Views: 121 Author: Site Editor Publish Time: 2021-05-17 Origin: Site
If you are wondering about PET or PVC which one is the best material for your job. Let’s read this article.
PET, also written as polyethylene terephthalate, is the most common thermoplastic resin of the polyester family. It is made from mono-ethylene glycol (MEG) and purified terephthalic acid (PTA). These two crude oil derivatives are reacted under a controlled set of conditions to form a polymer. Then, in a honey-like form, this polymer is extruded through a die-plate, cast into spaghetti-like strands, and cut into pellets. These pellets are then heated which converts them into a molten liquid that can be easily molded into items of any shape and size.
More than 60% of the total global PET production is for making synthetic fibers. In textile applications, PET is often referred to as polyester. Polyester fabrics are strong, flexible, and offer additional benefits of fewer wrinkles and shrinkage over cotton. Filament yarns are used in clothing, furnishings, tyre cord, and technical textiles. Staple fibres are employed in knitted and woven textiles for clothing and furnishings such as bedsheets, bedspreads, curtains, and draperies. Polyester fibrefill can be used to stuff pillows and cushion padding.
PET foam is made of PET which offers lots of benefits such as very low water absorption, good thermal stability, excellent surface properties, and good electrical properties. They are used in the automotive and electric industries. For example, we use PET in the production of exterior body parts and casing and housing of various automotive parts to substitute heavier materials. PET foams lead to an overall weight reduction of around 10% that results in a 3% to 7% improvement in fuel efficiency. Furthermore, there are lots of applications of PET foams, such as filler of windmill, the substrate in thin-film solar cells, waterproofing barrier in undersea cables.
PET packaging resin markets have seen very strong growth over the last 20 years. PET material is widely used in packaging food items because it is very strong and inert which does not react with food and beverages. For certain specialty bottles, like those designated for beer containment, polyethylene terephthalate sandwiches additional polyvinyl alcohol (PVOH) layer to further reduce its oxygen permeability. Other packaging applications of polyethylene terephthalate include rigid cosmetic jars, microwavable containers, transparent films, etc.
PVC, also written Polyvinyl chloride, is one of the most widely used polymers in the world too. It is made of polymerization of the vinyl chloride monomer (VCM). The VCM then undergoes a process called polymerization, which results in base PVC. It is a white, brittle solid material available in powder form or granules.
Due to the versatile properties of PVC, such as lightweight, durable, low cost, and easy processability, PVC is now replacing traditional building materials. For example siding and windows, wiring and cables, water pipes, floor, and so on.
PVC material plays a critical safety role in the medical field. Such as oxygen tents, bags, and tubing for blood transfusions, drips, and dialysis liquids
PVC is designed to withstand harsh impacts and extreme temperatures, making it another durable, chemical-resistant option for your plastic packaging needs. Manufacturers can rest easy knowing that products that are packaged in PVC plastic will always be protected and will reach their destination unharmed.
PVC has had a reputation for containing heavy metals. Until now, there are few local municipalities accept the #3 plastic in their recycling bins. However, PET is completely recyclable and is one of the most recycled plastic globally. Europe has a PET recycling rate of 52% and the US has 31%. PET plastic can be recycled into a variety of different items. Because PET is so easily recyclable it is a very popular option among companies wishing to adopt more environmentally friendly practices.
PVC pricing has been steady. PET contains more oil-based raw materials than PVC and hence its price changes with fluctuations in oil prices. But PET is at its lowest price level in several years past because more companies are extruding this material. Pound for pound, PET is about 20% less expensive than PVC.
Sealing PVC is easier than PET. You can seal polyethylene terephthalate, but it requires more tools than PVC. And, it is also harder to get a complete perimeter seal with PET.
Thermoforming is the ease of molding the plastic into shapes. PET has a higher thermal conductivity than PVC which means that it needs less energy for it to be molded during thermoforming and quicker cycle time. However, PET does not hold the heat as well as PVC, causing it to crystalize (turn white) if you overheat the sheet.
Winner: Both materials are very good for thermoforming, depending on your needs.