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Polyethylene Terephthalate PET Video 4 pptx

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P-e-t which stands for polythene triethylate is a clear strong and lightweight plastic belonging to the polyester family it is typically called polyester when used for fiber or fabrics in p-e-t or p-e-t resin when used for bottles jars containers and packaging applications p-e-t is the world packaging choice for many foods and beverages because of this hygienic

Strong lightweight shatterproof and for change freshness it is most commonly used to package carbonated soft drinks and water consumers can identify p-e-t containers by the triangular number one resin identification code found on the bottom of pet bottles and jars let’s take a look into into how pet is made the basic building blocks of pet are ethylene glycol and

Pterophalic acid which are combined to form pellets of pet this raisin pellets are then heated to a molten liquid that can be easily extruded or molded into items of practical practically any shape more specifically when the two raw materials of pet are combined under high temperatures and low vacuum pressure long chains of polymer are formed as the mixture becomes

Thicker the chains grow longer once the appropriate chain length is achieved the reaction is stopped the resulting spaghetti-like strands of p-e-t are then extruded quickly cooled and cut into small pellets now let’s take a look into how pet bottles are manufactured after cutting the raisin into small pellets the pellets are sent to the bottling manufacturer the

Bottle plant mixes p-e-t resin pellets into re-grind recycled plastics that has been reduced to flakes plastic loses some of this physical properties when repeatedly heated so manufacturers must limit the amount of regrind they use typically capping this ingredient at 10 percent of the total mix unless producing clear bottles dyes are introduced to the mix as well

When building a preform an extruder melts the p-e-t and re-grinds mixed at temperatures of about 500 degrees fahrenheit a screw inside the extruder compresses the p-e-t mix and injects the nearly molten material into moles the mole produces a bottle preform which is sometimes called a prism the preform looks like a thick wall test tube often including the bottles

Characteristics screw top the preform cools as it travels to a machine called a blow molder and may need to be brought back up to the manufacturer’s specific temperature for that operation if necessary the bottle manufacturer raises the temperature of the preform in a small oven for stretching the preform the preform enters a two-part mole that closes around it

The inside of this mole is shaped exactly like the finished bottle inside a long needle pushes up through the pre-form which is suspended with the screw in facing downward the needle stretches the preform upward towards the top of the mold which will be the bottom of the bottle and simultaneously blasts enough pressure air into the preform to force it against the

Size of the mold this stretches the blow molding process must happen quickly in order to maintain the bottles integrity in consistent shape some manufacturers weld a separate bottom piece to the bottle during the blow molding while other produces a bottom from the preform along with the rest of the bottle for cooling and trimming the bottle must be cool almost

Instantly or it will lose its shape when gravity causes it to creep downward in its malleable heated state some manufacturers cool the bottle by circulating cold water or liquid nitrogen through the mold others elect to fill it with a shot of air at room temperature the mole typically yields a clean bottle but some flash may occur at the bottom seams where the

Two molds have met if so operators will trim away the excess material and add it to the regrind outside of the bottle manufacturing process commercially available pet grades include unreinforced to glass reinforced frames retardants and high flow material for various engineering applications that typically require high strength and or higher heat resistance

Additions of fillers like glass fiber help improve the impact strain surface finishing reduced warpage and several other benefits some of the other key advantages of pet is that if known for its good gases like oxygen carbon dioxide and moisture barrier properties it exhibits excellent electrical insulating properties and it is recyclable and transparent to

Microwave radiation as i mentioned before pet products are 100 percent recyclable and is the most recyclable plastic worldwide pet offers significant advantages like weight durability versatility compared to alternative materials making it a widely used polymer in the packaging and textile sector as they have a short life span almost all pet products marketed are

Transformed into waste making pet a priority target for recycling load diffusion coefficient makes pet much more suitable than other plastic materials for use as a recovery recycled material now let’s take a look into the recycling process for pet post consumer pet bottles are collected and processed through a series of special washing processes or by a chemical

Treatment to break down the pet into its raw material or intermediates which are further used to produce or recycle pet flakes the growth of p bottles recycles has been facilitated by developing of processing technologies that increase products purities and reduce operational costs the most adopted method for pet recycling are chemical recycling by hydrolysis and

Mechanical blending chemicals recycling involving the production of pterophalic acids and ethylene glycol to to utilize them for making other synthetic chemicals however cost effectiveness and environmental friendliness makes mechanical recycling the most common for pet or recovering methods overall recycling and reprocessing causes a decrease in melt vicosity

And average molecular weight which can negatively affect the final products mechanical properties in terms of tensile and impact strength the use of recycled pet as a matrix for composite materials based on glass fiber reinforced virgin pet could be a cost effective and environmentally friendly way to upgrade the bottles grade recycling pet into an engineering

Very grade pet 4 and dec injection molding i found that very interesting this concludes my video on pet and here are the sources that i use to make this video thank you for watching you guys have a good day

Transcribed from video
Polyethylene Terephthalate PET Video 4 pptx By Eric Reid