Large tonnage injection molding machines (>500 tons) were not much beloved by plastic injection molders for many years. They were just so, well, unwieldy for lack of a better term.
Then there were the shipping costs. In a word, they were understandably high because of the sheer weight of the plastic parts which were being produced by the large tonnage behemoths. Many of these monsters were used for large-part molding for automotive/transportation, industrial and appliance customers. The result was that most custom molders didn’t like going much beyond the 400-ton range, with 500-ton presses being their absolute limit because of the expense of plant infrastructure to handle not only the presses but the large molds, as well.
That was then, this is now: over the past 10 years, the demand for large parts by the customers of plastic injection molders has taken off because of three main factors:
- increases in metal-to-plastic conversions for cost reasons and improved plastics technology
- advances in thermoplastics themselves
- the increasing capability of machinery manufacturers to build large, energy-efficient machines that offer fast cycle times
Exact metrics on the number of large-tonnage press sales the last few years are still unclear. However, what is clear is that large tonnage machines are now out-selling smaller machines by an increasing margin.
This shift to larger machines means plastic injection molding companies have been forced to build more plants, closer to their end-use customers, because of shipping costs. But it’s an investment many molders are willing to make because of the increased revenue large plastic part manufacturing is bringing them.
As note above, there are other considerations. Molding companies says you can’t just install a large press alongside smaller presses and call it a day. Beefed-up infrastructure has to be in place, such as reinforced concrete floors, bigger cranes for moving large finished parts, even bigger forklifts. Basically, you just need to make everything bigger and better.
But isn’t bigger and better what American manufacturing should be all about?!