In recent years, 3D molding technology has been rapidly popularized with the continuous progress of raw materials, computing power, and simulation technology. Today, the application of this technology has expanded from rapid prototyping to engineering manufacturing, home design, aerospace, and biomedicine.
This article will introduce the development process and current application of 3D molding technology from the perspective of front-line engineering and technical personnel. We will explore how it can help engineers improve efficiency and innovation in the design and production links. In addition, the article will analyze the technology’s technology’s current limitations and look forward to possible breakthroughs and application trends in the future.
Common processing methods
1. CNC machine tools
CNC (Computer Numerical Control) is an automated machine tool controlled by a computer. This system processes control codes or symbolic instructions according to pre-set program logic and translates them into specific machine tool operation instructions. The machine tool operates according to these instructions, cutting the blank through the tool to process semi-finished or finished parts.
In 1952, the Massachusetts Institute of Technology developed the world’s first CNC machine tool, which opened the CNC era of modern manufacturing. In the past few decades, CNC machine tools have been widely used in the manufacturing industry, especially in the automotive, aerospace, and military industries, promoting technological progress and industrial development.
Compared with ordinary machine tools, CNC machine tools have the following characteristics:
- High processing accuracy and stable processing quality;
- Multi-coordinate linkage can be performed, and parts with complex shapes can be processed;
- The machine tool has a high degree of automation, which can reduce labor intensity;
- Batch production and product quality are easy to control;
- The professional quality requirements for operators are relatively low, and the technical requirements for maintenance personnel are relatively high.
2. Tooling
Tooling/mold/die is a tool used to process raw materials into specific shapes and sizes. It achieves the manufacture of finished products by changing the physical state of the material. In processes such as blanking, forming stamping, die forging, cold heading, extrusion, powder metallurgy, pressure casting, and injection molding of plastics, rubber, and ceramics, the mold forms the material by applying external force.
In modern industrial production, 60% to 90% of products need to rely on mold processing. Therefore, the mold industry has become an important foundation for industrial development. The development and mass production of new products is also highly dependent on molds, especially in the fields of automobiles, light industry, electronics, and aviation. The development of these industries cannot be separated from the support of efficient molds.
According to the forecast of the International Production Technology Association, 75% of rough processing and 50% of fine processing will be completed by molds in the future. It can be seen that mold manufacturing has become the basic pillar of the machinery industry and the national economy.
Four major characteristics of modern molds
2.1 High precision
The precision of modern molds far exceeds that of traditional molds. The precision of some molds can reach 0.003mm or higher. For example, high-precision progressive dies and precision plastic molds can achieve burr-free stamping parts and ensure complete matching and interchangeability between components.
2.2 Ultra-long life
Modern stamping molds can usually withstand more than 5 million punches, and high-end carbide molds have a longer life of 20 million to 60 million punches. Injection molds can produce 400,000 to 600,000 pieces while die-casting molds can produce 500,000 to 1 million pieces. In contrast, the life of traditional molds is only 1/5 to 1/10 of that.
2.3 High production efficiency
Modern molds can handle more processes at the same time. For example, some high-efficiency progressive dies contain more than 50 stations, while plastic shoe molds have 18 stations. Some molds can also perform assembly tasks such as riveting and locking while stamping, realizing direct production of components. The design of one mold with multiple cavities allows dozens of products to be produced at the same time. For example, a plastic encapsulation mold can produce hundreds of pieces at a time, while an injection mold can produce plastic soda bottles at a speed of up to 8,000 pieces per hour.
2.4 Complex structure and flexible application
The structure and cavity of modern molds have become more complex with technological advances. For example, the complexity of some composite forming molds even exceeds that of precision machine tools. Large cover cover-formings are not only complex in structure but also require a high degree of coordination between multiple molds. Traditional processing methods make it difficult to meet these high standards.
3. Reverse Engineering
Reverse engineering is a process of “from existence to non-existence”. Simply put, it derives the design parameters of the product (such as drawings or digital models) through the existing product model. In this process, digital measurement tools such as coordinate measuring machines and laser measuring equipment are used to collect spatial dimension data on the surface of the object. Then, with the help of reverse engineering CAD technology, these data are converted into the CAD mathematical model of the product, and then the product is produced through rapid prototyping or CAM systems.
Industrial designers often use this technology to verify and adjust the appearance of products. However, some bad manufacturers also use it to illegally copy or plagiarize high-precision products developed by other companies.
Rapid prototyping and 3D printing technology
1. Rapid prototyping technology
1.1 What is Rapid Prototyping (RPM)?
Rapid prototyping (RPM) is an advanced manufacturing technology developed in recent years. Originating in the United States in the 1980s, it quickly spread to Japan and Europe, becoming a breakthrough in manufacturing. RPM is a digital molding technology that relies on the concept of discrete stacking molding. It integrates various fields, including CAD, CNC technology, laser technology, and materials science.
1.2 How RPM Works
RPM integrates several advanced technologies like CAD, CAM, CNC, precision servo drive, optoelectronics, and new materials. The process begins with a 3D model created using CAD software. This model is then sliced into cross-sectional contours. Using a laser beam or jet source, layers of liquid resin, metal powder, adhesive, or hot melt material are selectively applied and solidified. Each layer is gradually built up, forming the final 3D product. This technique transforms a complex 3D process into a series of simpler 2D processes, allowing rapid prototyping or direct part manufacturing.
Benefits of RPM
- Quick Prototyping: Allows for fast creation of prototypes to evaluate and modify designs.
- Cost-Efficiency: Reduces costs by quickly materializing concepts and minimizing the need for traditional tooling.
- Market Responsiveness: Speeds up product development, making it easier to meet market demands and improve competitiveness.
1.3Types of RPM Technologies
RPM technologies vary based on the materials used and the layer-building methods. Here are some common techniques:
These technologies use plastic materials, melting or softening them to create “ink” for printing.
These methods use liquid materials, solidifying them layer by layer to form the final product.
Each technology has its unique advantages and disadvantages, and companies often offer multiple printers to choose from, depending on the specific needs of the project.
2. 3D printing technology
3D printing (Three-dimensional printing), also known as additive manufacturing (AM), is a kind of rapid prototyping technology. It is a technology that directly manufactures three-dimensional entities of almost any shape based on digital model files.
3D printing uses powdered metal or plastic bondable materials to construct objects by stacking and accumulating layer by layer, that is, “layer modeling”. It uses the “selective laser sintering (SLS)” technology of rapid prototyping technology.
3D printers integrate various technologies, based on multiple different physical mechanisms, and use a digital model to construct a three-dimensional physical entity with common features. This molding is a stacking process. Unlike traditional molding methods, this technology does not cause a large amount of material loss. 3D printing is different from traditional machining technology, which is usually achieved by cutting or drilling technology (i.e., subtractive process).
The docking and the whole process of 3D printing technology and common CAD software.
2.1 PRO/ENGINEER
In 1988, PTC released PRO/ENGINEER, the first solid modeling software based on parametric design and feature association. It adopts a modular design, and users can choose modules according to their needs without installing all of them. PRO/ENGINEER is widely used in product development in industrial equipment, aviation, consumer products, and medical fields, and has undergone multiple version updates, such as Pro/ENGINEER 2001, Wildfire, and Creo Parametric.
In 2007, PTC acquired CoCreate and further optimized the user interface to make it easier for new users to get started and focus on design work rather than software learning. The latest version is Creo Parametric 3.0.
2.2 SolidWorks
In 1993, former PTC executives and CV vice presidents founded SolidWorks and launched the Windows version of SolidWorks in 1995. The software is widely used in aerospace, automobile, mold, and other fields with its powerful functions, ease of use, and innovative technology. SolidWorks can reduce design errors and improve product quality. The latest version is SolidWorks 2013.
2.3 Unigraphics NX (UG)
Siemens PLM Software launched UG (NX) in 1983 to provide users with digital modeling and verification functions. UG includes three levels of structure, subsystem, and component design, which can perform digital simulation in the early development stage, optimize products, and reduce dependence on physical prototypes.
Comparison between UG and PRO/ENGINEER:
- UG is more suitable for CNC processing and mold design;
- PRO/ENGINEER is more suitable for product structure design;
- The modeling ideas of the two are different: PRO/ENGINEER is a fully parametric design, while UG is a semi-parametric one.
2.4 Solid Edge
Solid Edge is another major CAD software of Siemens, which is positioned for general mechanical design. Compared with NX, it is more efficient in simple part design. It has excellent compatibility with Windows system and Office applications, which improves the convenience of operation.
CAD software integration with 3D printing
The software that comes with the 3D printer cannot create a 3D model. It can only be completed with the help of third-party CAD design software to complete the design model in advance and import it into the printer. The following uses a conversion plug designed by PRO/ENGINEER to complete this creation and uses two conversion plugs as examples to explain the entire process of 3D printer operation.
- Export the 3D drawing designed by PRO/ENGINEER and export the drawing to STL file format.
- Import the 3D drawing into the 3D printer software. Import the STL format file exported by PRO/ENGINEER into the computer and load it for printing, setting the print resolution (select the highest level of 0.15MM).
- After the above calculations are completed, click “ok” to start printing.
- Remove from the printer after printing
- Clean up the excess bracket filler and spray
Current status and limitations of 3D printing
Since the launch of the first commercial 3D printer in 1987, price reduction and material diversification have driven rapid growth in production and sales. Initially, 3D printing was mainly used to make models to help designers verify their appearance and feel. Today, it has expanded to functional testing and the production of some end products.
Currently, 3D printing is widely used in engineering design, automobiles, aerospace, jewelry, footwear, architecture, dentistry, and medical fields. In June 2013, Northwestern Polytechnical University successfully printed a titanium alloy aircraft part over 5 meters long. In November of the same year, an American company used a 3D printer to manufacture the first metal pistol and successfully fired 50 rounds of bullets.
Despite the rapid development of 3D printing, it faces challenges:
- Technology and cost: The long molding time hinders large-scale promotion.
- Material limitations: Mainly using chemical polymers, resulting in insufficient physical properties and safety hazards.
3D printing is changing the traditional manufacturing model, but to achieve wider application, these bottlenecks need to be broken through.
1. Market price limitations of 3D printers
After nearly 30 years of development, 3D printing technology has entered various commercial fields from research institutions and university laboratories. Although the manufacturing cost has been reduced, ordinary users still feel that 3D printers are generally expensive, which limits their popularity.
At present, the three major manufacturers in the 3D printer market are 3D Systems, Stratasys, and MakerBot. According to 3ders.org, a 3D printer with a size of 203×254×152mm, a nozzle diameter of 0.4mm, and a layer thickness of 0.1mm costs $2,899. Although this is not the most expensive printer on the market, its accuracy is relatively average.
2. Time cost limitations of 3D printing
Take the conversion plug mentioned above as an example. Two such simple conversion heads have an overall size of 49×42×42 (mm) and a weight of 31.3 grams, but it takes 5 hours and 31 minutes, plus the subsequent cleaning of residual materials, so the whole process takes at least 7 hours.
According to a report by Guangming.com on April 8, 2014, “It took three days to 3D print a miniature version of the Guangzhou Tower, which is 1.2 meters high.” The speed of 3D printing technology has become one of the key constraints to the large-scale promotion of this technology.
3. 3D printing consumable cost limitations
For the 3D printing industry, the price of printing materials has become the most controversial issue in the current development of this technology. End users will notice that 3D printers continue to invest in anti-competitive activities, locking customers to use only their consumables through key codes and radio frequency identification tags on the material “cartridges”, thereby effectively monopolizing the price of consumables.
According to the official quotation of 3ders.org, taking black ABS with a diameter of 1.75mm as an example, the current quotation per kilogram is US$175.2, equivalent to RMB 1,095. Calculated in this way, the material cost of the above-mentioned British conversion plug 3D printing is close to RMB 34.3, and this does not include the waste of bracket materials. The cost of consumables used in liquid metal 3D printing is even higher. The following figure lists the reference price of metal consumables:
At the same time, the research and development of new materials are hardened by 3D printer manufacturers, and the barriers for third-party consumable manufacturers to enter the 3D printing consumables industry are relatively high. The consumables manufacturers that have already entered the industry cannot form economies of scale because they cannot accelerate the research and development of consumables and form a competitive market.
3. Limitations of 3D printing technology
In terms of printing accuracy, the accuracy of 3D printed products is not satisfactory, and the printing efficiency is far from meeting the needs of large-scale production. In addition, due to the limitations of the working principle of the printer, there is a serious conflict between printing accuracy and speed.
At present, the accuracy of ordinary 3D printers is generally between 0.25 and 0.1mm, which is still a long way from the so-called “high-precision and cutting-edge”. There are some 0.01mm-level equipment, and its price is not meaningful for promotion.
Prospect analysis of 3D printing technology
1. Market prospects of 3D printing technology
1.1 Autodesk Enters the 3D Printing Market
Autodesk Software (China) Co., Ltd., a world-renowned software company, recently announced that it will officially enter the 3D printing market. The company plans to launch 3D printers and open-source 3D printing platforms in the second half of this year to promote the application of 3D printing in design and manufacturing.
1.2 A New Era for 3D Printing
Lu Zhiguo, director of the consumer products department at Autodesk China R&D Center, explained that 3D printers, which emerged in the mid-1990s, were initially used by designers, engineers, and scientists to create one-off prototypes and models. However, as three-dimensional design technology has moved into the consumer market, 3D printing is now gaining traction across various fields.
1.3 Advantages of 3D Printing Technology
Compared with traditional manufacturing methods, 3D printing offers several key advantages:
- Personalized Customization: 3D printing can quickly meet individual user needs.
- Flexibility: This technology allows for more adaptable and efficient production processes, especially for customized products.
As a result, personalized customization has become a critical development direction for 3D printing.
1.4 Driving Forces Behind the Growth of 3D Printing
Several factors are contributing to the rapid expansion of the 3D printing market:
- Increased Awareness： After years of media coverage and reporting, public awareness of 3D printing technology has steadily increased, sparking interest across various industries.
- Decreasing Printer Costs： The price of 3D printers has significantly dropped, making the technology more accessible to a wider audience.
- Growing Availability of Consumables： The range of printing materials and consumables has expanded, providing more options for users and businesses.
1.5 Market Growth and Industry Trends
The 3D printing market has seen explosive growth, largely due to the expiration of several key patents. This has allowed smaller companies to enter the market and produce lower-priced, consumer-grade 3D printers, further fueling media attention and hype.
In particular, companies like MakerBot have quickly overtaken older manufacturers such as 3D Systems and Stratasys, securing a dominant position in terms of installed units and market share.
According to international research organization Gartner, 3D printer sales are expected to rise significantly:
- From 56,507 units in 2013 to 98,065 units in 2014.
- Expenditures on 3D printers are projected to increase by 62%, reaching $669 million in 2014. Of this, $536 million will come from corporate expenditure and $133 million from consumer spending.
Gartner also predicts that the sales volume of 3D printers will double by 2015, indicating a vast and growing market for 3D printing technology and products.
2. 3D Printing Consumable Costs
2.1 Development of 3D Printing Consumables
The consumables used in 3D printing technology are continuously evolving. However, this development is mainly concentrated in universities and new material research institutions, meaning large-scale commercial use is still a distant goal.
According to the authoritative “Wohlers Report 2014” on the international rapid manufacturing industry, it is expected that by 2025, although manufacturers will produce tons of various consumables, photosensitive resins will continue to dominate the 3D printing consumables market.
2.2 The Challenge of Metal Powder Production
Currently, the production capacity of metal powders is less than 30 tons per year. This low production level is expected to persist for some time. However, the market will soon see rapid growth in this area. The higher raw material prices and processing costs are making the price of metal consumables decrease more slowly than other materials, such as photosensitive resins.
As a result, metal powders will gradually capture a larger market share. However, due to the continued dominance of a few consumable manufacturers, prices are likely to remain high in the short term.
In the medium and long term, the key drivers for the decline in consumable prices are twofold:
- Pressure from End-Users: The growing influence of end-users will push printer manufacturers to reduce consumable prices, further driving price reduction trends.
- Increased Market Competition: As new players enter the 3D printer manufacturing industry, customers will no longer be restricted to using only the printer manufacturer’s consumables. This will open up the market to third-party options, leading to more competitive pricing.
3. 3D printing technology IP expectations
3.1 3D Printing Industry Overview
Eleven major 3D printer manufacturers have achieved profitability. Although some universities in the United States and Europe have been very active and have obvious advantages in certain core areas, Chinese universities have also published detailed and more rigorous cross-border 3D printing technology-related monographs.
3.2 Lack of Intellectual Property Protection
At present, except for the Fraunhofer Institute in Germany, some other academic activities have not been transformed into intellectual property rights. 3D printing can be said to have been shrouded in various halos in recent years, with good investment opportunities, widely used application scenarios, long-term and stable returns, etc. However, these seemingly attractive aspects hide some fundamental problems.
3.3 Intellectual Property Challenges
The most obvious problem is the issue of intellectual property protection for this technology. The actual situation is that so far, no professional 3D printing technology standards have been published internationally. The one known standard is not issued by a professional organization for 3D printing, which creates a significant gap in the industry.
3.4 3D Printing’s Impact on IP Rights
Since 3D printing technology adopts a model similar to “what you see is what you get”, the current loss of property rights due to the lack of intellectual property rights is as high as $100 billion per year. This could be related to the absence of industry standards or perhaps to the technical characteristics of 3D printing itself.
3.5 Moving Towards Standardization in China
According to reports, relevant personnel from the China National Standardization Administration said that the first industry standard for China’s 3D printing technology has been officially established. However, there is still a lack of a solid standard basis to support it.
4. 3D printing market application expectations
4.1 Current Growth Drivers
The main areas that currently drive the growth of 3D printing spending include:
- Single-piece or small-batch models of newly designed products
- Fixtures and tools used in the manufacturing process
- Large-scale customization of finished products
With advancements in 3D printing technology—both software and hardware—along with reduced material costs and improved complexity in producing 3D printed models, the application market for 3D printing will continue to expand in the foreseeable future.
4.2 Expanding Industry Applications
3D printing is expected to gradually spread to several key industries, including:
- Aerospace
- Automation
- Consumer products
- Medical products
- Dental products
- Jewelry
- Construction
- Art design
The application scope of 3D printing is primarily focused on rapid prototyping, terminal product production, and mold technology.
4.3 From hype to industrial use
While the initial hype around consumer 3D printers has died down, more focused applications have emerged, such as:
- 3D-printed critical components for commercial airliners
- Fully printed rocket engines
- 3D printing in universities and schools
- Bioprinting, drug toxicity testing, and cosmetic applications
- 3D-printed electrical and embedded conductive functional peripherals
4.4 3D Printing in the Home Market
In the home market, 3D printers are mostly used by enthusiasts. However, the market share is expected to remain low due to the limitations of available printing consumables. Additionally, issues like the smoke and odor associated with ABS materials may deter potential users from adopting this technology.
4.5 Medical and Dental Market Growth
The medical and dental markets hold significant growth potential. According to survey data from Whalers Associates, the current market share for this industry is $141 million. It is expected to grow to $868 million by 2025.
4.6 Future Market Forecasts
The global 3D printing market is projected to continue growing both in depth and in breadth. By 2025, the market value is expected to reach at least $7 billion, with bioprinting estimated to account for $3 billion. Additionally, the market share of prototyping in traditional industries will continue to expand.
Conclusion
To sum up, the rapid development of 3D molding technology has not only brought significant changes to many industries but also provided engineers with unprecedented design and production tools. This technology helps engineers achieve greater efficiency in rapid prototyping and complex project implementation by optimizing workflow and increasing creativity.
