Polypropylene (PP) is actually one of the most common polymers in daily life. It has a translucent effect and is very resistant to chemicals and fatigue; coupled with food and microwave safety, it is usually used in household plastic containers.
Polypropylene (PP) is actually one of the most common polymers in daily life
And for 3D printing, PP is very suitable for making anything that is lightweight, waterproof or durable. For example, hinges represent a very common use because PP can be flexed repeatedly without breaking. PP's excellent durability makes it an attractive material, but it is well known that it is difficult to handle when applied to 3D printing. Let's look at the challenges of this material and several ways to solve them.
Warpage is caused by uneven heat shrinkage
The main problem with polypropylene is its poor adhesion. Although this may be good for some processing methods, it is not so good for the 3D printing process. This can make it difficult for prints to attach to the print bed and cause frequent failures.
Another challenge is that polypropylene has a semi-crystalline structure. During 3D printing, this means that high warping stresses are generated, which can cause the first layer that is stuck to the print bed to detach completely. Since print bed adhesion and warpage are the main issues we face, this is also the challenge that the industry wants to solve to successfully 3D print with polypropylene.
1. Paste the transparent packaging tape on the print bed
Tape is often used as an adhesion aid on print beds. Kapton tape and blue 3M tape are common choices. Unfortunately, these classic options do not work well when using PP materials because PP does not adhere well to various materials.
Fortunately, most transparent packaging tapes are made of polypropylene. Therefore, this is counter-common sense. You can try printing on transparent packaging tape. Although the surface of this tape is relatively smooth, it can make the same PP material more easily adhere to it. .
2. Use a larger base plate
In order to resist the high warpage stress of polypropylene, a larger base plate is needed, which will increase the surface area of the first layer to be printed, reduce the concentration point of warpage stress, and increase the probability of successful printing. It only needs to be peeled off after printing, and it has almost no effect on the outer surface of the model. When using PP, it may be necessary to increase the size of the base plate beyond that of other materials.
3. Increase the heat temperature
Raise bed temperature to reduce warpage and parts fall
Another way to reduce warpage is to increase the bed temperature. This can prevent PP from cooling too much, thereby reducing the amount of shrinkage. By reducing shrinkage, the amount of warping stress generated can be reduced. A good starting point is the PP default settings for the printer or filament manufacturer, if there is a recommended configuration. Otherwise, start at 85 ° C and gradually increase the hot bed by 5 ° C until you find the optimal temperature-it should be between 85 and 100 ° C.
It may also be beneficial to close the 3D printer to retain heat and prevent temperature fluctuations. If you want to get better 3D printing results, you can try to make the 3D printer's closed cover yourself, such as acrylic material.
Printing PP materials with Prusa 3D printer
Since PP materials are not so common in 3D printing applications, it is difficult to find mature solutions; but the raw material PP itself is one of the most widely used plastics, so it is necessary to try more during the printing process in order to obtain the ideal Print effect.