Air compressors and PET manufacturing

Polyethylene terephthalate or PET plastics are a safe and recyclable packaging material. Creating packaging material from PET requires the use of Air Compressors. In this article we will explain why you should get a compressor solution specifically designed for PET bottle blowing.

Polyethylene terephthalate is an inert plastic material that doesn’t react when in contact with chemicals, beverages, and organic material. PET is resistant to microorganisms and doesn’t biologically degrade. It is also light weight, durable and easy to transport. The unique properties of PET make it a preferred packaging material for food & beverage products, shampoo, hand soap etc.

PET packaging is more cost-effective and environmentally friendly than aluminum and glass packaging. Making a PET bottle produces 70% less CO2 than glass, and when you factor in the logistical efficiency of transporting PET the number can be as high as 90% less CO2.

PET bottles and packaging are created through a process called Blow Molding. A PET preform is heated and positioned inside a mould. Compressed air at high pressure is injected into the PET preform. The preform expands to take the shape of the mould. Once the plastic cools down, the moulded PET product is removed and sent for additional processing. Any common plastic water bottle that you find on supermarket shelves is made in this way.

A 2005 study concluded that improvements in compressed air efficiency at plastic manufacturing plants can result in an annual savings of about $27,143. Several improvements were suggested, the most important of which were repairing leaks, buying the right size of compressor, and regular maintenance.

Most of these improvements relate to the proper matching of air compressor size, type, design, and air quality, with the application. Plant managers and owners find the most benefit when they work directly with an air compressor manufacturer who can evaluate the needs of the plant and design a customized solution.

When consulting a professional from an air compressor manufacturer speak with them about your air quality requirements, your expected operating hours, and your required blow pressure.

Air quality of the compressed air can affect the taste and odor of the contents of the PET bottle or packaging. Ask how the air compressor manages filtration and if it follows ISO standards for blow molding. Start by looking into oil-free air compressors and what will be the final dew point and water content in the compressed air and inquire about multi-stage filtration systems that can be attached to it.

Work out how much pressure your equipment needs and let the consultant suggest options in that range. High blow pressures create more heat within the air compressor which could mean shorter maintenance intervals and higher energy costs. Optimal blow molding pressure is preferred over excessive pressure because excess leads to wasted energy.

Compressed air present 30% of the cost of producing PET bottle .

Give the air compressor consultant an accurate expectation of how many hours your blow molding applications will run per year. Smaller units can manage about 2000 hours of use per year. We recommend you invest in a service contract with the manufacturer because regular maintenance and durability is the key to maximum up-time.

In return for working directly with a respected air compressor manufacturer you will get:

- Energy savings by reducing leaks, pressure dips, and excess energy use.

- Maximum pressure for their PET manufacturing processes.

- Correct air temperatures and air purity levels.

- Durable filtration systems that clear contaminants and regular drainage     of excess fluids.

- An extended life cycle for the air compressor.

We recommend speaking to someone at Atlas Copco UAE about your PET bottle blowing needs. Atlas Copco has produced a range of air compressors that are specifically designed to handle these applications while offering maximum energy savings.

The simple concept of (ZD) combining the screw technology with the piston booster made a revolution in the PET compression by lowering down the power consumption by 25% on average , with large flexibility to have turn down and achieve energy savings for different volumes of bottles , thanks to operating Variable speed Oil screw compressors with heat of compression air dryer to generate pressure up to 10bar before boosting it at piston booster to 40bar, this combination utilize the best efficiency, reliability air quality for piston and screw .

Beside the efficiency, air auality specially water content not only  affect the final product but also affect the blow molding seals life time with the use of heat of compression air dryers before the high pressure boosting result on much lower water content and final dew point of +3 °C at the lowest pressure which result In doubling the life time of blow molds seals, while in the typical refrigerant dryers after the high pressure four stage piston compressor hardly dew point reaches to +7 °C.

Heat of compression air dryers consumes zero power consumption as they recycle the heat generated form the compressor to dry the air , this saves the traditional power consumption for the refrigerant air dryers with four stage piston compressor.

ZD concept of having low pressure compressor with high pressure booster provided another aspect to PET plants by having both low pressure and high pressure requirement fed from the same train , without the need to have separate low pressure for packing and instrument air apart from the high pressure compressor for the PET with the new concept called ZD Extend.

By enlarging the feed air oil free screw compressor to cover both low pressure plant air requirement and PET high pressure requirement gives the PET plan tremendous foot print reduction , ability to reduce high pressure piping by installing the packaged booster near by the blowing line.

If you’d like to learn how you can get a complete PET bottle blowing air compressor solution from a reputed manufacturer like Atlas Copco you can visit our product page and contact our experts for a free consultation today.