As the title of this magazine says, we cover the engineering, building and repairing of molds. The decision to get a mold repaired, refurbished or reworked is not an easy one. However, as a mold wears - gates and runners wear out, there is excessive flash on the parts when they come out of the press and product quality is uncertain - the question becomes how can you afford not to get the mold refurbished? The molder has to consider the downtime and cost involved in repairing a mold versus the cost of a new mold. If it is decided that a repair is the right course of action due to time and cost restraints, then the next decision is whether to try and fix the mold in an in-house repair shop or to outsource the job to a moldmaker.
According to Kevin Hartsoe, president of Neu Dynamics Corporation (Ivyland, PA) - a manufacturer of precision injection, transfer and compression molds and dies for the electronics, medical and insert mold industries - most mold shops don't have full repair capabilities in their facilities. "Usually companies that do a lot of molding have a machine shop, however they don't rework molds or have this capability," he states. "They basically do small repairs - fixing broken core or ejector pins - rather than correcting worn gates and runners."
In addition, it's not a good idea to tie up an in-house repair shop with a mold refurbishment. "Generally, a complete mold rework is like building an entire mold, except you don't have to buy most of the steel," he says. "It really does pay to outsource. For us, the time it takes to do a complete rework is generally 60 to 70 percent of what a new job would take and the result will be an almost brand new mold yielding the same high quality parts as when it was first purchased.
"It also puts the mold shop in a situation where it is getting quality parts out of a mold that's probably already paid for itself many times over, and the capital outlay isn't nearly as great on a rework as it would be on a new mold," Hartsoe continues. "And the potential downtime is reduced by up to 40 percent."
The Right Fit
Once the decision is made to send the mold out for rework, the molder must carefully screen the service provider to ensure its needs are met. Complete service is key - the service provider should possess the capabilities to do any and all of the work that needs to be done in-house - excluding plating and heat-treating.
"First, the molder should look for a company with engineering capabilities, because a lot of molds that are reworked are at least seven to eight, or maybe even 10 years old and have been in production around the clock. There are often no blueprints for them," Hartsoe says. "So, the mold may need to be reverse engineered before it can be refurbished. Also, with a mold refurbishment, you have the opportunity to actually improve on the original design and make the mold better. You get to see where the mold has worn, and by adding a different plating to strengthen a previously weak area, you'll actually get a longer cycle time out of a reworked mold than you would a new mold."
Another major concern when selecting a shop is its dedication to this type of work. According to Hartsoe, a great majority of mold builders only want to build new tooling and treat refurbishment as an inconvenience. In most instances, a rework mold has more critical delivery requirements because the mold is out of production and not making a profit.
It also is important to find out to what extent a service provider will rework the mold. Hartsoe points out that some companies simply replace the inserts, others offer complete refurbishment - everything from reworking the entire mold base, regrinding all components and replacing the ejector pins, springs and bushings.
Communication between the molder and the service provider is essential. Hartsoe finds that a mold evaluation checklist helps to keep the lines of communication open. "When the molder sends a mold in for rework, we'll examine it and list everything that we find wrong," he explains. "We then go back to the molder and say, 'Here's what we found, here are some wear areas, here's what needs to be replaced.' If necessary, we can go to the customer and evaluate the mold. In some cases, we can even build replacement inserts and redesign the tool in areas that wear a lot. So if an area gets damaged in the future, the molder only has to replace a small insert versus the entire cavity."
Having a mold that's just like new without paying for a new mold not only makes good business sense, but it also saves time and frees up cash for investment in new molds for new products. Factor in the added benefit of keeping your customers happy with a mold that continues to produce high-quality parts, and there's no good reason not to take the time to have that old mold refurbished.