20L plastic bucket made with 28s is difficult, which first you need very good quality injection mold, which core and cavity inserted CuBe material to make the cooling time short. And please check if your bucket design need slider or not. If there is slider on the mould, the cycle time will be longer.
For the normal design bucket mould core and cavity with CuBe the cooling time will be about 15 to 20s and ejection time is about 4s. 20L bucket plastic injection mold is very big. If you want to make it with 28s, you may need high speed injection machine, robit to take out the bucket from mould, and chiller to give better cooling. It is very costly to make all the equipment ready with you. I don't think you will out of the business if run this mould with cycle time 60s. Because in China 20L bucket run with 60s cycle is very normal, but they are still on the business.
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