The 3d-printed PSU composite plastic mold is used for injection of large helicopter parts
For large parts such as helicopter structural parts, it usually takes several to dozens of tons of molds to complete the injection. Such a mold through the traditional processing technology is not only expensive, the process is also full of challenges.Not only requirement machine tool working table can bear big weight, the equipment must have the characteristic of big bearing and high rigidity, still must have enough big mesa dimension and working stroke to suit with it.Because the strength and hardness of the mold is very high, plus often using a large elongation of small diameter end milling cutter processing mold cavity, so the processing process is prone to flutter.In order to ensure the machining accuracy and surface quality of the parts, the high speed universal milling machine manufactured by the mould must have high dynamic and static stiffness, so as to improve the positioning accuracy, tracking accuracy and vibration resistance of the machine.
Expensive equipment and extremely demanding processing techniques have made the injection mold for large parts a major challenge in mold manufacturing.
3D printing technology brings a new entry point for large-scale mold manufacturing.Take PSU plastics as an example. This plastic is steam resistant, hydrolysis resistant, non-toxic, steam resistant, transparent, and has good dimensional stability.This also means that the PSU plastic mold is processed through 3D printing technology, and then the final product is processed through injection molding.For small batch large parts preparation, this is a fast, good, economical shortcut.
Recently, a team of purdue university composite manufacturing and simulation center, Thermwood, applied composite engineering (ACE), and Techmer PM realized injection molding of helicopter parts through 3D printing of PSU composite molds.
According to 3D science valley, this may be the first time carbon fiber reinforced PSU plastics have been successfully used in 3D printing.Thermwood's lsam-large Additive Manufacturing system applied single-use 3D printing and machining to the helicopter molds.
Each member of the team played a key role in the production of helicopter parts: Techmer PM, a manufacturer of high-performance custom polymers, provided specialized PSU materials;Thermood provided its LSAM technology;ACE, a composite materials specialist specializing in the aerospace industry, used 3d-printed molds to create the final helicopter parts.
In order to compare the 3D printing method with the traditional manufacturing method, the team made a special economic analysis of the two manufacturing methods.According to the analysis, the cost of 3D printing mold material is 34% lower than that of standard mold material, and the production speed in labor time is 69% higher. 3D printing mold can be manufactured in only three days, while traditional mold manufacturing takes eight days.
The ability to use PSU materials as molds, mainly thanks to LSAM's powerful extrusion system, can reach the high temperature and torque level required in PSU processing engineering.
Thermwood development system of LSAM is increasing material manufacturing and machining the clever union of cutting process, performed by 3 d printing rough outline model, through the use of CNC milling machine parts processing to the accurate size, in the process of 3 d printing can be synchronous with the use of cutting machining, the mould used in the manufacture of helicopter parts of large construction volume of 3 d printers to 10 x 20 feet.
The helicopter parts were then molded in autoclaves at 275oF and 90PSI.3D printing molds remain vacuum and do not require special coating. At Tg (vitrification transition temperature) 372°F, this special PSU composite formulation can meet the requirements of the injection molding environment for parts up to 350°F, which is sufficient to meet approximately 95% of the composite parts processed today, according to 3D science valley.Of course, additional testing is required to determine the material's suitability and durability at high temperatures. Plastic mold.