Mixing dough is one of the most crucial steps in the biscuit, cookie and cracker production process.
Consistency is the key: each batch must be homogenous; every batch must be the same. Adjusting the plant to correct problems caused by inconsistent mixing is a hopeless task and we think everyone would agree that unless you start with a good mix there is no way you can finish with a good product.
Many of the causes of inconsistent mixing have been eliminated over the years but there is one that lingers – mixer blades with centre-shafts.
If you were mixing by hand, a shaft in the middle of your bowl would be a bizarre and unnecessary obstruction. Working round it would increase the mixing time, and ingredients would adhere to it. Mixing efficiency and quality would be lower and emptying the bowl would take longer. A shaft would simply make no sense.
These shortcomings apply to industrial scale mixing. We would suggest that the process has been compromised for manufacturing engineering reasons; a shaft makes it easier for engineers to build the machine. The shaft provides rigidity to the blade from an engineering design perspective, and this is important because of the significant power and torque being transmitted.
Often the blades are fabricated by welding at least two components together, which leaves it prone to fatigue and cracking. Also, the shaft flexes which can create seal wear and leakage from the bearing.
There are also operational problems: mix times are longer, mixed dough cannot be discharged without manual intervention, and the accumulation of ingredients and partially mixed dough on the shaft presents a hygiene problem.
To achieve the necessary levels of strength, rigidity and longevity in a curved blade profile, the optimum method of manufacture is casting. It is a slightly more costly option but the financial benefits arising from the increased operational efficiency and longer service life more than compensate.
At Baker Perkins we have been making shaft-less mixers for years and our customers swear by them. They understand that when it comes to starting your process right, cutting corners on blade construction makes no sense at all.
Click here for full details of Baker Perkins’ High Speed Mixers