Leather is a natural material made of collagen fibers that have been stabilized through a tanning process. One of the leather’s characteristics is that if it is gradually heated in an aqueous solution, it reaches a temperature at which the fibers deteriorate and a sudden and irreversible shrinkage occurs. This shrinkage is a consequence of the rupture of collagen fibers bonds. Depending on the level and quality of the tanning process it happens at different temperatures. The value of this temperature is an indicator of the degree of tanning of the leather. A higher value indicates more durable leather and higher quality.

The most widely used method to determine leather shrinkage temperature is the standardized method ISO 3380:2016. This method measures the temperature of leather contraction using a device that involves an operator attention throughout the test. This makes it an inaccurate and subjective method.

There are currently other methods to determine the temperature of shrinkage, mainly: scanning calorimetry, microscopic hot table, differential thermal analysis and thermomechanical analysis. All of them need expensive equipment and specialized personnel. The cost of using these methods as well as the accuracy required for practical purposes in the day-to-day operation of the tanning industry make it unfeasible to use them.

This work presents a new method to obtain the shrinkage temperature by measuring the force that the leather exerts when it contracts. The results obtained in the different leather samples are similar to those obtained with the ISO method, furthermore with smaller error and lower dispersion values. The material used has a low cost and it is commonly used in any industry, which makes highly feasible the implementation of the proposed method to perform quick tests by the production line.

皮革是由胶原纤维制成的天然材料，已通过鞣制过程得到稳定。皮革的特征之一是，如果将其在水溶液中逐渐加热，则会达到使纤维变质并发生突然且不可逆的收缩的温度。这种收缩是胶原纤维键断裂的结果。根据制革工艺的水平和质量，它会在不同的温度下发生。该温度值是皮革鞣制程度的指标。值越高表示皮革越耐用，质量越高。

确定皮革收缩温度的最广泛使用的方法是标准化方法ISO 3380：2016。该方法使用一种在整个测试过程中都需要操作员注意的设备来测量皮革收缩的温度。这使其成为不准确和主观的方法。

当前还有其他确定收缩温度的方法，主要是：扫描量热法，显微热台，差热分析和热机械分析。他们都需要昂贵的设备和专业人才。使用这些方法的成本以及制革业日常操作中实际目的所需的精度，使得使用它们不可行。

这项工作提出了一种通过测量皮革收缩时施加的力来获得收缩温度的新方法。在不同皮革样品中获得的结果与通过ISO方法获得的结果相似，而且误差较小且色散值较低。所使用的材料成本低廉，并且通常在任何行业中使用，这使得所提出的方法的实施在生产线上进行快速测试变得高度可行。