There is an emerging technique that is using welding to restore significant economic value to a huge number of assets that have been languishing on the shelves of manufacturing shops.

The technique involves the use of welding to start the process of reconditioning molds and dies used in the plastics industry for re-use, and it stands to give a new foothold to welding in the shops and plants that are used to using milling, drilling and other traditional metal chipping processes.

There are thousands of plastic molds and dies sitting on shelves and thousands of others that have been shipped to other countries that the plastics industry does not use anymore because the products that they were designed for are out of style or obsolete.

Those molds represent a huge investment in steel or aluminum, and the bulk of them the metal that helps to give them the inertia to withstand the pressures used in injection molding and extrusion processes is very re-useable. It never goes out of style.

They range from the huge molds used to produce automotive instrument panels to the multi-cavity molds used to make plastic forks and spoons. Some of them weigh several tons, and have cavities that represent less than half of their total original weight, and some of them are extraordinarily elaborate. The machining cost for the elaborate molds represents hundreds of times their value as scrap.

This new technique uses welding to lay down several layers of new metal in the cavities of those molds, so that the cavities could be re-machined to make a new product. The challenge in the technique is to get the metallurgical properties of the new layers of metal and the heat-affected zone to correspond to the properties of the base metal.

While the use of welding equipment to rework parts of molds has been done in the past, this technique offers a new perspective on using welding in a general and widespread way to refurbish molds and dies on a large scale.

It's a brilliant idea. It marries two metalworking processes welding and machining that seem to be dissimilar and that have been separated in the past, and the marriage promises to return unused and expensive resources to practical economic uses. The savings on the steel or aluminum could be immense and, because much of the cavities in these molds and dies has been removed in prior machining, the lead times for new products can be reduced sharply.

We are planning to write about that application of welding for a future issue, so keep a look out for it. In the meantime, I'm interested in hearing about similar brilliant ideas that break welding out of its traditional role and mark new grounds for its uses.

Dean Peters returns as a contributor
In this issue, Welding Design & Fabrication is welcoming Dean Peters, our former editor, back to our pages as a consulting editor.

Dean will be writing a column each month for this magazine on issues that he sees the welding industry facing and on developing and promising technologies that could affect the industry in the future.

We expect that he will be a valuable and a well-appreciated addition to our staff.

You can leave messages for Dean at 216-931-9332 or, via email at dpeters @penton.com