HDPE and PET are two popular types of plastics. They are useful for manufacturing a wide variety of products for industrial and domestic usage. Both have various qualities common, but PET has some distinct advantages that make it more suitable raw material.
What is PET?
Polyethylene Terephthalate or PET is another popular type of plastic. It is tough, shatterproof and clear. PET is an excellent barrier for gases (including Oxygen and Carbon-di-oxide) and water that make it the best material for carbonated drinks, foodstuff and milk. PET is one of the most widely used raw materials in the food industry. PET is useful in manufacturing a variety of food jars, containers and refill packs, serving trays, packaging material, industrial components, parts etc. It has been approved by food and safety authorities based on extensive toxicity studies. However, reusing of PET seems to have toxicity issues. Hence, it is recommended that PET should be recycled after single use.
Multiple times recycling of PET is possible. Also, the recycling process saves energy and helps in reducing emission of toxic gases. It creates various domestic jobs for small and medium industries who manufacture products using it. There are various forms of recycled PET like the fiberfill, strapping, fiber, thermoformed packaging, food or non-food bottles, trays and takeaway containers, etc.
It is a thermoplastic polymer resin of the polyester family, formed by combining Ethylene Glycol and Terephthalic acid or Di-methyl Terephthalate. Due to high clarity, good chemical resistance, and temperature tolerance, it captures a large market share of raw material supply for the packaging industry. Blow mold method or Thermoforming method are two popular methods of manufacturing. Like all other thermoplastics, PET is easily recyclable. In fact, it is easy and practical to recycle it as compared to others. Recycled PET is the raw material for manufacturing Polyester Fiber, a versatile product.
Recycling of PET
PET used bottles/containers are collected from recycling collection stations. The sorting department separates the lot according to the material type. Bundles of sorted material are dispatched to reclaiming section. The bundled material is unbundled and washed thoroughly to remove dirt and dust. Machines convert it into shreds and send to the washing section. Clean flakes stocks are ready for reuse. Flakes can be converted into polyester fiber useful in making clothing, pillows, carpets, and fleece clothes. It is possible to convert them into safe and convenient single-serve bottles also.
What is HDPE?
HDPE is the abbreviation of High Density Poly Ethylene. Polymerization process of Ethylene produces a lightweight thermoplastic resin with great mechanical resistance quality and lightweight. Because of good chemical resistance to a large spectrum of acids or organic solvents, it is an ideal material for producing containers. Food oils, petrochemical products, other chemicals and medicines can be stored without any risk of degradation/chemical decomposition.
It is produced by a special process known as cracking. When petroleum products get intense heat under controlled condition, ethylene gas produces. The molecules of Ethylene link together and form a substance known as Polyethylene. It looks like porridge which passes through tiny holes. Holes convert it into strings. These strings go to cutting machine and turn into little granules. HDPE contains very high density of Ethylene molecules.
Due to low transparency, it acts as a good barrier for light. However, it is little inconvenient from user’s perspective because the material can’t be perceived from outside. Some peculiar traits like high moisture resistance and lucidness stand out HDPE distinctly for variety of applications. It has a good capacity of storing items below freezing temperature. However, it is not possible to fill products above 110 degree Fahrenheit temperature. It is not suitable for essential oils or storing products that need vacuum sealing.
Various manufacturers offer a commendable range of jars and bottles with multiple sizes and shapes to meet demands of clients. Due to good holding capacity, durability, superior quality and long-lasting life, they get appreciation from users across the globe.
Recycling of HDPE
Recycle companies collect large pools of it and clean thoroughly before sending it for recycling. Other plastic polymers are separated out because it may spoil the entire lot. Since it has relatively low specific density, sink-float mechanism is useful for separating it from others. Near Infrared Radiation technique is another popular method of sorting other types of polymers. After that, the material is moved to shredding and melting section. Recycled HDPE is ready for further use.
Why are PET handle bottles better than HDPE handle jars?
- 1. It is remarkably lightweight than HDPE or glass. Typically, weight of 1L bottle of PET is about 20-26 grams whereas HDPE weighs around 38-44 grams. It makes a great difference in packaging costs.
- 2. There is no material cost during the production process.
- 3. High efficient, lower power consumption and fully automated process makes PET production cost-effective.
- 4. PET offers improved barrier properties for Oxygen and humidity. Hence, these containers keep food items free from odors.
- 5. Attractive and aesthetic tailor-made bottles are made from PET.
- 6. It has a smooth finish, no scratch marks like HDPE. It is possible to produce transparent or attractively colored bottles using this material.
- 7. It is a durable material with high shock-resistance.
- 8. Since PET is biologically inert material like glass, it resists attacks of micro-organisms.
- 9. It doesn’t contain BPA or heavy metals. It is a low-toxic and low-hazardous material.
Due to excellent usability, low cost and better quality products, PET successfully substitutes HDPE bottles, handled jars and other packaging materials. It is a cost-effective solution with incredible flexibility. As per statistics, PET is rapidly increasing market share across all countries. Research and development is going on to make it more environment-friendly and safe plastic material. With the increasing demand in top-rated developing countries like India and China, it has a bright future. These markets have shown remarkable economic growth in the last decade. Due to enhancement in lifestyle, there is a great thrust for packaged food industry. Manufacturers of developed countries expect exponential growth in the coming years. It is a good sign for the PET industry.