Corrugated boxes, as an ordinary paper packaging product, cardboard products account for more than 30% of the packaging industry. Based on its characteristics and environmental advantages, it is widely used in the outer packaging of various commodities, and is inseparable from our life and production. For example , the conventional slotted container is the most widely used type of box in transportation and storage. Corrugated boxes are low cost, durable and environmentally friendly. However, not all boxes are created equal. That said, they vary widely in factors such as compressive strength, thickness, chemical resistance, and more. therefore. The detection of all aspects of strength indicators of corrugated boxes is of great significance to ensure product quality and performance.

    To determine how corrugated boxes resist external influences—to help you make an informed decision when picking boxes—manufacturers use a variety of testing procedures. This is a compilation of commonly used corrugated box test methods for checking the strength of corrugated boxes.

    01 Appearance quality inspection
Qualified corrugated boxes require printed patterns, clear handwriting, no broken lines and missing; pattern chromaticity is consistent, bright and bright, and the printing position error is small, the error of the large carton is within 7mm, and the error of the small carton is within 4mm.
The surface quality of the corrugated box should be intact without damage and stains. For the shape of the carton, the tolerance of the inner diameter of the box and the design dimension should be kept within ±5mm for the large box and ±3mm for the small box, and the overall dimensions are basically the same. The flap of corrugated box should be opened and closed 180 degrees and folded for more than 5 times. The total length of cracks in the surface layer and inner layer of the first- and second-class carton, and the inner layer of the third-class carton should not be greater than 70mm. In addition, it is also required that the box body joint is standardized, and the edges are neat , without overlapping angles, etc.
    02 Edge Crush Strength Test (ECT)
The edge compression strength is the pressure that a sample of a certain width can withstand on a unit length, and it refers to the ability to withstand the pressure parallel to the corrugated direction. Edge pressure is the best way to assess the strength of corrugated paper. It directly affects the support strength of corrugated boxes. Through the edge pressure strength test of corrugated boxes, we can understand the bearing capacity of corrugated paper in corrugated boxes.
    03 Bursting strength test
The burst strength of corrugated boxes refers to the uniformly increased max pressure perpendicular to the surface of the sample that the paper or cardboard can withstand per unit area under experimental conditions. This test is to examine the ability of the carton to withstand static local compression in the actual transportation environment.
The bursting strength test of corrugated boxes can be used to understand the ability of the carton to withstand handling, loading and unloading, impact, and tearing forces during the circulation process. medium paper), and has nothing to do with the corrugated paper in the middle.
    04 Puncture Strength Test
The puncture strength is the work done by a pyramid of a certain shape through the cardboard, that is, the work required to start the puncture and tear and bend the cardboard into a hole, expressed in joules (J). Assess the energy that corrugated boxes can withstand against sudden external shocks.
The puncture strength test of corrugated boxes can understand the impact force of the carton during use or transportation, and the test reflects the resistance of the corrugated cardboard to the impact of sharp objects. The puncture strength is closely related to the fiber toughness, hardness, tightness, moisture content of the base paper, the bonding strength of the corrugated board and the thickness of the corrugated board.
    05 Bonding strength Test
Corrugated box bonding strength refers to the force required to separate the bonding ridges of corrugated cardboard per unit length under specified experimental conditions, expressed in Newtons per meter (N/m).
The bonding strength of corrugated boxes can be used to understand the tightness and firmness of the bonding between corrugated cardboard face paper and core paper. If it is not firm, it will affect the strength of corrugated cardboard. It is easy to peel off between layers during use, which will directly lead to The shock resistance and compression resistance of the finished carton are reduced, and the product cannot be better protected.
    06 Compressive strength test
The compressive strength refers to the maximum pressure value that the corrugated box can withstand when the empty corrugated box is placed three-dimensionally and the two sides are pressed at a constant speed.
This test can understand the maximum pressure value that corrugated boxes can withstand, and evaluate whether the carton can withstand enough stacking weight and whether it can protect the contents of the product, so as to prevent the use, handling, stacking, etc. of various packages due to insufficient strength. The occurrence of undesirable phenomena such as product deformation and damage during storage and transportation is also a comprehensive manifestation of verifying the protection performance of corrugated boxes.
    07 Moisture permeability test
The moisture resistance of corrugated boxes focuses on the water absorption capacity of the paper or cardboard surface. This test can understand the moisture content that the carton can block under the influence of the external environment. It can be proved by the water vapor transmission rate that the water vapor transmission rate is low, indicating that the corrugated cardboard material has good moisture resistance. The production environment, storage environment, use environment, weather, climate and other factors of corrugated boxes will affect the carton. In order to ensure the compressive strength of the carton, the impact of the external environment on the carton should be avoided as much as possible. The WVTR test instrument can directly provide relevant data for your current corrugated boxes at any time.