Injection Molding Theory

Improved Essays
THEORY
Injection molding is the most commonly used manufacturing process for the fabrication of plastic parts. A wide variety of products are manufactured using injection molding, which vary greatly in their size, complexity, and application. The injection molding process required the use of an injection molding machine, raw plastic material, and a mold. The plastic is melted in the injection molding machine and then injected into the mold, where it cools and solidifies into the final part. Figure 1: Injection molding.
Injection molding is used to produce thin-walled plastic parts for a wide variety of applications, one of the most common being plastic housings. Plastic housing is a thin-walled enclosure, often requiring many ribs and bosses
…show more content…
Clamping - Prior to the injection of the material into the mold, the two halves of the mold must first be securely closed by the clamping unit. Each half of the mold is attached to the injection molding machine and one half is allowed to slide. The hydraulically powered clamping unit pushes the mold halves together and exerts sufficient force to keep the mold securely closed while the material is injected. The time required to close and clamp the mold is dependent upon the machine.
2. Injection - The raw plastic material, usually in the form of pellets, is fed into the injection molding machine, and advanced towards the mold by the injection unit. During this process, the material is melted by heat and pressure. The molten plastic is then injected into the mold very quickly. The amount of material that is injected is referred to as the shot. The injection time is difficult to calculate accurately due to the complex and changing flow of the molten plastic into the
…show more content…
Cooling - The molten plastic that is inside the mold begins to cool as soon as it makes contact with the interior mold surfaces. As the plastic cools, it will solidify into the shape of the desired part. The mold cannot be opened until the required cooling time has elapsed. The cooling time can be estimated from several thermodynamic properties of the plastic and the maximum wall thickness of the part.
4. Ejection - After sufficient time has passed, the cooled part may be ejected from the mold by the ejection system, which is attached to the rear half of the mold. When the mold is opened, a mechanism is used to push the part out of the mold. In order to facilitate the ejection of the part, a mold release agent can be sprayed onto the surfaces of the mold cavity prior to injection of the material. Once the part is ejected, the mold can be clamped shut for the next shot to be

Related Documents

  • Improved Essays

    If a tooth becomes too damaged or decayed for fillings or other restoration methods to work, it might require a crown. This is a covering that goes over the entire tooth and used to stabilize the structure of the tooth while also preventing further damage. While Digital Dental Group in Dayton, OH, and other dental offices use to complete this procedure over two or more appointments, new technologies now allow them the possibility of offering patients same day crowns. In the past when patients came to their dentist for dental crowns, they would often have to schedule a primary appointment to have a mold made of their teeth for the custom crown.…

    • 471 Words
    • 2 Pages
    Improved Essays
  • Improved Essays

    If your periodontal disease is seriously advanced, one of your options in order to have a full set of functioning teeth is to begin the steps towards having full dental implants. It takes multiple steps spread out over many months for this entire process. Here is a brief rundown of how the process works. Step #1: Fabrication Of Immediate Dentures The first step towards getting full dental implants is the fabrication of immediate dentures.…

    • 456 Words
    • 2 Pages
    Improved Essays
  • Improved Essays

    A. After having viewed the 'Anatomy of a firework' interactive answer the following: What are the different parts that make up a firework? Fireworks have a few different parts such as Potassium Nitrate, Charcoal, and Sulfur and they use different chemical compounds to create three kinds of results:…

    • 671 Words
    • 3 Pages
    Improved Essays
  • Improved Essays

    2. Discussion: Pathophysiology How hip implant is engineered An artificial hip is also referred to as a prosthesis. A prosthesis is a mechanical device that is designed to replace a biological part of the body. Each hip implant is made up two main parts: the Acetabular component or socket replaces the acetabulum.…

    • 966 Words
    • 4 Pages
    Improved Essays
  • Decent Essays

    You can 3d print anything with materials that go from glucose (sugar) to ceramic (thersa.org). Say that you want a dog collar and you go online to buy one or of course go to any pet store to get one, but that is going to take days to ship and process. Instead you should go online and get a template to 3d print a collar for your dog. For obvious reasons you get to choose the color and you can even engrave the collar with the animals name (thersa.org). It could improve or not improve human life because eventually you may never leave your home because all you have to do is 3d print whatever you…

    • 568 Words
    • 3 Pages
    Decent Essays
  • Great Essays

    Between 1916 and 1949 a few other companies offered colored shellac discs, including a blue-shellacked series from Columbia during the 1930s and chocolate colored pressings from a budget label “Perfect Records” prior to the 1930s. In 1949 when RCA Victor launched their 45-RPM format they began color-coding their records based on genre calcification. They classifications are as follows: Black Vinyl – Pop Pressings (Prefix 47) Green Vinyl – Country Music (Prefix 48)…

    • 4415 Words
    • 18 Pages
    Great Essays
  • Improved Essays

    Micro-needling is a non-surgical procedure that is used for facial rejuvenation. This minimally-invasive procedure is designed to stimulate collagen and elastin production, which helps to diminish the signs of aging. A More Youthful Appearance is Possible with Micro-Needling As we age, collagen production slows down: This decrease in collagen production causes wrinkles and/or sagging skin.…

    • 625 Words
    • 3 Pages
    Improved Essays
  • Improved Essays

    It is melted and released with a needle at the top of the extruder that is needed for the next necessary…

    • 503 Words
    • 3 Pages
    Improved Essays
  • Superior Essays

    The M6 Assault Rifle

    • 1493 Words
    • 6 Pages

    When the trigger is pulled in fire mode, the hammer is sprung forward, striking the firing pin, which strikes the primer, which ignites the powder. Gas from the explosion powers the projectile forward through the barrel. Near the end of the barrel, a small portion of gas escapes through the top of the barrel through a small hole called the gas port (Morgan). The small portion of gas is pushed through the gas tube back toward the cylinder and the bolt (Morgan). The rotating head on the bolt grips the bullet as gas pushes the bolt back and depresses the spring that is located in the stock (Morgan).…

    • 1493 Words
    • 6 Pages
    Superior Essays
  • Improved Essays

    Orthopaedic Procedure

    • 326 Words
    • 2 Pages

    There are two kinds of bone cements for orthopaedic procedures, conventional cement (PMMA) and bioasorbable composites. Cement augmentation is a very useful technique for fixation of implants such as screws, plates, or IMnails in osteoporotic bone. Generally, cement augmentation features increased strength of implant fixation, rapid restoration of patient mobility, and reduction of the complications of implant failures. The occurrence of severe skeletal loss requires the stability provided by polymethylmethacrylate (PMMA). In a biomechanical study which investigated the treatment of osteoporotic trochanteric patients, femurs which had the lowest bone density showed a significant improvement in the initial fixation stability and total displacement of the femoral head was reduced by 39% on average in the group with the modified sliding hip screw (SHS) and PMMA compared to the standard SHS group (6).…

    • 326 Words
    • 2 Pages
    Improved Essays
  • Superior Essays

    Destin Briggs Lu Jack Chem 4235 11/4/2017 Original Synthesis of Cadmium Nitrate Tetra-Hydrate Cadmium nitrate tetra-Hydrate is an inorganic compound from the family of compounds with the general formula Cd (NO3)2.XH20, where X=4, hence the molecule has four molecules of water of crystallization in its structure. It exists as a salt but in its anhydrous state, it is known to be a volatile substance. It is a colorless substance as are all the compounds in the family of cadmium nitrates. Cadmium nitrate is a colorless, crystalline, inorganic compound that forms the toxic fumes produced when cadmium oxides are heated.…

    • 1315 Words
    • 6 Pages
    Superior Essays
  • Decent Essays

    In this experiment six unknown plastics ranging from #1 to #6 are being tested for its density (in water, rubbing alcohol, and corn oil), flame color, reactions with acetone, and the resistance to melting in order to lead to the identification of the six unknown plastic. The experiment must undergo in the order above, and the plastics that did not indicate signs of change are continued to be tested in the next test, until each six unknown plastics are separated into different groups (groups that share similar properties). Despite the fact that there are six different types of plastic (each belongs to a specific SPI resin code). However, all of them exhibited a consistent pattern in terms of density, flame color, reactions with acetone, and…

    • 227 Words
    • 1 Pages
    Decent Essays
  • Improved Essays

    M & M's Molding

    • 978 Words
    • 4 Pages

    M and M’s Molding • Liquid chocolate is poured into molds to create chocolate centers of the candy. • After the candies are formed they are tumbled to make the center smooth and rounded. Coating • When the centers harden, they are transported via conveyer belt to the coating area.…

    • 978 Words
    • 4 Pages
    Improved Essays
  • Decent Essays

    Rubber Band Lab Report

    • 479 Words
    • 2 Pages

    Method 1. Scissors were used to cut the rubber band, making the rubber band one straight line instead of a circular shape. 2. One end of the rubber band was securely tied to the middle of the skewer. The other end was securely tied to the hook of the 100g slotted steel weight.…

    • 479 Words
    • 2 Pages
    Decent Essays
  • Improved Essays

    The use of animal carcasses in make up Makeup is now trending more than ever, “currently there are a lot of different make up brands and products that ranges from high end to drug store”. (Oddee.net) Most make up comes with a list of ingredients on the wrapper or container, but do we really know what is in our make up? This document seeks to highlight the fact that major ingredients in some of the makeup products we use are indeed animal carcasses. This document serves to further highlight and explore some of the products that contains animal carcasses and from what animals they came from. Bronzer, blush, eyeliner, conciliar are what they call makeup, they are made with a diverse array of ingredients including oils, dyes, and other forms of pigmentation that doesn’t get mention as such as animal carcasses.…

    • 490 Words
    • 2 Pages
    Improved Essays