Recycled resin content

The bulk density of the feedstock at ambient temperature and pressure should be measured prior to the design of a new screw, especially if it contains in-plant recycle resin. The measurement method is extremely simple and requires only a calibrated cell and a scale. A calibrated measuring cell with a volume of 500 cm can easily be constructed by welding a thin-walled metal pipe to a flat sheet of metal, as shown in Fig. 4.2. The bulk density is measured by filling the cell with feedstock, leveling the top with a steel ruler, and then weighing the cell contents. A more formal measurement technique was developed by ASTM as standard method D1895. 

IBM has been coding plastic components to promote their recyclability since 1992, when it became the first computer manufacturer to do so. Computer and business equipment companies are also increasing their use of recycled-content resins in production. For example, Kobe Steel Ltd., announced in 1998 that it had developed a practical sandwich technique for applying virgin resin to a core of recovered plastic, which allows increased use of recycled resin. They plan to market the technology to manufacturers of office machines, home electronics, and toiletries. The Japanese unit of IBM is manufacturing some personal computers with about 20% recycled plastic from older IBM PCs. ... 

The North American markets for recycled resins are in no way subsidized by industry, government or the public and as a result, recycled resins must compete in price amongst themselves as well as compete with virgin resins in an open market. As will be discussed later several local attempts have been made by state governments to promote the use of recycled content in products by legislation but these have had little effect outside of the unique jurisdiction. 

A different strategy was adopted by Ford. The company recycles the PC/PBT Xenoy alloy bumpers (afer removing 99.7% of paint) into tail light assemblies. Alternatively, by adding 25 wt% of the recycled material to virgin resin, it is used to mold bumpers, guide brackets, etc. In 1996, the company used 17.5 kton, or 17%, of post-consumer recycled resin. The recyclates content is to grow steadily to 50% in the year 2000 [19]. 

Phenolics are consumed at roughly half the volume of PVC, and all other plastics are consumed in low volume quantities, mosdy in single apphcation niches, unlike workhorse resins such as PVC, phenoHc, urea—melamine, and polyurethane. More expensive engineering resins have a very limited role in the building materials sector except where specific value-added properties for a premium are justified. Except for the potential role of recycled engineering plastics in certain appHcations, the competitive nature of this market and the emphasis placed on end use economics indicates that commodity plastics will continue to dominate in consumption. The apphcation content of each resin type is noted in Table 2. Comparative prices can be seen in Table 5. The most dynamic growth among important sector resins has been seen with phenoHc, acryUc, polyurethane, LLDPE/LDPE, PVC, and polystyrene. 

Traditionally carpet tile backings have been made from bitumen, PVC or polyurethane. There are problems with the environmental impact of these materials and they are difficult to recycle. Shaw industries developed their EcoWorx carpet tile backing using a polyolefin resin. This has superior environmental profile to PVC and is easier to recycle than bitumen and the cross-linked polyurethane backings. EcoWorx has lower toxicity, better adhesion and good dimensional stability. It is easy to recycle and can be separated from any fibre type used in the carpet tile. It works particularly well with nylon-6 fibres. EcoWorx tiles contain 40% recycled content and Shaw have established a collection and return scheme to close the loop. 

Contaminants in recycled plastic packaging waste (HDPE, PP) were identified by MAE followed by GC-MS analysis [290]. Fragrance and flavour constituents from first usage were detected. Recycled material also contained aliphatic hydrocarbons, branched alkanes and alkenes, which are also found in virgin resins at similar concentration levels. Moreover, aromatic hydrocarbons, probably derived from additives, were found. Postconsumer PET was also analysed by Soxhlet extraction and GC-MS most of the extracted compounds (30) were thermally degraded products of additives and polymers, whereas only a few derived from the original contents... 

Raman is simple to use and require virtually no sample preparation. The vibrational spectra of polymer samples in their original forms can be measured and casting or hotpressing of the material into thin films (commonly used for FTIR measurements), a very time-consuming procedure that can affect the original structure of the material, are not required. It also offers remote analysis capabilities if combined with fibre optics [108, 109]. Accurate determination of contaminant content in recycled polymeric resins have been reported in the literature [110, 111, 112]. 

Steam fed to the vessel jacket maintains the contents at 90°C. At this temperature, the reaction proceeds to completion and essentially all of the carbon dioxide formed in the reaction between HCI and NaHC03 is driven out of the aqueous phase. The CO leaving the resin neutralizer is recycled to the waste liquor neutralizer (Step 8). 

PET is useful polymer used for fiber, film, and plastic containers such as carbonated beverage bottles. Recently, the recycling of polymers such as PET after use is attracting the attention of many researchers aware of environmental problems and wishing to find ways to save earth resources. Previous studies showed that unsaturated polyester resins can be economically prepared from recycled PET and the resins may be useful for resin concretes (1 4). However, there is little information on the molecular features of the UPE resins. Thus, we synthesized various UPE resins from PET. Especially, the PET content, chain flexibility and degree of unsaturation of the resins were systematically varied and the effects of those variables on the mechanical properties of the cured resins and polymer mortars made therefrom were studied. 

Various UPE resins based on recycled poly ethylene terephthalate(PET) were prepared and the properties of the polymer mortar made with the UPE as well as those of the cured resin itself were investigated. It was found that degree of unsaturation of the resins was the most important property affecting thermal and mechanical properties of the cured resin and PM. The cured unsaturated polyester resin or polymer mortar made from resins of higher unsaturation, i.e., less PET content or adipic acid content in the resin, showed higher glass transition temperatures,... 

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