Category blogs

A workable plastisol starts with the process, not the recipe. Two widely published starting-point viscosity bands for the same paste PVC differ by roughly threefold: one lands at 1,000 to 5,000 cP, the other at 2,000 to 15,000 cP at…

The right ESBO dose is really two doses. Run epoxidized soybean oil (ESBO) at 1 to 4 phr and it works mostly as a co-stabilizer, propping up your Ca/Zn system. Push it toward and past 5 phr and it starts…

One additive in a flexible PVC recipe both softens the compound and neutralizes the hydrogen chloride that degrades it during hot processing. Epoxidized soybean oil — ESBO on most spec sheets — does this at just 1-5 phr, working beside…

Two drums of isononyl alcohol can both certify above 99.5% assay and still make DINP with measurably different low-temperature flexibility. The parameter that governs cold-flex and volatility is not the assay figure on the front of the certificate. It is…

A phthalate plasticizer is an ortho-phthalate diester — phthalic anhydride reacted with two alcohol chains — that dissolves physically into rigid PVC to make it flexible. Roughly 90 to 95 percent of all phthalates go into flexible PVC, which makes…

CPVC carries 63 to 69 percent chlorine by mass against PVC’s roughly 57 percent. That extra chlorine lifts its glass-transition temperature about 30 °C higher and pushes its melt window past the point where PVC starts shedding hydrogen chloride. Those…

Most processors never run a resin test in-house. They accept the supplier’s certificate of analysis, file it, and find out a lot was borderline only when the defect shows up on the line weeks later. Reading that certificate parameter by…

E-PVC, S-PVC, paste resin, P-PVC — the labels overlap enough that the wrong resin gets ordered against a clear spec. The line that actually separates them is drawn at the moment of polymerization, where one route grows latex particles a…

A drum of PVC resin and a sack of PVC compound sit on the same shelf at the same supplier, and the compound costs $200 to $400 more per metric ton. The easy read is that compound is just pricier…

A processor seeing voids and splay on the line often assumes PVC needs the same hopper-drying step as the PET or nylon next to it. PVC is non-hygroscopic, so routine drying is usually unnecessary. The real question isn’t the polymer…

A QC engineer writing a flexible-PVC migration spec needs the D-number and revision year, not a methods narrative. Seven ASTM standards cover plasticizer migration, each addressing one failure mode — vinyl-to-coating transfer, sealant bleed, immersion extraction, volatile loss, cold-flex stiffness…

A flexible PVC tubing specifier swaps DEHP for ATBC to clean up the regulatory profile, and the polycarbonate luer cracks within the first week of service. Paul Kroushl at Teknor Apex documented this exact failure in 2016: at 3% strain…