The experts in PET Bottle Compressors

Belliss & Morcom offer an extensive range of oil-free high-pressure reciprocating compressors that are tailored made for the PET Bottle blowing sector. The range offers: 

• Volumetric flow from ~400 m3/hr to ~3200 m3/hr with a delivery pressure range from 20 to 45 barg. 

• V and W cylinder designs which facilitate dynamic balancing and reduce the need for special foundations and also limit the loading and wear of piston rings/cylinder liners. 

• Shaftless motors which transfer 100% of the power input to the compressor crankshaft and have none of the inherent losses associated with belt or flexible coupling drives. 

Since 1978, Belliss & Morcom has been a leading provider of PET compressors for the bottle blowing sector. Our range of oil-free compressors are engineered from the ground up. They meet the exacting requirements of the industry and provide unrivaled levels of performance, efficiency and reliability.

Our commitment to innovation and attention to detail, coupled with the engineering refinement of our designs, translate into tangible benefits for our customers. These include energy and maintenance cost savings and greater uptime, as well as peace of mind.

Experience the difference with Belliss & Morcom PET compressors and discover why every detail matters when the pressure is on.



Belliss & Morcom Oil-Free Reciprocating Compressors for PET Bottling Brochure Thumbnail!

Click the button below to gain access to our NEW PET Bottle Blowing industry brochure.

What you’ll find inside:

•  Belliss & Morcom company overview & industry expertise
•  PET bottle production considerations in regards to compressor choice
•  Our product range details & performance tables
•  Complete compressor systems overview


Read on to discover our range of highly efficient compressors and learn about the key considerations of the PET Bottle Blowing process.

What is the PET? 

Polyethylene Terephthalate (PET) is the plastic used to manufacture bottles and containers for a myriad of consumer products, including carbonated soft drinks and water.

PET is a thermoplastic and using it to produce bottles in the desired sizes and shapes typically involves blowing high quality air at high pressures (25 to 40 barg) into presets that take up the shape of a moulding cavity.

PET remains a very popular packaging material for a variety of reasons including:

  • it is light compared to glass and is only about 20 grams for a 2 liter container
  • can be molded into a variety of shapes and sizes
  • gives the product contained (juices, water, carbonated beverages)  –”shelf appeal”
  • it is environmentally friendly and can be easily recycled
  • does not extract nor transfer flavors to the package drink
  • offers great chemical resistance
  • can be easily sterilized
  • it is shatter-proof


The PET Bottle Blowing Process

The PET Bottle blowing process begins with PET resin which is crystalline, opaque and brittle in nature and softens at ~ 245oC. The resin is dried before going into an injection moulder, forming a PET preform. The preform is then heated and clamped in a PET blow moulder tool. It is moulded into its desired shape with the use of blown high pressure air.

pet bottle technical photo

PET bottle blowing can be completed in either single or two stage processes. In the single stage process, a blow moulding machine, that generates the preformed pellets, is linked directly to the PET bottle blowing machine. This process allows for PET resin pellets to be loaded at one end and for PET bottles to be delivered at the other end. A two stage process has the preformed pellets produced separately and loaded into a PET bottle moulding machine for production.

There are advantages and disadvantages to both processes, however, most high volume production applications use a two stage process as the volumes produced can be much higher, producing up to >70,000 bottles per hour.

pet bottle technical photo


Challenges Faced by PET Bottle Producers


PET bottle producers experience a variety of challenges, including:

  • Operational margins tend to be relatively low and as such, it is imperative that any capital expenditure offers a good ROI (Return On Investment) and relatively low TCO (Total Cost of Expenditure) throughout the life of the capital equipment.
  • PET bottles tend to be used in the food and beverage industry and as such it is important that the material is transparent and that there is no contamination in the container.
  • PET bottle production often requires the expansion of existing lines and/or the relatively quick set-up of new facilities. There is often limited space for new capital equipment and no ability to alter structural foundations.
  • Typically the largest cost associated with any PET Compressor is the cost of energy to run the unit. As such the high efficiency of the unit is critical as is the ability to re-use any of the excess air and heat generated by the unit

Compressors for PET Bottle Blowing

Belliss & Morcom offers an extensive range of cost-effective oil free high pressure reciprocating compressors that are tailored and made for the PET Bottle blowing sector. The range offers:
  • Volumetric flow from ~400 m3/hr to ~3200m3/hr with a delivery pressure range from 20 to 45 barg.
  • V and W cylinder designs facilitate dynamic balancing and reduce the need for special foundations and also limit the loading and wear of piston rings/cylinder liners.
  • Shaftless motors transfer 100% of the power input to the compressor crankshaft and have none of the inherent losses associated with a belt or flexible coupling drives. 


technical photo PET bottle blowing


• High efficiency and low energy consumption ensured by shaftless motors and the ability to run at reduced loading.

• Minimized maintenance costs due to unique "V" and "W" design which puts less load on rings and focus on component design and material selection.

• Unrivalled reliability backed up by a market-leading 5 year+ warranty with a re-warrant option.

• Maximum uptime given the dynamically balanced design which minimises the wear and tear on components.

• Space-saving potential enabled by a design that is more compact than those of our competitors and allows you to save your valuable floor space.

• Numerous customization options with a range of additional features offering operators enhanced levels of monitoring, control and cost savings.

Continue reading to learn how different Belliss & Morcom compressors' design features make them the equipment of choice for many market-leading companies in the PET bottle blowing sector.


On top of our standard PET compressors, our portfolio of products and services for the bottle blowing industry also encompasses a range of additional features. They are designed to offer your factory enhanced levels of monitoring, control and cost savings, and include:


  • The AirPET control system for multi-compressor networks – ensures accurate control of network pressure and effective plant management.
  • Variable Speed Drives for variable capacity control, accurate and repeatable pressure control, reduced energy costs and extended component life.
  • An Air Recovery System – designed to accommodate and “recycle” pressure returned from the blow moulding machines, and reduce compressor energy consumption.
  • A Heat Recovery System - The cooling system can be modified to pre-heat feed water for the heating systems.
  • Custom Components – a wide selection of ancillary items such as starter control panels, filters and optional cooling systems are available to suit all site conditions.
  • Energy Audits – to help you reduce energy costs and CO2 emissions at your bottle blowing plant.