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27-641: The chair was designed using technology for molding plywood that the Eames developed before and during the Second World War . Before American involvement in the war, Charles Eames and his friend, architect Eero Saarinen , entered a furniture group into the Museum of Modern Art 's "Organic Design in Home Furnishings Competition" in 1940, a contest exploring the natural evolution of furniture in response to

54-434: A blow molding machine and sold it to Hartford Empire Company in 1938. This was the beginning of the commercial blow molding process. During the 1940s the variety and number of products were still very limited and therefore blow molding did not take off until later. Once the variety and production rates went up the number of products created soon followed. The technical mechanisms needed to produce hollow-bodied workpieces using

81-569: A cooling period the blow mold opens and the core rod is rotated to the ejection position. The finished article is stripped off the core rod and as an option can be leak-tested prior to packing. The preform and blow mold can have many cavities, typically three to sixteen depending on the article size and the required output. There are three sets of core rods, which allow concurrent preform injection, blow molding and ejection. Injection Stretch Blow Molding has two main different methods, namely Single-stage and Double-stage process. The Single-stage process

108-498: A factor of 30 times. The process of injection blow molding ( IBM ) is used for the production of hollow glass and plastic objects in large quantities. In the IBM process, the polymer is injection molded onto a core pin; then the core pin is rotated to a blow molding station to be inflated and cooled. This is the least-used of the three blow molding processes, and is typically used to make small medical and single serve bottles. The process

135-409: A heated tube. Once the plastic is melted the screw stops rotating and linearly moves to push the melt out. With the accumulator method, an accumulator gathers melted plastic and after the previous mold has cooled and enough plastic has accumulated, a rod pushes the melted plastic and forms the parison. In this case the screw may turn continuously or intermittently. With continuous extrusion the weight of

162-440: A hole in one end through which compressed air can enter. The plastic workpiece is then clamped into a mold and air is blown into it. The air pressure inflates the plastic which conforms to the mold. Once the plastic has cooled and hardened the mold opens and the part is ejected. Water channels within the mold assist cooling. The process principle comes from the idea of glassblowing . Enoch Ferngren and William Kopitke produced

189-531: A hollow tube forming a tube like piece of plastic with a hole in one end for compressed gas - known as a parison. The parison is captured by closing it into a cooled metal mold. Air is blown into the parison, inflating it into the shape of the hollow bottle , container, or part. After the plastic has cooled, the mold is opened and the part is ejected. "Straight extrusion blow molding is a way of propelling material forward similar to injection molding whereby an Archimedean screw turns, feeding plastic material down

216-553: A painter and sculptor, continued experiments with molded plywood designs in the spare room of their apartment. In 1942 Charles left MGM to begin making molded plywood splints for the United States Navy. The splints used compound curves to mimic the shape of the human leg. The experience of shaping plywood into compound curves contributed greatly to the development of the LCW. The entries Charles Eames & Eero Saarinen submitted into

243-403: A plywood spine and supported by plywood legs. The result was a chair with a sleek and honest appearance. All of the connections were visible and the material was not hidden beneath upholstery. The seat was joined to the spine and legs with four heavy rubber washers with embedded nuts, subsequently called 'shock mounts'. The shock mounts were glued to the underside of the seat, and screwed in through

270-630: A section of a complicated object. This is generally only used for larger and more valuable objects. Blow molding is a manufacturing process for forming and joining hollow plastic or glass parts. A manufacturer who makes molds is called a moldmaker . A release agent is typically used to make removal of the hardened/set substance from the mold more easily effected. Typical uses for molded plastics include molded furniture , molded household goods , molded cases , and structural materials. There are several types of molding methods. These include: Blow molding Blow molding (or moulding )

297-410: Is a counterpart to a cast . The very common bi-valve molding process uses two molds, one for each half of the object. Articulated molds have multiple pieces that come together to form the complete mold, and then disassemble to release the finished casting; they are expensive, but necessary when the casting shape has complex overhangs. Piece-molding uses a number of different molds, each creating

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324-413: Is a manufacturing process for forming hollow plastic parts. It is also used for forming glass bottles or other hollow shapes. In general, there are three main types of blow molding: extrusion blow molding, injection blow molding, and injection stretch blow molding. The blow molding process begins with softening plastic by heating a preform or parison . The parison is a tube-like piece of plastic with

351-408: Is divided into three steps: injection, blowing and ejection. The injection blow molding machine is based on an extruder barrel and screw assembly which melts the polymer . The molten polymer is fed into a hot runner manifold where it is injected through nozzles into a heated cavity and core pin. The cavity mold forms the external shape and is clamped around a core rod which forms the internal shape of

378-429: Is the process of manufacturing by shaping liquid or pliable raw material using a rigid frame called a mold or matrix. This itself may have been made using a pattern or model of the final object. A mold or mould is a hollowed-out block that is filled with a liquid or pliable material such as plastic , glass , metal , or ceramic raw material. The liquid hardens or sets inside the mold, adopting its shape. A mold

405-460: Is then again broken down into 3-station and 4-station machines. In the single-stage process, both preform manufacture and bottle blowing is performed in the same machine. The older 4-station method of injection, reheat, stretch blow and ejection is more costly than the 3-station machine which eliminates the reheat stage and uses latent heat in the preform, thus saving costs of energy to reheat and 25% reduction in tooling. The process explained: Imagine

432-687: The Herman Miller furniture company in Zeeland, Michigan. In 1947 Herman Miller moved the production of the chairs to Michigan, where production continues—after a hiatus from 1957 to 1994. In Europe, Vitra became the producers of Eames furniture. Herman Miller and Vitra are the only two companies producing chairs licensed by the Eames estate as represented by the Eames Office. Molding (process) Molding ( American English ) or moulding ( British and Commonwealth English ; see spelling differences )

459-487: The Organic Furniture competition were designed with the seat and backrest joined in a single 'shell'. The plywood, however, was prone to crack when bent into the sharp curves the furniture demanded. The competition entries were covered with upholstery to hide these cracks. Through extensive trial and error, Charles and Ray arrived at an alternate solution: create two separate pieces for the seat and backrest, joined by

486-531: The blowing technique were established very early on. Because glass is very breakable, after the introduction of plastic, plastic was used to replace glass in some cases. The first mass production of plastic bottles was done in America in 1939. Germany started using this technology a little bit later but is currently one of the leading manufacturers of blow molding machines. In the United States soft drink industry ,

513-419: The bottom of the chair. The backrest was also attached using shock mounts. From the front and top the seat and back are uninterrupted by fasteners. The rubber mounts were pliable, allowing the backrest to flex and move with the sitter. This technology is also one of the chair's greatest flaws. The shock mounts are glued to the wooden backrest, but may tear free for various reasons. A common response to this problem

540-614: The molding process. This is trimmed off by spinning a cutting blade around the container which separates the material. The excess plastic is then recycled to create new moldings. Spin Trimmers are used on a number of materials, such as PVC, HDPE and PE+LDPE. Different types of the materials have their own physical characteristics affecting trimming. For example, moldings produced from amorphous materials are much more difficult to trim than crystalline materials. Titanium nitride -coated blades are often used rather than standard steel to increase life by

567-443: The molecules are small round balls, when together they have large air gaps and small surface contact, by first stretching the molecules vertically then blowing to stretch horizontally the biaxial stretching makes the molecules a cross shape. These "crosses" fit together leaving little space as more surface area is contacted thus making the material less porous and increasing barrier strength against permeation. This process also increases

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594-421: The number of plastic containers went from zero in 1977 to ten billion pieces in 1999. Today, an even greater number of products are blown and it is expected to keep increasing. For amorphous metals , also known as bulk metallic glasses, blow molding has been recently demonstrated under pressures and temperatures comparable to plastic blow molding. In extrusion blow molding, plastic is melted and extruded into

621-617: The parison drags the parison and makes calibrating the wall thickness difficult. The accumulator head or reciprocating screw methods use hydraulic systems to push the parison out quickly reducing the effect of the weight and allowing precise control over the wall thickness by adjusting the die gap with a parison programming device. Continuous extrusion equipment includes rotary wheel blow molding systems and shuttle machinery , while intermittent extrusion machinery includes reciprocating screw machinery and accumulator head machinery . Containers such as jars often have an excess of material due to

648-423: The preform. The preform consists of a fully formed bottle/jar neck with a thick tube of polymer attached, which will form the body. similar in appearance to a test tube with a threaded neck. The preform mold opens and the core rod is rotated and clamped into the hollow, chilled blow mold. The end of the core rod opens and allows compressed air into the preform, which inflates it to the finished article shape. After

675-445: The rapidly changing world. Eames & Saarinen won the competition. However, production of the chairs was postponed due to production difficulties, and then by the United States' entry into WWII. Saarinen left the project due to frustration with production. Charles Eames and his wife Ray Kaiser Eames moved to Venice Beach, Los Angeles, in 1941. Charles took a job as a set painter for MGM Studios to support them. Ray, formally trained as

702-411: The strength to be ideal for filling with carbonated drinks. In the two-stage injection stretch blow molding process, the plastic is first molded into a "preform" using the injection molding process. These preforms are produced with the necks of the bottles, including threads (the "finish") on one end. These preforms are packaged, and fed later (after cooling) into a reheat stretch blow molding machine. In

729-469: Was to drill directly through the backrest and insert fasteners between the backrest and the lumbar support. This devalues the chair, since it changes the original aesthetic of smooth, uninterrupted wooden forms. Coming out of an age where furniture was heavy and complex; made from multiple materials and then covered in upholstery, the Eames design was striking. The chair was produced from 1946 until 1947 by Evans Molded Plywood of Venice Beach, California , for

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