The hottest new rapid prototyping technology

2022-09-28
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The new rapid prototyping technology

low flow layered manufacturing (lvlm), as a design method throughout the entire manufacturing industry, has been well known by everyone. In a very short time, it is a good choice for engineers. Whether you call it rapid manufacturing (RM) or direct digital manufacturing, low flow layered manufacturing has the potential to redefine product design. The benefits of this technology to plastic engineers are obvious, such as improving product quality, reducing costs and saving time

using the low flow layered manufacturing method to design and manufacture parts can help designers design parts without any restrictions, and it is easy to measure the benefits of the project. Using this method can also reduce costs by eliminating unnecessary parts processing or merging some processes. In addition, low flow layered manufacturing can improve the efficiency of process improvement. If you want to manufacture a slightly different new part, it can be completed in a few days. The result of using this new method is obvious, which is to design and deploy faster and better

define low flow layered manufacturing

low flow layered manufacturing is a way to use rapid prototyping (RP) equipment to manufacture end products. By using additives and rapid prototyping equipment, parts are manufactured, that is, materials are continuously added from the bottom of the manufacturing to fill the part space until the final part is formed (Fig. 1)

Figure 1 rapid prototyping equipment can use materials with sufficient strength for the production of parts

this layer by layer progressive process is actually to eliminate the part design limitations or design hidden rules existing in traditional manufacturing processes, such as numerical control processing and injection mold processing

at present, there are probably three rapid prototyping technologies suitable for the production of end products: filament material selective cladding rapid prototyping process (FDM), powder material selective sintering process (SLS) and photosensitive resin selective curing process (SLA)

however, these three rapid prototyping technologies have certain advantages and disadvantages (table). In order to replace the traditional manufacturing methods, parts manufactured with low flow layered technology must meet the needs of practical applications: powerful, multifunctional, accurate and attractive. These three technologies can meet the above needs, and how to choose the appropriate processing technology depends entirely on the actual needs. Comparison of functional characteristics of several rapid prototyping materials

traditional processing methods

traditional design methods need to have a full understanding of the restrictions imposed on the manufacturing process, which is precisely used to process parts. For example, the parts to be processed by CNC machine tools must be designed without deep and narrow grooves, because the rotating tools of CNC machine tools cannot process these deep and narrow grooves. The design of injection molded parts must consider that the draft surface is consistent with the direction of mold movement, so as to ensure that the product can be demoulded smoothly after molding. When using injection molding products, it should also be noted that the design has no undercut or mouth lock function. This rule of design for manufacturing (DFM) or design for assembly (DFA) exists in the part processing process and is enforced

for the comprehensive promotion of low flow layered manufacturing technology, the biggest challenge is to re educate and train designers, because they should really understand the free design concept brought by low flow layered technology, and use this technology to engage in part design and assembly

flexible design

the use of low flow layering technology can discard all the original design rules, because the products are manufactured from the bottom, layer by layer, so the restrictions on design are all lifted

when the limitation of product design is removed, the demand for product design flexibility can be met and the continuous improvement of products can be realized. Since the use of lvlm technology to manufacture parts, there is no need for any processing commitment. Even if you are on a business trip, you can use the network to continuously improve products according to customer needs and performance feedback. This continuous product improvement can improve customer satisfaction and market response

after using lvlm technology, on-demand inventory of products with improved design can be realized. Conceptually, parts with improved design can be processed within a few days. After using this technology, the obsolete parts inventory will no longer exist, because the existing design schemes are up-to-date and timely, and the improved parts can be manufactured quickly

change is innocent

generally speaking, parts produced for processing investment are often considered to be delivered on time and cannot be changed, because the cost of remanufacturing the mold must be considered, that is, the new mold may be more inappropriate. In short, the weak links of part processing are not allowed to be changed

once the parts are designed, changing the design process does not mean that it needs to pay high costs and long delivery time. Nowadays, the use of lvlm technology makes redesign possible and even encourages this practice. Because it does not involve mold investment and there are no restrictions on design, the design parts can be improved in real time, and it only takes a few days to manufacture and process new parts

lvlm encourages this kind of positive redesign, which we simply call "positive process", because both the part design and the subsequent product performance can be improved according to the shipment of each unit. More importantly, this positive process can focus all your energy on meeting customer needs

focus on combined parts

in order to make full and effective use of lvlm technology, designers must constantly change the design mode and make good use of combined parts. To put it simply, the so-called combined parts is to design some simple parts into a part through combined assembly, so that they can be easily processed through lvlm technology. Now it seems that the coexistence of multiple parts is caused by some restrictions imposed on the processing of these parts through existing processes

l sometimes in order to reduce weight, aluminum alloy and other non-ferrous metals and special metals are also adopted. The emergence of VLM technology has lifted the shackles of these restrictions, so that designers can combine many original parts into few combined parts. Of course, these parts can only be manufactured by lvlm technology

for example, for the manipulator shown in Figure 2, the initial wrist design required 3 panels, 3 isolation posts and 2 adapters, a total of 8 parts, and did not include the screws inside. However, after using lvlm technology, these components can be combined into a simple part, but it is impossible to use traditional CNC or molding processing. The most obvious benefit is that eight different parts are reduced to one. The original mold for manufacturing these eight parts is no longer needed, and seven parts are also reduced on the material purchase order. Figure 2 illustrates the benefits of using lvlm technology to process composite parts to customers

Figure 2 the original machine wrist is integrated into a single part, which is finally manufactured and formed by using high impact ABS resin through SLA process

assembled into a part

lvlm is very good at designing different parts and combining them. This is a typical way of designing for assembly. The manipulator shown in Figure 3 was originally designed to be divided into many different parts: each finger, palm pad, pin and washer. However, using lvlm version can generate a complete hand part independently, and using lvlm for design and processing can fully meet the product processing needs (multi-functional, accurate and durable)

Figure 3 through lvlm technology, the robot hand is designed by using rapid prototyping equipment and is manufactured and assembled as a single part. The design and manufacturing "growth" of parts are carried out synchronously. This manufacturing process uses SLS process to process glass filled nylon

15 individual parts, which are finally reduced to one (inventory reduction), and the mold required for the production of each single part can be saved (cost reduction, delivery period shortened), It is not difficult to change this hand part to meet the needs of customers even on business trips (whether it is a small version of hand parts or a large version). This diagram shows us the benefits of using lvlm technology to design and assemble multiple parts into one part

unlimited geometry

how does this layered manufacturing method produce parts with geometries that previously seemed unimaginable? The processing of parts starts from the bottom, so the original restrictions no longer exist. In almost all processing cases, if the parts can be designed in 3D CAD software, then the rapid prototyping processing equipment can be used to manufacture these parts

limitations

all processing technologies have certain limitations, and lvlm technology is no exception. In the way of processing with layered technology, the most noteworthy thing for users is the ability of the materials used to process and manufacture parts

it has been more than 15 years since China was the first largest country in the world in terms of plastic consumption, output and export of plastic products, and production and sales of plastic machinery to manufacture parts, but until now, materials with sufficient strength have been used for end commercial applications. The parts processed with lvlm technology can be used in ABS resin, medical and food grade ABS, polycarbonate, nylon and epoxy resin. The mechanical properties of all these products are no different from those of plastics produced with injection molds

surface roughness is the second prominent problem among its limitations. The surface roughness of products processed with lvlm is not as good as that of parts processed with CNC processing equipment and injection molding. Based on the size of the parts to be processed, lvlm processing technology also has its established processing tolerance, but it is not as good as CNC or injection molding parts

what can we do now

from Figure 4, we can see the whole process from concept to CAD design to the final use of rapid prototyping equipment for part manufacturing. Now that you have everything, you know how to use lvlm to start the design. Consider the past design methods again, and think about how to design and manufacture the equipment under the condition of limited technology. The experimental force refers to the accuracy level 1 parts, and which parts can be combined into a composite part

Figure 4 using lvlm technology can make you avoid the restrictions on design and mold investment in the whole process from conceptual design to 3D CAD and then to mass production, but the degree of freedom of combined parts and the design method of one-time assembly are key

next, you need to determine a candidate project, and then use lvlm method to create an unrestricted free design method. Through the new design in hand, we can get the quotation according to the number of new parts to be processed. Then calculate the cost of manufacturing these parts by using lvlm

lvlm is obviously a very beneficial processing method for plastic manufacturing. Lvlm can enable designers to greatly improve the design quality, achieve unexpected efficiency and cost advantages, and there are no longer any restrictions on part design. From historical experience, there are many restrictions on the use of CNC processing and injection molding processing technology, but

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