Filler and desiccant in one
Our desiccant filler replaces part of a conventional filler while removing moisture, helping formulators control porosity and shelf life without adding a separate drying agent.
Specialty Chemical
Desiccant Filler — Dual-Function CaO Filler for Rubber, PVC and Sealants
A calcium oxide filler that adds body to compounds while scavenging moisture, reducing porosity, blistering and storage problems in rubber, PVC and sealant systems.
PowderMasterbatch Blend
ISO 9001 certified processes
NABL-accredited lab testing
CoA, TDS & MSDS with every shipment
Export packaging worldwide
Overview
What is Desiccants Filler?
Desiccant filler is a dual-function additive that does two jobs in one: it serves as a mineral filler and it removes moisture from the formulation. It is based on calcium oxide combined with mineral carriers and dispersion aids, and is designed to be used at filler-type loadings in rubber compounds, PVC plastisols and sealants, rather than at the low dosages typical of a pure desiccant.
Fillers such as calcium carbonate, clay and silica always bring some moisture into a formulation, as do plasticisers and polymers. In rubber this water causes porosity during cure. In PVC plastisols it can produce bubbles and blisters when the coating is gelled. In one-component moisture-curing sealants and adhesives it starts the curing reaction inside the cartridge or drum, causing skinning, viscosity rise and short shelf life. Replacing part of the conventional filler with desiccant filler captures this water while keeping the overall filler level in the recipe.
The calcium oxide reacts with water to form calcium hydroxide, a stable solid that remains in the compound as part of the filler package. High CaO activity, typically above 85 %, and a controlled particle size allow the product to disperse evenly in mixers, planetary dissolvers and kneaders. Compounders gain moisture control and filler volume from a single ingredient, which can simplify recipes and stock holding.
Obsidian Minerals manufactures desiccant filler in Gujarat, India, under ISO 9001 certified processes, with testing in an NABL-accredited laboratory. Two grades are offered: a CaO-based Filler Grade for general rubber compounding and a High-activity Grade for critical polymer and sealant systems. Each shipment is supplied with an SDS, Technical Data Sheet and Certificate of Analysis. If you need moisture scavenging alone at low dosage, our Desiccants range may be more suitable.
Desiccants Filler grades
Select a grade for its typical properties, applications, usage guidance and FAQs.
Desiccants Filler
CaO Filler Grade
A calcium oxide filler for rubber compounds that takes the place of some conventional filler while absorbing the moisture it brings in.
Rubber Compounding Desiccants FillerHigh-activity Grade
A finer, more reactive calcium oxide filler for sealant, adhesive and PVC systems where even traces of water cause failures.
Critical Polymer Systems| Grade | Specification | Primary use | Link |
|---|---|---|---|
| CaO-based Desiccant Filler Grade | On TDS | Rubber Compounding | Specs |
| High-activity Desiccant Filler | On TDS | Critical Polymer Systems | Specs |
From deposit to dispatch
- 01
Selection of limestone and carriers
- 02
Calcination to calcium oxide
- 03
Fine milling and blending
- 04
Surface treatment or masterbatch blending
- 05
Activity testing and sealed packing
Why source Desiccants Filler from Obsidian Minerals
Two activity levels
A CaO-based Filler Grade for general rubber work and a High-activity Grade for sealants and critical polymer systems, both developed and tested in-house.
Activity tested per batch
Available CaO and particle size are measured in an NABL-accredited laboratory, and results are reported on the batch Certificate of Analysis.
Where Desiccants Filler is used
Desiccants Filler — frequently asked questions
What is a desiccant filler?
A desiccant filler is a mineral additive that works both as a filler and as a moisture scavenger. Ours is based on calcium oxide with mineral carriers. It is used at filler-level loadings in rubber, PVC plastisols and sealants, replacing part of the normal filler and reacting with water that would otherwise cause defects or short shelf life.
How is desiccant filler different from a standard calcium oxide desiccant?
A standard calcium oxide desiccant is a concentrated drying agent added at low dosage, mainly to rubber compounds. Desiccant filler is formulated with carriers and dispersion aids for use at higher loadings, where it contributes to the filler volume of the recipe as well as removing moisture. It is aimed especially at sealants, adhesives and PVC plastisols.
Can desiccant filler replace calcium carbonate in my formulation?
It is normally used to replace part, not all, of the calcium carbonate or other filler. Typical replacement levels are a few percent of the formulation, chosen to match the moisture load. Because it is alkaline and reacts with water, it should be trialled for its effect on cure speed, viscosity and adhesion before scale-up.
Which industries use desiccant filler?
The main users are rubber compounders making extruded and moulded goods, producers of PVC plastisol coatings and automotive sealants, and manufacturers of moisture-curing polyurethane, silane-modified and silicone sealants and adhesives. It is also used in construction sealants where long shelf life in humid climates is important.
How should desiccant filler be stored?
Store the product in its original sealed packaging in a cool, dry place, away from water and acids. Use opened bags promptly and reseal them tightly, because the calcium oxide reacts with humid air and gradually loses activity. Contact with water releases heat, so follow the handling advice on the SDS.
How can I get a sample of desiccant filler?
Tell us your polymer system, current filler package, processing method and approximate monthly volume. We will recommend the CaO-based Filler Grade or High-activity Grade, share the Technical Data Sheet and send a sample for laboratory trials. Commercial terms follow once the grade and packing are agreed.
What packaging options are available for Desiccants Filler?
Standard export packing is 25 kg or 50 kg HDPE / paper bags and 1 MT or 1.2 MT jumbo (FIBC) bags, palletised and shrink-wrapped on request. Custom and private-label packaging can be arranged for volume orders.
Do you provide MSDS and technical datasheets?
Yes. A Technical Data Sheet and MSDS are available for every grade, and each shipment is accompanied by a batch-specific Certificate of Analysis.
Request a quote
Interested in Desiccants Filler?
Tell us your application, preferred grade and volume. Our engineering team will recommend the right grade and send a datasheet, sample and quotation.
- Technical Data Sheet & MSDS
- Samples for qualification trials
- Bulk and recurring supply pricing