1. Introduction and test principle of compression strength measuring The compression testing machine is to measure compression strength of corrugated boxes in the situation of pressure and protect functions of packages for the objects filled in the packages. Test principle: (1) Corrugated boxes compression strength test, loading to the corrugated boxes using a compression testing machine at a certain constant rate untill corrugated boxes are broken or till certain load or displacement are reached. (2) Corrugated boxes stacking test, loading a certain force to the corrugated box using a compression testing machine untill corrugated box is broken or sustain a certain time period. When measuring deformation of corrugated box during compression test, an original load should be set as a datum point. The datum point can refer to the following chart: Average compression force(N)Original force(N) 101-200 10 201-1000 25 1001-2000 100 2001-10000 250 10001-20000 1000 200001-100000 2500 2. Functions of compression testing machine This machine is applicable to metal, cementing compound, tubes, sectional bars, aerospace, petrochemical, waterproof rolls, wire and cable, textile, fiber, rubber, ceramics, food, mechanical packaging, geo-textile, film, wood, paper and other industries and quality supervision department, and it also can be used in college for teaching demonstration. 3. Specification of compression testing machine 1 Max. Load 20KN 2 Resolution of test force 1/300000 3 Resolution of displacement 0.001mm 4 Precision of crossbeam displacement 0.5% 5 Precision of deformation 0.5% 6 Measuring range of test force 1%-100%FS 7 Relative error of test force 1% 8 Relative error at zero point 0.5% 9 Speed of crossbeam 0.01-500mm/min 10 Precision of crossbeam speed 1% 11 Speed range of load 0.005%-5%FS/s 12 Precision of load speed When speed is less than 0.05FS/s, precision is within 1% of set value, when speed is more than 0.05FS/S, precision is within 0.5% of set value 13 Speed of deformation 0.005%-5%FS/s 14 Precision of deformation speed When speed is less than 0.05FS/s, precision is within 1% of set value, when speed is more than 0.05FS/S, precision is within 0.5% of set value 15 Stroke of crossbeam 900mm 16 Effective tensile height 650mm 17 Effective test span 400mm 18 Effective compression height 800mm 19 Diameter of compression platen 100mm 20 Voltage and power 220V,50Hz, 700W 21 Dimension of main machine 650X450X1650mm 22 Weight of main machine about 300kg