Ceramic Industry

PPP: Much Ado About Resin

August 1, 2004
The benefits of resin dies and RAMTM pressing are making this a popular combination for an increasing number of production potters

Above: These High Plains medium elliptical serving/baking dishes, produced by Davy Pottery, are RAM pressed with resin dies.


Several years ago, a number of articles were published describing the emergence of porous resin dies in the U.S. market.1-4 Benefits such as cost reductions, a simplified manufacturing process, an enhanced die life (compared to plaster) and improved lead times were touted, but there was one major drawback-the upfront cost, especially for companies that were not already pressing their products. It seemed clear that the major applications for this technology would exist only in the large manufacturing realm, and that small pottery producers would have little or no interest in pursuing this expensive new forming method.

Of course, appearances are often deceiving. While the technology has provided a competitive advantage to a number of large tile, dinnerware, sanitaryware and architectural ceramic producers, it has also quietly made significant inroads within pottery production circles. Potters who were initially wary of the costs involved and concerned about losing their unique styles and designs have discovered that pressing with resin dies is much more efficient than many other forming methods, and that the money spent on the press and dies is quickly recouped in higher yields and fewer mold replacements. Additionally, the enhanced quality and consistency achieved by pressing with the resin molds is leading to increased sales and higher profit margins. For an increasing number of potters, the benefits of pressing-combined with the new resin mold technology-are making this forming method an essential part of a growing business.

The Petree Pottery bundt pan uses a plaster die for the top half…

Solving a Complex Problem

When John Petree of Petree Pottery, Wilberton, Okla., designed a new bundt pan in late 2002, he had no idea how popular the new piece would be. The company produced a number of functional pottery lines, all of which were hand-thrown by John. Although business had been growing steadily since the company was founded in 1992, John had been able to keep up-until the new bundt pan was introduced. John suddenly realized that the company was at a crossroads.

"I was maxed out on the number of products I could throw, but we weren't exactly where we wanted to be financially, and the demand for the new bundt pan was overwhelming," he explains. "We either had to back off and change the situation, or we had to find another way to produce more pottery. Pressing seemed to be the ideal solution."

The company contacted RAM Products Inc. in Columbus, Ohio, and sent them the original bundt pan design so that RAM could make the mold for the new press. John assumed the new mold would be plaster, so he was surprised when RAM told him that the bottom half of the die needed to be made out of resin.

"The design of the piece was quite complex-in fact, RAM told us that it's probably one of the most difficult dies they produce," John says. "They couldn't get the plaster to work correctly for the bottom half of the die, so they used resin instead."

Petree Pottery subsequently purchased several other plaster dies for some of its other popular product lines. But the more John worked with the bundt pan die, the more impressed he became with the performance of the resin.

…and a resin die for the bottom half.
"It's easier to run the resin die than plaster-it functions much better, and it's much more durable," he explains. "We produce about 300 to 400 bundt pans per week, and we're constantly replacing the plaster half of the die. The resin die, on the other hand, is good for 10,000 or more cycles, so we'll go through four or five top halves before we even begin to see wear on the bottom half of the die."

Petree Pottery has also seen benefits from the improved consistency of their products as a result of using a press. Because the company produces functional tableware pieces, quality is paramount. But with hand-turned pottery, no two pieces are ever exactly alike-especially if they're being hand-turned by more than one potter. As Petree's business has continued to grow, the press has been crucial in enabling the company to produce a larger volume of products while ensuring the optimum quality of each piece.

"You can only grow so much, and then you have to figure out how to get across that line. Using a press has enabled us to do that," John explains.

Although the company has primarily focused on retail sales in the past, it expects to move completely into wholesale by 2005. As it makes the transition, it also plans to transfer most of its products to pressing-exclusively with the resin dies.

"With the plaster, it seems like we have a die wear out every time we get really busy," John says. "If we've forgotten to order an extra die in advance, then we have to wait around, and all that downtime costs us money. As we switch over our operation from hand turning to pressing, we plan to go strictly to the resin dies."



Eliminating Plaster Hassles

For Susan Davy of Davy Pottery, Burlington, N.D., the decision to transfer some product lines to a press was made 11 years ago, before resin dies were available. Like John, Susan discovered that she couldn't hand-turn enough pottery to keep up with demand, and she couldn't find enough qualified potters to hire. After seeing a demonstration of the RAM(tm) Press at a trade show, she decided to give it a try-but it wasn't exactly an easy switch.

"It was a whole new technique, and I wasn't at all machine-oriented. It took about five years for me and that press to become friends," she laughs.

In the process, she also became friends with Dick and John Pelleriti, officers of RAM Products. When RAM first began supplying the resin dies through ResTech-US in early 2000, the Pelleriti's immediately thought of Susan, who had been replacing some of her plaster dies quite frequently.

"Because the resin lasts so much longer than the plaster, John thought it would be perfect for some of my more popular products. Of course I picked a really hard shape for them for my first piece. But it forced them to work out some bugs, and I have not needed to order a new die since for that particular piece because it has lasted so long," Susan says.

Susan still hand turns 60% of her products, but she has purchased several other resin dies and plans to transfer more of her plaster dies to resin in the future, as the dies need to be replaced. Although the resin dies are more expensive, Susan believes that eliminating some of the hassles associated with plaster makes the resin dies well worth the extra price.

"When I think of all the plaster dies I would have had to buy for the products where I've switched to resin dies, it was definitely worth it," she says. "The resin dies are more expensive, but by the time you've purchased two plaster dies, you could have already paid for one resin die. And if you're buying two to three plaster dies per year for a really good selling item, you have more than made up the cost."



High Plains stoneware mugs produced by Davy Pottery, Burlington, N.D. The mugs are RAM pressed with resin dies and are then reshaped by hand to achieve their unique look.

Considering All the Angles

Both John and Susan caution that neither the pressing process nor resin dies are right for every studio. According to John, potters who only sell their products through retail outlets and art shows are often stigmatized if they switch to pressing.

"People don't treat our products the same as if I were hand-turning every one of them," he says. "The products are seen as having less value, so we have to sell more to make the same amount of money. But we're also making a lot more pieces in less time.

"If you have a successful pottery business, then I think you can't avoid being in the situation where you have to figure out whether you want your company to keep growing or remain small," he adds. "If you want to move toward the wholesale market, then the only way to keep up with demand is to change to a pressing process."

Once a company has made the decision to use a press, the question of resin vs. plaster dies remains. Susan admits that there are some learning curves to using resin. "It takes an entirely different approach compared to using plaster dies," she says. "When we first started using the resin dies, the clay wanted to stick and pull, and create dimples here and there. It took us a little while to figure out that we had to use hot water-not just warm water-to water the die down. We now keep a couple of teakettles in the studio so that we can easily heat water for the dies."*

According to Susan, prepping a resin die takes approximately two hours compared to the one hour required to prep a plaster die, but this extra time is more than compensated for by the resin die's durability. "With plaster dies, after a couple hundred pressings, my dies become quite pitted. I use a fire clay with a lot of tooth, so everything pressed with those dies looks like heavy-duty gritted sandpaper, and we have to spend a lot of time sponging that off. That will never happen with the resin dies," she says. "So even though it takes longer to get the resin dies up and running, in the end they save us a significant amount of time compared to plaster."

Storing the resin dies also carries some special requirements. Unlike plaster, which should be as dry as possible before storage, resin dies should not be purged completely of moisture or they will shrink. Since moisture encourages the growth of bacteria, the dies must periodically be run through a chlorine bleach bath.

"You just have to approach the resin dies differently than the plaster. Once we figured that out, they've been a dream," says Susan.

John agrees. "The difference in how the resin die runs and the quality that it's giving us more than makes up for the initial learning curve and upfront costs. I'm really sold on the resin," he says.

*Note: According to ResTech-US, the temperature of the water used to prepare resin dies should be between 130 and 160°F. The use of boiling water is not recommended.

For more information about resin dies, contact ResTech-US, 1091 Stimmel Rd., Columbus, OH 43223; (614) 443-0626; fax (614) 443-4813; e-mail info@restechus.com ; or USG Corp. - Industrial Products Division, 125 South Franklin St., Chicago, IL 60606; (312) 606-5691; fax (312) 214-5805; e-mail dbrandt@usg.com .