PET / PETE Polyester, Its advantages, and its Health issues

PET / PETE Bottles, Jars, Pots, PET Films,

for Food, Water & Beverage Packaging

Polyester, which are primary known for the production of synthetic fibers, are now used for many different applications. Nowadays, PET used as raw material for production of packaging, including food packaging, bottles for water & beverages, films and engineering plastics.

PET polyester used for those products are modified by adding co-monomers and additives which influence the properties of the co-polyesters, such as:

1. melting temperature,
2. high clarity,
3. crystallization rate,
4. neutral color,
5. low acetaldehyde during perform production,
6. second order transition temperature.

Modified resins for rigid packaging, in general, are of higher molecular weights than standard PET resins, the required viscosities as well as the lowest acetaldehyde levels are reached by solid state poly-condensation.

PET [Poly-Ethylene-Terephthalate] polyester manufacturing process:

Pure Terephthalic Acid or Dimethyl-Terephthalate and Ethylene glycol are used for esterification or trans-esterification and further poly-condensation to Poly-Ethylen-Terephthalate [PET]. Diols or Dicarbonic acids are added as co-monomers, they are built into the polyester chains to reduce the melting temperature and the crystallization rate of the so produced co-PET, this modification is necessary to achieve the required product quality for rigid packaging products, with lower temperature and longer resident time technology, gives many benefits, such as minimal reaction by-products, low acetaldehyde formation, excellent product quality, and greater energy efficiency, in the manufacturing process of PET, it uses Antimony-based catalyst [Sb₂O₃], but now has changed with heavy metal free catalyst and stabilizer system

Solid State Poly-condensation process:

Amorphorous PET chips are crystallized in crystallizers, then fed to a reactor where the solid state polycondensation process takes place, the principle of solid state polycondensation process involves high temperature treatment of poly-ethylene-terephthalate [PET] chips in an oxygen-free and moisture-free environment for sufficiently long resident time to achieve the desired molecular weight, the removal of reaction products and volatile impurities, such as volatile organic compound [VOC] acetaldehyde are carried out by diffusion to the PET chips surface and from there into a gas stream, purified and dried nitrogen [N₂] is used as an inert carrier gas.

Advantages of PET Bottles:

• High clarity and free of particles,
• High brilliance, excellent gloss, crystal clear, glass like,
• Un-breakable, breakage resistant / no fear of breaking, customer friendly, easy to dispense,
• Low weight, 90% lighter than glass bottles, easy to carry, saving in transportation cost,
• Non toxic,
• Good chemical resistance, such as acids, alkalis, alcohols, organic solvents, oils, and fats,
• No taste influence on the filled products, totally inert,
• Retain good aroma of the filled products,
• Good barrier properties,
• Good mechanical properties, customizing bottle designed and specification can be tailor made as required,
• Good chemical resistance, such as acids [fair to good], alkalis [poor to fair], alcohols [good], organic solvents [good], oils [good], and fats [good],
• Good form stability, bottle dimensional accuracy gives consistent filling point and brimful volumes, filling efficiency lines possible, bottles blow molding & bottle filling can be synchronized on one production line,
• Good printability, glued and heat shrink labeling possible,
• Can be recycled, eco-friendly.

PET has become the material of choice for bottled water & beverages because it is lightweight and breakage resistant, and PET has been extensively tested for safety, bottles made with PET are widely used for everything from water and fruit juice to soft drinks and even beer.

Advantages of PET-Film Packaging:

• Excellent transparency and gloss,
• High brilliance, excellent gloss, crystal clear, glass like,
• Low weight, 90% lighter than glass made, easy to carry, saving in transportation cost,
• Non toxic,
• Un-breakable, breakage resistant / no fear of breaking, customer friendly, easy to dispense,
• Suitable for food packaging including fats,
• Good chemical resistance, such as acids [fair to good], alkalis [poor to fair], alcohols [good], organic solvents [good], oils [good], and fats [good],
• Low water absorption,
• Good gas barrier / low gas permeability,
• Easy thermoform,
• Good mechanical properties,
• Good printability, glued and heat shrink labeling possible,
• Can be recycled, eco-friendly.

PET Bottles and Health issues:

PET packaging is cleared for safety in food and beverage packaging for single and repeated use, because it is suitable, convenient and recyclable, the U.S. Food and Drug Administration [FDA] has reviewed migration testing data and concluded the PET containers do not leach harmful amounts of substances into their contents under foreseeable conditions of use, all bottles that are re-used should always be properly cleaned, using soap and hot water and then dried thoroughly after that to prevent bacterial growth.

Antimony catalyst used in manufacturing PET:

Antimony trioxide [Sb₂O₃] is often used as a catalyst in the production of PET, metallic antimony [Sb / Stibium] is not used, the function of the catalysts are to ensure that a process happens fast enough, it is just because catalysts speed chemical reactions, to make it commercially practical, antimony was chosen based on its effectiveness as a catalyst; productivity and safety, a 1997 study showed that antimony trioxide has very low toxicity, the compound is relatively inert and does not participate in biological life, a report by the International Life Sciences Institute showed less than five parts per billion (<>

Refill use of PET bottle:

The PET bottle itself poses no danger when refilled. PET is an inert plastic and does not leach harmful materials into its contents, either when a beverage is stored closely, or when bottles are refilled and frozen, the PET containers have been safely used for 20 years and have undergone rigorous testing under FDA guidelines to ensure their safety as a food and beverage containers suitable for storage and reuse, opened bottles can contain bacteria, so that, all PET bottles should be washed with hot, soapy water and dried thoroughly prior to reuse.

Beverages stored and frozen in PET bottles:

It is not danger to freeze PET bottle with beverages content in it, no dioxins are leached from frozen PET bottles into bottle contents.

Leaving a filled PET bottle in a hot car:

The issue that PET bottles leach chemicals when heated in hot cars is not based on any science, and is unsubstantiated by any credible evidence.

PET Bottle leaches Phthalates, DEHA, or Bisphenol-A issues:

1. Phathalates: Poly-Ethylene-Terephthalate [PET / PETE] bottle does not contain plasticizer orthophthalates. PET bottle used terephthalates [different with orthophthalate] as raw material in its manufacturing.
2. DEHA [Di-Ethyl-Hexyl-Adipate]: PET bottles does not use additive substance Diethylhexyl-Adipate, PET bottle does not contain any carcinogenic elements, and DEHA itself is not classified as a carcinogen and has been cleared by the FDA for use to make other kind of plastics (not PET).
3. Bis-phenol A [BPA]: There is no connection between PET plastic and Bis-phenol A. PET does not contain BPA because BPA is not used in PET’s manufacturing, BPA is used in polycarbonate bottles [#7]. Bisphenol A itself belongs to a group of substances which have a hormone-like [oestrogen] effect, this substance may be contained in plastic objects including objects that come into contact with food, some examples are baby bottles [Polycarbonate baby feed bottles #7], beakers, plastic cutlery [knives, forks, spoons used fro eating] or the inner lining of cans.

Also Read:
Safely use of Plastic FoodPackaging
Safely use of Baby Feed Polycarbonate Bottle