Rotary stretch-blow moulders for PET bottles

EBS E ERGON series

EBS 20 E ERGON - Rotary stretch-blow-moulders with output rate up to 50,000 bph

After applying it to secondary packaging machines, SMI extended the ERGON design concept to its stretch-blow moulders and launched a brand-new machine series called EBS E (Electronic Blowing System) ERGON, where advanced electronics took the lion's share in the complete redesign of the entire equipment. The EBS E ERGON project is based upon all-electronic processes which allow to get rid of the whole of mechanical movements and related cams and ultimately make the blower a cam-less machine.

The new range is composed of 4 models, from 12 to 20 cavities, suitable for the production of bottles with a maximum output of 2,500 bph/cavity.

The EBS E ERGON series of rotary stretch-blow moulders ensures high performances in the stretch-blow moulding of PET, rPET and PP bottles, mainly used in the “food & beverage” sector. Thanks to high-tech components, minimized maintenance and operational costs and excellent quality/price ratio, the EBS E ERGON series is the ideal solution for the production of plastic containers of different capacities, featuring various shapes, from the simplest to the most sophisticated ones.

Max. output (BPH)30000350004000050000
Bottle sizemin Ø = 44 mm
max Ø = 120 mm
min Ø = 44 mm
max Ø = 120 mm
min Ø = 44 mm
max Ø = 120 mm
min Ø = 44 mm
max Ø = 75 mm



1Preforms feeding
The preforms are transferred from the hopper to the unscrambler through a lifting belt; the unscrambler conveys them to an inclined guide, from where they reach the spacer star wheel at the heating module infeed, by gravitational fall. The star wheel feeds the rotary mandrel chain, through which the preforms are “captured” and let into the heating module.


2Preforms heating
Before entering the heating module, equipped with infrared lamps, each preform undergoes accurate checks, which detect its size and vertical position and automatically eliminate the preforms not compliant with the pre-set parameters. The preforms, supported by the mandrels, start moving along the heating module. During the heating process, the preforms constantly turn around themselves, so as to ensure an excellent and symmetrical heat distribution. The heating module is equipped with two different cooling systems: a liquid-fed cooling system, in order to cool the protection ring preventing the preforms thread deformation during the heating process; an air-fed cooling system, in order to keep the temperature inside the heating module as low as to avoid the exposure of the preforms outside walls to too high temperatures. At the heating module outlet, a sensor detects the preform temperature and compares it with the temperature set point; if the two values do not correspond, it increases or decreases the heating module lamps power.


3Preform stretch blow-molding
A special rotary group of grippers picks up the preforms from the oven and sets them into the stretch-blowing stations. The stretch-blowing process includes two phases:
- stretching and pre-blowing, which occur simultaneously through the descent of the motorized stretching rod and the supply of low-pressure compressed air;
- final blowing with high-pressure compressed air, through which the containers take their final shape. A counter-pressure air system ensures the perfect locking of the moulds, whereas the mechanical locking of the mold-holders allows bearing the strengths generated by the stretch-blow moulding process with the maximum reliability. Also the stretch-blowing stations are equipped with a liquid-fed cooling system, which keeps the molds temperature constant.


4Bottles outlet
During the blowing process, an accurate measurement system checks that the process follows the pression profile required. In fact, a pressure drop would alter the container shape which would cause the automatic rejection of the container. The finished bottles are picked from the stretch-blowing stations by another rotary group of grippers and put onto an air conveyor which finally transfers them to the filling machines.

  • Modular, standard design for all models of stretch-blow moulders
  • Compact and easily accessible solution for the maintenance operations carried out by the operator
  • Desmodromic control of the rotary groups of grippers by means of a double cam
  • Motorized stretch rod for a more flexible control of the stretch process
  • Infrared lamps, positioned horizontally and grouped in panels, whose parameters can be set and modified through the POSYC operator panel
  • Heat-reflecting panels, made of composite material, mounted on the front and at the rear of the infra-red lamps to increase radiation intensity and, therefore, reduce energy consumption
  • Stretch-blow moulding stations characterized by a low dead volume thanks to high-performance valves and optimized circuits
  • Electrical panel integrated into the heating module, with a significant reduction in the machine size

Rotary stretch-blow moulding system

High-efficiency rotary stretch-blow moulding system equipped with motorized stretch rods, whose functioning, controlled electronically, does not need pneumatic cams. This allows a precise management of the rod path and an accurate control of its position, as well as a significant energy saving.

Compact preform-heating module

The length of the heating tunnel has been reduced by 50 % compared to the previous solution, thereby halving the number of preforms that in a given moment move in front of the heating panels. This translates into a shorter discharge conveyor, that guarantees a quick machine emptying in case of emergency stops.

Reduction of blowing times

The new valves provide a faster reaction and a saving by 15% on the useful blowing time; this time saving can be used to reach higher speeds, let the bottle cooled down or obtain a compromise between the two things.

Easy format changeover

The new fully motorized stretch rod allows to control easily the format changeover, with greater control on the stretch-blow moulding cycle and the stretch process (speed up to 2.4 m/s).

Safe and easy cleaning and maintenance operations

SMI stretch-blow moulders, characterized by a compact and ergonomic structure, are equipped with slightly rounded safety doors; this allows to have more space inside the machine in order to carry out cleaning and maintenance operations easily and safely.

Quick delivery times

The EBS E range is covered by just 2 machine modules, one from 12 to 14 moulds and the other from 16 to 20 moulds, ensuring quicker delivery times.

Images are for illustrative purposes and data are not binding, as they have to be confirmed by SMI according to the container weight and capacity, machine user's production conditions and technical specifications.