Injection molded plastics manufacturers including plastic injection molding, plastic injection mold, plastic gears, injection molded plastics, plastic injection molders, and molded plastics.  

Information Page Links:

Featured Injection Molded Plastic Manufacturers

About Injection Molded Plastics

Injection Molded Plastic Terms

Injection Molded Plastic Associations

Injection Molded Plastic Resources

Trade Shows

Featured Injection Molded Plastic Articles

More Articles

ISO - International Organization
for Standardization

Back

About Plastic Molding

Injection plastic molding is the most common method used by plastic suppliers in the plastic processing industry. Since its invention in 1872, plastic molding and the plastics industry has become a multi-billion dollar industry, with 32% of all plastics processed by injection plastic molding. Injection plastic molding machines are used to produce complex plastic parts. An injection plastic molding machine has a barrel section which is heated first. Plastic pellets or granules are fed into a hopper where a screw pushes them to the heated barrel. In the barrel, the pellets or granules are heated to the melting point. The molten plastic material is then injected into the cavity of a split die chamber/mold, which is then clamped shut. The plastic resin cools as water or other fluids circulate through the cooling system of the mold, extracting the heat. The molded plastic part is held in the mold under high pressure until the part solidifies. The plastic part is finally ejected from the plastic mold, and the process begins again.

Plastic suppliers accomplish the injection molding process using equipment that is available in many configurations. Most commonly, a hydraulic oil injection molding machine is used to produce many molded parts. Hydraulic oil machines use the force of hydraulic fluids to move the mold through the machine. Next in popularity is the toggle plastic molding machine. Toggle machines use mechanical links to advance the mold in the machine. Hybrid hydraulic/toggle machines are beginning to emerge in the plastic molding industries. Hybrid machines are used to eliminate some of the problems of other injection plastic molding machines, such as slow processing rates of parts and rapid wear and tear of machines. All injection molding machines inject molten plastic material into a mold, but they may use various methods to move the mold, move un-melted plastic pellets and accomplish other parts of the process.

There are many advantages to the injection plastic molding process. Some advantages of injection molding include high production rates and a wide range of plastic material which can be used. Normally there is little need to finish parts after the molding is complete. The cost per part is very low despite the high cost of tooling. Injection plastic molding can produce very complex parts, and often parts for which no other process is available. Other advantages of the injection molding process include the efficient use of materials and energy, precision-formed parts and a negligible amount of waste produced.

From medical equipment, computer and automotive parts to office supplies, toys and tools, molded plastic parts are found in almost every sector of industry and our lives. Some specific examples of parts made using the injection plastic molding process are screwdriver handles, catheters, contact lens containers, monitors, mop buckets and video game cartridges. Injection plastic molding is primarily used for thermoplastics. However, a small amount of thermosets and elastomers are also subjected to this process. Biodegradable plastics are also molded. Products such as biodegradable cutlery and plastic pots are now being produced using this molding process. Injection molding has made possible the inexpensive and durable construction of many industrial items that have a profound impact on industry and society.

Images Provided by Universal Plastics Injection Molding

Featured Articles

“Multi-Shot Plastics Injection Molding Hits Target with Faster Processing and Wide Range of Design Possibilities”
http://www.appliancemagazine.com/editorial.php?article=214
 
“How to Reduce Sinks”
http://www.plasticstechnology.com/articles/200407fa2.html

Types of Plastic Molding

• Double-shot molding is a two-step process in which either the color or the material is injected first. Upon the hardening of the material, a second color or material is injected into or around the first shape.
  
• Gas-assisted injection molding is a process in which inert gas, such as nitrogen, is forced into the melt while it is entering the mold, packing the plastic into the cavities. Gas-assisted injection molding reduces cycle time, part weight, warpage and stress to the cooled parts, as well as minimizing other problems.
  
• Injection blow molding (http://www.blowmoldedplastic.com) is the process in which plastic is injected into a mold to form a plastic tube. The tube is then blown into a cavity mold to form a hollow part.
  
• Injection molding is a process by which plastics parts and products are formed.
  
• Molded plastic pieces are parts that are formed by pouring heated plastic into molds.
  
• Plastic injection molding is a process by which plastic is heated into a malleable form and pressed into molds.
  
• Plastic insert molding is an injection molding process in which plastic gets injected into a cavity surrounding an insert piece just prior to molding. Plastic insert molding results in a single piece encapsulated by the plastic.
  
• Plastic manufacturers make a variety of plastic goods.
  
• Plastic molders are the tools and dies used to mold molten plastic.
  
• Push-pull molding is a process that involves multiple layers with different orientations, providing more uniform properties to the parts than if they were molded from a single direction