Overview
The tensile properties of paper are important indicators of its mechanical strength, which directly affects the processing suitability and end-use performance. By simulating the tensile process of paper under controlled conditions, the tensile strength tester can accurately measure key parameters such as tensile strength and elongation at break. These data are of fundamental technical significance for evaluating the durability, flexibility, and structural integrity of paper, and are widely used in the paper industry, packaging material testing, and printed quality control.
Test Principle:
The tensile strength tester works on a static tensile test: a standard-sized specimen is clamped between the upper and lower clamps, and an axial tensile force is applied at a constant rate until the specimen breaks. During the test, the instrument synchronously records the load and elongation, and calculates the relevant performance indicators accordingly. International and domestic standard systems provide standardized guidance for this, such as the ISO 1924 series and GB/T 12914 standards, which clarify technical requirements such as sample preparation, environmental conditions, and test speed to ensure the reliability and comparability of test results.
Performance parameters
The tensile performance of paper is mainly characterized by the following parameters: tensile strength refers to the maximum tensile force of the specimen per unit width before breaking, reflecting the ability of the material to resist tensile failure; The elongation at break characterizes the elongation percentage of the specimen at fracture, reflecting the ductility of the material. Tensile energy absorption combines strength and elongation characteristics to represent the total energy absorbed by the specimen before breakage, and is often used to evaluate the breakage resistance of packaging materials. These parameters can be calculated using the following basic formula:
Tensile strength = maximum tensile force / specimen width
Elongation at Break = (Elongation at Break / Original Gauge) × 100%
Operational points
The standardized testing process includes specimen preparation, instrument calibration, test execution, and data analysis. The specimen should be cut lengthwise and horizontally along the paper to evaluate anisotropy. Balanced treatment is required in a standard temperature and humidity environment before testing. During operation, it is necessary to ensure that the specimen is clamped and centered to avoid biased load; Choose the stretching speed that meets the standards specified by the standard. After the test, outliers should be eliminated, and the average value and coefficient of variation of multiple groups of samples should be counted to evaluate the stability of performance.
Influencing factors
The results of paper tensile properties are influenced by a variety of factors. The material factors include fiber type, pulping degree, filler content and humidity status; The instrument factors involved the type of fixture, the accuracy of the load cell and the frequency of data acquisition. The operating factors include specimen clamping strength, tensile rate control, and environmental temperature and humidity maintenance. During the test, attention should be paid to controlling these variables and regular measurement calibration of the instrument to ensure data accuracy.
Applications:
Tensile performance data have specific guiding implications in different application scenarios. For example, high tensile strength and moderate elongation are often required for packaging paper; Cultural paper may be more concerned with uniform strength distribution; Special paper needs to be comprehensively evaluated based on specific functional requirements. In addition to paying attention to absolute values, longitudinal and transverse performance ratios and stress-strain curve morphology can also provide reference for process improvement.
With the advancement of sensing technology and digital control systems, modern tensile strength testing machines continue to improve in terms of testing accuracy, automation and data integration. In the future, combined with online detection technology and mechanical model simulation, it is expected to achieve more efficient performance prediction and process closed-loop control, providing further support for paper product development and quality control.
References
GB/T 12914 Paper and cardboard - Determination of tensile strength
ISO 1924-2 Paper and cardboard - Determination of tensile strength - Part 2: Constant speed tensile method
TAPPI T494 Standard Test Method for Tensile Properties of Paper and Paperboard