How to improve the strength of plastic buckets?

Now I use Saudi HDPE bl3 and the weight is about 84 5 grams, but the strength of the barrel is not very hard, and then I added some Zhongtian T03 PP, the strength is not very good, only hardened A little bit, adding too much will affect the swelling. There are too many defective products, which are far from the strength of other people's barrels. Other people's barrels give me the feeling that it feels a little frosted and looks a little bit opaque. , Slightly black, almost invisible, and then it is hard, the same weight, but ours is whiter. . . What else do I need to add, teachers!