A roundness tester is a measuring tool that uses the rotation axis method to measure the roundness error of a workpiece. The roundness tester is divided into sensor rotary and workbench rotary. During measurement, the measured part is installed concentric with the precision shaft system, and the precision shaft is equipped with an inductive length sensor or workbench for precise circular motion. The roundness meter consists of an instrument's sensor, amplifier, filter, and output device. If the instrument is equipped with a computer, the computer is also included in this system. A roundness tester is a precision instrument used to measure the out-of-roundness of a rotating surface (shaft, hole, or spherical surface) of a component. There are usually two types: small desktop, where the workpiece is mounted on a rotating workbench and the measuring head is mounted on a fixed column; and Large floor mounted, with the workpiece installed on a fixed workbench and the measuring head installed on the rotating spindle. During measurement, the measuring head contacts the workpiece's surface, and the instrument's rotating part (workbench or spindle) rotates for one cycle. Due to the extremely high accuracy of the supporting bearings in the rotating part, the measuring head will generate a high-precision circular trajectory on the measured surface during rotation. The out-of-roundness of the measured surface causes the measuring head to shift and transform into an electrical (or pneumatic) signal. After amplification, it can be automatically recorded on a circular recording paper, and the out-of-roundness of each part can be directly read out for accuracy evaluation and process analysis and widely used in precision bearings, machine tools, and instrument manufacturing industries.
The Roundness Testeradopts a radius measurement method and operates in a rotating manner. The rotation axis system of the roundness meter adopts a high-precision air floating spindle as the measurement reference; The electrical part of the roundness tester is composed of advanced computers, precision circular grating sensors, and precision inductance displacement sensors. The circular grating sensors and precision inductance displacement sensors measure angle and radial displacement, ensuring the accuracy of measuring the angular displacement and radial value of the workpiece; The roundness meter measurement software adopts a roundness measurement software based on the Chinese version of WinXP operating system platform, completing data collection, processing, and measurement data management. China Roundness Measuring Instrument,Roundness Tester Machine,Mitutoyo Roundness Tester Manufacturer Zhejiang dexun instrument technology co., ltd , https://www.dexunmeasuring.com
Glutinous paper processing technology
In the past, glutinous rice paper was typically made using refined starch. However, this process now uses potato starch as an alternative, which not only helps reduce food waste but also expands the raw material sources for the food industry, which is in high demand for glutinous rice paper. Each ton of the final product requires approximately 15 tons of potato starch. The main equipment used in production includes a gelatinizing pan and a frying machine. Here's a detailed breakdown of the process:
First, potato starch is emulsified by passing it through a 100-mesh sieve and then placed into a container. It is immersed in warm water at 50-55°C to create a smooth mixture. The amount of water used is 2.5 to 3 times the weight of the starch, resulting in a concentration of about 15-17° Baumé.
Next, the emulsified starch is continuously stirred to ensure even dispersion in water. After being filtered through a 100-mesh sieve, it is pumped into the gelatinization pot using a syringe pump.
For the phospholipid emulsion, a 1% to 2% caustic soda solution is prepared first and heated to 85–100°C. Then, phospholipids are added while maintaining a caustic soda dosage of 0.8% to 1.8% of the phospholipid weight. This ensures complete solubility in the alkali solution. Once cooled to 30–40°C, the mixture is filtered again through a 100-mesh sieve to produce a 1% to 2% phospholipid emulsion with a pH of 8–9, making it slightly alkaline.
The starch paste is then transferred to the gelatinization pan and heated to 50°C. A preheated phospholipid emulsion (at 84–90°C) is added while stirring at around 40 rpm, and the mixture is incubated at 90°C for 1–2 hours. The concentration is maintained between 7% and 8%.
Finally, the starch paste is fried using a rotating copper foil system, where the film thickness is controlled to 2–3 wire. After drying, it becomes glutinous rice paper. The steam pressure during frying must be carefully controlled at 0.15–0.25 bar. Too much pressure can cause excessive bubbling, while too little may prevent proper drying. Since the final product needs a moisture content of at least 30%, steam is sprayed into the frying machine to maintain humidity and prevent brittleness.
To enhance the strength of the paper, 2% alginic acid can be added before the gelatinization process, increasing its tensile strength by about 10%. This method offers a sustainable and efficient way to produce high-quality glutinous rice paper.
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Glutinous paper processing technology