IT Published

Four done, nine to go: CMW upgrades thirteen blast machines to keep up with moulding lines

An upgrade to four drum-type shot blast machines at CMW in Tianjin, China, has reduced cycle time by 25%, ensuring the blast machines can keep up with the production output from the foundry’s 3 DISAMATIC moulding lines. A team from Wheelabrator carried out the blast wheel upgrades on an initial four out of 13 non-Wheelabrator blast machines.

CMW, part of China Metal International Group, has a monthly output of more than 9000 tonnes, producing automotive parts and components for leading brands, as well as other mechanical and compressor parts.

The problem: blast equipment that can’t keep up

The team at CMW was not satisfied with the quality from its 13 existing drum-type machines, with castings frequently requiring re-blasting. Capacity was also falling short of requirements, with blasting throughput unable to match the moulding lines’ monthly output of 1500 tonnes each.

Mr. Xuejun Zhao, manager of the maintenance department at CMW, explains: “We have invested in high-quality, high-volume moulding lines to efficiently produce excellent castings for demanding customers in automotive. To ensure high overall productivity of our operations, we need our blast machines to be in tune with the rest of the line in both speed and quality. These thirteen drum-type machines were no longer achieving that.”

Instead of replacing the equipment, CMW contacted Wheelabrator in Changzhou to discuss options for increasing the performance of the machines through upgrades.

The solution: strategic upgrades add precision and power

The shot blast experts at Wheelabrator recommended upgrading the blast wheels on the machines to powerful, easily adjustable Wheelabrator “Universal” U70X500 blast wheels with 30kW power each. The “U” wheel is a heavy-duty blast wheel and particularly suited to foundry and forge applications. It features a relatively compact design, high performance and high efficiency.

The low height of the wheel shaft of the U blast wheel means that, once installed on the old drum-type machines, there is sufficient clearance around the wheel to adjust the abrasive stream. This, as well as the ease and precision of setting the angle of impact, ensures optimum blast cleaning efficiency and minimizes wear on liners and machine.

The more precise and more powerful blast process has brought shot blast cycle time down from 15 to only 11 minutes, a reduction of more than 25%. Castings no longer have to be blast-cleaned a second time, maintenance requirements are reduced.

“We are very satisfied with the results of these first four shot-blast machine upgrades. They have already optimised and streamlined production, meaning we are now getting the most out of our equipment investments up and down each line, without bottlenecks. Changing only the blast wheels has given us the performance improvement we need at a relatively low cost – especially when compared to buying new equipment.”

Mr. Xuejun Zhao, maintenance department manager at CMW

The four blast wheel upgrades were completed between October 2019 and May 2020, with the remaining nine to follow soon. In addition to the four drum-type machines, the Wheelabrator team also upgraded 1 Wheelabrator hanger-type blast machines with new U70X500 blast wheels (with 45kW each).