Basic Plastic Plugs and How They Are Used

Keeping containers closed with an airtight seal was much harder before the invention and widespread use of plastic. Did you know that most containers had to use metal lids? And if an airtight seal was necessary, the lids had to be shrunk and sealed much like the process of canning food into traditional glass jars. Plastic has taken over most of the packaging world. There are good reasons behind this. Plastics are inexpensive, durable, and easy to make completely airtight. Factories all over take advantage of the benefits that these plastic containers can bring.

Many closures for containers are made from plastic. These have become a popular choice for the temporary closing of containers in use and for previously-opened containers. The plugs prevent the contents of a container from leaking out and help extend the life of the product inside the container. These plugs can create an airtight seal that is ideal for preventing the evaporation of liquids and contamination of the product that is stored inside.

A variety of factories help create their own customized plastic plugs for specific applications. But there are four main types of plugs that most factories can use for different scenarios. Most of these prevent the need for creating customized stoppers for different containers and products.

Tapered: These plugs are designed to fit in a simple opening. They are narrow at one end and they expand to a larger size on the other end. This makes them easy to place into a hole and plug it up without having to worry about the plug falling into the containers.

Push-fit: These plugs are similar and are designed to fit flush with the exterior of the container.

Cylinder valves: These valves are designed to be used as closures and are usually used with volatile materials, like gasoline.

Threaded plugs: These are used to screw in container openings. This provides an airtight seal that will not pop out of place.

The Best Products for Dip Molding

A dip molder is a molding machine that dips a mold into liquid plastic. The plastic sticks to the mold, creating the reverse of the object. After the plastic cools, it is removed from the mold and retains the shape of the mold. Dip molding is available for a variety of different products and uses, but some products are better suited to dip molding than others. Use this simple guide to help determine the best products to use with dip molders:

Gloves: Gloves are the perfect material to make using a dip molding machine. A mold shaped like a hand is easy to create, and it takes just a few dips into the plastic, latex, or rubber to create sturdy gloves for a variety of uses.

Tool handles: Tool handles are one of the original products that inspired industrial dip molding. Rather than create wooden tool handles, manufacturers started to dip the back end of tools into plastic to create sturdy, weather-resistant handles for tools.

Plugs: Plugs come in a variety of sizes and shapes. The nature of plugs are that they must fit snuggly into the space they are supposed to fill. Dip molding is better for this process than injection molding because injection molded items often have seams and inconsistencies that make them poorly suited to plug manufacturing.

Caps: Dip molding machines are the perfect tool to use in the creation of plastic caps. Dip molds are easy to create to look like any cap imaginable, from water bottle caps to gas caps. Dip molders are ideal for creating these caps free of seams, ridges, and other inconsistencies.

Flexible containers: Dip molding is ideal for flexible containers, such as water bottles, flexible liquid bladders, and medical equipment containers. The dip molding process is perfect for creating flexible, yet strong containers for a variety of uses.

PVC Coating: Plastisol Explained

Plastisol uses a unique formulation process that suspends PVC particles in a plasticizer. The plastic is heated to 177 degrees Celsius, which dissolves both the PVC and the plasticizer. Next, the mixture is cooled to 60 degrees Celsius. This creates a plasticized product that remains permanently flexible due to the dissolved properties of the plastic. Often, this plastic is used for molding, but it has a variety of other uses as well.

Plastisol is often used in the manufacturing of roof coatings, furniture coatings, screen printing, and textile ink. Plastisol is often used for dip molding, because it coats objects in a flexible coating that is both attractive and durable. Industries use plastisol coatings for a variety of tasks, such as coating tools, protecting surfaces, creating waterproof barriers, and protecting delicate parts from impact.

Surprisingly enough, many of the printed images on modern clothing is created from plastisol coatings melted into the fibers of the fabric. Plastisol is perfect for screen printing because the plastic soaks deep into the fibers of the fabric, allowing the image to stay in place longer. Plastisol will not dry on its own, but requires a curing process to harden the plastic. Plastisol-coated clothing must be cured in an oven before it can be sold in retail locations.

Another popular use for plastisol is as a material for slush molding. In slush molding, the plastisol is placed inside a metal mold, which is then spun rapidly to force the plastic to take on the shape of the mold. The mold is then heated and excess plastic is poured out. This creates flexible, hollow molds perfect for a variety of industrial and commercial uses.

Where Dip Molded Products are Used

Dip molding is the process of using a metal mold shaped like a finished product and dipping it into a plastic product to create an object. Many industries use dip molding, because the dipping process is often less expensive than injection molding or other molding forms. It may surprise you how many different industries use dip molded objects. You can find dip molded products used in the following industries:

Tools: Many tools have dip molded handles. After WWII, manufacturers started replacing wood handles with plastic handles, and the dip mold process is the least expensive form of creating plastic tool handles. Depending on the type of plastic used, the handles can be inflexible or soft to the touch.

Automotive: A surprising number of plastic parts in the automotive industry use the dip molded process. A variety of things, such as tubes, caps, containers, and interior elements of a vehicle are often formed using the dip mold process.

Shoes: Manmade shoes and boots often used the dip molded process. Rain boots, work boots, dress shoes, and some everyday plastic shoes are formed with the dipped mold process.

Plumbing: Many plumbing products use the dip molded method as well. Anything with a hollow inside can be formed through dipped molding. Pipes, pipe fittings, weights, floaters, and other attachments are some of the most commonly dipped plumbing pieces.

Electrical: The electrical industry also uses some dip molded parts. Casings for wires, small plastic screws, rubber gloves, safety equipment, and other parts necessary for electrical work to prevent danger are often created with the dip mold process.

Medical: The medical industry also uses a wide variety of dip molded parts. Catheters, tubes, balloons, masks, gloves, inflatable medical devices, and nearly any other plastic object in the medical industry can be formed using the dip mold process.

Plastic Closures: Watching a Cap Forming Machine First-Hand

Most plastic caps and many other plastic closure types are created using large industrial injection molded plastic machines. Injection molded plastic injects a small amount of plastic into a cap-shaped mold. The plastic is then dried and released from the machine in one smooth motion. Watching a plastic cap machine in first-person action is an interesting process. It is amazing to see how humans have been able to transform basic parts into fully-functional parts that can create other useful tools and pieces for everyday life. Many plastic cap machines can create hundreds or even thousands of plastic caps within just a minute or two.

A plastic closure machine works something like this:

The plastic pellets are added to a large hopper in the machine. The hopper melts the plastic and carries it to the part of the machine that will inject the hot plastic into the mold.

32 or more rotating piston molds rotate around a central motor. The plastic is injected into the molds in one smooth motion by the pistons as they travel around in a circle. The pressure from the two sides of the piston give the plastic caps the desired shape and quickly dry the plastic until it is hard enough to release from the mold.

In one smooth motion, the pistons release the cap at just the right moment and it releases into a metal passageway that directs the cap into a storage bag or another conveyor belt. The process is so fast, that there are always at least 4 or 5 plastic caps inside the chute at any one time. Most machines can create thousands of plastic caps in just a few minutes.

Depending on the machine, it is possible to program the machine to create caps of varying sizes and specifications. Some machines can create threaded caps, while others create pop-off caps or plugs only.

Dip Coatings-Your Protection Solution

Dip coatings are normal used in the industry to protect the surface of objects and quickly apply additional texturing, non-stick coatings, or corrosive-resistant coatings to a variety of materials. Construction, metal working, and the automotive industry all use dip coating. There are specifically three dip coating methods-dip painting, glass coating, and metal coatings. All three offer additional protection on an object while bonding to the surface. They also prevent the coating from wearing off in the normal weathering and usage conditions.

Dip painting is fast and effective at bonding the paint with the base item. With this style, we also see the elimination for the need of spray nozzles. No brushes or manual labor is needed either. Objects are dipped into paint and it is as simple as that. Sometimes the paint is heated to help the paint bond better with the base object. We see this style in coating tools, gloves, metal, and a variety of other materials. We see these materials in both industrial and household uses.

Similarly, metal coatings are applied in the same way as dip painting coatings. A base metal is dipped in chemical baths to prepare it for the coating. Chemicals activate different particles in the metal and help the coating bond better with the base metal. We often see metal coating used to galvanize metal. Additional uses are another coating that won’t come off from washing, weathering, or normal use.

Dip coatings are also applied to glass. Some of the main coatings applied to glass are window tinting and other UV protective coatings that eliminate the passage of UV rays through the glass. Other glass coatings are used to keep the glass from shattering if the glass breaks. We see dipped glass coatings used in the construction of commercial and residential properties. They are also prevalent in the automotive industry and household use. Some common uses are in the construction of glass tables or other furniture.

The Last Place You’d Expect Them: Plastic Dip Moldings In Your Car

It’s no secret that the first cars weren’t built for luxury. There sure wasn’t any plastic pieces in them either. The early stages of automobiles use materials like metal, wood, and rubber to create parts in a vehicle. With the discovery and widespread use of plastic after WWII, cars were able to start using the inexpensive and flexible material in vehicle production. The cost of vehicles has dropped dramatically because of this. It also helped the manufacturing process become easier and faster.

Look around in your car, there’s plastic pieces all over. These pieces are most likely made from plastic dip moldings that are created by dipping a mold into plastic over and over to create a steady layer of plastic.

Most likely, the dip molded plastic is used in the areas below:

Containers: Many of the containers inside your vehicle are created with the dip molding process. Plastic containers for water, oil, coolant, and other liquids inside your vehicle are formed with dip molding. This keeps the containers strong and flexible at the same time.

Caps: The caps on a vehicle are also formed using the dip molding process. The caps that you see on your vehicle are formed using the dip molding process. These molds look different than those from a container. This is because the bottom of the cap has to remain open so that it can fit over the nose of the container. The mold that comes with ridges is what helps the caps screw into place.

Tubes: The tubes inside your vehicle are also formed through plastic dip moldings. Almost all of the plastic tubes in your vehicle use the dip molding method. This helps shape the plastic and keep it flexible. Interior plastics: Some of the interior plastic pieces in your vehicle are formed through dip molding. The steering wheel, cover on stick shifts, emergency brake, and door panels may be formed with dip molding.