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www.taiwanmoldmaker.com We make plastic injection molds, die-casting molds, silicone rubber molds, liquid silicone rubber molds, LSR molds, rubber molds, press molds and hot runner molds (MoldMaster, MasterFlow, LKM, Incoe systems…etc). We are especially good in dealing the undercut molds,…
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www.controlplastics.com – In this video you are seeing a robot remove the part from the machine and place it on a conveyor belt where it will take it to a machine operator who will inspect the part and then place it into a box. The part being made in this video is a baby bottle, on another machine, a cap and cover are being made that will make the bottle complete. Visit our website for more info on all our capabilities, and contact us for your next plastic or metal injection molding project.

The Real Facts Of Plastic Injection Molding

Plastic injection molding is often thought to be a hard process which is a wrong notion of the people. A variety of parts are manufactured using Injection molding process which varies from the smallest component to an entire body component of a car.

The machinery involved in plastic injection molding is costlier and very sensitive and complex equipment. These machines are called as injection molding machines. The machines used are also heavy and some even weigh upto tons of kilogram. But only when these kind of machines are used the final product turns out to be a quality product. This is so because the plastics are fed into these machines and they are heated until they become fluid. This shows that the machines should withstand high temperature and hence the need for a complex equipment.

Plastic materials used for the injection moulding process are thermoplastics or thermosetting plastics. Both the thermoplastic and thermosetting plastics are polymers. Some widely used thermoplastics are nylon, polyethylene, and polystyrene while bakelite, vulcanized rubber are the widely used thermosetting plastic. Sometimes a polymer with a very high elasticity is also used. Such a polymer is called elastomer.

The plastic takes the shape of the cavity or the mold used and get solidified or settled in it. After being solidified it is ejected out  After some time molded material is ejected out from the cavity. The same cavity can be used to make any  number of molds. The mold is of any desired shape.

The injection molding machine has two components namely the injection unit, the mold and the clamping unit. One should not forget that the process involved in plastic injection molding is not as tough as the size of the machinery. It is a very simple and a systematic process. Initially the injection molding process starts with the injection of the plastic resins or polymers into the injection barrel. The resins are heated to melting point and now the fluid is poured into the mold which is of the desired shape needed. The mold has two components namely the injection mold and the ejector mold. The melted plastic resin in poured into the mold using a sprue the injection mold. And the ejector mold helps in ejecting the plastic part after it is solidified in the mold without any damage using ejecting pins.

The next step is the application of hudraulic or mechanical pressure. This is done in order to allow the trapped air in the mold to escape. This is called the dwelling process. After the pressure is applied the air cavities move to one corner of the mold. Then the fluid is allowed to solidify and the mold is cooled. Finally the solidified plastic part is ejected from the mold either manually or automatically.

After the cooling process there is often change in the mechanical that is both physical and chemical properties of the plastic part. The thickness of the mold is one of the important design considerations of the injection molding process. Usually a mold with an uniform wall thickness is preferred. Thus it reduces the change in mechanical properties of the plastic part.

Question by Robert R: For plastic injection molding what are the 3 significant factors from back pressure??
3 distinguished factors that back pressure might lead to for injection molding. I would like an explanation for each.

Best answer:

Answer by Edesigner
First there is STRIATION-this is thickness incompatibility…,,, then there is HONEYCOMB- this is the hole you see in the plastic where there is not suppose to be a hole… and there is also COMPACTION –this is when the air is pressurized out of the plastic making it a too brittle …All of these can be controlled by temperature modification and of course pressure..there is also another problem which factor into injection molding this is draft point- the place where the little piece of excess runs out and in the actual process if bead are used contamination will really blow out the dies …after all that’s what we need to save the most are the dies……Well there ya go …Good luck with the plastic billet business..From the E…

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Plastics Injection molding application using KUKA robots. More information at www.kukarobotics.com.
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The basics of a plastic injection molding system. From BeechmontCrest.com

Medical Plastic Injection Moulding ? Procedure and Products

In 1868, John Wesley Hyatt developed the first plastic injection mold, and the plastic injection moulding process. He used the plunger method to successfully inject hot, liquid celluloid, often called the first thermoplastic, into a split-die mold. This process was little changed until James Hendry built the first screw plastic injection mold in 1946. Today, nearly all industrial and medical plastic injection moulding processes use the screw method.

Plastic moulding is a very methodological and technical process. Thus it needs experts in this type of manufacturing business for it to meet the safety terms and to be competitive in the market. A very scientific and systematic mechanical study is first made before going into this endeavor. Here I have discussed some known plastic injection moulding process that can help you to understand the various ways it is done for industry specific plastic products.

1. Injection Moulding.

Examples of applications: Medical plastic laryngeal mask components, laboratory products, extraction systems, toys, aircraft undercarriage components, kitchen utensils, bottle caps, and cell phone stands.

In Injection Moulding, melted plastic is forced into a mold cavity. Once cooled, the mold can be removed. This plastic injection moulding process is commonly used in mass-production or prototyping of a product. Typically this process is used to produce plastic mouldings where the relatively high tooling cost can be justified by low unit costs and tolerances which cannot be achieved by other moulding processes.

2. Blow Moulding.

Examples of applications: Automotive, Toys, Recreational, tubes and containers, Medical, Housework Appliances

The process is divided into three steps: injection, blowing and ejection. Blow moulding is like plastic injection moulding except that hot liquid plastic pours out of a barrel vertically in a molten tube. The mold closes on it and forces it outward to conform to the inside shape of the mold. When it is cooled, the hollow part is formed. Equipments needed in setting-up a blow moulding business are relatively higher than injection moulding.

3. Compression Moulding.

Examples of applications:  Automotive exterior panels especially for commercial vehicles, Radio & appliance knobs, ash trays & electrical parts.

In this type of plastic moulding, a slug of hard plastic is pressed between two heated mold halves. Compression moulding usually uses vertical presses instead of the horizontal presses used for injection and blow moulding. The parts formed are then air-cooled. Prices of equipments used for compression moulding are moderate.

4. Film Insert Moulding.

Examples of applications: FIM can be used to apply clear scratch-resistant hard coats, logos, text and graphics in any color or combination of colors to plastic parts prior to injection molding.

This plastic moulding technique imbeds an image beneath the surface of a molded part. A material like film or fabric is inserted into a mold. Plastic is then injected.

5. Gas Assist Moulding

Examples of applications:  Flat panels for office equipment, Computer enclosures, Furniture, i.e. tabletops, Automotive panels, Domestic appliances – e.g. fridges.

Also called gas injection moulding is used to create plastic parts with hollow interiors. Partial shot of plastic is then followed by high-pressure gas to fill the mold cavity with plastic.

6. Rotational Moulding.

Examples of applications:  All kinds of plastics mostly hollow Plastic Parts.

Hollow molds packed with powdered plastic are secured to pipe-like spokes that extend from a central hub. The molds rotate on separate axes at once. The hub swings the whole mold to a closed furnace room causing the powder to melt and stick to the insides of the tools. As the molds turn slowly, the tools move into a cooling room. Here, sprayed water causes the plastic to harden into a hollow part. In this type of plastic moulding, tooling costs are low and piece prices are high. Cycle time takes about 40-45 minutes.

7. Structural Foam Moulding.

Examples of applications: Typical products are large trash containers, freeway sand safety containers and in-ground housing for water systems.

Structural foam moulding is a process of plastic injection moulding usually used for parts that require thicker walls than standard injection moulding. Inserting a small amount of nitrogen or chemical blow agent into the plastic material makes the walls thicker. Foaming happens as the melted plastic material enters the mold cavity. A thin plastic skin forms and solidifies in the mold wall. This type of plastic moulding can be used with any thermoplastic that can be injection molded.

8. Thermoforming.

Examples of applications: Clamshells, Trays, Blisters, Displays, Guards, Covers, Totes, Shields, medical plastics

In this plastic moulding process, sheets of pre-extruded rigid plastics are horizontally heated and sucked down into hollow one-piece tools. When the hot plastic solidifies, its shape conforms to that of the mold. Tooling costs are usually low and piece prices vary on the machinery.

Question by Dimpy: Does anyone know how to calculate cycle times for a product on Plastic Injection Moulding Machine?
I have all the data like product size, weight, melt flow rate of PP resin, injection rate of machine, plasticizing rate, mould open close rate. Am I missing something here?

Best answer:

Answer by ***KREEM YUNG***
….

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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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Question by fred: how to give quotation of plastic injection products?
I want to learn how give the quotation of plastic injection products!

Best answer:

Answer by waterstreet
first of all, you need to know your own costing. tooling cost, mould cost, raw material cost, time of production cost, equipment overhead cost, power consumtion cost…… then factor in your profit margin and, voila! that is your quote.

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