The following items affect the function of the stabilizing box: 1. Air flow of the stabilizing box: After installation and adjustment, check whether the fan belt is properly tensioned, whether the air flow valve is set to the correct position, and whether the heater is clean. 2. Position of the stabilizing box: Adjust the stabilizing box position according to drawings before startup. Mark this position for reference, so re-adjustment is unnecessary when replacing the dry fabric. 3. Cleaning of the stabilizing box: Especially the air outlet slots. Clean it once a month for optimal performance. Test the negative pressure gauge every month and keep records for data comparison. 4. Air temperature: If moisture or dripping water appears on the surface of the stabilizing box, measure the temperature of the outlet air. Normally the air temperature shall be around 70–80°C. Condensation easily occurs below this temperature. Increase steam supply to raise the air temperature in such cases. 5. Position of the stabilizin

As the operating speed of modern paper machines continues to rise, runnability has become a critical factor for modern paper machines. In the press section and dryer section, maintaining intimate contact between the paper web and felts / dryer fabrics ensures trouble‑free, stable operation of the paper sheet at high speed, high efficiency and superior quality. 1. Runability Issues on Conventional Paper Machines Conventional paper machines adopt two‑tier dryer groups in the dryer section, with open draws between dryer cylinders. The paper web tends to flutter even at relatively low speeds, frequently causing web breaks — a typical drawback of two‑tier dryer configurations. Modern paper machines generally switch to single‑row dryers or a combined single‑row plus two‑row dryer layout. Nevertheless, even with single‑row dryers at high operating speeds, moving air currents can form blisters or wrinkles on the web, destabilizing web travel and greatly increasing the risk of web breaks and sheet defects. 2. Impro

Basic Principles of Bleaching ① Destroy or modify the structure of chromophoric groups (delignification or alteration of lignin structure). ② Prevent or eliminate the combination between chromophoric groups and auxochromic groups. ③ Block the conjugation of chromophoric groups. ④ Inhibit the formation of new chromophoric groups. ## Auxiliaries for Hydrogen Peroxide Bleaching ① Sodium silicate: On one hand, sodium silicate buffers the pH value of H₂O₂ bleaching liquor; on the other hand, it inhibits the ineffective decomposition of H₂O₂. ② Oxygen: Introducing oxygen during H₂O₂ bleaching can strengthen the delignification process. High-consistency Oxygen Bleaching Tower The basic principle of oxygen bleaching is to utilize the strong oxidizing property of molecular oxygen to oxidize and degrade lignin in pulp under alkaline medium, so as to dissolve out lignin. Hydrogen Peroxide Bleaching During bleaching, H₂O₂ continuously releases HOO⁻ under alkaline action. HOO⁻ reacts with pigments continuously to a

Correction of felt and dryer web tracking follows the 4-character principle: Move against for inward, move with for outward. This principle means: at the felt/dryer web correction station, if the correction roll is moved against the running direction of the felt (dryer web), the felt (dryer web) will shift toward the operator. If the correction roll is moved in the same direction as the felt (dryer web) travel, the felt (dryer web) will shift away from the operator. This rule applies to top and bottom felts/dryer webs, regardless of the paper machine orientation, left-hand or right-hand machine, and whether the correction roll is on the drive side or operation side. As long as the correction roll is installed underneath the felt/dryer web, the positional relationship between felt/dryer web, correction roll and operator always obeys this principle. Loose felt or dryer web will disable the tracking system and cause web deviation. Tension the felt/dryer web to its normal tension to restore proper operation. I

1. Concept of Formation Paper formation refers to the uniformity of fiber distribution within the paper sheet structure. It is generally inspected by transmitted‑light viewing. Uniform fiber distribution indicates good fiber dispersion. Poor fiber dispersion manifests as clumpy formation, disjointed formation, wavy fiber texture, stock streaks, and cloud formation. Rules of fiber dispersion and flocculation: During sheet forming, longer fibers tend to flocculate more readily. Higher stock consistency promotes flocculation, while lower shear force also favors flocculation. Conversely, these conditions facilitate fiber dispersion. 2. Causes of Various Formation Defects Clumpy formation: Fibers flocculate into irregular lumps scattered across the paper. Under transmitted light, the lumpy areas have thicker paper layers, whereas regions between lumps are thinner, resulting in uneven light transmission across the web. Causes: Insufficient beating; improper headbox consistency; poor performance of flow‑straightenin