Novel Dual-Wheel Blow Molder Allows Quick Product Changes

A rare combination of high output capacity plus versatility to accommodate high-mix, quick-change production is afforded by a new style of wheel blow molding machine from Wilmington Machinery. Founder and president Russ LaBelle says this is the first model of this type he has built, and he does not know of any other such machine on the market—though he notes that a processor many years ago built a machine for itself along somewhat similar lines.

Guide rails allow one wheel to be slid offline while the other is in production. Availability of two wheels fully tooled for different products permit changeover in minutes rather than hours, for modest additional investment.

Quick-Change Dual Wheels

The essence of this continuous-extrusion blow molding machine is two wheels mounted side by side, only one of which operates at a time. That way, the wheels can be tooled for different products and different output rates—with single or dual cavities, for instance. Each wheel is mounted on rails so that one machine can be slide out of action and the other moved into the molding position. This means that changeover time from one bottle size and shape to another can be reduced up to 75% compared with changing molds and mold positioning on a standard wheel, according to LaBelle.

Change from one bottle size and shape to another in just one-quarter of the usual time.

The new model MSBW60-DC has two all-electric, 60-station wheels, each of which can carry single or dual cavities. Throughput capacity is said to be up to 600 bottles/min with single cavities and double that with dual cavities. The machine is suited to small bottles from 1 to 10 oz for single-serve drinks, personal-care, and chemical products.

Quick disconnects for air, water and electrical services reduce wheel setup time to a matter of minutes instead of hours. Further, preventive maintenance can be performed on one wheel while the other is in production. Trimmer setup is also said be comparatively quick.

The new system has a common extruder, die head and trimming system. The cost of the machine with two sets of molds is said to be only 15-20% more than a single wheel with two sets of molds. If volume requirements increase, the extruder can be dedicated to one wheel, and the other wheel can be retrofitted with its own extrusion and trimming systems. This minimizes the investment for a second production line.

The machine is available in several configurations with different clamp force, bottle-size capability, single or dual parisons, one to six layers, and radial mold positioning (aka variable pitch), and custom features as required.