Plastics & Injection Molding Manufacturer Blog

Custom injection molders use ultrasonic welding as a secondary operation when two thermoplastic parts need to be joined together. The bonding of two parts into one may be specified when there is a complex design that is not feasible to mold as one part – so the part design is changed to be manufactured as two or more parts that must be assembled. This is determined early in the Design for Manufacturing phase (DFM) of new product development.

Truth be told, although Ferriot has been around for close to a century accumulating an unlimited wealth of experience and applied expertise, we've really only been blogging for a short time. However, since 2020 marks the start of a new decade, we felt it was apropos to share our TOP 10 injection molding blog posts. The front-runners are determined by you, our frequent readers, after nearly 20,000 views of dozens of blog articles on a variety of topics. The majority of these articles are a quick read, requiring only a few minutes to consume. No doubt you'll find them quite valuable. You be the judge...  

Injection molding is a tried and true manufacturing method that has experienced small, incremental changes over the years. It used to be, if you had a product or part to be manufactured, your injection molding manufacturer would provide you with a list of polymers to choose from. Your design and engineering team would work together along with the injection molding team to select a resin that would suit your needs. A variety of factors would be considered including durability, cost, flexibility and cosmetics.

Ready for a secret? It still works like that.

With most manufacturers, you are going to need to select the resin for your part from a list of available options. However, modern facilities have moved into a more advanced method of providing an option not previously available on that list—custom engineered resins.

Structural foam molding offers an alternative to traditional injection molding. 

Here at Ferriot, we’ve been proud to be a leader in thermoplastic injection molding since the 1940s. Our clients turn to us for professional assistance with contract manufacturing, custom injection molding, painting and assembly. Structural foam molding is another capability we offer when traditional injection molding may not meet part design requirements.  The structural foam process creates parts with a high strength-to-weight ratio and is often used for large parts and in metal to plastic replacement.

Structural foam molding is an option available to manufacturers who are looking for a way to create stronger, more rigid plastic parts.  It is also a method used to reduce potential part weight for larger parts. Almost any type of resin can be used with this type of injection molding. Structural foam  injection molding uses lower pressure and a foaming agent mixed in with the resin. The foaming agent expands within the resin, leaving a dense outer and inner wall with a foam or honeycomb-like center. This cellular core in the part is what contributes to the decreased part weight.  During the expansion process, internal shrinkage or "sink" is reduced which creates a more uniform and aesthetically pleasing part. This process can also contribute to less internal stress in the part with better stability. 

Part 1 of this blog post discussed some important considerations for custom mold designs for injection molding projects. Topics included the impact of resin selection and mold construction materials. Now, let’s consider how the resin is injected into the mold and the impact of the wall thickness of the part.

Designing custom molds for your injection molded products can be a complex process. However, working with the right team can greatly reduce the complexity and cost while improving the quality of the completed part and minimizing the length of the production cycle. Take the time to answer the following questions before you attempt to design molds for injection molding.

As discussed in Part I, chrome plating offers an attractive, durable finish for plastic parts used in a wide range of applications. Although chrome is the ultimate finish for a plastic part, adding chrome plating can’t be an afterthought in your product design. Any surface defects on the part will only become more pronounced once a decorative chrome finish is applied. Chrome requires advance planning and attention to detail in the design of the part, the mold and the specific molding techniques used.

Are you designing injection molded parts for a new product or looking to update an existing product? There are numerous finishes that may be of interest. Perhaps you are considering a chrome finish on your ABS or PC ABS part? Beyond the snazzy, visual appeal, there are other good reasons to use chrome. First and foremost is that it adds an attractive, decorative finish. In addition, it may also provide a level of corrosion protection, make cleaning the surface easier and increase the overall durability of the part.

Design engineers and their employers have shifted focus from the days when their company created an injection-molded part, turned it over to a contract manufacturer, and the purchasing department followed-up on delivery.