Plastics are synthetically produced non-metallic compounds. It can be molded into various forms and hardened for commercial use. Plastic molding products can be seen everywhere. Examples are jars, protective caps, plastic tubes, grips, toys, bottles, cases, accessories, kitchen utensils and a lot more.
Even the keyboard and the mouse that you use are made through plastic molding. Even the plastic parts of the chair that you are sitting on are created this way.
The basic idea in plastic molding is inserting molten liquid plastic into a ready shaped mold, for example the mold of a bottle. It will be then allowed to cool, then the mold will be removed to reveal the plastic bottle.
Plastic molding can also custom-mold a wide variety of plastic products including: garden pots, cabinets, office trays and boxes, barriers, barricades and traffic signage and displays for product and marketing promotions.
If you are planning to go into plastic molding business, you should first know the different processes. Choose from a plastic molding process that fits your budget, your expertise, and your resources. Here are basic definitions of various methods of plastic molding.
The Plastic Molding Processes:
1. Injection Molding
In Injection Molding, melted plastic is forced into a mold cavity. Once cooled, the mold can be removed. This plastic molding process is commonly used in mass-production or prototyping of a product. Injection molding machines were made in the 1930's. These can be used to mass produce toys, kitchen utensils, bottle caps, and cell phone stands to name a few.
2. Blow Molding
Blow molding is like injection molding 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. Examples of blow molding products are bottles, tubes and containers.
Equipments needed in setting-up a blow molding business are relatively higher than injection molding.
3. Compression Molding
In this type of plastic molding, a slug of hard plastic is pressed between two heated mold halves. Compression molding usually uses vertical presses instead of the horizontal presses used for injection and blow molding. The parts formed are then air-cooled. Prices of equipments used for compression molding are moderate.
4. Film Insert Molding
This plastic molding 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 Molding
Also called gas injection molding 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 Molding
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 molding, tooling costs are low and piece prices are high. Cycle time takes about 40-45 minutes.
7. Structural Foam Molding
Structural foam molding is a process of plastic molding usually used for parts that require thicker walls than standard injection molding. 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 molding can be used with any thermoplastic that can be injection molded.
8. Thermoforming
In this plastic molding 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.
Plastic molding is a very technical process. It needs experts in this type of manufacturing business for it to be competitive in the market. Therefore, a very scientific and systematic study should be first made before going into this endeavor.
First step: to conduct a feasibility analysis for the plastic mold design products ,taking computer chassis as an example, the first drawings of the components make use of design software products for group analysis of legislation, that is what our work of plans to ensure that plastic mold design drawings prior to the correctness of each product, on the other hand, we can be familiar with the various components in the entire chassis to know the importance of the key size, which in the plastic mold design is very good. Step two: after Product analysis job bing carried out, we will analyze what kind of plastic mold structure, and product scheduling process to determine the work of workers and to make use of design software products start at the beginning of Products general follow-up project forward from the start, such as one in five Product requirements processes, and stamping is completed at the beginning of Products Products Drawings from the start to the four projects, three projects, two projects, one project, and launched after a copy of a graphical re - before the project started one job, that is, five projects completed work products, and then carry out detailed work, note that this step is very important, in need of special care at the same time, the step is completed well, then die at rendering savings plans will be a lot of time stamping of each project to determine the content of good, including in the forming plastic mold, the product material thickness to retain the internal and external lines to determine the convexity modulus size to use for the product launch here at the Ways no longer show that will be at Ways to start specific Product Introduction.
The third step: preparation, depending on product launch plans for preparation, in the drawings identified in the template size, including the fixed plate, discharge plate, convex and concave plastic mold, such as inserts, direct attention to the product launch plans in preparation, it would draw die Figure it will be greatly beneficial, I have seen there is a lot of plastic mold design directly on product launch plans for manual calculation to get the materials ready, the efficiency of this method is too low, directly in the drawing template to draw up specifications for size, to group-li map form of expression, on the one hand, preparation can be completed on the other hand, in the plastic mold of the accessories work saved a lot of work, because at rendering the work of the various components in the preparation drawings only add positioning, pin, lead column, screw-hole that is can be.
Step four: after the completion of the preparation can be a comprehensive mapping into the plastic mold, in the preparation of re-drawing of a system out of the drawing of various components, such as add screw holes, hole lead column, positioning holes, such as pore spaces, and Piercing Die at various holes to be wire-cut silk dress of the hole, in plastic molding, the upper and lower plastic molding die clearance, must not forget that after the completion of these tasks so a product of the plastic mold has been completed map almost 80 percent, while in the drawing die chart the course to note: the processes that produced lines such as fitter, wire-cutting until the different production processes have a complete good layer, so that on-line cutting and drawing management has been of great benefit, such as color distinction and so on, the mark size is also a very important job, but also one of the most troublesome job, because too much time to waste.
Step five: after the completion of the above drawings, in fact, also should not issue drawings, drawings of dies needed for proof-reading, all the accessories group lap, one for each different plastic mold plates produce different types of layers, and the same benchmarks such as lead-chu hole until the plastic mold Legislative Analysis Group, and will start the process Products Group plans to introduce legislation sets of plans in place to ensure that the template holes line up and down as well as the location of bending modulus with the gap is correct.
After the above-mentioned work, a product of plastic mold drawings be formally completed, the above is in the direction of plastic mold and plastic molding design. By steven cheng CEO of plastic mold www.sino-mould.com.cn plastic molding www.plasticmoulds.net business
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