The use of calcium/zinc stabiliser systems has been common in PVC applications for over 25 years.
These materials are generally based on metal carboxylatesand will sometimes incorporate other elements to boost performance such asaluminium or magnesium. Because the heat stability in some applications mayrequire some enhancement when using calcium/zinc, organic co-stabilisers willalso often be added to […]
The suspension polymerisation process is most widely used process tomanufacture PVC.
First, the raw material VCM is pressurised and liquefied, and then fedinto the polymerisation reactor, which contains water and suspending agents inadvance. Through high-speed agitation within the reactor, small droplets of VCMare obtained. Next, the initiator for polymerisation is fed into the reactor,and PVC is […]
Organotin compounds for stabilising PVC have been in commercial use forover 40 years and the commercial products currently available are well provenin their respective applications. The tin used in heat stabilisers for PVCaccounts for about 3.5 per cent of the world’s total tin consumption.
Tin stabilisers for PVC compounds are characterised by acentral tin atom, surrounded […]
When PVC is heated to 170~180°C,chlorine and hydrogen in the molecules are eliminated and release of hydrogenchloride becomes evident. Once such decomposition starts, unstable structuresare formed in the molecule, which further accelerate HCl elimination anddecomposition. As PVC is heated to soften during the extrusion or mouldingprocess, prevention of hydrogen chloride elimination due to heat and […]
PVC is an amorphous polymer and as a result its products are basically transparent. PVC products are non-transparent when they are manufactured using compounding agents that are non-compatible. The haze value is used to measure the transparency of plastic products.
This value is a percentage value calculated by dividing the diffused light transmittance of the test […]
The chemical process for making PVC involves taking the simplest unit, called the monomer, and linking these monomer molecules together in the polymerisation process. Long molecular chains are formed called polymers (which are also called macromolecules).By thermal cracking of naphtha or natural gas, the basic petrochemical industry manufactures ethylene and propylene, etc. Naphtha is mainly […]
Polyvinyl chloride (PVC) is a versatile and resource efficient thermoplastic with the widest range of applications of any of the plastics family making it useful in virtually all areas of human activity.
Without additives PVC would not be a particularly useful substance, but its compatibility with a wide range of additives – to soften it, colour […]
PVC is replacing traditional building materials such as wood, concrete and metals in many applications.
Versatility, cost effectiveness and an excellent record of use mean it remains the most important polymer for the construction sector, which accounted for more than 60 per cent of European PVC production in 2011. Substitution of PVC by other materials on […]
The processability of PVC is not necessarily easy, Processing aids are unique additives which improve the processability of PVC dramatically with only small addition.
Acrylic process aids have very good compatibility with PVC and have longer chains than PVC, the number of entranglements will increase during processing and under shear.
These entranglements acting as physical Cross-links during […]
1) Additives Make Plastics Easier To Process.
it is clear that there are many different ways of forming plastics. Most of these processes involve melting polymer powder or granules inside a heated tube. This ‘melt’ is forced through a shaped die, injected into a mould, or rolled or blown into flat film. The ease with which […]
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