Aria Polymer slip additives, known as Aria Add®, have a variety of slip agent and anti-block additives, formulated for PE and PP films. These mastebatches can improve slip behavior and also lead to a positive effect on reducing blocking of polymeric layers. For various applications, Aria Add® s offer different performance, initial slip, and anti-blocking development. These additives are cost-effective and work well in small quantities without affecting odor nor the transparency of the product.
Inherently, polyolefin films have a very high Coefficient of Friction (COF) so polyolefin films tend to adhere to each other (film-to-film) and metal surfaces (film-to-metal) and it leads to problems during manufacture, processing and consumption.
There are several factors affecting the development of polymers friction, including:
– Polymer type (nature, polarity, crystallinity)
– Process (temperature, type, etc.)
– Film gauge & structure
– Additives present in formulation (anti-fog, anti-static, pigment, etc.)
In polymer processing, it is necessary to reduce the friction of polymer films to:
- Facilitate the production process
- Reduce waste
- Reduce machines friction
- Improve film surface quality
- Reduce adhesion to surfaces
Slip agents are fatty acid additives, mainly used to reduce coefficient of friction of polymers at the surface of polymer films. Following figure shows the action mechanism of slip agents:
When using slip agent, additives are uniformly distributed in the melted polymer, so they migrate to the outer surface after getting cool down, and form a partial layer; this is why friction drops after melt processing. Forming a complete layer of slip agents on the surface leads friction to reach its optimum status.
Slip behavior is measured in terms of static or kinetic (COF), which is a dimensionless coefficient representing slide resistance of the two surfaces in contact with each other. In general, COF values higher than 0.50 are considered to be low-slip surface, and on the other hand, values less than 0.20 are viewed as high-slip surfaces.
Another common challenge is film ‘blocking’. Anti-block agents are organic or mineral additives mainly used to reduce the adhesion of the polymer layers to each other.
Anti-blocks prevent films from stacking or sticking together and help them open more easily. They also prevent polymer-to-polymer contact by creating roughness on the film surface or by reducing surface friction coefficient.
It is important to note that slip-agent reduces shear between the surfaces and makes the surfaces slide smoothly on each other, while anti-block reduces the vertical force of the two levels and causes the two levels to open. Next schematic shows the difference between slip-agent and anti-block action.
There are various additives differing in terms of migration speed, final coefficient of friction and appearance properties of the finished product. Depending on its properties and expected characteristics, each polymer product requires a special additive to achieve the ultimate quality.
We have formulated Aria Add® 2124, Aria Add® 2125, Aria Add® 2126 and Aria Add® 2136 for polyethylene based products. These grades differ in terms of friction speed and improved anti-block property; they also cause no change in transparency, nor in odor.
- Aria Add® 2124 is suitable for multilayer films, has high friction coefficient, yet more transparency.
- Aria Add® 2125 has less final coefficient of friction, better anti-blocking performance, much heat and color stability, higher organoleptic terms and less volatility.
- Aria Add® 2126 achieves the desired friction in less time
- Aria add® 2136 can smooth polymer products simultaneously with anti-blocking properties without altering the smell or appearance of the product.
On the other hand, Aria Add® 2226 and 2227 are specifically formulated for polypropylene based products. These grades can reduce coefficient of friction and blocking force, without changing product’s haze and gloss.
- Aria Add® 2227 improves softness of the manufactured product.
- Aria Add® 2226 is extremely beneficial in injection molding processing, since during the process, these additives migrate to the surface of products, and result in faster and more uniform A better surface and also reduction of pin marking effects are other benefits of using Aria Add® 2226.