Volume reducing agents for expanded polystyrene, methods and apparatus for processing expanded polystyrene using the same

Abstract

A volume reducing agent for processing polystyrene, containing 65-97 wt % of a first plasticizer having a solubility parameter less than the solubility parameter of the polystyrene; and 3-35 wt % of a second plasticizer having a solubility parameter higher than the solubility parameter of the polystyrene. The volume reducing agent is in liquid state, has a Ferdor solubility parameter close to that of polystyrene to be processed in the mixed state and transfers the resulting materials having reduced volume into gel-type products to be floated and easily separated.

Description

[0001] 1. Field of the Invention[0002] The present invention relates to a volume reducing agent for expanded polystyrene (EPS), methods and apparatus for processing expanded polystyrene using a volume reducing agent to reduce the volume of EPS known as bulky waste, as well as to recycle used EPS and recover high quality polystyrene.[0003] 2. Description of the Related Art[0004] Expanded polystyrene, also known as foamed styrene, has excellent thermal-protective or insulating properties and buffering effects. Expanded polystyrene is used throughout the world for a variety of different purposes including, for example, but not limited to transport packaging boxes for sea foods and shock-absorbing packing materials contained in package for home appliances.[0005] EPS product is generally bulky, potentially causing disposal problems. For example, burning disposal of EPS generates a substantial amount, interfering with operation of a combustion furnace, and also has the problem of producin...

AI Technical Summary

Benefits of technology

[0008] Accordingly, an object of the present invention is to provide a safe and effective method for volume reducing of EPS and to raise recycling capability thereof.

[0009] According to one aspect of the present invention, there is provided a volume reducing agent for processing polystyrene, containing a first plasticizer having a solubility parameter less than the solubility parameter of the polystyrene; and a second plasticizer having a solubility parameter higher than the solubility parameter of the polystyrene, wherein the agent is in liquid state, has the solubility parameter in the mixed state close to that of polystyrene to be processed, and transfers the resulting materials having reduced volume into gel-type products to be floated and easily separated.

[0010] According to another aspect of the present invention, there is provided a method for processing expanded polystyrene comprising the steps of: preparing a volume reducing agent, the volume reducing agent containing a first plasticizer having a solubility parameter less than the solubility parameter of the polystyrene; and a second plasticizer having a solubility parameter higher than the solubility parameter of the polystyrene, wherein the agent in the mixed state is in liquid state, has the solubility parameter close to that of polystyrene to be processed and transfers the resulting materials having reduced volume into gel-type products to be floated and easily separated; dipping in the volume reducing agent an expanded polystyrene which is crushed and is in a status having a specific shape or nonspecific shape to thereby reduce the volume of the expanded polystyrene; and dipping the volume-reduced expanded polystyrene in a neutralization solution to thereby obtain recycled polystyrene material.

[0020] Also, the present invention relates a method for processing the EPS which is to be re-used, the method comprising permeating (or infiltrating) EPS materials in shape or shapeless states prepared by preliminary crushing treatment into the volume-reducing agent, then soaking the result product into neutralizing solution (or counteragent solution) to obtain the re-usable polystyrene product which can be easily changed into virgin polystyrene.

[0041] In the neutralization vessel 7 filled with counter agent 15 (neutralizing solution) processed EPS 1 is infiltrated into the neutralizing solution 15. Such solution, for example, a water solution containing 0.01% chlorine or 0.1% hydrogen peroxide prevents the further promotion of gelling or plasticizing reaction of EPS I already reduced in volume and enables the EPS 1 to be solidified.

Problems solved by technology

EPS product is generally bulky, potentially causing disposal problems.

For example, burning disposal of EPS generates a substantial amount, interfering with operation of a combustion furnace, and also has the problem of producing harmful gases.

An additional problem of EPS having bulky property (or voluminous nature) is that there is a high vehicular transportation cost.

However, such a plant must be run on a large scale and there are known potential environmental problems deriving from the resulting liquid product.

However, limonene has very low ignition point of 48.degree. C. and is toxic and has an irritating odor, all of which are undesirable properties.

As a result, limonene is considered an undesirable compound to be used within disposal plant with respect to safety and environmental concerns.

Images