Injection Molding Post Processing

From part decoration for a more pleasing aesthetic to kitting solutions that deliver the complete package at once, many injection molding post-processing methods are available to suppliers today. Here's what Crescent Industries has to offer.

Whether you're building life-saving surgical supplies for the healthcare industry or advanced components for defense, a vast array of products are made by plastic injection molding.

There are all sorts of injection molding post-processing methods that your plastic product’s manufacturer may use to achieve the specs you want, but there are four broad categories that customers should especially consider: part decoration, part bonding/assembly, post-machining, and kitting solutions. We'll look at each one here so that you know how to get the final design you need.

Plastic Part Decoration

One of the most common injection molding post-processing methods involves adding graphics or text to a part. Examples could range from instructive markings and labels to decorative logos or safety warnings.

There are several part decoration methods that clients can choose from, and selecting the right one will depend on multiple design properties — material, application, and environmental conditions to name a few. A few part decoration methods we offer are:

Pad printing. This part decoration method transfers 2D images onto a 3D surface using a silicon pad. It’s beneficial for printing images onto curved surfaces and hollow, cylindrical, or spherical structures.
UV laser marking. This form of printing uses ultraviolet light, which has a higher frequency (and therefore a higher energy level) than other printing wavelengths. Despite its higher energy, UV laser marking imposes less thermal damage on the product, which is why it’s sometimes called "UV cold working.”
Inkjet printing. Much like the printers you have in your home, these printers place layers of ink on post-processing products and instantly cure them with UV rays. This allows customers to have a wide range of color schematics and multiple parts to be printed at one time.

Whether adding units for medical administration on a pharmaceutical product or the attractive logos your brand is known for, printing images onto a part is an essential part of the manufacturing process — and part decoration is how it happens.

Plastic Part Bonding/Assembly Methods

It's often more efficient to manufacture multiple sub-parts of a product and bond them into a single unit rather than building the entire part as one piece. For example, certain parts may have complex geometries and intricate design features that make some assembly required, and others can easily be united after production through a part bonding process.

Mechanical fasteners. Bolts, screws, pins, and rivets are just a few mechanical fasteners that we can integrate into your product. These allow you to add all the electronic components needed for your product and give the option to disassemble when needed.
Adhesive bonding. Instead of joining multiple components mechanically, it may be better to apply an adhesive across two component joints and compress them until it dries. This form of adhesive bonding can create a more unified assembly, and the adhesive may be cured under air or UV light, depending on the materials being joined.
Ultrasonic welding. It uses the micro-vibrations of a small tool called a horn to heat two plastic components, melting them into one. This bonding method is incredibly diverse, as it can even join different types of resins together as long as their chemical structures are similar and their melting points are within 30° F of each other.

Utilizing a plastics manufacturer with part bonding capabilities allows for more efficient production and consolidation of vendors.

Post Machining of Injection Molded Components

Whether a part has tight tolerances and complex features or clients only require a low production volume, there are many times when it's more efficient to go back and tweak the product after it has been injection molded. These post-machining operations are critical to getting the final product right.

Crescent Industries provides a wide range of these post-machining operations, but a couple of common ones are:

Custom fixtures. Many complex parts couldn't be built without the stocks and support structures required for adding extra features. So, in addition to fabricating the actual part, our manufacturing facilities can make the custom fixtures necessary to hold your product in place during machining and all post-processing operations.
CNC machining. Once supported by the fixtures we fabricate, our CNC machines can carve even the most detailed design features into your product according to the pre-programmed tool paths encoded by our state-of-the-art software. Possible design features include tight tolerances, gates, highly specific curvatures and splines, and more.

As critical as it is to machine a part into its final design after it's been injection-molded, it's equally essential to be able to plan the entire manufacturing process. Design for manufacturability (DFM) achieves this by formulating the design process around considerations of how best the part can be built, reducing defects, and improving quality. In addition, by accounting for injection molding post-processing methods like bonding or part decorating from the start, DFM begins with the end in mind, making it a valuable service for any plastics manufacturer to offer.

Packaging and Kitting for Plastic Parts

As any supplier knows, fabricating a part isn't enough to bring it to market — it must still reach the end user. Our kitting and packaging services take the burden off of you, so you don’t have to take this step internally or source it from another vendor. When a product should come to the customer as a unit consisting of multiple components, kitting is often the solution. Each sub-product is placed into a single unified kit, which is especially helpful for healthcare products like surgical supplies or disposable medical equipment. Packaging, however, refers to placing several components of the same type into a single container — like fasteners that would come in a bag.

Both packaging and kitting solutions can be helpful when deciding how best to deliver a product to the customer, so make these a part of your post-processing considerations.