esins such as high-density polyethylene (HDPE) are inherently capable of being manufactured into highly capable products. With minor alterations to the chemical composition of the mixture through additives, manufacturers can enhance the performance of the material in certain areas to meet more stringent project demands. While additives can bring new capabilities to plastic products such as geosynthetics, some additives can migrate out over time, causing the products to lose those benefits. For this reason, manufacturers should consider the qualities of the chosen resin first.
This article describes the purpose of additives in plastics, how the performance of plastic products can be improved through a materials-first policy and ways manufacturers have leveraged the benefits of coextrusion to min-max the benefits of certain additives.

Some additives, including plasticizers, can migrate out of the product with long-term exposure — eventually causing the product to lose the benefits derived from the additives. Fortunately, installers have many options when it comes to geosynthetics. While PVC may be the material of choice in some applications, it can be better to choose a material that offers innate physical and chemical characteristics that match the desired specifications.
Material-first manufacturing aims to achieve performance through resin selection, with additives serving to augment rather than supplant material qualities (see figure 2). In some applications, it also makes sense to go beyond polyolefins and consider semi-fluorinated and fluorinated polymers. These materials can enable manufacturers to create products with improved chemical and thermal resistance with minimal use of additives, which is especially important for high-purity applications.
Of course, there will be situations where additional capabilities will be required to fulfill project requirements. In these cases, manufacturers can turn to coextrusion.


