pH value test in leather

The PH300F pH Meter allows quick and simple determinations of the pH value of leather with 0.01 pH accuracy and timed-reading by setting within 30 s to 60 s.

Leather technicians rely on a pH determination to optimize dyes, coating, and softening agents in order to preserve the fiber structure and prevent damage to leather. Leather is acidic.

The pH requirements of leather and leather leather for clothing standards are 3.2 ~ 6.0, and the pH requirements of leather clothing and fleece-filled leather clothing standards are ≥3.5. All fur (wool fur, rabbit fur, goat hair, fox fur, mink fur, raccoon fur) leather clothing, fur clothing standards for fur pH requirements of 3.8 ~ 6.5, fur standard for fur pH requirements of 4.0 ~ 6.5.

1.Reference Standard

BS EN ISO 4045-2018 Leather -Chemical tests -Determination of pH and difference figure

2.The work Principle

This document specifies a method for determining the pH value and the difference figure of an aqueous leather extract. It is applicable to all types of leather.

Preparation of an aqueous extract from a test portion of the leather and measurement of the pH of the extract, using a pH meter. In cases where the pH value obtained is below 4,00 or above 10,00, the pH value of a tenfold dilution of the aqueous extract is also determine

3.Recommend pH meter

PH300F pH meter measuring range pH -2.00~20.00pH,Accuracy 0.01pH

• pH Accuracy meets ±0.01 pH.

• Multi-reading feature allows auto-read, timed-read and continuous-read. 

• Automatic/Manual temperature compensation ensures accurate results.

• Automatic electrode diagnosis with pH slope and offset display.

Aqueous extracts of heavily fat-liquored leather may in time make the electrode membrane dirty. In such cases, the membrane shall be lightly rubbed with a piece of cotton wool dipped in acetone or the electrode should be suspended in a 1:1 water:acetone mixture. After cleaning, the membrane should again be thoroughly soaked in water.