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Question by jsanky: Injection mould design is there any information?
Need feed system for Injection mould for round Plastic polycarbonate article, is there any information available?

Best answer:

Answer by Marianna
You may find what you need to know here:
http://www.rtpcompany.com/info/molding/index.htm

Know better? Leave your own answer in the comments!

8 Ways to Design Injection Moulding Parts with Consideration for Process

To ensure a successful finished product, you need to be aware of the process that goes into making your component. This should be at the forefront of your mind when considering the design of your part. Injection moulding will provide you with the component you want, and if you are able to consider its process in your design concepts you can guarantee a successful finished product.

Coherence. Try to make your design uniform throughout. That is, wall thickness, rib thickness and corner radii, for instance, should all be the same values. This will help the part to cool uniformly.
Wall thickness. Keeping your walls thin will ensure a faster cooling rate and less materials used. Lower cooling rate and less materials used will result in a shorter cycle time, allowing you more parts in a shorter amount of time, for less production cost.
To strengthen parts, ribs are more effective than thicker walls. Adding ribs at right angles to a wall will add considerably to its overall strength. It is a common mistake to thicken the walls of a design to achieve this effect when ribs are a cheaper and more effective option.
Ribs should be about half the main wall thickness.There can be some leniency here, but not too much or the ribs will be completely ineffective. Half is the generally accepted standard and is more than enough to increase a wall’s strength.
Corners and edges should be rounded wherever possible. Sharp edges do not always come out perfectly when the part is ejected from the mould.
Add a slight angle to the sides of your mold to allow easy release. A one or two degree angle should be applied to the mould on the face perpendicular to the parting line. This will allow for easy removal of the part from the mould.
Avoid undercuts. Protrusions on the part that will snag on the mould core or cavity when it is opened can make it impossible to remove from the mould.
Where possible, use lighter colours for your moulds. The mould is already cool when the molten material is being injected. As such it begins the setting process immediately and will sometime leave setting patterns. Using lighter colours will help y.to hide these patterns.

Injection moulding is the industry standard for creating lasting, quality parts. To be able to take advantage of this technology your design must meet its minimum requirements. Small considerations are all it takes and the result is a successful product that will meet all of your quality needs.

More Plastic Injection Articles

8 Design Rules for Injection Moulded Products

Injection moulding is a versatile process and can be applied to almost any product. Although injection moulding is the industry standard for fabricating parts for products, it is not without its holdups. There are a few basic limitations to be taken into account. Here’s eight rules to follow when designing your product to ensure quality and durability:

Maximum wall thickness. The wall thickness of your part is directly proportionate to both the total materials needed to make the part and the cooling time required. By reducing the maximum thickness of the wall of your part, you reduce both these factors, resulting in lower cycle time, thus lower production costs. If the wall of your part is too thick or is inconsistent, problems can be caused involving sinkage and warpage, resulting in rejects and costly redesigns. Ensure your wall thickness is matched to the capabilities of the machine.
Corners. They can be a problem in a mould and will not always come out flush. It is almost impossible to force plastic into a perfect corner, and the result will look messy and amateurish, not to mention the strength of the part could be compromised. Round all corners where possible to enhance aesthetics and durability.
Applying a draft. A draft is a tiny angle — usually one or two degrees — applied to the mould on the face perpendicular to the parting line. This will allow for easy removal of the piece from the mould. Not including a draft in your design will mean the automatic ejection system of the injection moulding machine will not operate.
Ribs. Ribs are structural elements for your part, used for overall stability control. They are thin wall protrusions that extend perpendicularly from a wall or plane. Adding ribs rather than thicker walls will offer greater structural support.
Bosses. Bosses are hollow, cylindrical protrusions usually included in a design for accepting screws or other mating components of your deign. Ensuring these are secured by either attaching them to a wall or adding ribs will mean the bosses will remain straight and accept the part it was designed for without a problem.
External undercuts. A protrusion or depression in the outside of your mold — the cavity half — can create problems when trying to separate parts from the mold. Adjust your parting line to accommodate this.
Internal undercuts or overcuts. Similar to external undercuts, these protrusions or depressions are on the inside of your mold — on the core half. Adjust your parting line to accommodate this.
Threads. If your mould contains a thread, always arrange it perpendicular to the parting line. This will ensure that the fragile thread is not damaged. It is better, if possible, to not include a thread at all in your design. Simplifying your design will lower the chance of something going wrong.

Injection moulding design ensures a quality product and the countless possibilities far outstrip the limitations. Designing for a quality injection moulded product is the essence of the design process, and these limitations are the guidelines for creating a versatile end product.

Conformal Cooling Channel Design for Plastic Injection Molding

The constant temperature mold of molding plastic parts with high precision contours is of significance in determining not only the productivity of the injection molding process but also the product quality. A solution to this challenge is the rapid thermal response molding process in which uniform temperature overall the mold part ensures the product quality by preventing differential shrinkage, internal stress and mold release problems (Li, 2001). Many Computer-Aided-Engineering (CAE) and optimization methods have been carried out to observe and fine-tune the influences of the thermal system (Park et al., 1998). The results of these research works are obtained by using thermal analysis modules of commercial CAE packages such as C-Mold or Moldflow which are based on the initial designs generated by the human. By given an initial thermal configuration design, efficiency and quality of the molded part can be predicted before an actual plastic mold is manufactured. One more necessary step for the complete automation in the molding thermal system is to generate the initial design for the conformal cooling channels.For example <a rel=”nofollow” onclick=”javascript:pageTracker._trackPageview(‘/outgoing/article_exit_link’);” href=”http://www.cikmold.com”> casting mould,mold making,plastic injection mold </a> etc. In this paper, a featured-based approach to this problem is proposed. Super-quadrics is presented as a tool for recognizing the plastic part shapes and an algorithm is applied for generating the center line of the thermal sub-system of each individual surface. Finally, these sub sets of center lines are combined to create a unique center line which is the guide line for generating the cooling channel of the thermal system.

Conformal cooling channel, as the name implies, refers to the channels that conform to the surface of the mould cavity. Conformal cooling channels have demonstrated simultaneous improvement in production rate and part quality as compared with conventional production tools. In the previous researches, cooling line design and fabrication have been confined to relatively simple configuration, primarily due to the limits of the fabrication method used to make tools, but also due to the lack of appropriate design methodology. Emergence of Solid Freeform Fabrication processes with the ability to fabricate 3-D feature with almost arbitrary complexity is exceedingly useful to mould design process (Xu et al., 2001). The remaining problem to be solved is how to optimize the design process of the thermal system. In this paper, a systematic method for designing cooling channel is proposed. Firstly, the feature recognition algorithm is applied to identify and decompose the moulded part into manageable sections so-called cooling zones. In the next step, a sub-system of cooling channel is generated for each cooling zone. These sub-systems of cooling channels are further decomposed into smaller elements called cooling cells which are easy to be analysed. Lastly, the combination process of these sub-systems is done to create a complete conformal cooling system for the whole plastic part based on the constraints of the combination algorithm and design rules.

Nowadays, feature-based modeling has been a standard for 3D designs. Most of the complex shapes are obtained by synthesizing from sets of simple features. This design strategy is not sensitive to the part geometry; therefore, it keeps the simplicity of the design routine no matter how complicated the geometry of the part is. For the same purposes of simplicity and efficiency, the molded part is segmented into sub-features that must be recognized for the partial thermal system designs. Feature recognition has drawn much attention from researchers and been proposed in literatures (Lentz et al., 1993). The majority of these has based on machining feature recognition techniques which can be classified in three categories: graph-based methods, volumetric methods and hint-based methods. Although recent machining feature recognition technique can be a good solver for parts with complicated intersecting feature, this technique is not appropriate for detecting shape feature for thermal system design of plastic products. In plastic products, free-form surfaces are mostly used and hence, free-form features have to be processed. Furthermore, a shape feature in a plastic part may blend smoothly to another feature and the boundaries between features can not be explicitly defined. With these two reasons, neither graph-based methods, volumetric methods nor hint-based methods can be applied.

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