The Forming Principle And Advantages And Disadvantages Of The Current Mainstream Rapid Prototyping Process

- May 08, 2019-

Several kinds of rapid prototyping manufacturing are as follows:

1. Build sexual selection Laser Sintering (SLS - Se1ected Laser Sintering)

SLS equipment can be used to directly manufacture the special-shaped hot runner system of metal molds and injection molds, whose hardness can reach high rockwell hardness and performance can reach the level of forgings, and also directly produce special and complex functional parts.It is because of the small batch special and complex function SLS technology of rapid manufacturing capability, and can be multiple parts one-time molding manufacturing, achieve rapid manufacturing many varieties, small batch of individuation, make this kind of technology in the aerospace, military industry, automobile engine testing and development, has been widely recognized and applied in medical areas.

2. The vacuum infusion molding rapid tooling (VCM - Se1ected Laser Sintering)

Also known as vacuum injection type complex mode, it is using the original template, silicone mold was produced under the vacuum state, and casting in vacuum using PU materials, thereby to clone the same copy with the original sample, is one of the most commonly used rapid tooling technology, through this technology, can produce various features of similar engineering plastics products, also can undertake small batch production.

In general, one set of VCM silicone mold can replicate 20 sets of products, especially suitable for small and medium-sized, fine parts of the replication, such as instrumentation, auto parts manufacturing industry.This kind of processing technology can satisfy the application in the product trial-manufacture process with short time, low cost and fast speed.

Usually the process flow is: 3DP/SLA rapid prototyping (handplate, prototype)------ VCM vacuum injection machine (rapid mold making)------ small batch replication and production

3. Reaction Injection Moulding (RIM)

Also known as "low-pressure perfusion", it is a new process applied to the production of rapid molding products. It is a process in which the two-component polyurethane materials are mixed and injected into the rapid mold at room temperature and low pressure environment to form the products through the chemical and physical processes such as polymerization, cross-linking and curing of the materials.Because the raw material is liquid, the cavity can be quickly filled with a small pressure, so reduce the closing force and mold cost, especially suitable for the production of large size, large area parts, such as car bumper, dashboard, tail, etc..A RIM mould can replicate 200 products and has been used in automotive research and development, instrumentation, creative sculpture, architectural design and other fields.

General process flow is: SLS/CNC rapid prototyping (handplate, prototype)------RIM rapid mold making ------ injection molding (small batch copy, production)

4. Computer Numerical Control (CNC)

CNC is a programmed automatic machine tool.The control system can logically process the program with the control code or other symbolic instructions, which is decoded by the computer, so that the machine tool can perform the specified action, and the raw material can be processed into semi-finished parts by cutting tools.Since the United States Massachusetts institute of technology developed the world's first CNC machine tool in 1952, CNC machine tools in the manufacturing industry, especially in the automotive, aerospace, and military industry is widely used, CNC technology in both hardware and software, have developed rapidly.

CNC compared to traditional machine tools, it has the characteristics of digital, efficient, mass, in addition to the structure of the complex shape of the workpiece, the basic can cope with, so although not strictly the sense of rapid prototyping technology, but the industry usually put it under the category of rapid manufacturing.