PVA (POLYVINYL ACETATE) MANUFACTURING PLANT

A PVA manufacturing plant is a process plant in which polyvinyl acetate (PVAc) emulsion, commonly known as white glue, and water-based binders are produced by emulsion polymerisation of vinyl acetate monomer (VAM) in water. On the market the abbreviation PVA is used for both polyvinyl acetate and polyvinyl alcohol; the plant described on this page is designed for polyvinyl acetate emulsion production.

What Is Polyvinyl Acetate (PVAc)?

Polyvinyl acetate is a thermoplastic polymer obtained by polymerising vinyl acetate (CH2=CH–O–CO–CH3) monomer. It is not water-soluble; it is produced and used as an emulsion (dispersion) of fine polymer particles in water. The milky white emulsion turns transparent once the water evaporates and a film forms. Adding fillers, plasticisers and other additives gives products with different viscosities and properties. The water-soluble polymer is polyvinyl alcohol (PVOH), produced by hydrolysis of PVAc; polyvinyl alcohol is also used as a protective colloid in PVAc emulsions.

Applications of PVAc Emulsion

• Wood and furniture adhesives (white glue)
• Adhesives for paper, board, packaging and bookbinding
• Vinyl or vinyl-acrylic binder in water-based paints
• Textile finishes and coatings
• Additive in construction chemicals such as renders, primers and joint fillers

PVAc Emulsion Production Process

PVAc emulsion is usually produced by semi-batch emulsion polymerisation. First, an aqueous phase of deionised water, protective colloid (usually polyvinyl alcohol), emulsifier and buffer is prepared in the reactor and heated. Vinyl acetate monomer and the initiator solution are then dosed in a controlled manner over several hours. The heat of the exothermic reaction is removed by cooling water in the reactor jacket and by the reflux condenser. When dosing is complete, a post-polymerisation step reduces residual monomer; the emulsion is cooled, its pH is adjusted and the required additives are added. Finally, the product is passed through filters to remove coagulum and particles, transferred to storage tanks and filled.

PVA Manufacturing Plant Equipment

• Jacketed, agitated stainless steel polymerisation reactor
• Reflux condenser controlling reaction heat and monomer vapour
• Protective colloid dissolving and aqueous phase preparation vessel
• Vinyl acetate monomer storage tank and dosing system
• Initiator preparation and dosing tanks
• Final blending vessel for additive addition and pH adjustment
• Filtration unit with bag or cartridge filters
• Product storage tanks and IBC, drum or pail filling unit

As vinyl acetate monomer is a highly flammable liquid, safety measures such as ex-proof equipment, nitrogen blanketing and vapour balancing lines are built into the design of the monomer storage and dosing area.

Turnkey PVA Manufacturing Plants by Makfen

Makfen designs PVA (polyvinyl acetate) manufacturing plants for the required product type and capacity, and carries out engineering, manufacturing, installation, instrumentation, piping, insulation, electrical installation, performance testing and commissioning on a turnkey basis. Environmental parameters such as energy efficiency, reduction of washing water and control of monomer emissions are also taken into account in the design. Stainless steel reactors and tanks are manufactured at the Dilovası facility.

• Design and manufacture of pressure equipment in line with the PED 2014/68/EU directive and EN 13445 / ASME VIII
• AISI 304L/316L stainless steel, certified materials and polished internal surfaces that reduce build-up
• Jacket or coils for heating and cooling, with thermal insulation
• Impellers, baffles and agitator speed control suited to emulsion stability
• Mechanical seals suited to the system
• Precise dosing of monomer and initiator by weighing or flow meters
• PLC/SCADA control of temperature and dosing, ex-proof motors and instrumentation
• Complete operation and maintenance documentation

Contact Makfen for information and a quotation for a PVA (polyvinyl acetate) manufacturing plant.