtsaft der Schattenmorelle
+| fruit juice of the shadow morello
 |style="background-color: #FF9900; text-align: center"| 2,7
 |-
-| Essig
+| vinegar
 |style="background-color: #FF9900; text-align: center"| 2,9
 |-
-| Orangen- und Apfelsaft
+| orange and apple juice
 |style="background-color: #FFCC00; text-align: center"| 3,5
 |-
-| Wein
+| wine
 |style="background-color: #FFDD00; text-align: center"| 4,0
 |-
-| Saure Milch
+| sour milk
 |style="background-color: yellow; text-align: center"| 4,5
 |-
-| Bier
+| beer
 |style="background-color: yellow; text-align: center"| 4,5–5,0
 |-
-| Saurer Regen
+| acid rain
 |style="background-color: yellow; text-align: center"| &lt; 5,0
 |-
-| Kaffee
+| coffee
 |style="background-color: yellow; text-align: center"| 5,0
 |-
-| Tee
+| tea
 |style="background-color: yellow; text-align: center"| 5,5
 |-
-| Regen (natürlicher Niederschlag)
+| rain (natural rainfall)
 |style="background-color: yellow; text-align: center"| 5,6
 |-
-| Mineralwasser
+| mineral water
 |style="background-color: #44BB33; text-align: center"| 6,0
 |-
-| Milch
+| milk
 |style="background-color: #339933; text-align: center"| 6,5
 |-
-| Wasser (je nach Härte)
+| water (depending on hardness)
 |style="background-color: green; text-align: center"| 6,0–8,5
 |-
@@ Line 118: / Line 117: @@
 |style="background-color: white; text-align: center"| 7,0
 |-
-| Menschlicher Speichel
+| human saliva
 |style="background-color: green; text-align: center"| 6,5–7,4
 |-
-| Blut
+| blood
 |style="background-color: #009988; text-align: center"| 7,4
-|style="text-align: center" rowspan="8"| basisch
+|style="text-align: center" rowspan="8"| basic
 |-
-| Meerwasser
+| sea water
 |style="background-color: #006699; text-align: center; color: #FFFFFF"| 7,5–8,4
 |-
-| Pankreassaft (Darmsaft)
+| pancreas juice (intestinal juice)
 |style="background-color: #0066AA; text-align: center; color: #FFFFFF"| 8,3
 |-
-| Seife
+| soap
 |style="background-color: #0000FF; text-align: center; color: #FFFFFF"| 9,0–10,0
 |-
-| Haushalts-Ammoniak
+| household ammonia
 |style="background-color: #0000FF; text-align: center; color: #FFFFFF"| 11,5
 |-
-| Bleichmittel
+| bleach
 |style="background-color: #0000CC; text-align: center; color: #FFFFFF"| 12,5
 |-
-| Beton
+| cement
 |style="background-color: #0000CC; text-align: center; color: #FFFFFF"| 12,6
 |-
-| Natriumhydroxid|Natronlauge (Ätznatron)
+| sodium hydroxide solution (caustic soda)
 |style="background-color: #000099; text-align: center; color: #FFFFFF"| 13,5–15
 |}
 </center>
-<werbebanner />

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Difference between revisions of "PH value"

Latest revision as of 21:21, 6 December 2021

The pH-value of leather

Additional information