The print quality of 3D printers is affected by multiple factors, such as temperature and printing materials. Understanding these factors can help us improve print quality.
The accuracy of the 3D printer itself lays the foundation for printing
The manufacturing and assembly accuracy of 3D printers, as well as the vibration during operation, have a fundamental impact on printing quality. When purchasing a 3D printer, it is necessary to confirm its accuracy, which is to some extent determined by the mechanical structure of the printer. Unlike ordinary printers, 3D printers not only move in the X and Y directions, but also move longitudinally in the Z axis. During this process, the movement of the wire is accompanied by friction between the components, which inevitably leads to deviations. For example, the XY plane error is affected by the frame structure and the stiffness of the materials used. The stronger the stiffness, the higher the stability. For professional users, 3D printers made of heavier printing loads and more metal materials have better stability and durability. In addition, nozzle diameter is also a key factor affecting accuracy. The diameter of the nozzle determines the width of the extruded filament, which in turn affects the detailed performance of the finished product. A smaller nozzle diameter can reduce the thickness of the printed layer and make the finished product more delicate, but the minimum diameter is also limited by the non-Newtonian fluid flow properties of the consumables. For example, the common nozzle diameters are 0.2mm, 0.3mm, and 0.4mm. If it is too small, it will cause excessive flow resistance.
Temperature affects print quality in many ways
(1) Nozzle temperature
The temperature factor in 3D printing is complex and important, and the nozzle temperature is the first to be affected. The nozzle temperature determines the adhesion performance, stacking performance, wire flow, and extrusion line width of the material. Improper temperature setting will seriously affect the printing quality. If the temperature is too low, the material viscosity will increase and the extrusion speed will be slow; if it is too high, the material will tend to be liquid, the viscosity coefficient will decrease, the fluidity will increase, and it will be difficult to form precise and controllable filaments if extruded too quickly. Therefore, a suitable nozzle temperature range should be set according to the characteristics of the printed material before operation to ensure the smooth progress of welding and forming (mainstream printing technologies such as SLA and FDM are affected by this).
(2) Chamber temperature
The temperature of the forming chamber has an impact on the thermal stress of the components. For example, when printing ABS materials, the temperature of the forming chamber is usually maintained at 55 degrees Celsius. Although high temperature helps to reduce thermal stress, the surface of the parts is prone to wrinkling. If the temperature is too low, quenching the metal wire extruded from the nozzle will increase the thermal stress of the parts, leading to warping. PLA needs to maintain ventilation and heat dissipation as much as possible, and a reasonable chamber temperature can avoid the impact of internal stress on the accuracy of the parts.
The combined influence of layer thickness and compensation
(1) Layer thickness affects the roughness of the finished product
Layer thickness refers to the thickness when slicing. Since 3D printing constructs objects by stacking layers, each layer has a certain thickness, which creates a visible step effect on the surface of the formed product. When using a large diameter nozzle, the layer thickness will increase accordingly, and although the printing speed is faster, the finished product will be rougher. Conversely, reducing the layer thickness can obtain a more delicate finished product, but the printing time will increase. Although this step effect cannot be completely eliminated (especially for FDM technology), it can be improved by setting a smaller layer thickness reasonably, although it will sacrifice some printing speed.
(2) The importance of compensation
The compensation amount refers to the distance between the actual machining contours of the parts. For models with high precision requirements, compensation (especially for inner holes) should be considered during modeling. The compensation amount should be reasonably set and compressed, and the influence of factors such as wire diameter on its correlation should be considered. An appropriate compensation amount strategy can help improve the printing accuracy of high-demand models.
the balance between extrusion speed and filling speed
In the 3D printing process, the reasonable matching of extrusion speed and filling speed cannot be ignored. If the extrusion speed is reasonably matched, the larger the cross-sectional width of the extruded yarn, the greater the extrusion speed. When the extrusion speed increases to a certain value, the extruded filaments may adhere to the outer conical surface of the nozzle, affecting the appearance of the model surface. When the filling speed is faster than the extrusion speed, it is easy to break the filament due to insufficient material filling, making it difficult to form a complete part; conversely, when the filling speed is slower than the extrusion speed, the fuse is easy to accumulate on the nozzle, making the forming surface material uneven and producing defects that affect the printing quality. It can be seen that only by setting the filling speed and extrusion speed within a reasonable range can good printing results be guaranteed.
The influence of various characteristics of printing materials
(1) The impact of material type
There are various types of printing materials, such as common materials such as ABS, PLA, and paraffin wax. Different types of materials or the same material may have different qualities, resulting in significant differences in glossiness and other aspects of the printed model. Users need to choose the most suitable material based on the printer type and model requirements in order to achieve the ideal quality of the printed model. For concrete 3D printing, materials need to have suitable characteristics such as fluidity, stacking, fast setting time, and high early strength for smooth extrusion and stacking. Cement-based materials suitable for extrusion lamination printing process also need to have characteristics such as extrudability, stacking, suitable printing time, and workability. Different printing technologies require materials to have different properties to meet high-quality printing needs.
(2) The impact of consumable quality
Under the same material, the quality of consumables is also a factor affecting printing quality. If there are problems such as uneven thickness and wire diameter errors in the consumables, it will directly interfere with the extrusion system of the 3D printer, causing deviations in the extrusion of each layer or uneven fillers, ultimately affecting the surface smoothness and structural strength of the finished product. For example, some low-quality consumables are prone to breakpoints or adhesion, which affects continuous printing and ultimately affects the molding effect.
Equipment stability and working environment should not be underestimated
(1) Equipment stability
The stable state of the entire 3D printer during operation is a necessary element for printing high-quality models. If the printer is placed on an unstable table or its support structure, it is easy to shake during printing, which can cause deviations in the printing path, misalignment in hierarchical stacking, and ultimately affect the printing accuracy. Especially for printing some high-precision and long-process models, stability is more important. For example, if a large 3D printing project is in progress and the printer suddenly shakes, the entire model may be scrapped.
(2) Working environment
The temperature and humidity conditions of the working environment cannot be ignored. Excessive cold or heat, excessive humidity or dryness will affect different printing materials. For example, some printing materials may soften and deform in high temperature environments, affecting their normal extrusion and accumulation; low temperature environments may cause materials to become brittle and increase the risk of wire breakage. At the same time, if dust and impurities in the environment fall into the printing material or printer, it may cause problems such as blockage and wear, affecting printing. In addition, in some printing scenarios that require special environments, such as photocurable 3D printing, excessive or insufficient ultraviolet light conditions have a key impact on the curing effect during the printing process. If the UV light energy is inappropriate, it will cause incomplete or excessive curing, resulting in component deformation or strength not meeting requirements.
Design and slice processing link associated printing effect
(1) Model design
At the source of 3D printing projects – the model design part, there are many factors that affect printing quality. Designers need to have a clear understanding of the printing system’s capabilities (such as printing size, achievable curvature, ability to handle hyperboloid surfaces, hollowed-out structures, local suspension situations, etc.), and create models based on these limiting conditions. If the model contains elements that are difficult for printers to achieve, such as excessively sharp corners, excessive local suspension, etc., it is easy to cause printing failure or low quality. For example, when the print nozzle cannot construct a long-distance suspended structure without support, it is necessary to modify the design in advance or add temporary support structures.
(2) Slicing operation
The slicing process determines the basic parameters of the printing process. The thickness of the slicing directly affects the layering thickness of the print, which is closely related to the surface quality of the finished product. Different slicing path planning will lead to differences in printing motion trajectories, which in turn affects the printing quality of the components. The advancement of the slicing software algorithm, the accuracy of the operation, and the rationality of the user’s setting of the slicing parameters are all ultimately reflected in the quality of the printing model. For example, for a complex model, if the slicing software’s segmentation algorithm is poor, it will produce burrs or defects at the boundaries.
The subtle role of operator level and operating status
(I) Operator level
The operator’s proficiency in operating 3D printers and their mastery of relevant professional knowledge can greatly affect the printing quality. An experienced operator can accurately adjust various parameters (such as nozzle temperature, layer thickness, printing speed, extrusion speed, etc.) to adapt to different printing job requirements before printing; correctly select printing materials and set material size parameters, and be able to monitor the equipment’s operating status in a timely manner during the printing process, anticipate and effectively handle possible faults (such as nozzle blockage, material depletion, etc.). Beginners may make mistakes in parameter settings (such as selecting the wrong extrusion speed or inappropriate chamber temperature), or fail to handle some unexpected situations during the printing process in a timely manner (such as sudden blockage of consumables), resulting in a decrease in print quality.
(2) Operator operating status
The operator’s operating status at that time can also inadvertently affect the printing quality of the 3D printer. For example, if the operator is tired and inattentive, they may ignore some prompt signals emitted by the printer (such as abnormal sounds or vibrations during the printing process), and fail to adjust the printing status in time, which may gradually develop small problems into big problems that affect the printing quality. Moreover, in some manual intervention processes (such as manually adding support structures, calibrating the initial printing platform, etc.), if the operator’s operation is inaccurate or not delicate enough, it will leave hidden dangers that affect the printing quality.