pet water bottle production

The Role of Booster Compressors in PET Bottle Manufacturing

Polyethylene terephthalate (PET), polyethylene (PE), polypropylene (PP), and polycarbonate (PC) plastic kinds are usually used to manufacture various forms of plastic containers and bottles. For containing carbonated drinks and beverages, PET is the most suitable option. This article explores how booster compressors aid PET bottle manufacture. Keep reading to find out how a PET bottle is made.

PET Bottle Production

PET bottles are manufactured through a blow molding technique. Reheat and blow molding, reciprocating blow molding, and extrusion blow molding are the most common blow molding techniques for PET bottle production.

Reheat and Blow Molding

This bottle manufacturing process uses a Reheat and Blow Machine (RBM). It starts from the injection molding stage where melted plastics are injected into multi-cavity molds. They assume a long, thin tubular shape with a neck and threads suited for the bottle caps. These tubes are generally called parisons.

The parisons are subsequently loaded into the blow molding machine for reheating and blowing. Quartz heaters reheat the parisons; while a mandrel, after sliding into the parisons through the neck, passes pressurized air into the mold. This stretch blow-molds the parisons to form a bi-axially and radially oriented plastic bottle with a CO2 barrier that is suitable for storing carbonated drinks. The product is cooled indirectly with water or directly with pressurized air or CO2. Note that the parisons formation stage and the reheating and blow-molding stage are two separate processes.

Reciprocating Blow Molding

Utilizing a reciprocating blow molding machine, this PET bottle production technique is similar to the one above. However, it pushes an accumulated shot over the mandrel to create the parisons.

Extrusion Blow Molding

This manufacturing process incorporates the parison formation and blow-molding into a single process. It utilizes an extrusion machine that continuously produces vertical parisons whose wall thicknesses are varied by the orifice the parisons extrude through. This wall thickness variation ensures uniformity throughout the formed PET bottle. Additionally, the fabricated bottles are cooled in a similar way explained above.

What is Polyethylene Terephthalate?

Also known as PET, Polyethylene Terephthalate, which is produced by reacting ethylene glycol with terephthalic acid, is a thermoplastic polymer. Depending on its material composition, it can either be transparent or opaque. Additionally, it is usually polymerized to create a long chain of hydrocarbons that enables PET bottle fabrication.

PET polymerization sometimes produces impurities. Diethylene glycol and acetaldehyde are the two typical kinds of impurities. Acetaldehyde is not only produced by polymerization but also during PET bottle manufacture. If it is produced in large quantities in the PET used for the bottle manufacture, it can give its contents odd tastes.

pet manufacturing

The Role of the Compressor

Out of all the components in the PET bottle blowing industry, compressors are the most essential. Hence, they must be handled with great caution and given the most attention in the overall process. Their importance is as a result of the need for the injection of pressurized air to form and shape the PET bottles. Also, the extreme temperature and pressure conditions of the fabrication process at extended periods require an accurate airflow within the system. This role is played by the compressor, thus emphasizing its importance to the success of the process.

What Is a High-Pressure Booster Compressor?

A piece of equipment that amplifies the pressure of pre-compressed air in an industrial system is known as a high-pressure booster compressor. This system receives air from a low-pressure compressor and multiplies it to yield air with much higher pressure. A standard high-pressure booster compressor can multiply a pre-compressed air pressure by up to ten times.

Types of PET Air Compressor Systems

PET air compressor systems come in different variants suitable for the PET bottle process. These systems help fabricate high-pressure plastic bottles. The main categories include:

  • Three-Stage Lubricated Air-Cooled Piston
  • Single-Stage Boosters
  • Single-Stage Boosters
  • High-Pressure Four-Stage Centrifugal
  • Three-Stage Water-Cooled Piston

Three-Stage Lubricated Air-Cooled Piston

Its properties are:

  • Maximum Flow Rate of 80 CFM
  • Lubricated configuration
  • Compresses air from atmospheric pressure (14.7 psi) to 580 psi
  • Usually used in multiples
  • Service life of 10-20 years
  • It is moderately efficient, can serve as backup, and cost-effective

Single-Stage Boosters

Its properties are:

  • Maximum Flow Rate of 500 CFM
  • Available in lubricated and non-lubricated configurations
  • Compresses from air from 125 psi to 175 psi
  • Efficiently utilizes space
  • Service life of 10-15 years
  • It is very cost-effective for PET plastic company application

Single-Stage Boosters

Its properties are:

  • Maximum Flow Rate of 2000 CFM
  • Non-lubricated and water-cooled configuration
  • Compresses inlet air pressure 125 psi
  • Its large size requires a huge amount of space to contain it
  • Service life of 20-30 years
  • High procurement and maintenance cost

High-Pressure Four-Stage Centrifugal

Its properties are:

  • Maximum Flow Rate of 5000 CFM
  • Non-lubricated configuration
  • It also efficiently utilizes space
  • Inefficient power cost
  • Comparatively low maintenance cost
  • Service life of 10-15 years
  • Efficient choice for large systems

Three-Stage Water-Cooled Piston

Its properties are:

  • Maximum Flow Rate of 1400 CFM
  • Water-cooled configuration
  • Used by many large production PET plants
  • Space efficient
  • Service life of 20-30 years
  • High investment and maintenance cost

Contact NiGen for High-Quality Air Pressure Booster Systems

NiGen presents its clients with outstanding experience in air pressure boosting systems. Our advanced booster compressor solutions are built to satisfy several industrial requirements. For guaranteed high-quality air pressure booster systems, NiGen is the right fit for you.

To learn more about our products and services, please contact us online today.