Capim™ Brazilian clays
Optimal brightness, opacity and printability with our Capim range
Capim clays from our high-quality kaolin deposit in northern Brazil exhibit a “naturally engineered” morphology that gives them an unparalleled combination of high brightness, narrow or “steep” particle size and low abrasion. Capim clays make excellent functional fillers and coating agents where they confer optimum brightness and opacity along with excellent printability to the final paper.
The combination of a coarse, steep Particle Size Distribution (PSD) together with high brightness and low abrasion gives coarse Capim filler grades a unique balance of properties. Their coarse, steep particle size boosts machine runnability through improved dewatering, better retention and good paper strength, while low abrasion prolongs wire life.
Capim grades also improve paper quality due to the combination of high natural brightness and decreased absorption.
In SC paper production, Capim kaolins are good alternatives to neutral conversion if high brightness is required without the compromise in surface properties and ink demand seen in neutral papermaking. Alternatively, the scatter and brightness benefits can be traded for cost reduction through reduced pulp bleaching.
Capim makes an ideal filler for LWC-base papers where high loadings can be achieved resulting in benefits to surface quality after coating.
When used in the topcoat, Capim grades deliver optical benefits, increased bulk and improved mottle performance against conventional glossing kaolins. These benefits in bulk and optics can enable gloss to be optimised through calendering. Their use can help reduce expensive opacifiers such as TiO2 in coating recipes.
The low level of ultrafine particles and low surface area of Capim clays improve coating strength enabling binder reduction compared to fine glossing kaolins or giving improved glueability in board and packaging applications.
The Capim coating range is ideal for:
- Coated B&P: Brightness, reduced mottle, glueability
- LWC: Brightness, rheology, MSP runnability, gloss
- MWC/CFS: Excellent scatter, rheology, gloss, opacity
- Topcoat CWF: Brightness, reduced mottle, for gloss, silk matte and single coat
Used in silicone release papers for self-adhesive labels, Capim fine coating kaolins give good coverage and low porosity thus improving silicone hold-out.
Silicone is applied to the release base paper through a curing process using a platinum catalyst. It is vital that the release base paper does not affect this process and mineral purity is extremely important to avoid "poisoning" this process. Capim clays guarantee high purity and chemistry ensuring compatibility with the platinum catalysts used in the siliconization process. Their specialised processing minimises any compounds that can adversely affect the silicone curing process that uses platinum catalysts.