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📷 | Hiroshima / Motoujina Beach Photographer who keeps picking up garbage Marine plastic garbage World's challenges


Hiroshima / Motoujina Beach Photographer who keeps picking up garbage Marine plastic garbage World's challenges

If you write the contents roughly
"There are still few plastic pipes (derived from oyster farming) and styrofoam today.

Marine plastic trash is a problem all over the world, but a local photographer who keeps picking up trash on the coast of Hiroshima City ... → Continue reading

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Wikipedia related words

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Derived from oyster farming


Styrofoam(Happo Styrene, foamed styrol)Synthetic resinA type of materialBubblesWas includedpolystyrene(PS).Foam plasticA kind of.なお、スチロールとはWhat is styrene?styreneIs another name for.また、発泡スチロールの98パーセントはAlso, XNUMX% of Styrofoam空 気.

As another nameExpanded polystyrene (foamed polystyrene),Styrofoam (foamed styrene),Polystyrene foam (polystyrene foam),Styrene foam (Styrene foam),Styrofoam There is (styrofoam). 「スタイロフォーム」は"Styrofoam"RiceDow ChemicalExtruded polystyrene (XPS)Trademark nameBut America,カナダThen, the word that refers to Styrofoam in general (Standardization of trademark) Has become[1].


It is a material obtained by foaming and curing polystyrene with fine bubbles.Lightweight and excellent in heat insulation, extremely easy to mold and cut, inexpensive, elastic and excellent in shock absorption, so it is a cushioning / packing material for fragile items (→包装-Cushioning material), Which requires heat and cold insulation by utilizing heat insulationInsulationUsed for[2].

PolystyrenehydrocarbonSo when you burn itWedとcarbon dioxidebecome.しかしHoweverNormal temperature-atmosphereWhen burned inside, incomplete combustion occurs and a large amount煤Is easy to generate.


There are three types of manufacturing methods, which are chemically the same, but have different shapes and bubble characteristics, so they have different uses.

  • Expanded polystyrene (EPS)
  • Polystyrene paper (PSP)
  • Extruded polystyrene (XPS)

Since EPS was first developed and is used for the widest range of purposes, EPS is sometimes referred to as "Styrofoam in a narrow sense", and it is also referred to as "Styrofoam in a broad sense" including other PSPs and XPS. ..However, these are all "expanded polystyrene" because they differ only in the manufacturing method.

Sometimes it just can't be recycled together due to the additives added to add performance, or it's a similar looking but foamed material from another synthetic resin.Foamed polypropyleneBecause there isRecyclingAttention should be paid to the above division (Later).


On the contrary, the low heat resistance enhances workability,Electric heatingOn the lineDry cellfrom電流Was generated by flowingheat(Joule heat) Is used to cut with a small force, and there are various types.HandicraftFor or short-term exhibition彫刻It is also used as a material for (promotional POP, etc.).

Adhesives that use organic solvents can be bonded by heat, but adhesives that use organic solvents dissolve easily and most of the volume is gas, which makes them look like they have been eroded. Not suitable for use.For the same reasonMagic inkOily such aspaintYou can't even paint with.Dedicated adhesive that does not contain organic solvent, or adhesive that does not use organic solvent such as for woodworking between large areasadhesiveIs used.

PorouswoodSince the properties are very similar to those of (but not permeable), water-soluble paints can be used for painting because the pigments are relatively easy to get on as long as they have a certain viscosity.塗装の際には表面をWhen painting, the surfacesand paperRoughening with such means is also performed to improve the adhesion of the paint.1980 eraThe water-soluble resin paints that have become popular since then are familiar.note thatTermiteEasier to eat than wood[4].

Since it does not completely block light, it is necessary to add a colorant etc. when light blocking property is required.[2].

Styrofoam bubbles are sealed inside,glass woolThe sound absorption effect due to the viscosity of air seen in porous substances such as is not expected at all.


It is the oldest Styrofoam material, and it is used for various purposes and is a material that is often seen in general.When broken, small particles appear to gather and solidify, each of which is a foam of small polystyrene particles called "beads".

Manufacturing method

Expanded polystyrene (EPS) is made of polystyrene, mainlybutane-PentaneSuch ashydrocarbongasManufactured by foaming in.具体的には、直径1mm程度の細粒状ポリスチレンであるポリスチレンSpecifically, polystyrene, which is a fine granular polystyrene with a diameter of about XNUMX mm.beadsAbsorbs hydrocarbon gas to 100℃Higher temperaturevaporTo soften the resin and apply pressure to foam it.The foamed beads fuse with each other and form various shapes when cooled to form Styrofoam.


1950ToGermanyWas invented inJapanThen.1959More production has begun.


Polystyrene has a heat resistant temperature of about 80 to 90 ° C, so if it is heated further, it will soften and melt.ほとんどのEPSは、発泡時にMost EPS when foamingMoldIt is heated inside and processed into a final product or a general-purpose plate material.

Because it is soft and easily melts with heat, general-purpose products areCutlery,Heating wireIt is cut with and processed into any shape.A cutter dedicated to Styrofoam processing with a heating wire at the tip is also commercially available.

There are also products that are made by foaming beads but not molding or cutting at all, and are also called polystyrene beads.


Because it has excellent heat insulation and water resistance and is lightweight,seafood(Later someAgricultural productsBoxes manufactured with this for shipping (also)Toro box) Was used, and because it is lightweight and has excellent shock absorption, it has become popular as a packaging material for precision machinery.In Japan, nearly 20 tons are produced annually, the majority to 6% of which is used as containers, 3% is used as cushioning material, and the rest is floats in building materials and the sea.buoy,Fish cageIt is used for floating) etc.

Since it can be integrally molded into the desired shape, it has a predetermined shape such as a cushioning material or a heat / cold box.ProductIs processed into.

It has excellent heat insulation, is easy to process, and has high water resistance.Cooler boxThere are products that use this material between the inner and outer surfaces, and there is also a cooler box that is made by compressing and shaping Styrofoam itself as an inexpensive product.

The foamed polystyrene beads are packed in a cloth bag or the like as an inexpensive cushioning material.cushionSuch asFurnitureIt is used as a packing material for filling () or for transporting precision equipment.

Equipment that requires weight reduction because it is easy to process, lightweight, and has a certain level of strength.Monocoque structureIt is also used as a structural material for.例えばFor exampletoyButAerosoaraModel airplane (orRadio controlIt may also be used for airplanes).

in recent yearsLightweight embankmentIt is also used in civil engineering as a material,20098 OfSuruga Bay EarthquakeOccurred inTomei ExpresswayIt was adopted for disaster recovery.


Polystyrene paper (PSP) is not heated and foamed with high-temperature steam like EPS, but it is made by adding a gas or foaming agent for foaming to the raw material melted by applying heat, and the thickness is about several millimeters from the liquid. It is stretched into a sheet and foamed at the same time.The foaming rate is about 10 times.

Food trayAndCup NoodleUsed for containers.To process it into food trays, etc., cut it into the required size and press it with a mold while heating to shape it.

As mentioned above, it is easily dissolved in some edible oils and has low heat resistance. Therefore, when it comes into contact with high-temperature oil, it melts due to heat, and the bubble structure collapses and erodes.このとき、泡内のAt this time, in the bubblebutane,PentaneIs released to the outside air, but due to the impurities contained in these, it has a peculiar odor commonly referred to as "Styrofoam odor".この臭気はThis odorappetiteIt becomes a problem in food containers because it reduces the amount of food.なおポリスチレンは一切No polystyreneDigestion / absorptionOutside the body withoutexcretionTherefore, it is said that there is no health problem even if you eat the melted resin.

Many cup noodle containers have a sheet made of another synthetic resin material adhered to the surface in order to increase strength and heat resistance.PVCBy adhering a protective sheet made of resin such as polypropylene or polypropylene, impact resistance is increased (cup noodles do not damage the cup even if dropped during transportation), so large containers and products that are expected to be severely transported. Widely used in containers.接着前にシートにOn the sheet before gluingPrintMany cup noodles have various designs so that they will be noticeable when they are lined up in stores.


Extruded polystyrene (XPS) is primarilyBuilding materialsIt is a hard and flame-retardant Styrofoam used in Japan.Since it is a building material, it is difficult for the general public to see,Energy ConservationIt was modernized from the viewpoint of住宅 OfInsulationIt is often used under roofing materials and under outer walls.

The flammability of Styrofoam is fatal as a building material, soFlame retardantsThe flame retardancy is improved by such means.When EPS is also used as a building material, a flame retardant is added in the same way.

The liquefied raw material, foaming agent, and flame retardant are mixed well under high temperature and high pressure, and blown out to an environment of normal atmospheric pressure and temperature to continuously foam and cure, and this is the required size (approximately 2 m in height). Cut into a plate with a width of 1 m and a thickness of 10 cm).Because of this continuous manufacturing method, it is called an "extruded board".Due to the manufacturing method, many of them have larger bubbles than EPS.It has a certain degree of flame retardancy and may be colored with light blue to distinguish it from general Styrofoam.


Styrofoam, Styrofoam (STYROFOAM), StylofoumDow ChemicalBy XPSRegistered trademark.

Sometimes used as a general noun for XPS, or more often as a synonym for Styrofoam, but not appropriate.

Environmental hormones

Polystyrene is the main raw material for Styrofoam, but styrene is contained in trace amounts.DimerAnd styreneTrimmerBut in Japan1998In addition, the Environment Agency (currentlyMinistry of the Environment)SPEED '98(Ministry of the Environment related page)soEndocrine disruptorIt was listed as a suspected substance (commonly known as an "environmental hormone").そのため、従来はTherefore, conventionallyFinal disposal siteStyrofoam, which had been landfilled in Japan, was suspected to be one of the causes of environmental pollution.業界団体からの反発を受け、環境省はIn response to the backlash from industry groups, the Ministry of the Environment2000In November, I removed styrene dimers and styrene trimmers from this list.

Disposal and recycling

garbageAs a result, bulkiness for the weight has become a problem due to soaring disposal costs.また、衝撃を受けた場合に細かい破片を撒き散らすためにAlso, to disperse small debris in the event of an impactMarine litterThe harm as is also great.

In response to this in developed countries, manufacturing industry groups of the same material and major companies that sold a large amount of these productsDepartment store-supermarketEtc., as a resourceRecyclingIn recent years, Styrofoam recovered after use is reprocessed with a solvent or high heat and recycled as a resource or used as a fuel.In Japan, there is an active movement to collect food tray collection boxes from consumers in department stores and supermarkets.

With solventLimoneneEtc.citrusA product was developed using a product that can be collected from Styrofoam, and in a small facility, Styrofoam is dissolved and liquefied, significantly reducing the waste volume and the dissolved product.boilerIt is used as a fuel for such things.In addition, the reprocessing plant by heating requires a certain amount of large-scale equipment, but it is returned to polystyrene beads and used as a raw material for another Styrofoam product, or a raw material for plastic products that does not require much strength or heat resistance. ..

Styrofoam recycled plastic,Videotape cassette,文 房 具(Ballpoint pen shafts, etc.) are produced.

On the other hand, in the past, when burned, it burned too well at high temperatures, soIncineratorAs it hurtMunicipalitiesIt was treated as a nuisance at the garbage disposal facility in Japan, but in recent yearsDioxinHigh temperature type as a countermeasureIncineratorIs widespread, andRDFInstallation of power generation facilities is underway, and it is abolished to increase the burning power of garbage.PlasticAnd waste styrofoam are often mixed.

EPS, PSP, and XPS are the same polystyrene as chemical substances, so they can be recycled on the same line.However, since the packing material for EPS, which accounts for most of the recovered amount, is high-purity polyethylene, there is a big problem such as quality deterioration when impurities are mixed.Complex printed items such as cup noodle containers are often excluded from collection because sheets made of different materials are adhered to the surface.Those with a direct surface coating may also be excluded.Naturally, food cannot be recycled with it attached, and it may give off a foul odor or attract pests during the collection process, so it should be washed well and discharged.

In home appliances, cushioning materials using recycled paper are being replaced to protect the environment.Products used as sea floats and floats are easily worn by waves, and the problem is that separated small pieces float on the sea.

It has been reported that Styrofoam is thermoplastic and has adhesiveness when heat is applied, so it can be used as an adhesive for wood.発泡スチロールを接着剤としたStyrofoam was used as an adhesivePlywoodとParticle boardHas sufficient strength, and the latter can be remolded by simply heating it after molding by mixing 20% ​​or more of Styrofoam.さらに廃棄の際も600℃程度の温度で焼けば、発泡スチロールは分解してしまい、炭化した木材だけが得られるというFurthermore, when disposing of wood, if it is baked at a temperature of about XNUMX ° C, Styrofoam will decompose and only carbonized wood will be obtained.[5].

Foamed polypropylene

Processed by the same manufacturing method as StyrofoampolypropyleneAnd, in terms of chemical structure, polystyrenePhenyl group Methyl groupHas been replaced by.

Used for similar purposes as Styrofoam,Heat-resistant-Oil resistanceExcellent for. It can withstand up to 90 ° C compared to 130 ° C of PSP.

It looks very similar to Styrofoam and is often confused.It is often mixed into polystyrene recycling lines.Separation is possible because it is insoluble in polystyrene solvent,Resin identification codeIt is desirable to separate and collect by looking at.


EPP (expanded polypropylene) is polypropylene processed by the same manufacturing method as EPS.

Since it is more elastic than EPS, it is preferred as a work material.The foaming rate is standardized to 15 times, 30 times, 45 times, and 60 times.


PPP (polypropylene paper) is polypropylene processed by the same manufacturing method as PSP.

Convenience storeBox lunchIt is,microwaveHeat-resistant PPP is often used for the container because the temperature of the oil may exceed 100 degrees when heated with.However, lunch boxes with a lot of oil have insufficient heat resistance even with PPP.PolycarbonateMade of containers may be used.

Like the PSP container, a sheet made of other synthetic resin material may be adhered to the surface.


[How to use footnotes]
  1. ^ Its Not A Cup
  2. ^ a b c Japan Broadcasting Corporation. “"Wishing for a day when it will no longer be used" Thoughts in a small black box". NHK News. 2021/7/22Browse.
  3. ^ Insulation building again Fire-flammable materials become building materials for insulation New Tang Dynasty Broadcast on November 2010, 11
  4. ^ Tokyo University of Agriculture Termite feeding damage test report of heat insulating material
  5. ^ Kiyoharu Fukuda, Shinji Kashiwai, Yoji Tominaga, Masayo Omi. 2001. Reuse of Styrofoam waste as an adhesive for wood materials. Wood Industry Vol56. No10. 458 -463

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