Complete systems for large size bottles

Large containers are customarily made of HDPE and tinplate cans. Converting these containers to PET brings great advantages in terms of costs, speed and ease of production, as well as logistics: all elements are absolutely competitive compared to the customary solutions. In fact, these containers are stackable and have plastic handles that can even be attached automatically.

For the production of bubble tops for water coolers, SIPA offers 15 and 20 litre sizes or 4 and 5 gallon sizes to meet the requirements of the US market. These containers are available in both returnable and one-way versions.

SIPA offers machines that can produce 15, 20, 30 litre PET barrels with both a single-stage system (from resin to finished container in a single machine) and two-stage systems (preform injection separate from bottle blow molding). One-way PET containers as an alternative to the customary metal barrels are a totally absolutely economical solution that tangibly reduces logistics costs.

In the case of containers for very large sizes, such as 20, 25, 30, 40 litres, SIPA has always supplied single-stage systems. Now the two-stage option for preform injection and subsequent container blow moulding is also available. In particular, the PPS300L injection press and the SFL2/2 blow moulding machine.

The technical features of this preform injection machine are the result of the evolution of a standard injection machine, and therefore a fully tested system. The production of preforms for large sizes is made by 12 or 16 cavity injection moulds and the possibility of injecting preforms weighing up to 413g.

A three-stage cooling robot ensures the high quality of the preform. In fact, the preform stays in the cooling plate for the duration of three machine cycles. With this system, heavy, very thick preforms (6-7mm) have time to cool and be discharged gently in a controlled manner (soft drop), which prevents the typical damage, such as knocks and scratches, caused by handling and packaging.

The cooling plate system guarantees a safe and clean approach, as the temperature is lowered only by contact between the external surface of the preform and the walls of the plate wells, through which water circulates at 8°C. The preform is extracted from the plate not by air but using a mechanical system that acts on the support rings of the preform. Furthermore, there is no contact between the mechanical parts and the inside of the preforms while they are being handled.

The PPS 300 L guarantees total control of the system through a touch screen operator panel used to access all the machine and injection process control parameters. In particular, the injection profile can be constantly monitored to guarantee the repeatability of the high quality of the preforms over time.

The architecture and components of this stretch blow moulding system, designed for the production of large sizes from 5 to 40 litres, are based on SIPA linear blow moulding machine models SFL 6 and SFL 4. These products, launched in early 2006, had such an instant success that as many as 300 units were put on the market.

The SFL 2 linear blow moulding machine maintains all the features and standards that SFL models reliable and highly productive systems:

- Fully electric machine driven by servo motors

- Efficient heating oven with innovative and technological features that allow high oven performance and a wide process window for very thick preforms, rapid start-up and low energy consumption.

- Blow moulding circuit based on the rotary technology.

- Electrical stretching.

- Integrated and total control on 'touch screen' operator panel.

The machine can be configured with two blow moulding cavities (SFL 2/2) for the production of containers up to 25 litres and neck up to 65mm or with one blow moulding cavity (SFL 2/1) for the production of containers up to 40 litres and neck up to 85mm.

The preforms are loaded continuously by loading star wheels and taken to the heating ovens using the same principle as the SFL 4 and SFL 6 systems. As per all blow moulding systems provided by SIPA, the preform conveyor chain is made of technopolymers. It is therefore light and strong, with high resistance to wear and requires no lubrication or maintenance.

The heating oven is conceptually based on the features of the rotary range oven with innovative and technological qualities that allow high performance and a wide process window. The SFL2/2 heating oven also has a greater heating capacity for processing large sizes (it can house up to 16 lamps). Its effectiveness assures a wide process window, a rapid system restart and moderate consumption. As in the traditional structures, the screw pitch change system is used for the transfer of the preforms from the ovens to the blow moulding process.

The protective cabin is integrated in the machine. This translates into a considerable reduction in installation/commissioning time and easy handling, even via freight container.

Energy consumption is reduced to a minimum by the ARS blow moulding air recovery system, which is optimised for this specific application where volumes are considerable (20, 30, 40 litre containers).

The whole system operation is managed and monitored from a touch screen operator panel. Operating data are regularly recorded by the machine PC, allowing all information regarding each specific size (recipes), all production reports and complete operating diagnostics to be stored in the memory.

SIPA Plastic Packaging Systems is based in Vittorio Veneto, Italy. www.sipa.it

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