Warm congratulations to our company for winning the bid for the procurement project of "Electronic Mixing Machine" at Huazhong University. In this project bidding, other competitors have demonstrated strong competitiveness. With the strong support of the manufacturer, our project personnel have demonstrated a more competitive solution advantage, which has been unanimously recognized by users and experts. We are honored to have won the bid.

American National and Mixograph
Kneading machine and dough mixer electronic kneading machine

1 Structure and principle
The kneading machine is an important instrument for detecting wheat quality by measuring the changes in rheological properties during dough mixing. Since its invention in the 1930s, the National Kneading Machine in the United States has played an important role in wheat quality breeding and flour industry in North America and developed Western countries through continuous improvement. Its structure mainly consists of a stirrer, damping arm, recorder, and data collection analyzer (Figure 1). Its working principle is to knead the dough, measure and record the dough's resistance to kneading, and obtain a kneading curve graph (Mixogram) (Figure 2), which provides indicators such as the optimal kneading time, stirring endurance, other dough rheological properties, and baking estimated water absorption value of the dough, so as to compare and distinguish the quality differences between different types of wheat and the adaptability of specialized flour.

2 Comparison with powder analyzer
The Farinograph from Brabend in Germany and the Mixograph from National in the United States serve as instruments for measuring the rheological properties of dough during kneading. Both have the same status and have been used for a long time in wheat quality laboratories in developed countries around the world. Comparatively speaking, the advantages of the kneading and mixing machine are: firstly, the manufacturing cost and price are cheap (only 1/3~1/2 of the powder analyzer); Secondly, the sample requires a small amount (10g); Thirdly, the analysis speed is fast (the experimental time for one sample is only 10-15 minutes). In addition, the peak mixing time of the mixer curve has a high correlation with the actual and experimental baking mixing time (0.95). Therefore, the kneading machine has a wider range of applications in the wheat breeding industry and the research field of wheat quality chemistry.

3 Technical indicators and applications
The various indicators of the kneading graph reflect the rheological properties and quality of wheat dough, as shown in Figure 2. The center kneading peak of the kneading graph is at point C, and the height of point C represents the resistance to kneading peak. The length of the CD line segment is the optimal kneading peak time, and angle 2 is called the fading angle. The larger the angle, the worse the kneading resistance. The width of the graph and the area below the line are related to the gluten strength of the dough. The rheological properties of dough affected by changes in internal factors and external conditions of wheat will be specifically reflected on the kneader chart. The usage method of the National Blender in the United States has been approved as the American Association of Grain Chemists (AACC) standard method (54-40A), with a kneading speed of 88 ± 2rpm, a preferred ambient temperature requirement of 25 ± 1 ° C, a kneading peak range of 0-250px, a kneading time of usually 0-10 minutes, and a sample dosage of 10 ± 0.01g for the 10 gram kneading machine.