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Injection Molds and Rotational Molds - Manufacturing For a Demanding Marketplace

The world has become very dependent upon plastic products. From household items to industry and aerospace, plastic in its many formulations has transformed modern manufacturing and created conveniences and economies unimagined in the early decades of the 20th century.

Injection Molds

The injection molding industry took hold in 1946 when James Hendry built a screw injection molding machine. But, his technology was based on an earlier invention by John Wesley Hyatt who, in 1868 injected hot celluloid into a mold to make billiard balls. Hyatt's method used a plunger to force the material inside a mold. Hendry's improvement was revolutionary because it eliminated the plunger and replaced it with an auger-type action that better distributed material and facilitated the use of plastic inside molds.

Today's injection molds use much the same process and produce a wide variety of products from car panels to outdoor furniture, small toys and tools. Injection molding is ubiquitous in manufacturing and uses many different materials from polymer plastics to aluminum, copper and other metals. The plastic bottles and kitchen implements people use in everyday life are products of the injection process.

Because the metal molds are generally expensive to produce, injection molding is most economically used when thousands of pieces are being manufactured. Molds are made of hardened steel or, more recently, aluminum which is less expensive.

The Injection Process

Described very simply, molten plastic is injected into the mold under high heat and pressure. The goal is to have the molten plastic material evenly flow to all parts of the mold, creating an exact, consistent, solid plastic replica of the mold cavity. After a brief cooling cycle, the mold or tooling mechanically ejects the plastic part which then moves on through the manufacturing process. In the injection molding industry, this is a completely automated process that's very fast and extremely efficient.

Rotational Molding

Rotational molding is yet another method of producing multiple products, most often made with a variety of plastic powders. This process is usually used in making hollow products such as traffic cones, canoes, kayaks, bicycle helmets and giant tanks used for water or chemical storage.

Like Injection molding, rotational molding had its roots in the 1940s. But it was not until the technology was more sophisticated and new polymer and plastic formulations became available that the rotational process became a mainstream manufacturing method.

Rotational Process

The two processes are quite different. Let's consider, for example, a 300 gallon water storage tank made of polyethylene. Picture a master mold made of aluminum or steel. The plastics manufacturer pours poly resin powder into the mold that is fitted inside an oven. Once sealed, the mold is mechanically turned on at least three axes, moving much like a gyroscope. At the same time, the oven is raised to an appropriate temperature and the polymer - or other material - tumbles inside and slowly coats the inner walls of the mold, melting as it rotates.

Once the optimal temperature is reached, the mold is cooled. As the temperature of the mold itself falls, the product on the inside shrinks away from the inner walls and is easily removed. This is not always the case with injection molds that are often more difficult to successfully remove. The shrinking action of rotational molding is particularly desirable when the product is very large and awkward to handle.

Rotational molding is also more economical for some products because less material is used. In addition, the polymer that is left over from one mold can be used in another. The method itself is more streamlined than injection molding, which requires more interlocking parts.

Materials Improve and Expand

Most products made with the rotational molding method are from the polyethylene family. Other materials include nylons, polypropylene and PVC plastics. Some manufacturers have developed formulas that integrate the use of natural materials such as sand and chips of stone to make products.

Plastic and resin products are now an integral part of everyday life and supply us with items as tiny as paper clips and as big as storage tanks. As the industry developed, so too has environmental awareness about the safety and use of these petrochemical-based products. Today, materials can meet the specifications of FDA requirements, and other health and safety related regulations. Producers are also cooperating to create products that can be recycled.

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Creating The Best Tuscan Kitchen Design

Tuscan kitchen design immediately conjures images of Italy and sunlight and warmth.  In fact these kinds of images are just what you need to think of when coming up with the perfect Tuscan kitchen design.  

Tuscany a region in north central Italy is known as a warm place almost year round an Tuscan kitchen design should reflect this.  Tuscan kitchen designs are defined by colors such as siena, terra, and sepia.  Tuscan Kitchen design uses a lot of soft warm colors and textures.  Windows in the kitchen should provide as much natural sunlight as possible.

The Tuscan style has evolved through the centuries, influenced by Etruscan metal craft and pottery as well as the Italian Renaissance.  The Tuscan style can be seen in mosiac tiles, wrought iron gates, bridges and architecture.

Tuscan kitchen design and décor can enhance the look and feel of any kitchen.  You can add a big wooden table, open cupboards, along with ceramics, pots, pans and Tuscan-inspired dinnerware.
These items can also make great decorations when you are not using them.

Kitchen island design in the Tuscan kitchen design style has its origins from ancient Roman times.  This is the origins of the nice ornaments you will find with all tuscan kitchen design.  The Tuscan kitchen island is usually of a dark color painted on oak.  Sometimes the islands are given one coat of white paint.  Scratches are added to give the wood a more antique look.

In Tuscany families tend to eat and cook together.  A good Tuscan kitchen design should provide for adequate room for you and your family to more around the kitchen freely.

The Tuscan kitchen design style is very popular now.  One reason is that this design style be quite affordable while be stylish and providing more comfortable kitchen.  The Tuscan kitchen design style accessories include pottery, jars, and hand crafted tiles depicting grapevines and vineyards as well as grapes, tomatos, and olives.  Having these design elements just naturally goes with Tuscan meals.

Walls - Wall should be painted in a rich Tuscan color such as rich reds, intense yellows, or strong yellows.  Consider a wall treatment such as molding, or murals to create a more Tuscan feel to the walls.

Floors - Use Terra cotta or clay tiles, glazed ceramic and marble inlay in intricate patterns.  Wooden floors can be left plain with natural color and finish with a Persian rug.

Furniture - For a Tuscan kitchen design use sturdy pieces of furniture that is also strong and functional.  Kitchen tables and chairs should also be well-built and strong.

Cabinetry - Cabinetry should feature open shelves for displaying your ceramics, as well as baskets, and cooking utensils

Sink - Kitchen sink should be white ceramic to be more compatible with your Tuscan kitchen design.  You might also consider a large rectangular marble sink.

As for other Tuscan kitchen design ideas you can add racks to display copper pans.  Also wrought iron pull for drawers, and wrought iron light fixtures.  You might even want to add a brick-fired oven just like the type found in large Italian farmhouse kitchens.

By designing your kitchen with the Tuscan design style and bring in the look of old Tuscany your kitchen and home will never be quite the same.

About the Author

Read about growing alfalfa and alfalfa grass at the Alfalfa Benefits website.

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This entry was posted on Monday, February 11th, 2008 at 10:48 pm and is filed under Cookies. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.