Recycled plastic lumber applications

There are numerous applications for recycled plastics (Table 9.1) [124], From reuse in the same application as initially used (whether at 100% or more commonly compounded at some lower quantity), to being used in less demanding applications, recycled plastics utilization has made dramatic inroads in many industries. The manufacture of plastic lumber, however, exists almost solely because of recycling. Plastic lumber does not age or splinter as does real wood but its cost to manufacture is sig-... 

As a structural element to support paneling and wall mounts, there is growing interest in the use of plastic lumber produced using the recycled scrap or waste of polyethylene (HDPE), polypropylene, and PET materials from various packaging and other high turnover applications... 

The major market for recycled film in the U.S. in 2011 was the manufacture of plastic lumber, 55% of the total. Film and sheet applications totaled 16%, with various other applications comprising the remaining 29%. The export market is also very important, accounting for over 40% of the total recycled film [13]. 

A major use of recycled LDPE and LLDPE is in the manufacture of trash bags. Some is also used in the manufacture of merchandise bags. A use of growing importance is, mixed with wood fibers, plastic lumber for applications such as window frames. 

As mentioned, one application for recycled commingled plastics is in plastic lumber. The plastic lumber business has grown rapidly in the last five years. Not aU plastic lumber is made using recycled plastics, but much of it is. Some companies using recycled plastics for plastic lumber use mixed plastics, and others use relatively pure streams of material. Some use primarily postconsumer materials, while others use mostly industrial scrap. 

Secondary recycling is the recycle of plastic resins into new products with less demanding physical and chemical characteristics than the original application. Mixed plastics are applied most easily in the secondary recycling market because less separation of resin types and less complicated production methods are necessary to achieve a finished product. The most readily recognized secondary plastic product is "plastic lumber" (thick extrusion molded slabs of resin in which some types of resins act as fillers). Plastic lumber is used to make park benches, fence posts, boat docks, playground equipment and the like. The fabrication of mixed plastic lumber is discussed in Part II of the book. 

A major market for recycled plastic film and bags is the manufacture of trash bags. Recycled plastic has also been used in the manufacture of new bags, bubble wrap, plastic lumber, housewares, and other applications. 

The majority of recycled plastic is PET (or PETE) or HDPE. PET is used for bottles of soda pop and other beverages. Recycled PET can be remolded for strapping materials and fibers for clothing or carpeting. HDPE is most commonly used for plastic milk jug containers. HDPE can be used as a plastic material in plastic pipe, bottle, and lumber applications. 

Jacob Liedner I referred to it in my Separation lecture. However, the most important is to find the right applications for the recycled plastic waste. Here, imagination is necessary. For example, some years ago in Canada, two companies produced plastic lumber . One sold it as a substitute for wood and went broke, the other marketed it as a material for transport containers that can be steam-cleanable and made profit. 

Restabilization must be achieved as the end-products of processing of the recyclates are in outdoor applications, such as non-pressure pipes, cable ducts, waste bins, crates, bottles, drums, pallets, playground material, plastic lumber, etc. 

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