SIG Corpoplast - Stretch Blow Molding Machinery for Cost Savings

SIG Corpoplast is a leading manufacturer of stretch blow molding machines.

STRETCH BLOW MOLDING - TOTAL COST OF OWNERSHIP

SIG Corpoplast creates the best conditions for continuous optimization in Total Cost of Ownership (TCO). We take into account all the factors affecting bottle production to identify savings potentials. An analysis of the TCO confirms that SIG Corpoplast - with its bottles and shapes expertise, its BLOMAX stretch blow molders, and its service offering - allows its customers to minimize production costs.

OPTIMIZED PLASTIC BOTTLE MATERIAL DISTRIBUTION

Our analysis starts with the bottle's requirements in terms of size and design, and mechanical properties. With 80% of the bottle costs, material input offers the biggest opportunity for savings.

We adjust the material distribution in the bottle through optimizing process parameters to ensure that wall thickness always meets minimum requirements and avoid unnecessary thick spots.

Optimizing material distribution begins with designing the preform geometry. Stretching certain zones of the bottle directly influences its mechanical and thermal properties.

STRESS-CRACKING RESISTANCE

To ensure sufficient stress-cracking resistance, the material distribution in the bottom zone must be designed so that a perfect transition from the amorphous phase near the gate to the stretched (crystalline) phase near the legs is achieved.

"If the design of the bottom and the geometry of the preform are optimized in this respect, you can also achieve an added benefit of minimizing the material input", says Frank Haesendonckx, Product Manager BLOMAX at SIG Corpoplast.

Mechanical stretching system used on BLOMAX Series III blow molding machines also helps save on materials. The precise repeatability of our mechanical stretching systems pushes lightweight molding to the limit. This perfectly stable process also gives extremely low variations in bottle wall thickness.

EFFICIENT BLOW MOLDERS FOR MAXIMISED BOTTLE PRODUCTION

High output rates offer the biggest value creation potential for any investment. With 1,800 bottles per hour per station in continuous production, the BLOMAX Series III machines have again set the pace.

Our stretch blow molders use circulating transport mandrels to carry preforms through the machine. This reduced preform transfer leads to markedly lower abrasion, prevents problems with PET dust in the mechanical parts, seals and filters, and reduces maintenance to a minimum. The transport of the mandrels through the heating oven in a train of rigid carriages also avoids the need for a chain that would be subject to wear and tear.

Quick-change systems such as Speed-Loc significantly accelerate the product changeover. With Speed-Loc, the conversion of a blowing station can be achieved in less than two minutes, which directly translates into higher availability.

ENERGY-EFFICIENT BLOW MOLDING

Thanks to a number of design features, BLOMAX machines are among the most energy efficient stretch blow molders in the market.

The very small preform pitch of only 38mm ensures a significantly more efficient utilization of the energy when the preforms are heated.

The control of the individual heating lamps is optimized with a special program that operates at a higher temperature and pulses on and off. Since shorter wavelengths are used in this process, the penetration depth is improved. This shortens time in the oven and reduces energy consumption. Efficient mandrel cooling contributes to lower time and energy costs.

COMPRESSED AIR-FREE STRETCHING SYSTEM

Our AIRBACK air recycling system helps save on compressed air during the stretch blow molding process. This system reuses as much as 100% of the inflation air P2 (28 to 40 bars) for preblowing process P1 (four to five bars). The arrangement of the valve set reduces dead space, and so limits compressed air. The lack of compressed air in our mechanical stretching system adds to overall energy efficiency.

MAINTENANCE

The modular and highly standardized design of the BLOMAX machines also allows users to devise a maintenance plan that is among the most efficient in the industry. Spare parts expenditure adds up to just about 2% of the investment and only 225 to 250 hours of maintenance per year (at 8,000 operating hours).