Crosslinkers for the Paper Industry
MEL supply the Bacote®, ZirmelTM & XL ranges of formaldehyde-free insolubiliser, for pigmented paper and board coatings; offering unparalleled quality and consistency.
Insolubilisers are important additives used in pigmented paper and board coatings to impart the properties required to achieve the highest quality print.
Formaldehyde free and with FDA and BfR approvals they are the crosslinkers of choice at mills worldwide.
Bacote® consists of a clear, aqueous alkaline zirconium. There is a slight ammonia odour associated with Bacote®, and ammonia is released upon evaporation. There is no odour associated after curing.
Where an ammoniacal odour is considered undesirable, ZirmelTM is recommended. ZirmelTM consists of a clear, aqueous alkaline zirconium solution and offers all the benefits of Bacote®.
Bacote® and ZirmelTM products are all stable at ambient temperatures for a minimum of 12 months and can be used in the temperature range of 0-70ºC. The XL range of products gives a cost effective alternative to othe products.
Benefits for Coating Mills
As inorganic crosslinkers, Bacote®, ZirmelTM and XL are totally formaldehyde free.
Effective with all commonly used binders, Bacote®, ZirmelTM and XL react rapidly with binder funtionality as water is released in the drying section. No need for elevated temperatures or extended cure time.
Achieved by optimal water resistance, reduction of contact angle, uniform distribution of binders within the coating and open coating structure.
No adverse effects on optical properties - no time or heat exposure yellowing.
Approved under FDA and BfR regulations as a component of paper and paperboard in contact with aqueous and fatty foods.
Mode of Action
When added to a coating or size press formulation, Bacote®, ZirmelTM and XL interact weakly with oxygenated sites, mainly carboxyl or hydroxyl groups on the binder molecules. Removal of water and carbon dioxide during the drying stage drives the reaction to completion due to the generation of reactive zirconium cations.
Covalent bonds are formed and the reaction is irreversible under normal coating conditions. The reaction is not heat dependent. The dried coating will exhibit optimal water resistance but will remain hydrophilic in nature and the microporous structure of the coating surface will be "open" or unblocked.
Please contact us for further information about Bacote®, ZirmelTM and XL.