Polystyrene

Polystyrene is a thermoplastic resin that is easily processed. As such it is used in many applications such as disposables, packaging, toys, construction, electronics and housewares. There are also different grades of polystyrene resins. General-purpose (also referred to as crystal or straight) resin is sold in three common grades: high-heat, medium-flow and high-flow grades. High-impact resin is sold in high and medium grades, an environmental stress crack–resistant grade and ignition-resistant and high-gloss grades.

These resins are formed into intermediates and/or final products via processes such as injection molding, extrusion and thermoforming. Extruded resins are in the majority, consumed in sheet production that is sold as sheet stock or used internally by the sheet producer in thermoforming. In thermoforming applications, a large amount of resin is recycled as scrap. Foam molding and extrusion of resins use blowing agents such as pentane, butane and hydrochlorofluorocarbons (HCFCs).

Polystyrene manufacturers have been adjusting their approaches to a challenging world landscape over the last ten years. After years of subpar performance, in the way of eroding margins compressed by rising crude prices and tightening global feedstock supplies, the polystyrene business instituted significant price increases for resins prior to the recession, which compounded results by severely reducing sales volumes. During this period polystyrene producers were encountering price increase resistance, exacerbated by polystyrene's higher-density penalty associated with fabrication. Thus, many converters switched their polystyrene fabrications to lower-cost and lower-density resins, such as polypropylene. This has led to erosion in some of the traditional large-volume applications, particularly in general-purpose and high-impact resins. In addition to intermaterial displacement, loss of market volume has been further compounded by the move of some domestic polystyrene converters to lower-cost countries, enabling them to gain a foothold in some injection-molding applications.

The following pie chart shows world consumption of polystryrene:

Asia is the overall leader in production and consumption of polystyrene, with 53% of total world production and 47% of total consumption of polystyrene in 2010. North America and Western Europe follow distantly at about 17–19% of the total production and consumption each.

Another dynamic of the global market has been the slow erosion of the domestic markets of mature countries and regions such as North America, Europe and northeast Asia (excluding China). In the United States, expandable polystyrene (EPS) in particular has been hard hit with the influx of lower-cost imported resins. Through the recession, the percentage of imports of EPS resin relative to consumption rose from 40% to 44% over 2007 through 2010. As a result, domestic EPS manufacturers saw operating rates fall from 99% in 2006 to below 80% at the depths of the recession, severely impairing return on production assets, as demand for EPS actually held up fairly well in favored applications during the recession. Similar effects were also seen in Western European markets. A critical question is—will domestic converters continue to import resin or as local prices decline, will it be more favorable to buy domestic?

Asian consumption of all types of polystyrene is forecast to increase at an average annual rate of slightly over 3% during 2010–2015, slowed by less than 1% annual growth in the developed countries of northeast Asia, while North American demand is expected to decrease 0.5% and Western Europe will show only modest growth of 1.6% over the next five years.

Table of Contents