In this article, we will highlight pressures, forces, and temperatures. The previous article already hinted at other parameters and how they can be used to control different scenarios when manufacturing. If you are new to this series, we recommend starting with the article about end-effectors – the layup tools used to place CFRP material. From there on, you can easily catch up.
The control of internal valves (e.g., for feeding and cutting the material) in most cases happens in integrated programs of the layup tool. Controlling the pressure for material clamping, feeding, and cutting are usually determined during the design of the end-effector, and their trigger points can be derived from the layup programs. Controlling these parameters using external programs can be done but is often error prone.
Controlling the heater (e.g., a laser heating unit or an infrared light source) on the other hand, is often realized by explicitly setting the heating values in the NC program that controls the machine movement, since the CAM software has information about the underlying material and can therefore adjust the heating parameters accordingly. For example, if the material of the first ply is laid directly on the layup surface, the heater should be heated longer and hotter than when material is laid underneath. There are several parameters that control the heating unit; some of which are listed below.
|Heater off [%]||The value that the heating unit is set to when no material is being laid.|
|Heater on [%]||The value that the heating unit is set to when material is being placed.|
|Heating offset begin [mm]||Describes, how long in advance the heating unit is to be switched on before the next material is laid.|
|Heating start [%]||Before touching the surface, the heater is set to this value.|
|Heating start time [t]||The machine waits this long before touching the surface to heat it up (the value of the heating unit during this time is set to heating start).|
These five parameters control the most important trigger points and temperatures for infrared and laser heating units. Values for the heating power are given in % of its maximum capacity. To see a heating unit in action, check out this video (also availabe on our youtube channel).
In next week’s article we will show you how CAM software can be used to simulate the layup process and verify the correct path the machine will take.
Until then, stay safe and stay tuned.