polyethylene terephthalate advantages and disadvantages polyethylene terephthalate advantages and disadvantages

Chemical structure of polyethylene terephthalate (PET) polyester. The miscibility of PLA/PET blends was also confirmed over the entire blend composition range by Fu et al. | The Definitive Guide. Web(2021) Hasibuan. The use of P.E.T. By continuing you agree to the use of cookies. PET polymers are highly resistant to moisture and chemical resistant to organic material and water. Which Plastic material is better? Scott has a masters in science and environmental journalism and a bachelor's degree in conservation biology degree from the University of Lincoln in the U.K. During his academic and professional career, Scott has participated in several animal conservation projects, including English bird surveys, wolf monitoring in Germany and leopard tracking in South Africa. He found, though, if he produced aromatic polyester, the properties significantly improved. Suitable for food packaging applications. Due to its abundant waste products, it has become a problem for the environment. PEF is referred as the next generation polyester which exhibits great potential to replace polyethylene terephthalate (PET), a durable polymer derived from conventional synthetic resources. PET has a glass transition temperature of 6781C and melting point of 260C. PET polymers are used for films and for fibers. The biggest utilizer of PET is the textile industry, in which thermoplastic is mostly known by the name Polyester. Aggregate, bitumen of grade 60/70 and crushed plastic bottle waste were utilized in this study. Different grades of this polymer are used in various industries with a wide range of molecular weights and the manufacturing of beverage bottles. These PET degradation alternatives including various methanolysis and hydrolysis methods are reviewed. Click on the polymer name to learn about them in detail. 74; Table 22. According to the ILIS study, PET is biologically inert if ingested, is dermally safe during handling, and is not a hazard if inhaled. Fig. It is what it is, Ask a relief, usage of PET is steadily decreasing worldwide bcoz of its severe effects on the environment. Table 6.18. L'H. Various depolymerization techniques such as glycolysis, methanolysis, aminolysis, ammonolysis, hydrogenation, and hydrolysis rely upon chemical agents used for PET chain scission. We use cookies to help provide and enhance our service and tailor content and ads. High electrical and insulation properties, Better heat resistance, XLPE power cable can typically stand up to 260C, Has better tensile strength and impact resistance, Higher eligibility for higher rated current applications. Packaging materials have advantages and disadvantages in the packaging of vegetable oils depend on their functions, so the oil stable during distribution and storage. As shown in Fig. Because PET has phenomenal water and barrier resistive properties, it is often used to manufacture plastic bottles for mineral water, alcohol, and carbonated drinks. Thanks for reading the article. The Global Market for Bio- and CO2- based Plastics and Polymers - Bio-based polymers are sustainable polymers synthesized from renewable resources such as biomass (e.g. Just we should know what we're doing. It also looks at the different grades of Polyethylene Terephthalate, its characteristics, uses, and the advantages and disadvantages of using it in plastic injection molding. New scientific studies conducted in the US show that PET and HDPE bottles have a significant market share in the American bottling industry and can be recycled at least 10 times. Dacron fabric is used to make fibers for clothing, storage containers for food and beverage, thermoplastic resins, and more. The by-products, fumaric acid and glycols, dissolved in the aqueous solution can be recovered and separated. Unlike other types of plastic, PET plastic is not single-use -- it is 100% recyclable, versatile, and made to be remade. Growing demand for polyethylene terephthalate glycol from food packaging and plant waste, algae) rather than conventional petroleum feedstocks such as oil and gas. How many times PET bottles can be recycled? Using single-screw extrusion, partial miscibility of PLA/PET blends was reported for a maximum content of 7.5wt.% PLA [72]. Main elements and BE energy values can be detected in the surveys reported in Fig. Blow Molding is commonly utilized for manufacturing transparent bottles. Heres how it works. Dacron is generally found in the same common applications as polyester in the textile industry. Ans. They offer significant advantages over traditional plastic Figure 4.32. If cooled rapidly from the melt to a temperature below Tg, PET solidifies in amorphous form. Copyright 2023 Elsevier B.V. or its licensors or contributors. The packaging industry is also very dependent on PET for microwave containers, rigid jars, transparent films, sheets, etc. Cancer is a disease caused by an abnormal growth of cells, also called malignancy. The major benefit of any thermoplastics when it needs to be processed in injection molding is that when it melts, the liquid form can be cooled and reheated without large degradation. The thermal and mechanical characteristics of blends of PLA and PET were studied by Girija et al. Initial Property Values for Fig. Condensation polymers can easily be depolymerized into monomers in the absence of alcohol or water, which can act as both solvent and reactant. Although the discovery offers hope in the fight against mounting plastic, scientists caution that we are still years away from widespread commercial use. In addition, it has a wide range of printing temperatures and may be slow to print. LDPE can be processed by injection molding or rotomolding also. Web#1: Polyethylene Terephthalate (PET or PETE) Polyethylene terephthalate is the most commonly used plastic in the world. As a result, its melt viscosity is extremely high and normally can only be processed by powder sintering methods. Figure 6.12. Some of the important properties include water resistance and toughness (the strength to weight ratio is impressive). He suggested the classification of polymers into two groups, condensation and addition polymers. Permeation of Oxygen at 23C and 75% Relative Humidity Through DuPont Teijin Films Mylar PET Films [12], Table 6.14. Depolymerization kinetics of PET are indispensable for building a commercially viable depolymerization process. Thus, easy and inexpensive to transport. Scott is a staff writer for How It Works magazine and has previously written for other science and knowledge outlets, including BBC Wildlife magazine, World of Animals magazine, Space.com and All About History magazine. Cancer is a disease caused by an abnormal growth of cells, also called malignancy. WebIn general, high density grades of polyethylene have densities up to 0.97 g/cm^. The low diffusion coefficient is the prime reason for PET is the best when used with recycled material. PET can be used for blow-molded bottles in automotive applications. document.getElementById( "ak_js_1" ).setAttribute( "value", ( new Date() ).getTime() ); Sagar Habib, a certified plastics engineer, and aficionado. At the moment, the latter ones aren't discussed in this guide, but a detailed list of commercially available grades is just a click away! Polyethylene terephthalate is used for textiles, packaging, and other applications. This study evaluates the performance of Polyethylene Terephthalate (PET)-modified hot mix asphalt. Easily Avoid Disruptions in Your Injection Molding or Extrusion Production Line, Bon article de synthse sur LES LES POLYETHYLENES. It contains polyethylene terephthalate (PET or PETE or polyester). Advantages and Disadvantages of Polyethylene Terephthalate. Disadvantages: Very susceptible to heat degradation. An antimony or titanium compound is usually employed as a catalyst, a phosphite is added as a stabilizer, and a bluing agent such as cobalt salt is added to mask potential yellowing. Even with its popularity, there are some advantages and disadvantages you should consider before using HDPE for your application: Advantages. Advantages of PET Resin. Additionally, PET bottles and containers that are discarded in landfills pose no risk of harm or leaching. The material is virtually shatterproof, which improves its applicability by many nautches. PET does protect against diluted acids, oils, and alcohols that attack HDPE. Polycarbonate VS Plastic Lenses | A Complete Analysis, What is Warpage? Dioctyl terephthalate (DOTP) obtained from waste PET is an oily substance and is compatible with concrete raw materials, which can make it an attractive material to be used as building materials. Just 16% of all plastic produced is recycled to make new plastic, according to the BBC (opens in new tab). Polyethylene is a whitish, semi-crystalline, and effectively opaque engineering thermoplastic which, chemically, is a very high molecular weight (3-6 million) HDPE. The glass conversion temperature of PET is about 165, and the temperature range of the material is 120~220. Table 4.29. PET or PETE is originally a homopolymer but can be modified to produce copolymers ( polyethylene terephthalate glycol-modified ) depending on the application. Temperature resistance up to 80C continuously and 95C for shorter times. The essential elements of PET are ethylene glycol and terephthalic acid, combined to form a polymer chain. Manufacturers use these recycled PET flakes for strapping, films and sheets, Food and beverages containers, carpets, flee bags, etc. Webreview is to present the advantages and disadvantages of thermoplastic polymers used in industrial applications, the processes used in the recycling and perspectives for a green bio-industry. Despite all these studies, Li et al. The PET processability to produce hollow objects for food packaging was critically discussed. They are quite similar on the surface but do have some differences that set them apart. The thermosetting resin in flame-retardant polymers can be recycled to materials with the aid of hydrolysis using subcritical aqueous media. However, instead of direct use of PET in building materials, alternative methods may also be preferred. (According to DS/IEC 544-4). The Effect of Ionizing Irradiation on the Mechanical Properties of Polyethylene Terephthalate with Internal Lubricant (According to IEC Standard 544 and ISO Standard 178) [14]. ScienceDirect is a registered trademark of Elsevier B.V. ScienceDirect is a registered trademark of Elsevier B.V. Polyethylene terephthalate (PET) in the packaging industry, https://doi.org/10.1016/j.polymertesting.2020.106707. [68,69]. Researchers used thermogravimetric and differential scanning techniques to analyze the change in thermal and crystalline properties of fibers before and after electrospinning. PET provides a strong gas and moisture barrier, making it a popular choice for plastic bottles WebPolyester is the given name to a group of materials, whereas Dacron is a brand name of polyethylene terephthalate (PET). Aluminium triisopropoxide (AIP) promoted the methanolysis of polyethylene terephthalate (PET) to form monomers, dimethyl terephthalate (DMT) and ethylene glycol (EG), in an equimolar ratio. Aggregate, bitumen of grade 60/70 and crushed plastic bottle waste were utilized in this study. Can I know when antimony that is sometime found in PET Plastic is appeared i.e., at what temperature and duration in direct sunlight? PET polymers are highly resistant to moisture and chemical resistant to organic material and water. Resins made from PET can oxidize, resulting in a degradation in the taste of food and beverages when the items have a long shelf life and are stored in PET packaging. Since disposal of PET by pyrolysis methods leads to carbon emissions, waste PET utilization by building materials, especially in concrete production, is the most preferred option. 6.14, the molecular structures of PET, poly(butylene terephthalate) (PBT), and poly(trimethylene terephthalate) (PTT) are very similar, although their properties such as strength, rigidity, impact resistance, and glass transition temperature are different. This article was written by various Xometry contributors. It is available in abundance and is Vapor permeation at 23C through Mitsubishi Polyester Film Hostaphan RN 25 biaxially oriented PET Release film [13]. [9] studied the immobilization of heparin to develop thrombus-resistant PET grafts producing surface modification by Denier reduction to produce functional carboxyl groups. Discover how plastic-eating bacteria were discovered and re-engineered to help tackle the worlds plastic problem. Millions of plastic bottles are used for the production of polyester. #CreatingNewLife #Recycled #Polyester #RecycledPET #RecycledPolyester #Polyester, Jl. Effect of beta (electron) irradiation on the physical properties of PET [17]. Being lightweight also provides for cost savings when transporting products using PET packaging. The rheological properties of PET from recycled bottles were negatively affected by the presence of PLA (up to 5wt.%) [74]. PET has flexible, but short, (CH2)2 groups tend to leave the chains relatively stiff and PET is noted for its very slow crystallization. In these immiscible blends, both PLA and PET crystallization were hindered. What is PETG Material? It shows fantastic electrical insulating properties. PET exists both as an amorphous (transparent) and as a semicrystalline (opaque and white) thermoplastic material. "}},{"@type":"Question","name":"How many times can PET plastic be recycled? Polyethylene terephthalate is called polyester when used as a fiber or fabric. 4.2: C1s at 284.8eV, O1s at 531eV, Si2p at 102eV, N1s at 400eV, Na1s at 1072eV, and S2p at 163.9eV. 800North Bethesda, MD 20852240-252-1138, ITAR | ISO 9001:2015 | AS9100D | ISO 13485:2016. | The Definitive Guide, What is Polypropylene Material? Polyethylene terephthalate (PET) is the third most widely diffused polymer exploited in the packaging industry, monopolizing the bottles market for beverages, and Cost-effective; Can withstand temperatures from -148 to 176 degrees Fahrenheit; Non-leaching; UV-resistant; Dishwasher safe; Resistant to most chemical An artistic illustration of plastic-eating bacteria. A PET-woven band has been used in reconstructive knee surgery in sheep as a reconstructive device. Total market size is likely to increase from US$ 2,747.8 million in 2023 to US$ 3,818.9 million by 2033. The Advantages and Disadvantages of HDPE. The semicrystalline PET has good strength, ductility, stiffness, and hardness. This article explores the advantages and disadvantages of both forms of feeding. The material liquefies at high temperatures (as opposed to burning) also makes it an ideal material for recycling. PET is the most common thermoplastic polyester and is often called just polyester. This often causes confusion with the other polyesters in this chapter. Polyethylene terephthalate (PET) or (PETE) is an important commercial engineering polyester thermoplastic with good thermal and mechanical properties, low permeability, and chemical resistance. PET has a strong hygroscopicity at high temperatures. | Causes of Warpage | Warpage Variations, Heat-deflection temperature 0.45 MPa ( C ), Heat-deflection temperature 1.8 MPa ( C ), Coefficient of thermal expansion ( x10-6 K-1 ). Chemical structure of polyethylene terephthalate (PET) polyester. Polytrimethylene terephthalate (PTT) production capacities 2019-2033 PET can be utilized to produce films and sheets, which can be thermoformed later. While many consumers have erroneous assumptions about PET, it does not contain BPA, phthalates, dioxins, cadmium, lead, or endocrine disruptors. PRO/CONS ? A bacterium that degrades and assimilates poly(ethylene terephthalate), Enzymatic Remediation of Polyethylene Terephthalate (PET)Based Polymers for Effective Management of Plastic Wastes: An Overview, Characterization and engineering of a two-enzyme system for plastics depolymerization. Film thickness: 0.012mm; test method: in-house method except for water: DIN 53122. Harms: PET is known to leach antimony trioxide and phthalates. We use cookies to help provide and enhance our service and tailor content and ads. Advantages PET possesses a high strength-to-weight ratio (a rare quality found). Permeation of hydrogen sulfide vs. temperature through DuPont Mylar PET [9]. Typically, the high-density material is more linear and consequently more crystalline. Cost-effective; Can withstand temperatures from -148 to 176 degrees Fahrenheit; Non-leaching; UV-resistant; Dishwasher safe; Resistant to most Being and ideal material for injection molding process, it is majorly used for batch and continuous production. Depending on the chemical agents used to break down the polyester chain, depolymerization route can be classified: glycolysis, methanolysis, hydrolysis, etc. Any performance parameters, geometric tolerances, specific design features, quality and types of materials, or processes should not be inferred to represent what will be delivered by third-party suppliers or manufacturers through Xometrys network. September 19, 2022. PET can be used in monofilamentsbrushes, sports equipment, clothing, carpet, and bristles. The effect of beta (electron) irradiation on the color of PET [17]. Acts as a barrier for moisture. It has excellent mechanical properties such as high abrasion resistance, impact strength and low coefficient of friction. If youd like more information about how you could reduce your plastic use, check out "How to Give Up Plastic: A Guide to Changing the World, One Plastic Bottle at a Time (opens in new tab)" by Will McCallum and "How to Save the World For Free (opens in new tab)" by Natalie Fee. 6.12. The main achievements in the PET processing for food packaging are presented, analyzing advantages and disadvantages of each technology. The chemical composition per element of native heparin, native collagen, unmodified PET, PET-NH2, PET-Hep, and PET-Hep-Col was determined using the XPS survey spectra and measuring the area under the curve of each principal peak per element. JURNAL PANGAN. WebPolyester also blends easily with natural fibres in fabrics, and resists wrinkling. Effect of beta (electron) irradiation on the resistivity retained at 170C versus dose for polyethylene terephthalate [13]. ","acceptedAnswer":{"@type":"Answer","text":"Recycled PET is ued by manufacturers for applications like strapping, films and sheets, Food and beverages containers, carpets, flee bags, etc."}}]}. The main drawbacks are the low purity of TPA and the fact that this is a comparatively slow option since it is a weak nucleophile. Lets talk about them. The thermal stability of PLA was enhanced by the incorporation of PET, but if the addition of PLA to PET increased its stiffness, it decreased the impact and tensile strengths and the elongation at break of PET. Polyethylene terephthalate is a common plastic in many products such as viscose rayon for clothing, and packaging material in the food and beverage industries. Laurence W. McKeen, in Permeability Properties of Plastics and Elastomers (Fourth Edition), 2017. Also, regulations, testing methods and analytical Post-consumer poly (ethylene terephthalate) (PET) waste disposal is an important task of modern industry, and the development of new PET-based value added products and methods for their production is one of the ways to solve it. The material is almost totally inert, therefore it is used in the most corrosive or aggressive environments at moderate temperatures. Polyethylene terephthalate is commonly referred to as polyester. PET is a semiaromatic polymer synthesized from ethylene glycol and terephthalic acid. PET has a glass transition temperature of 6781C and melting point of 260C. It is commonly used in industrial applications due to excellent moisture and fair oxygen barrier characteristics. Talking about PET, its products have slightly better impact resistance than products made from polypropylene. However, the PLA crystallinity decreased only when PET was crystalline. PLA binary blends with petroleum-based nondegradable thermoplastics, Permeability Properties of Plastics and Elastomers (Fourth Edition), Engineering Thermoplastics: Acrylics, Polycarbonates, Polyurethanes, Polyacetals, Polyesters, and Polyamides, Plastics in Medical Devices (Third Edition), Encyclopedia of Renewable and Sustainable Materials. PET is a semiaromatic polymer synthesized from ethylene glycol and terephthalic acid. The main features concerning the use of PET in the packaging industry were discussed. Save my name, email, and website in this browser for the next time I comment. Initial Property Values for Fig. 1 summarizes the global plastic distribution by continent based on production from various industrial sectors, a summary of single-use plastics, and the life cycle of plastics. Advantages and Disadvantages of PET Resin. [67]. The branched form of polyethylene , known as low-density polyethylene (LDPE). Polyethylene terephthalate or P.E.T is derived from plastic soft drinks and bottles. For glass fiber reinforced PET materials, bending deformation is very easy to occur at high temperatures. Polyethylene terephthalate has high strength and stiffness. The amorphous PET has better ductility but less stiffness and hardness. Thermoplastic polyesters are produced with an ester, CO, repeating link. Kelapa Hybrida, Blok G1/3,Kelapa Gading, Jakarta Utara, 14240. top 10 injection molding machine manufacturers in china, Top 10 Plastic Injection Molding Companies In United States, Top 6 injection Molding Machine Manufacturers, Top 10 Injection Moulding Companies In UK 2022, Recycling of PET Plastic and its Effects on the Environment. Insulation for high voltage electrical cables. Polyethylene Terephthalate is a 100% recyclable material and, to its credit, is the most recycled thermoplastic in the world. and Torres-Huerta et al. Updated on January 13, 2020. Its temperature range for the PET extruder is quite wide at 160C to 210C. DuPont later labeled its PET fiber as "Dacron." In addition, PET containers are often regarded best for maintaining the taste and aroma of food, thanks to their great oxygen barrier properties. The Effect of Ionizing Irradiation on the Mechanical Properties of Polyethylene Terephthalate (According to IEC Standard 544 and ISO Standard 178) [14]. This commodity plastic is produced by addition or radical polymerization. Water Vapor Permeation at 38C and 90% Relative Humidity Through DuPont Teijin Films Mylar PET films [12], Table 6.15. The only major difference for PET is the combination of hydrocarbon ethylene glycol and terephthalic acid. Property retention of Mylar PET film after irradiation in a nuclear reactor [25]. The major advantages of PBT are evident in its resistance to solvents and low shrinkage rate when forming. Polyethylene terephthalate (PET) is a thermoplastic material commonly used in the form of fibres and films, whose stability in environmental applications is of substantial interest.23, From: Fibrous and Composite Materials for Civil Engineering Applications, 2011, Myungwan Han, in Recycling of Polyethylene Terephthalate Bottles, 2019. Irradiation sources for room-temperature (RT) tests: ASTRA 7MW pool reactor in Seibersdorf (Austria); Industrial cobalt source Ionisos in Dagneux (France), a panoramic 21015Bq source delivering a dose rate of the order of 4kGy/h. On the other hand, PP containers fare better in moisture, alcohol, and chemical resistance. WebRecycle of Polyethylene Terephthalate (PET) Bottles. Excellent barrier properties. It has a After analyzing the bacteria, the scientists found that it produced two digestive enzymes called hydrolyzing PET or PETase. PET or Polycarbonate? PET is a semiaromatic polymer synthesized from ethylene glycol and terephthalic acid. Acts as a barrier for moisture. WebReviu Jenis, Aspek Perlindungan dan Migrasi Bahan Kemasan dalam Pengemasan Minyak Nabati (Review of Types, Protection Aspects, and Migration of Packaging Materials in Packaging of Vegetable Oil) Thankfully, they'll all miss. PET is somewhat vulnerable to oxidation (But nothing is rock solid proof about this). WebPolyethylene (PE) is one of the most popular thermoplastic materials. .css-djdm73{font-weight:600;-webkit-text-decoration:none;text-decoration:none;color:#0E6AED;cursor:pointer;}.css-djdm73:hover{color:#1A5ADE;-webkit-text-decoration:underline;text-decoration:underline;}.css-djdm73:active{color:#1A5ADE;}3D Printing Service, .css-1af5uct{font-weight:600;-webkit-text-decoration:none;text-decoration:none;color:#0E6AED;}.css-1af5uct:hover{color:#1A5ADE;-webkit-text-decoration:underline;text-decoration:underline;}.css-1af5uct:active{color:#1A5ADE;}Metal 3D Printing Service. Polyethylene terephthalate (PET) polyesters were invented by Dr W. H. Carothers in 1929 when he was looking to find a super polyester resin. Permeation of oxygen, carbon dioxide, and methane versus temperature through amorphous PET [10]. It is easier to fabricate than polycarbonate and the standard grade is made from FDA approved resin. Heat treatment of recycled PET flakes removes any volatiles, making them safe and meeting the requirements for direct food contact. 4.38 [13]. On land, the majority of plastic ends up either building up in landfills or burnt into incinerators, which releases toxic fumes. Ultra-high-molecular-weight polyethylene (UHMWPE), High-molecular-weight polyethylene (HMWPE), Get more information about polymer properties here , polyethylene with a crosslinked structure, Here is the list of all XLPE grades suited for wires and cables , View several recycled PE grade options available today , High degree of short chain branching + long chain branching, Linear (or Low degree of short chain branching), Using radical polymerization using tubular method or autoclave method, Using Ziegler-Natta catalyst or metallocene catalyst, Low crystalline and high amorphous (less than 50-60% crystalline), High crystalline and low amorphous (>90% crystalline), Shrink wrap, films, squeezable bottles garbage bags, extrusion moldings, and laminates, High performance bags, cushioning films, tire separator films, industrial liners, elastic films, ice bags, bags for supplemental packaging and garbage bags, Excellent resistance to acids, bases and vegetable oils, Molecular weight distribution is relatively narrow, has applications in injection moldings or flat yarns, and the latter type, Molecular weight distribution is wide, is used to make film products, hollow plastic products and pipes, Either modifying natural gas (a methane, ethane, propane mix), Or the catalytic cracking of crude oil into gasoline, Very good resistance to alcohols, dilute acids and alkalis, Poor resistance to hydrocarbons (aliphatic, aromatic, halogenated), Continuous temperature: -50C to +60C, relatively stiff material with useful temperature capabilities, Higher tensile strength compared to other forms of PE, Low-cost polymer with good processability, Excellent electrical insulating properties, High-frequency welding and joining impossible, Good resistance to alcohols, dilute alkalis and acids, Limited resistance to aliphatic and aromatic hydrocarbons, mineral oils, oxidizing agents and halogenated hydrocarbons. .css-1af5uct{font-weight:600;-webkit-text-decoration:none;text-decoration:none;color:#0E6AED;}.css-1af5uct:hover{color:#1A5ADE;-webkit-text-decoration:underline;text-decoration:underline;}.css-1af5uct:active{color:#1A5ADE;}High-density polyethylene (HDPE) is a ubiquitous plastic used in manufacturing. Which Plastic material is better? [71] in injection molding experiments. These kinds of occurrences have caused deaths, injuries, evacuations and major property damage. In addition, it was expected the amount of nitrogen increased in PET-Hep and PET-Hep-Col, and finally the traces of sodium and sulfur presented in native heparin and native collagen were observed only on the surface of PET-Hep and PET-Hep-Col as a result of successful immobilization of heparin, and coimmobilization of heparin and collagen. PET bottles can be recycled by chemically depolymerizing PET chain into its monomers or various valuable chemicals. Have a fantastic day. It absorbs very little water. Figure 4.30. et aussi face la radicalaire. They confirmed that PET/PLA underwent phase separation in 70/30 and 50/50 blends during the electrospinning process and cold crystallization. 6.13 and6.14 and Tables6.116.18. The material has lower heat resistance when compared to other polymers. Nara Loca Abadi is a recycled plastic specialist that promotes the use of recycled PET flakes, recycled PET chips, recycled PP & HDPE granules to various plastic and polyester manufacturers. HDPE and PET are both very popular for manufacturing bottles. 8.9. The disadvantages of polybutylene terephthalate plastic injection molding include weakness in extreme environments and against stronger acids and bases.