Method and apparatus for recycling styrene resin

DETAILED DESCRIPTION Meanwhile, in the above recycling system, there are left in the solution obtained on dissolving expanded styrene or styrene cabinets insoluble impurities less than hundreds of microns in size, including water content, dust, animal oil, such as fish oil, inorganic particles, such as carbon black or dyestuffs, or other insoluble components, these insoluble impurities frequently detracting from the quality of the regenerated styrene.
For removing impurities from the solution containing high-molecular materials, metal mesh filters, bag filters of polyolefin or polyester fibers, or filter cloths, are routinely used.
Although solid impurities in the solution can be removed to some extent with these filters, sludges containing the moisture or animal oils, or inorganic pigments, such as carbon black, cannot at present be removed.
If the filter mesh size is refined, the rate of removal of solid impurities, such as sludges or colorants, is improved, however, if the solution is of high viscosity, the rate of percolation is lowered, while the filter clogging is significant, thus impracticably increasing the rate of filter exchange.
On the other hand, phosphorus pentoxide, potassium hydroxide, concentrated sulfuric acid, calcium sulfate anhydride, magnesium oxide, sodium hydroxide, calcium oxide, calcium salt anhydride or copper sulfate anhydride are known as chemical dehydrating agents for organic solvents.
Of these, molecular sieve, calcium sulfate anhydride and calcium chloride anhydride, are routinely used.
These dehydrators, known to exhibit dehydrating effects for organic solvents, are not sufficient in their effects in dehydration or removal of sludges or colorants in a solution of styrene or the like resin in the organic solvents.
It is therefore an object of the present invention to provide a processing method for efficiently and promptly removing insoluble impurities contained in a solution of a styrene resin waste material to enable recycling of high-quality regenerated styrene