Plastic is one of the most common materials for producing numerous products, from consumer goods to medical devices. Plastic is a broad and versatile category that includes thousands of different polymers that each has is its specific property and functionality.
The Four Factors to Consider in Plastic Manufacturing
Due to the extensive plastics, there are not one by dozens of ways plastic can be made depending on the application and type of plastic. For every engineer or designer, the most crucial aspect is to know about the plastics in detail and the manufacturing options available.
The factors that one needs to consider when selecting the process for making a plastic product are
- Form
The first step during the manufacturing of any minor or significant product is its design specifications. The form of the plastic depends on
- The geometry of the product design
- Any complicated internal structure or features
- Tolerance requirement
Sometimes, due to the complexity of the design, the manufacturing options seem limited, so one should select a modern and sophisticated plastic manufacturing machine in Miami that can make it economical to produce the plastic product.
- Material
The material selection is another vital aspect, and while making the selection, the strains and stresses the product will go through must be kept in mind. The best material for a given product and its design depends on different factors. You have to consider the cost by evaluating both the functionality and aesthetic design of the product.
To select a particular plastic manufacturing process, you can weigh in the plastic product’s specific features and then analyze them with the available material and choices you have.
- Lead time
The time it takes to produce parts of the product is also critical. It can take a day to make many of the small and common plastic parts. Depending on the design’s volume and complexity, some of the delicate features can take even weeks and months.
- Volume and Cost
The volume and cost are the two last aspects to consider. The first question is how many parts you need to manufacture. Most plastic parts have a high cost due to tooling and setup, but the parts are inexpensive. On the other hand, low manufacturing processes have low cost initially, but the regular slow cycle, manual labor, and cost per part increase with time.
Different Types of Plastics
Plastics come in hundreds of different forms depending on various additives, chemicals, and derivatives. The numerous plastics are manufactured to fulfill various functions. The two broad categories of plastics are ‘thermoplastics’ and ‘thermosets.’
Thermoplastics are the most popular and common type of plastic that is widely used all across the world. Thermoplastics are different from thermosets due to their ability to go through solidification processes without any degradation.
The thermoplastics come in small pellets that take the desired shape when adequate heat is supplied. Thermoplastics can easily melt, recycle, and be used again as there is no chemical bonding. Some of the common types of thermoplastics are
- Polyvinyl chloride (PVC)
- Polycarbonate (PC)
- Acrylic (PMMA)
- Polyethylene (PE)
- Polyamide (PA)
The thermoset plastics decompose on heating as opposed to melting like the thermoplastics. Thermoset plastic will not reform upon cooling, so recycling them is not possible. Some of the common types of thermosets are epoxy, polyester, silicone, and polyurethane.
Different Types of Plastic Manufacturing Processes
Plastics are formed from a wide variety of natural and organic materials such as coal, salt, crude oil, cellulose, and natural gas. Crude oil is composed of several hydrocarbons, and it needs to be processed and refined before it can be of any use. The different types of plastic manufacturing processes include Injection molding, Blow molding, Polymer casting, CNC Machining, and Extrusion.
- Injection Molding
The most widely used process is none other than the ‘Injection Molding,’ where various plastic parts and products are mass-produced. Some examples of products made from the injection molding process are chairs, toys, disposable cutlery, consumer electronics, and Lego bricks.
Injection molding is a simple process where one has to melt the plastic, inject it into a mold, and then let it cool, and then the finished product comes out. But practically, injection molding is a complicated and intricate process. The three main parts of the injection molding machine are mold, clamp, and the injection unit. The injection molding process involves
- Setting up mold where a hydraulic press is used to close the mold and a person or machine can add pellets.
- Plastic extrusion is the function where the pellets are melted and extruded to a heating chamber with the help of a screw.
- Molding is the name of the process where molten plastic is injected into the mold
- The plastic is allowed to cool and then eject out when plastic takes a solid form
Due to high temperatures, hard metals like steel and aluminum are used to form the mold. Injection molding is best for producing complex plastic parts, but specific intricate designs can increase costs. But no matter the complication of design, injection molding is the most cost-effective method to make plastic for various applications.
- Blow Molding
The blow molding method is where hollow plastic parts are made by inflating a heated plastic tube in a mold until a particular shape appears. Blow molding is a common technique to make plastic bottles, packaging, toys, automotive parts, and other hollow plastic shapes.
The preforms previously injected are reheated by passing them in an oven. The preform is placed inside the blow mold, and the high air pressure and pusher blow the bottle. After a while, the mold opens to eject the bottle. Blow molding works at pressures that are relatively less than injection molding.
Conclusion
The printing methods are evolving rapidly with advancements in technology, and one such new technique is 3D printing that is said to be a game-changer in the plastic industry. The need to make a better improvement, cut production cost, shorten lead times, and improve quality are few factors that will always lead to new plastic manufacturing processes.
