PVC (Polyvinyl Chloride) cannot be processed only by PVC Resin itself, unlike other resins. That’s because demineralization occurs due to heat or light.
It is necessary to add a stabilizer to prevent this phenomenon. PVC Compound is made by adding various functional additives to RESIN
These basic formulations of compounds do not fully meet customer requirements.
We add flame retardants, lubricants, antioxidants, crosslinking agents, emulsifiers, emulsifiers, processing aids,
and impact modifiers so that the compound possesses the characteristics required by customers.
The manufacturing method of PVC compound
PVC Resin is the basic raw material used in PVC compound manufacturing.
The nature of PVC Compound is determined by PVC Resin.
PVC Resin is polymerized by VCM (Vinyl Chloride Monomer) under initiator and catalyst at high temperature and pressure.
PVC Resin can be made as follows.
The polymerization degree of PVC
For more information on polymerization methods and PVC Resin, visit the homepages of LG Chemistry or Hanwha Chemical.
– LG Chemistry : www.lgchem.com
– Hanwha Chemical : hcc.hanwha.com
Plasticizer is a material to facilitate workability and to ensure flexibility in PVC Resin.
It loosens the bond of molecular strings connecting the resin molecule and makes PVC compound flexible.
The types of plasticizer
Change in hardness according to the plasticizer content is as follows.
Flexibility of PVC compound varies depending on the content of plasticizer.
The greater the plasticizer content, the lower the hardness (Shore A Type).
※ PHR: Part per Hundred Resin, which is a figure when PVC Resin is 100.
※ The above data are values using Shore A Type hardness tester.
PVC Stabilizers have been developed as the most important part of the processing technology because PVC begins to discolor by thermal decomposition from around 170℃.
Stabilizers are added to prevent the decomposition of PVC by heat and must be added for manufacturing PVC compound.
Stabilizers are classified according to their basic raw materials as follows.
For more information on stabilizers, visit the websites of Dansuk Industrial, Shinwon Chemical,
Leochem, Adeka Korea, Songwon, Woochang Chemical, KD Chem, Kyungsan Chemical or C&A.
PVC stabilizer manufacturers are as follows. There are many other companies other than the following companies
Calcium carbonate is usually called crushed rock and its formula is CaCO3. It is divided into heavy calcium carbonate and light calcium carbonate. Light calcium carbonate is mainly used for PVC compound. Calcium carbonate is used for coloring, electrical insulation, prevention of shrinkage, improvement of workability and prevention of aging. It also used for providing special functions, and for economic purposes when its volume is simply increased to reduce the cost.
Manufacturers of calcium carbonate are listed below.
Clay’s formula is Al2Si2O5(OH)4. Clay is an additive used to increase the insulation resistance of PVC to the production of insulation compounds with insulation resistance. Clay is effective for dielectric properties, electrical stability and water resistance.
Talc refers to the natural mineral talc with slip property and is a soft white clay mineral.
It is composed of hydrated magnesium silicate with the chemical formula 3MgO, 4SiO2, H2O. Talc has a specific gravity of 2.6–2.7, high whiteness, electrical insulation, heat resistance and chemical stability. It is easily peeled due to weak layered structure and interlayer bonding force
Anti-Oxidant is a substance added to polymer substance to prevent autoxidation by the action of oxygen.
Polymer substance becomes aged and discolored when it is oxidized. Anti-Oxidant is added to prevent such aging or discoloration.
Types of Anti-Oxidant
For more information on anti-oxidants, visit the websites of Adeka Korea or Songwon.
Manufacturers of antioxidants are as follows
Polymers such as plastics and rubbers are degraded not only by heat but also by light, resulting in aging.
In particular, ultraviolet rays of 290-400 nm in sunlight have a strong energy and act as the main cause of plastic aging such as discoloration of plastic, surface cracks, and deterioration of physical properties.
Ultra Violet Scavenger selectively absorbs ultraviolet rays from sunlight and converts them into heat energy.
It prevents decomposition of plastic by destroying free radicals generated by decomposition from ultraviolet rays
Types of Ultraviolet Stabilizer
Flame retardant is a substance that physically and chemically improves most plastics which burn easily.
Flame retardants are classified into halogenated, phosphorus, chlorinated and inorganic flame retardants.
Chlorinated paraffin, chlorinated polyethylene, aliphatic chlorinated flame retardant
Chlorinated paraffin and polyethylene are cheaper in price.
Aliphatic flame retardants with low stability are expensive.
Chlorinated flame retardant has lower efficiency than that of bromine retardants.
Active radicals such as OH radicals generate heat through chemical reaction during combustion. The latent heat acts as an energy source for burning surrounding flammable materials. Flame retardants, like the above substances, reduce the concentration of active radicals OH∙ and O∙ and stop the chain reaction to give a flame retardant effect. Cutting C-X bond during combustion has an effect of reducing the combustion heat of combustible materials through an endothermic reaction. They have an effect of blocking oxygen by generating incombustible gas upon decomposition. Actual flame retardant effect is produced by HX and is converted into X-radical of low-energy source in response. Halogen-containing flame retardant exhibits a flame retardant effect even on a solid phase, and HX acts as a catalyst for oxidation of combustible materials. Oxidized materials are cyclically structured, resulting in a carbon compound. This carbon compound serves to prevent oxygen and latent heat, thereby helping the combustible materials to stay below the combustion level. Act of combustion covers surfaces with heavy gas in liquid or solid stats and helps to generate a compound with double bonds that are easily carbonized to block heat and oxygen.
Flame retardant effect sequence
Phosphorus flame retardant
Types of phosphorus flame retardant
When burning, the phosphorus compound generates polymetaphosphoric acid by pyrolysis,
which forms a protective layer and produces a dehydration effect.
It has a dehydration effect when polymetaphosphoric acid is produced.