A hopper is a container that is widely used in a wide range of different industrial processes to dispense a material at different rates.
The hopper is predominantly used in food production to hold a volume of material such as flour or sugar, which can then be distributed at a particular feed or rate into another container or vessel.
Why produce the hopper in stainless and not mild steel?
Due to the chromium element found in stainless steel, this creates a material surface that is oxidised and therefore less susceptible to corrosion compared to other steels. In addition to this, stainless steel is generally chemical resistant and does not breed bacteria easily, of which both are vital to the food production industry.
How do you make the form a stainless hopper from a sheet of metal?
In simplistic terms, a tool or former is made, which has the required dimensions of the hopper, so when the material is formed against the tool will result in forming the shape of the hopper .
The tooling process takes a great deal of skill to take a solid steel billet and then gradually remove material to create the required form.
This video has been slowed down to show the material being removed.
Artec Engineering Precision Metal Spinners has the in-house capability to produce all of our tooling, which reduces not only lead time but maintains high standard and quality, synonymous which is at the core of our business. The tool shown in the video, was made form a solid billet of EN24T.
Why use a CNC spinning lathe?
For this particular part, was produced on our bespoke DENN CNC spinning lathe. Due to the form of the hopper, the material has to be stretched a long distance across the tool. As the CNC is fully automated, this can apply the correct amount of pressure to stretch the material enough without splitting.
In addition, with high volume parts, the CNC can produce dimensional repeatability each time. The machine is also designed to use tooling weighing over 1.3 tonne and will produce high and low volume production runs with world class quality finish and dimensional repeatability.
This DENN bespoke CNC spinning lathe was built to our specification and will produce spinning’s up to 1500mm in dia. from all materials up to and including 5mm st/st, 6mm m/st & 7.00mm Alloy.
How does the spinning process begin?
The first stage of the process, is to work out what size lasered blank is required to be spun over a metal former.
When any new part is being spun, the blank size is always approximate. When the parts has been spun , the operator can establish if the blank size will require increasing or decreasing.
Too much metal will result in excess material having to be removed or tool little material will result in the material not stretching enough, being short of the end of the tool or can thin too much and split.
What happens during the CNC spinning process?
Once the spinning programme has been created, the CNC operator will then load a stainless steel blank onto the tool, which is located by a ctr. hole. A lubricant is then applied to the material to reduce the friction on the wheels and a pressured pad is engaged to hold the blank in place.
You can see from the video that pressure is applied from the automatic rollers to produce the requires shape at different points.
How do the spun parts get finished?
Once the part has finished the spinning cycle, there may be some material that may require removing to ensure the spinning is dimensionally correct.
This particular part had to go onto the turning lathe, where the the rear diameter is skimmed and the nose section, so the part is dimensionally correct.
Depending on the finish spec stated on the drawing, some parts will require an additional finish such as polishing, painting, alocrom and anodising to name a few.
Due to the hooper being used in the food industry, each spun part then goes onto our polishing bay, where any internal and external marks are removed and the surface is given a 320 grit finish.
The goods are then inspected and packaged ready for dispatch to the customer.
Please check out our other projects @ www.artecengineering.co.uk or www.instagram.com/artec_engineering_ltd
If you have an existing or upcoming project, then get in touch with Artec Engineering Precision Metal Spinners.
Tel: 01243 375555
Email: [email protected]
