Especially with ABS but also with less common materials like nylon, the materials sometimes wants to deform during printing. This warping leads to unsuccessful products and sometimes even to a hard hit: the printhead clashes up against the pulled up material. Naturally you want to avoid that!
Why does a product warp?
A print can distort because the material shrinks when it cools down. How much a product shrinks depends on the shrinkage strength of the material. Because the printbed is nice and warm, the shrinkage at the bottom will be minimal. The higher the products, the more shrinkage. This difference creates stresses in the material and ultimately a warped model. Warping can occur at two locations in the model. First of all, there is delamination. Two layers in the model pull away from each other and a crack is created. This is mainly due to adhesion errors. If you use the correct settings, delamination should not occur. The second variant is the warping at the bottom of the product. This is more persistent, but fortunately there are a number of methods to prevent this.
Place a raft
A raft is basically an underground for your product. You print a number of very light layers under your product. This ensures less shrinkage differences and tensions at the bottom of your product. If there is warping, then this mainly affects the raft instead of your product. It is therefore important that the raft is wider than your product, so that it does not cause problems when the corners curl up.
Temperature control is very important in countering wrapping. Choose a printer where the cooling of the product is as gradual as possible. For this purpose, a closed and conditioned box is essential, among other things. This way you have control over the temperature in the cabinet to minimize differences in shrinkage.
‘Glue’ your model
When the product is warped, two forces oppose each other: the tensile force of shrinking material in the upper layers versus the tensile force of the printbed circuit board. In short: if the bottom is firmly fixed on the PCB, it will not be able to pull up easily.
There are a number of tools to think of to get the model firmer on the plate. A common method is the lubrication of Dimafix. This liquid changes in a type of adhesive layer when reaching a temperature of 80 degrees. It holds the product on the plate. When the bed cools down, the Dimafix goes back to a solid phase and simply releases the product from the plate. Another method is to lubricate a slurry, which you can make yourself from acetone and ABS. However, be careful with this because this slurry also remains sticky during cooling. You can not easily remove the product from the printbed. Broken glass plates can be the result of an excess of slurry. We therefore always recommend choosing the safer option; Dimafix.