DB44 High Insulation Plasticizer for Power Cables and Wiring Materials

DB44 High Insulation Plasticizer for Power Cables and Wiring Materials

What governs insulation performance in a plasticized PVC cable compound? Volume resistivity. A plasticizer contributes to it through its polarity, its ionic content and its permanence in the compound, and those three factors also decide how the compound behaves through ageing. DB44 is designed for cable sheathing and insulation formulations with stable insulation resistance, heat resistance and ageing behaviour, suited to conventional 70°C and 90°C cable compound systems. Where lower temperatures or a longer service life are required, it can be adjusted with DOS / DOA or TOTM.

Volume resistivity: the number that decides the grade

Volume resistivity expresses how strongly a material resists the flow of current through its bulk volume. In a plasticized PVC insulation it is affected more by the additive package than by the resin. Polar plasticizers, residual catalysts, moisture and migrating additives all lower it, and a compound that is acceptable when freshly produced can fall out of specification after ageing or after exposure to a hot and humid environment.

DB44 is designed for the first two lines in that table. That is what makes it a fit for sheathing and insulation formulations rather than for general flexible goods.

Substitution position and what the manufacturer data says

Per the manufacturer data, DB44 is evaluated as a replacement direction for DOP / DBP / DOTP in cable granulation at roughly 30% to 70% substitution, with improvement directions in gloss, volume resistivity and flame retardancy. Those are directions rather than guarantees: the actual result depends on the full formulation, filler loading, stabilizer system and the extrusion conditions on your line.

A staged substitution is the usual approach: change part of the plasticizer, produce a granulation trial, and confirm volume resistivity, tensile properties after ageing, cold bend and surface quality before moving to the next level. Electrical test results depend on sample preparation and conditioning, so the comparison should always be made between specimens produced and tested under the same conditions.

Meeting 70°C and 90°C ratings, and when to blend

Cable compounds are normally classified by the conductor temperature they can sustain. For a conventional 70°C compound the plasticizer has to retain its properties through the service heat history without excessive loss; for a 90°C rating the demand on volatility and heat ageing performance is higher, and the stabilizer system carries more of the load.

Blending is a normal part of cable compound design. The reason to start from DB44 is that the base compound already sits in the right electrical and ageing window, so adjustments move a good starting point rather than rescue a weak one.

Process notes for granulation and extrusion

Mixing sequence affects electrical results more than most formulations expect. Plasticizer should be added at a stage where the resin is fully wetted so that the compound gels uniformly; incomplete gelation leaves domains that read as weak points in a resistivity measurement and as surface defects on the extruded insulation. Screw temperature profiles should stay inside the stabilizer window, and residence time should be consistent between the reference and the trial run so that the comparison is meaningful.

Frequently asked questions

Does DB44 replace DOTP one for one? No. Substitution is by design and by trial. The published direction is roughly 30% to 70% in cable granulation, and the offset depends on the rest of the formulation.

Which test decides whether the compound is acceptable? Volume resistivity, together with the mechanical ageing and cold bend tests required by the applicable cable standard for the compound type.

Can DB44 be used in a 90°C compound? It is described as suited to conventional 70°C and 90°C cable compound systems. For higher continuous temperature or longer life, blending with TOTM is the usual adjustment direction.

Does the plasticizer affect flame retardancy? Per the manufacturer data the substitution direction shows an improvement in flame retardancy alongside gloss and volume resistivity, but flame performance is dominated by the filler and the whole additive package, so it must be verified on the finished compound.

Is DB44 available for cable granulation trials? Yes. Samples are provided for evaluation, and trial order MOQ is 1 MT.

Request a sample and a recommendation

We can provide a 1kg complimentary testing sample of DB44 dispatched worldwide via DHL or FedEx, along with the current technical data for your evaluation. Bulk shipments are loaded as 23 MT flexitank containers from Ningbo or Shanghai, and our team can advise on a staged substitution plan for your granulation line.