The Plastics Industry is changing continuously, getting renewed day after day. The multiple applications under development are ever increasing in novelty and amazement.

There are different transformation processes and raw material requirements in this industry. The additives are organic or inorganic materials which, incorporated to the plastics, before or during their transformation, modify their properties: Improving their presentation, extending their useful life, blocking the attack of physical-chemical factors, and creating new applications. These additives are classified into two main categories: Process additives and functional additives.

The process additives comprise thermal stabilizers, anti-oxidation agents, sliding agents, flow modifiers, viscosity modifiers and lubricants. Waxes play a very important role in the lubrication of plastic materials

Lubricants are widely utilized in the plastic transformation processes, such as injection, extrusion, blowing and others. Their functions include minimization of the heat generated by friction between the polymer and the spindle, viscosity reduction, and avoidance of sticking of the melted mass with the spindle. They are classified as internal lubricants, external lubricants and internal-external lubricants

The action of internal lubricants takes place in the resin molecules, when the material is still melt. They are compatible with the work polymer and they act also as flow promoters. Within this group are the alcohols, esters, fatty acids and amides from fatty acids with a relatively short chain, 14 to 18 carbon atoms.

The external lubricants are utilized mostly in materials like PVC. They have the characteristic of being incompatible with the polymer, so when they are combined with the material and charged to the feeding bin, a surface layer that separates the molten plastic from the equipment metal is created, thus avoiding an excessive friction in the work material. The following waxes are classified within the external lubricants category:

Paraffin Waxes.- They slow down the melting process and reduce viscosity during the initial melting. They have molecular weights of 400-1,000, mainly with straight chain structures and, to a minor extent, some ramified structures; their softening point varies between 147 °F and 162 °F. These lubricants are mostly utilized in the fabrication of tubes and PVC sections.

Polyethylene Waxes.- They can be found in their oxidized and non-oxidized forms. They are synthetic waxes with a molecular weight of 2,000-8,000, with a slightly ramified structure, and with typical melting points of 203 °F to 266 °F. These waxes show a better behavior at high temperatures, enabling to cover the deficiency interval for the lubricants elaborated from paraffin waxes. The polyethylene waxes are widely used in the fabrication of rigid PVC piping and in the plastic molding by injection.

Multiceras has developed a wide experience in the formulation of waxes for the Plastics Industry, offering a product line with an excellent proven performance. The company’s R & D department works in the formulation of new products, in accordance with the specific needs of its customers.

Application Table for the Plastics Industry

Notes:
Melting point is determined by the ASTM D36 method for 1038 wax, by the USP 741 Class II method for 9011 wax, and by the ASTM D127 method for 9060 wax. Color is determined in all cases by the ASTM D1500 method.