These are testing times.
But we’ve always liked it that way
Since the Bonnot Company was founded in 1891, we’ve built our reputation as one of the world’s foremost suppliers of custom designed extrusion equipment. Our long-term success is based on the quality of our extruders, plus our absolute, unwavering commitment to testing.
So how does this benefit you? Well, let’s pretend you’re a new customer who wants to invest in a brand new Bonnot extruder. There are two scenarios at play here: Scenario #1, you already have a product and a recipe, and you simply want another Bonnot extruder on your production line. And scenario #2, you’ve never had a Bonnot extruder and you want one because of our great reputation, build quality and reliability traits. The outcome is the same…you guessed…we run a test. And then some more tests just to be sure. Because we will always want to test before you buy.
By running tests, we ensure that both parties are absolutely delighted with the machine performance. You because you get an extruder that does what you want it to do. Us because we are confident the machine designed for you will achieve your objectives.
This is the process for validating our extruder is the right fit for you, your business and your product. As there is no reliable theoretical modeling that accounts for all the variables factors in the extrusion process, it’s our best practice to a series of tests with your formulation to confirm machine performance.
First, we’ll identify and document your objectives and the any manufacturing constraints (i.e. maximum temperature) for the product.
We also need to understand what success looks like [literally] by confirming the product success factors:
- Surface finish/appearance
- Length and diameter (L/D) of the pellet/profile
- And the allowable tolerance or variance [if any]
We then need to reconfirm your expectation of production throughput (i.e. lb/hr) and whether the machine can achieve your objectives. Our proven testing methodology considers all your objectives and constraints and captures rates that either achieve your objectives or provide essential data for scale-up modeling.
After we conduct trials considering all of these variables, we then move to the design phase of your extruder, including any necessary ancillary equipment. This is based on the understanding we’ve built of your objectives and constraints; the type of extruder, and kind of screw/barrel selection; and including the mixer, batch size and level of intensity required..
We leave no stone unturned in our testing process, and by far the most important aspect is the health and safety of the people using the machine. This is why safety training is included as part of our standard testing process. The training involves a full understanding of the risks involved with the safety guarding of the machine, its hot surfaces, and sharp hazards like the cutter head. We’ll also train you on where personnel should position themselves around the extruder and ensure safe operation.
The scope of our testing includes die design. Extrusion dies are a critical component in the formation of the desired product profile. The design difficulty centers on achieving the desired shape within set limits of dimensional uniformity at the highest production rate possible.
Die design criteria considers:
- Open area % – lower = higher pressure
- Thickness – the thicker the die, the greater “land” area, the more drag created, the greater the pressure required to push product, the denser the pellet
- Material of construction (MOC) – varies coefficient of drag (i.e., Delrin vs. steel)
- Addition of a spacer – equalizes the flow across the die by eliminating the leading-edge pressure from the screw flight, creating more uniform length if cutting. Note, not all materials will flow without mechanical aid.
- Addition of heat – often improves flow and/or surface finish of extrudate. Often just a pre-heat at the die face is sufficient.
Another processing variable that we consider is the effect of temperature management. Our Test Facility is fully equipped with temperature control units (TCU) to optimize the extrusion process. Some of the factors they are used for are:
- May be a criterion of the process to heat the product.
- Mechanical energy is generated through shear as material passes through the screw and barrel.
- TCUs are often used to cool or dissipate this heat.
- Basic principle – “stiffer” material pushing softer material.
- If material softens with heat applied, have the first barrel(s) running cooler than the exit barrel(s)/die.
Testing is of course useless if it is not recorded accurately. At Bonnot we pride ourselves in meticulous Data Collection at every stage. Not just what worked, but also what didn’t. So that once a stable output state is reached and you are completely satisfied, we collect and record essential data including operating Amps, HP, RPM, throughput (lb/min.), temperature, pressure, etc.
The test data is then summarized and recorded in a report, including videos, and shared with you.
In short, we record everything. We test everything. And we ensure that you are delighted.
We hope this sheds some light on our thorough approach, and we’d welcome the opportunity to test your product with you in person soon. Please feel free to contact us to discuss your application requirements or to learn more about our products and services.