5 Common Plastic Molding Processes

Plastics are being used to make everything from human body parts to automotive parts. Each application requires a special manufacturing process that can mold the part based on specifications. To help understand the different requirements, here is a brief overview of the different types of molding along with their advantages and applications. 5 Common Plastic Molding Processes Blow Molding – Perfectly suited for hollow objects, like bottles. The basic steps used in glass blowing are also found in blow molding. A heated plastic mass is inflated by air. The air pushes the plastic against the mold to form the desired shape. Once it’s cooled, the plastic is ejected. The blow molding process is designed to manufacture high volume, one-piece hollow objects. If you need to make a lot of bottles, this process is perfect for you. Blow molding creates very uniform, thin walled containers and in an economically way. Injection Molding – Suited for high-quality, high-volume part manufacturing. Injection molding is one of the most versatile of all molding techniques. The presses used in the process vary in size and are rated based on tonnage or pressure. Larger machines can injection mold car parts, while smaller machines can produce very precise plastic parts for surgical applications. In addition, there are many types of plastic resins and additives that can be used in the injection molding process, increasing its flexibility for designers and engineers. Extrusion Molding – Well suited for long hollow formed applications like tubing, pipes and straws. While other forms of molding uses extrusion to get the plastic resins into a mold, this process extrudes the melted plastic...

Key Terms for Plastic Injection Molding

In the manufacturing world, there are many things said that not everyone understands. It’s not to say that plastic injection molding is rocket science, but it comes pretty close when it comes to the hundreds of terms used in the industry. To help you get a better understanding of the terms used for plastic mold design, we’ve highlighted the most commonly used terms when discussing mold parts, materials, and problems. Additives – These compounds are added to resins to improve the overall performance and appearance of finished products. A key trend in this area today is using additives that are made from organic materials such as wood pulp, rice hulls, eggshells or materials that improve the biodegradability of the plastic. Alloy – This is a physical modification of an existing plastic to achieve higher performance and/or functionality. These alloys are often used in the automobile industry and to replace metal parts. Annealing – Annealing is the heating and slow cooling of a plastic part that allows the polymer chains to recoil and relieve internal stresses. Assembly – This is a secondary manufacturing function of joining finished parts together. Backing plate – A plate, which supports the mold, pins and bushings in the injection machine. Blister – This is a part defect that appears as a small bubble or blister on the surface of a part and it generally is created by gas or air bubbles. Blow molding – This is the proves that follows the basic steps found in glass blowing. A parison (heated plastic mass, generally a tube) is inflated by air. The air pushes the plastic against...

The Heavy Truth About Injection Molding

The average weight of a stainless steel injection mold is seven hundred pounds. Some can weigh over a ton, some just a few hundred pounds, but any way you cut it, you certainly don’t want one to fall on your foot. So how do you get this massive piece of metal to produce complex plastic parts? It’s all in the tooling. When using CNC EDM machines to create the base of mold cavitation, it is the work of the tool maker to refine the steel to exact specifications. Precision work on the cavities is only part of the process. The tool must also include gating to allow for proper melt flow and vents to allow gas and air to escape. Without proper placement of these key features, parts will be subject to imperfections. If you are working with a turnkey plastic injection molder, they will test the mold cavities to uncover any flaws in the tooling or the design. This is an important step because it can help save thousands of dollars in re-tooling costs. Don’t let questions about plastic injection molding weigh you down. Get the answers you need by contacting Design-Tek Plastics today at...

What Millenials Think of the Manufacturing Industry

In the video above, it’s clear that young people are shying away from STEM education because of a distorted perception of manufacturing employment and careers. Although the people in this film are bright, they are not very knowledgeable about manufacturing or technical careers. When you watch this video, you see that some of the statistics that are cited are quite interesting. Over 17 million people are employed in the manufacturing world and on average the compensation for these careers exceeds $77,000. So while the jobs are there and they pay well, young people show little if any interest. According to the National Association of Manufacturers (NAM), 18-24 year olds rank manufacturing 5 out of 7 for career preferences. However, more than 80% believe manufacturing is important to our economy and standard of living. The fact is that we need to address the skills gap before we can develop the engineers and technicians of the future. A study from The National Defense Industrial Association reported that between 5th and 12th grade 74% of the children do not have access to or interest in STEM the coursework they need to thrive in today’s advanced manufacturing environment. Without this baseline education, our younger generations won’t be qualified to fill the highly technical careers that are now the benchmark of a manufacturing environment. Many companies are addressing this gap by working with local educators and school administrators to support and encourage STEM education. Some organizations partner with workforce development agencies to identify and groom future manufacturing candidates. Still, others are using the old model of apprenticeships to grow their own talent internally. The...