Zinc Stearate is obtained from stearic acid.
It is a fine, white, silky to the touch powder with the following properties:
Very stable under high temperature conditions Insoluble in water, alcohol and ethers.
Highly resistant to water, giving it repellent properties.
A very effective release agent.
It serves as a source of zinc, thus benefiting some processes.
The main areas of application are:
Zinc stearate is a vulcanization “activator” because zinc has a beneficial effect on the reaction of sulfur with polyolefin.
Zinc stearate facilitates dispersion because it is very soluble in the non-polar part of polyolefins.
It acts as an antacid with polyolefins, thus contributing to color stability and preventing corrosion.
It is used as a lubricant as well as a thickener and to hold the liquid and oily parts of the cosmetic together.
In addition, it improves the final appearance of the product. It usually appears in make-up formulations as well as eye lines, eyeshadows, mascaras, lipsticks, powders, and foundations.
Zinc stearate does not harden, flows very well, and adds a silky feel to the mixture.
It is an ideal release agent for difficult parts, whether made of metal or plastic. It helps parts not to stick to the mold, therefore improves the finish.
In its most refined form, zinc stearate has transparent properties and is therefore used in the manufacture of paints and varnishes.
It has great dispersibility and acts as a sealant for surface imperfections and as a thickener. In addition, it protects the paint from humidity due to its waterproofing properties.
Zinc stearate is mixed as a lubricating additive with metal powder. The proportion of the lubricants varies from 0.5% to 5.0% by weight.
In the press compaction stage, lubricants improve the flow and compressibility characteristics, while binders have the opposite effect. Different amounts of both additives influence the porosity and final properties of the material. Zinc stearate has the advantage over other lubricants of providing zinc to the alloy, which is beneficial in some processes.
Finally, the additives volatilize from the “green” part in the sintering furnace after compaction in the press.
Like other stearates it is used in the plastics industry:
In order to improve productivity in extrusion production and lamination of plastics and metals, calcium stearate is added. It acts as a solid additive as well as lubricant by adding 0.3-1.0% calcium stearate to the mix in the feed hopper. It remains stable at high temperatures as well as improves the following points in manufacturing;
ADPLAST® has tailor-made solutions capable of achieving excellent quality-performance ratios.