Lubricants can either be used for process aids during compounding and extrusion or have utility post extrusion down stream. Traditional down stream applications are improved anti-blocking, improve processing, improved release, lubricating conversion processes, or controlled release over time.
Process aid lubricants for compounding and extrusion needs can vary significantly. This is why there are so many options in the market place. The first decision is between an internal lubricant and an external lubricant or process aid.
Generally, internal lubricants are additives that will affect melt flow of the polymer by better dispersing the filler, coupling additives with the resin, plasticizing the polymer chains themselves or by simply adding a lower viscosity material which dilutes the resin blend. The net effect will be lower torque, faster output and sometimes better mold flow. The drawback is that too much of these types of additives can reduce the physical properties of the resin and it will almost always reduce melt strength. Careful selection is critical. Traditional PA’s are polyethylene waxes, EBS, EBO.
An external lubricant or process aid is different in that it does not generally have much effect on melt flow. Instead, they will coat the surfaces of the process equipment and lubricate the bulk flow of the compound through the melt contact. This lubrication can also help with down stream equipment just after extrusion. The materials have to have relatively quick migration and some affinity to metals. They tend to build up as a microlayer on the contact areas and slough off and regenerate as it is being processed. The benefits are generally reduction of laminar flow in the extruder that improves process pressures and reduces gels and melt fracture. Downstream processes usually benefit from lubrication in a variety of ways as would be expected. Chemistries used for process lubricants are silicones, siloxanes, amides or other fatty acid directives, fluorinated oligomers and phosphate esters.
Trillium offers a variety of solutions in this area. We have listed only a few of the standard materials on this page. Please contact us so that we may be able to understand your goal and offer some guidance.
