𝐓𝐨𝐝𝐚𝐲'𝐬 𝐊𝐍𝐎𝐖𝐋𝐄𝐃𝐆𝐄 𝐒𝐡𝐚𝐫𝐞 : 𝐖𝐡𝐲 “𝐦𝐨𝐫𝐞 𝐩𝐥𝐚𝐬𝐭𝐢𝐜𝐢𝐳𝐞𝐫” 𝐜𝐚𝐧 𝐬𝐭𝐢𝐥𝐥 𝐥𝐞𝐚𝐝 𝐭𝐨 𝐛𝐫𝐢𝐭𝐭𝐥𝐞𝐧𝐞𝐬𝐬 𝐢𝐧 𝐭𝐡𝐞 𝐟𝐢𝐞𝐥𝐝. 𝐈𝐭 𝐬𝐨𝐮𝐧𝐝𝐬 𝐰𝐫𝐨𝐧𝐠.

𝐓𝐨𝐝𝐚𝐲'𝐬 𝐊𝐍𝐎𝐖𝐋𝐄𝐃𝐆𝐄 𝐒𝐡𝐚𝐫𝐞

𝐖𝐡𝐲 “𝐦𝐨𝐫𝐞 𝐩𝐥𝐚𝐬𝐭𝐢𝐜𝐢𝐳𝐞𝐫” 𝐜𝐚𝐧 𝐬𝐭𝐢𝐥𝐥 𝐥𝐞𝐚𝐝 𝐭𝐨 𝐛𝐫𝐢𝐭𝐭𝐥𝐞𝐧𝐞𝐬𝐬 𝐢𝐧 𝐭𝐡𝐞 𝐟𝐢𝐞𝐥𝐝.

𝐈𝐭 𝐬𝐨𝐮𝐧𝐝𝐬 𝐰𝐫𝐨𝐧𝐠.

Plasticizer makes PVC flexible.

So more plasticizer should mean less brittleness, right?

At day one, usually yes.

But field performance is not only about day-one softness.

It is about retained flexibility after heat, time, extraction, migration, UV, stress, and real service exposure.

That is where “more plasticizer” can backfire.

Not because plasticizer is bad.

Because the wrong plasticizer, in the wrong application, may not stay where it needs to be.

Higher loading can increase the risk of:

• migration into contact materials

• extraction by oils, fuels, water, or detergents

• volatility loss at elevated temperature

• surface tackiness followed by property loss

• dimensional change

• reduced tensile strength

• poor aging retention

• cracking after plasticizer depletion

The compound may start softer.

But if the field removes part of the plasticizer, the material can become harder, less ductile, and more brittle than expected.

That is why Shore A at 23°C can mislead.

A soft compound today does not guarantee a flexible compound after service exposure.

The real question is not only:

“How much plasticizer did we add?”

It is:

“How much plasticizer will remain effective after real exposure?”

For flexible PVC, plasticizer selection matters as much as plasticizer level.

Compatibility.

Molecular weight.

Volatility.

Extraction resistance.

Migration behavior.

Low-temperature performance.

Contact material.

Service temperature.

More phr can hit a hardness target.

But it cannot fix a poor match between plasticizer and application.

Because in the field, flexibility is not what you add.

It is what the compound retains.

source : Orbimind AB

#PVC #FlexiblePVC #Plasticizers #PVCCompounding