Old
VAT dye VAT dye, insoluble in water, in the alkaline solution by sodium
dithionite reduction processing powder (insurance), and make the fiber
dyeing dye. Its fast and washing fastness especially, can be used for
cotton, linen, viscose, whalen fiber dyeing and printing, etc.
In
the molecular structure of VAT dye excluding sulfonic group, carboxylic
acid base, such as water soluble groups, insoluble in water, therefore,
cannot be directly dyed; The molecular conjugated double bond systems
containing at least two carbonyl, interaction with insurance powder in
the alkaline solution, carbonyl reduction into hydroxyl, become water
soluble compounds ─ ─ the leuco body. Is leuco body has affinity to
fiber, fiber after adsorption, oxidized by air or other oxidants, leuco
body back for VAT dye fixation on fiber staining. Leuco body staining
method shortcoming is dye into the fibers not easily, if the suspension
pad dyeing, the reduction of the outstanding dye made from suspension
solution, borrow machine rolling pressure make dye fine, evenly
distributed on the dyed fabric treated with insurance powder and make
dye reduction by fiber adsorption, good is thicker and uniform can be
obtained by the oxidation dyeing effect.
Its
chromatographic is full, bright color, soaping, tanning fastness are
high, but because the price is more expensive, some yellow, orange and
other color with photosensitivity brittle damage phenomenon, make its
application is limited by certain.
Because Vat Dyes does
not dissolve in water, so the side effects of it on the human body easy
to control, more safe and convenient for environmental protection, but
its cost is generally high.
Vat Dyes, Vat Red Dyes, Vat Dyes Manufacturer Dynasty Chemicals (NingBo) Co., Ltd. , https://www.dychemco.com
I. Construction process quality management and control 
    Process quality control should pay special attention to the key processes that affect the quality of the project and the key parts and key work contents that affect the quality of each process. The process quality control also pays special attention to the requirements of the connection between processes and control the handover between the upper and lower processes.
    Quality factors affecting specific processes include operators, implements, raw materials, monitoring techniques, process methods, and production environments.
    The quality improvement of each process begins with the status quo. The current status of the process can be analyzed by using methods such as Wang Zuo ability analysis and control chart.
The focus of quality control during the construction phase is the construction process and construction process.
   A mature process should include process objectives (indicators) and technical conditions, process flow, machine equipment, operational requirements, quality standards and inspection methods, and product protection and use requirements. Ensuring the quality of the process, including the planning, execution and inspection feedback on these contents, it embodies the basic principles of quality management.
    Second, the quality management and control of construction process
    For the quality control of the process, as well as the basic principles of quality management, constitute a circulation system. The process quality control cycle can be represented by Figure 1G420081.
November 09, 2021