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Applications
LIWEI CHEMICAL CO. LTD
Usage | PVA type |
Adhesive | PVA2499/2699/1788/2488/2099 |
Sealant of type | PVA2499/2699/2688/2488 |
Adhesive of paper | PVA2499/2699/1799/2099/1788/0588 |
Plywood/ timber processing/ Man-made board | PVA1799/2099/2499 |
Emulsion Stabilizer | PVA2499/1899/2099/1799/1788 |
Construction | PVA2099/2488/0588/2499 |
PVA film | PVA2099/2499/1795/1788 |
Hydrophobic fiber | PVA1799/2095/1795 |
Hydrophilic fiber | PVA1588/1788/2088 |
Printing | PVA2488/1788 |
Non-woven agents/ architectural coating | PVA1799/2499/2699 |
Casting Industry | PVA1788/ |
Agriculture | PVA1788/2499/2099 |
Glue | PVA1788 |
1. PVA Film
Polyvinyl Alcohol Film has many unique
advantages unmatchable for general polypropylene and
polyvinyl
chloride due to its properties of bearing static electricity, good optical transmission, good gloss,
low oxygen permeability, and coriaceous coating.
In this sector traditional varieties are seldom used. Due to low viscosity of PVA 1799 series,
generally for membrane not easily soluble, PVA 2099 and polyvinyl alcohol 2499 may be
used, whereas
the PVA 1795 and PVA 1788 may be
often used for production of water-soluble membranes.
2.Papermaking & Processing
In papermaking, water-soluble polymers are mainly applied to surface sizing agent, pigment binding
agent, and paper addictive. In the past starch-based pigment was used as a surface sizing agent and
casein as a binding agent. Today since the adhesion of PVA fibers is stronger than casein, with
better film-forming property and higher intensity of the film, the demand of PVA for paper
processing is on the rise. Along with the large-equipment involving, high efficiency and high-grade
papermaking and reasonable ways of packing, such demand will be even greater. Main applications: (1)
binding agent for paper; (2) re-moistening agent; (3) paper surface sizing; (4) paper pigment
coating; (5) papermaking (paper internal sizing). Applicable varieties: PVA 24-99, PVA 20-99, and
PVA 1788 etc.
3. Plywood, Artificial Board and Timber Processing
PVA Polyvinyl Alcohol can be a
de-characterizing agent of thermosetting resin mainly used as a
binding agent such as carbamide, formaldehyde resin and melamine, for plywood, artificial board and
timber processing. When mixed with melamine-formaldehyde resin, the PVA size paste helps increase
the viscosity and shortens both curing and cooling time with stronger initial cohesion. Commonly
used varieties: 1799, 2099, and 2499 etc.
4. Emulsifying and Stabilizing Agents
With its very low surface tension and its ability to disperse VAC in water into very fine granules,
PVA is applied to produce PVAc emulsion. It is also a very good protective colloid that enables the
polymerized, colloidal and granular PVAc to form a stable aqueous emulsion and keep it from
coagulation or degradation. Selection from a variety of PVA products depends on their properties. As
for latex with a strong cohesion at the beginning of production, the complete alcoholysis type PVA
can be selected, such as those labeled 2499, 1899, 2099 and 1799; on the contrary, for production of
latex with low viscosity despite high content of solid, a PVA with a low degree of polymerization
may be mixed with a PVA with high alcoholysis, and 0388 can be used together with 1799.
5. Construction Industry
Polyvinyl alcohol is used as an addictive to cement and mortar for efficient increase of their
cohesion and fluidity, and reduce the drying time for the concrete surface, thus increasing coating
adaptability and preventing concrete cloth from chapping. Besides, due to its simple application
method with desired effects, PVA is suitable for wall and ceiling decoration and tile facing.
PVA can be also used as an adhesive agent for profiles, e.g. prefabricated plasterboard and sound
absorption board that are made of organic fibers (cane, residue and wood-shavings) or non-organic
materials on which highly cohesive and waterproof PVA series can be applied to make profiles through
compression and cohesion.
The PVA solution, a poly vinyl formal PVFM high molecular compound, finds its wide application in
internal wall coating, plasterwork and joint sealing due to its favorable properties of weather
resistance, waterproof, non-swell with water, non-embrittlement, non-poison, tastelessness, and
inexpensive prices.
In the coating sector the traditional varieties can only be used in making profiles. PVA with a
higher degree of polymerization, such as the models 20-99 and 24-99, are often selected as a
substitute.
6. Printing
For the PVA film which contains dichromatidgelatin or cinnamon acid, after ultraviolet radiation,
part of the PVA combines with dichromatidgelatin to produce insoluble complex salt, or with cinnamon
acid to have a water-insoluble meshwork due to the bridging effect. After heat treatment for
increase of physical strength, the meshwork can be used for screen printing.
7. Textile
Functional PVA is now the most efficient synthetic sizing agent for warp paste with the following
advantages:
(1). PVA membrane has a good sizing effect and can improve the weavability of high-density and
high-grade textiles due to its excellent properties of obdurability, smoothness, wear resistance and
adhesiveness on fibers.
(2). PVA has a powerful cohesive force on fibers as well as good protective effects to reduce times
of textile yarn breaking and improve weaving efficiency.
(3). PVA size paste doesn’t not get corrosive easily and degraded without any change in viscosity
after long-time heating, which ensures stable sizing and minimizes hard size spots.
(4). At textile factories the moisture of starch paste must be at 80-85%, while the moisture
requirement for PVA size mixture is just 70-75%, which makes it possible to improve operating
environment and production efficiency.
(5). To minimize desizing in the process of sizing and weaving and keep the factory area clean, PVA
series with medium degrees of polymerization and 90-97 (mol/mol)% alcoholysis, such as 20-95 and
17-95, are applicable.
8. Vinylon
Polyvinyl Alcohol PVA fibers can be used
to made vinylon.Though the clothing property of vinylon may be far less
popular than other synthetic fibers, Vinylon is still known for its properties of moisture
absorption and wear resistance and can substitute some cotton-made bedding, knitwear, decorative
cloth, canvas, uniform, work clothes, fishing net and curtain. Other properties of vinylon meet
industrial requirements, such as high strength, low elongation, high modulus, acid/alkali/weather
resistance, good adhesiveness to rubbers. So high-strength and high-membrane vinylon can be used as
an alternative to asbestos.