Optimization of the manufacturing process dfa is a tool used to select the most cost effective material and process to be used in the production in the early stages of product. Fit between plastics parts and metal parts make sure that the joint between the plastic and metal allows the plastic part to expand without regard to the expansion of the metal part. Actual weight savings can vary, but parts made using structural foam molding can be as much as 1030 percent lighter than other parts, while retaining durability. So working with us early in the design process is important. As far as possible, all these walls should be the same thickness. Sharp corners act as stress risers or concentrators, reducing part strength and causing premature failures.
In this article, we will show you some of the aspects we take into consideration when designing plastic parts for injection molding so we can save our customers time and money in. A glossy finish can enhance the appearance of a part while a textured surface may help to mask sink marks or parting lines. When designing plastic parts, your team should consist. Nov 16, 2016 engineering guidelines to designing plastic parts for injection molding 1. This creates higher contact pressure on the core surface and increases friction between the core and the part, thus making ejection of the part from the mold difficult. Parts made using structural foam molding generally weigh less and arent as dense as traditional injection molded parts. Sharp corners may also effect plastic flow, producing parts with. Appearance parts guidelines for injection molded design 77 appearance parts guideline to maintain a class a surface on a molding, the side behind the appearance surface must be free of projections and depressions. Jun 10, 2018 download designing plastic parts for assembly. When designing plastic parts, your team should consist of diverse players, including conceptual designers, stylists, design engineers, materials suppliers, mold makers, manufacturing personnel, processors, finishers, and decorators. Dfm is the method of design for ease of manufacturing of the collection of parts that will form the product after assembly. Designing plastic parts for assembly sciencedirect. For over 22 years, designing plastic parts for assembly has been the definitive guide for both seasoned part designers and novices to the field.
Tres designing plastic parts for assembly book isbn. Bosses are the cylindrical elements in the plastic parts which are used as a. During both the injection and cooling stages of the. May 06, 2016 plastic is cheaper and easier to work with.
The detailed yet simplified discussion of material selection, manufacturing techniques, and assembly procedures enables the. Designing plastic parts for assembly this book provides an excellent tool for both seasoned part designers and novices to the field, facilitating cost effective design decisions and ensuring that the plastic parts and products will stand. May 23, 2015 during plastic part designing, there are many critical parameters that should be maintained, these could be the drafting angle, parting line, maintaining a uniform wall thickness and so on, so that by maintaining these parameters stress in mold, sink marks, warpage, and tolerances during the molding of the part can be avoided. The following suggestions are fundamental practices to follow when designing a thermoset molded part.
Designing plastic parts for assembly the english editions of the textbook are distributed worldwide by carl hanser verlag munich, germany and hanser publications cincinnati, ohio, usa. Ribs are important in the design of plastics parts because they allow us to make a component rigid without making it too thick. The chinese edition of the textbook is published and distributed by chemical industry press of beijing, china. It is not easy to generalise what the wall thickness should be.
Designing plastic parts and components involve implementing wide knowledge from different engineering areas. Designing plastic parts for assembly hanser publications. Plastic part design for injection molding hanser publications. Applying draft and radii to a part is vital to a properly designed injectionmolded part. Plastic component design considerations design considerations radii in the design of injection molded parts, sharp corners should be avoided. If a projection can not be avoided, then the maximum thickness at the intersection is half the nominal wall thickness.
Additionally, plate thickness is important in designing parts having close tolerance fits. Plastic design issues injection molded plastic parts offer an important combination of flexibility, toughness, and chemical resistance for cost effective, longterm performance in a wide range of applications. Because of shrinkage of plastic material, injection molded parts have a tendency to shrink onto a core. All variables, such as materials, design, and conditions under which the finished product will be. Pdf designing plastic parts for assembly free download pdf. Designing plastic parts for assembly hanser elibrary. Designing plastic parts for assembly hanser fachbuch. The designers and engineers at api have over 250 combined years of experience in designing parts for plastic injection molding, selecting materials, and. Matching halftongue and groove align the two parts edges, within normal tolerances.
A straight pull mold is designed so that when the two halves a side and b side of the mold separate from each other, there is no plastic blocking the path of the metal in the direction of the pull. We are jaycon systems where a bunch of geeks got together to bring peoples product ideas to life. The higher usage pattern of plastic can be easily attributed to its strength, light weight and low cost for reproduction. Trantina, design with plastics, materials selection and design, volume 20, asm handbook, asm international, 1997, pages 639 to 647 the key to any successful part development is the proper choice of material, process, and design matched to the part performance requirements. For over 22 years, designing plastic parts for assembly has been the definitive guide for both seasoned part designers and novices to the field, facilitating costeffective design decisions and ensuring that the plastic parts and products will stand up under use. Nov 21, 2016 in this article, we will show you some of the aspects we take into consideration when designing plastic parts for injection molding so we can save our customers time and money in the long run. On this basis, a snapfit joint is a frictional, formfitting joint. However, not every plastic part design can be efficiently injection molded. Tres book isbn 9781569905555 hanser hanser publishers, munich hanser publications, cincinnati sample. Engineering guidelines to designing plastic parts for.
Designing your plastic part when designing parts for injection molding, the manufacturing process is an important consideration. In addition to functional and structural issues, processing issues play a large role in the design of an. When designing parts for injection molding, the manufacturing process is an important consideration. Designing plastic components plastics technologies and services qmr plastics offers a wide range of technical services and production capabilities for producing close tolerance components. Part design guidelines for injection molded thermoplastics. Tres book isbn 9781569905555 hanser hanser publishers, munich hanser publications, cincinnati sample pages. Semantic scholar extracted view of designing plastic parts for assembly by paul a. As with other plastic materials, good thermoset plastic part design requires consideration of a number of aspects. There are many things that must be carefully considered and planned for.
Design consideration for plastic part design and its. Structural foam molding also scales well, so large or. Cost analysis in injection moulded plastic parts designing. Plastic part design for injection molding design engine. The structural features of a snapfit joint are hooks, knobs, protrusions, or bulges on one of the parts to be joined,which after assembly engage in corresponding depressions undercuts. Pdf cost analysis in injection moulded plastic parts designing. Pdf designing plastic parts for assembly semantic scholar. Injection molding is a process in which solid thermoplastic resin pellets are melted, injected into a mold, and then cooled back to a solid state in a new form.
Designing plastic parts is a little different from designing metal parts. Detailed plastic product design will always require detailed knowledge of the application, the processing method and the selected plastic. May 30, 2012 molded plastic parts may be designed with a variety of surface finishes, from a high gloss to a rough texture. Draft angle design is an important factor when designing plastic parts. There are many different methods for welding two parts together. Engineering guidelines to designing plastic parts for injection molding 2. Draft helps a part release from a mold with less drag on the part s surface since the material shrinks onto the mold core.
The choice of surface finish is usually based on cosmetic considerations. Designing of plastic products for injection moulding dsource. Designing plastic parts is a complex task involving many factors that address a list of requirements of the application. Design, converting and handling techniques for electro.
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