Difference between PET(polyp-benzene) and PETG

PET: Poly(ethylene terephthalate) A dynamic process in which different industries or different industries of the same industry interpenetrate, intercross, and finally fuse together. #PETsheetmaking machine

PETG:  Poly real (ethyleneterephthalateco - 1, 4 - cylclohexylenedimethylene terephthalate) #GAGsheetextrusionmachine

PET synovial products#jwellPETsheet

PET polyethylene terephthalate this condensation polymer is mainly used in food packaging film and textile fiber and other purposes. Now, its use as a packaging material is increasing, not only for soda beverage bottles, but also for non-crystalline PET (APET), crystalline PET (CPET) cans and saucers. In the last five years, engineering grade PET and copolyester, as new polymer products, have been used for engineering and specialty packaging materials, respectively.

The successful application of PET in soft drink packaging materials is due to its toughness and transparency, orientation ability, excellent economic value and the development of high-speed bottle processing technology. PET beverage cans have the advantages of light weight, shattering resistance, reusability and good airtight performance. A filled 2-liter PET beverage bottle weighs 24% less than a similar glass bottle. The empty bottle weighs 1/10 of the same size glass bottle. It saves labor, energy and costs in every link from producer to consumer. #PETrecyclingmachine

Chemistry and properties

PET for beverage bottles is produced from terephthalic acid (TPA) obtained by oxidation of paraxylene. Terephthalic acid can be purified or reacted with methanol to produce dimethyl terephthalate (DMT), or further oxidized to produce pure terephthalic acid (PTA). The other basic material for PET is ethane, which is converted by reaction into ethylene glycol (EG). PET is a polycondensation produced by the polymerization reaction of DMT (or PTA) and EG in the continuous melting state, and then in the solid polymerization process to obtain large grains and final molecular weight, inherent viscosity. The solid-state process also makes the ethanol content of the polymer sufficiently low.

General commercial PET resin melts at about 480F(), but the melting point of highly crystalline PET is about 520F(). Directionally crystallized PET has excellent strength. Toughness and transparency, and resistance to weak acids and bases and many solvents.

Special class #petbottle

Stretch blow molded PET is available in solid, green and pale yellow PET. The colored polymers in the reactor do not require recombination that adversely affects physical properties and improve color uniformity. A variety of pure resins with different intrinsic viscosities are available. PET copolymers crystallize slowly, which allows for the production of high quality soda bottles under a wide range of processing conditions. An extrudable blow molded polymer is also available. This material has the advantages of excellent melt strength and slow crystallization rate, and can be easily processed on suitable extrusion and blow molding equipment. A variety of reinforced, flame retardant and other specialty polymers are constantly being introduced or modified to meet new applications. PETG copolyesters are another example of many copolyesters. Unlike PCTA modified with acid, PETG is a diol modified polymer made of CHDM diol combined with TPA (terephthalic acid) and ethylene glycol. PETG copolymers can be molded or extruded and generally retain their amorphous, transparent, and virtually colorless properties, even in large cross sections. It has high stiffness, hardness and good toughness, even at low temperatures also maintain due toughness. The combination of transparency, toughness and melt strength allows it to be used for injection molding, blow molding and extrusion of profiles, tubes, films and plates. 

PETG is available in unmodified form or with various additives, including release agents, masterbatches and impact modifiers, for injection molding. 

PETG should be dried at 120 ~ 160F for about 4~6 hours before molding or extrusion. In both processes, the melt temperature ranges from 420F to 510F. The pressure holding time of the processing equipment at higher temperatures should be as little as possible to prevent excessive degradation. Injection molding should be carried out on the injection machine, requiring each injection volume to be 50% to 80% of its capacity. PETG can be extrusioned and blown at melt temperatures between 400-450F to make shampoos, liquid detergents, hygiene products, mineral oils and clear bottles for food packaging. The material meets FDA standards and can come into contact with food. Extrusion produces a wide range of profiles, as well as tubes, films and sheets for packaging, including medical equipment packaging. PETG and PCTA can be sterilized with ethylene oxide and Y rays. When used for injection molding, PETG is usually processed in the melting temperature range of 450-510F, and the mold temperature is about 70-130F. Current applications include instrument covers, machine shields, cosmetic containers, lever device Pointers, display components, and toys. PET is mainly used in soft drink packaging. PET has occupied nearly 100% of the 2-liter packaging non-recyclable container market, and 1.5 liter, 1 liter, 0.5 liter and smaller PET bottles have also been widely recognized. PET is used in food, wine and detergent. Uncarbonated beverages and industrial product packaging, the demand for PET is expected to continue to grow. Packaged foods include mustard, gelatin products, peanut butter, flavorings, cooking oils, cocktails and juice concentrates. New colors, especially Wieber PET in medicine. Vitamins and cleansers are popular in packaging. One of the newest and fastest growing applications for PET containers is food or beverage packaging, which requires filling at high temperatures. Many foods, especially fruits or foods or beverages with high fruit content, must be packaged at 180F or higher. This provides pasteurization (disinfection) of products and containers at the time of filling. Usually oriented containers, such as soft drinks and soft drinks packaging bags, tend to shrink and deform when subjected to high temperatures above 160T, which is due to a certain stress relaxation. Stress concentration occurs when the container is stretched and blown. Heat resistance technology has been developed to improve processing, often referred to as "heat setting" technology. According to the specific processing process, there are several processing technical details, which are highly patented, according to which containers suitable for perfusion at 190 ~ 195F can be produced. Products requiring packaging with this characteristic include pure fruit juice. High juice content beverages, teas, certain isotonic and sports drinks, condiments, fruit juices concentrate and certain mineral waters. Other end uses for PET are widely used in extruded coatings and extruded films and sheets. PET is used as an extruded coating material for bakeable cardboard packaging, and crystalline PET (CPET) can also be used as a base material to make plates in ovens. PET film is usually biaxially oriented and is used as X-ray and other photographic film, meat and cheese packaging, magnetic tape, electrical insulation, printing plates and bottle packaging. PET is also used as an industrial tape material. Amorphous, unoriented PET films and sheets are beginning to expand for forming containers, plates, foamed products and beverage cups. Summary: PETG is an upgraded version of PET, with higher transparency, higher toughness, better impact resistance, and of course, a higher price.