4 Common Mistakes to Avoid When You Choose an Electroplating Vendor

Electroplating over injection molded plastics is a great way to add a high-end metallic finish to a part that would be difficult and cost-prohibitive to make in metal. However, injection molded plastics come with their own set of challenges. In the competitive marketplace we have today, OEM’s need to take advantage of every opportunity to ensure quality while minimizing costs. For electroplated plastics, you need a supplier who specializes in both.

If you’re still reading, it’s a good bet that you deal with electroplated plastics and have been burned by a quality or delivery problem on a past project and want to know how to avoid that in the future. You’re in the right place. The following are the 4 most common mistakes to avoid when choosing an electroplating vendor for your next project.

1. Neglecting the Value of Early Supplier Involvement
2. Mold There, Plate Here
3. Failure to Specify Plating Performance Levels
4. Failure to Consider Total Landed Cost

Now, let’s get to it.

1. Neglecting the Value of Early Supplier Involvement

Most new product development takes a familiar path, starting with conceptual design, moving to mechanical design, quoting, technical review, project award, product introduction, and production. Many OEM’s use the technical review with prospective suppliers as a time to gain confidence that the supplier can execute the project before an award decision is made.

What’s actually happening at this stage is the supplier is demonstrating how capable they are at overcoming problems that have been induced by a product design that is nearly frozen. The time to make any real changes that will positively impact the cost and quality of the part has long passed.

Imagine what could happen if the molding and plating supplier was involved at the mechanical design stage? This is the stage where some of the most basic decisions about a molded and plated part are made that impact the design and manufacture of a part.

If an engineer was faced with a decision between A and B, neither of which affected the product design differently, that engineer would just make the decision and move on. But, what if that same decision between A and B, (having no effect on product design) had a significant impact on the cost to manufacture? How would the engineer know unless they were also an expert in injection molding and electroplating?

The truth is, a design engineer is faced with hundreds of these types of decisions that affect both product function and cost to manufacture on every product.

There is a reason this is the number 1 mistake to avoid: because it has the greatest impact on product quality and cost. Engaging an expert supplier at the design stage prior to the technical review will increase the quality of your products, reduce costs by optimizing the molding and plating processes, be more sustainable by reducing scrap and improve the timely delivery of parts to your factories.

2. Mold There, Plate Here

Consider the following scenario: One of your best injection molding suppliers has been running production on a component to one of your products for a year. The product design team decides that a refresh is in order, and the market is calling for a stainless steel finish on the visual parts. Next, an Electroplating/PVD supplier is identified and parts sent from Supplier A to Supplier B for finishing. Simple enough?

Then imagine that parts come back from Supplier B warped, half plated, and appear burnt (as if they’ve been in a campfire). The Electroplating/PVD supplier claims that the root cause of the failures have to do with the way the parts were molded. The injection molder stands by the fact that they have been providing zero defects for over a year to the OEM.

If a chill just ran up your spine, chances are good you’ve lived this scenario before. So what was the answer in your case?

Instead of playing the finger-pointing game, let’s explain the root cause of these three most common defects when parts are molded at A and plated at B so that you can avoid this mistake once and for all.

• Warped: Injection molding involves pushing melted plastic into a mold and cooling it before removal from the mold. High pressures and temperatures are needed. When the state of the part changes and cools, those high pressures and temperatures are converted to internal stresses. So far, you still have a part that is flat and to dimension. However, in the electroplating process, the parts spend 2+ hours in various plating tanks at 150°F. The process relieves some of the molded-in stress, resulting in warpage. The solution to this problem is to mold the part with minimal internal stress while still remaining dimensionally true.
• Unplated Areas: Electroplating on plastic relies on a mechanical bond between plastic and the copper layer for adhesion. Butadiene molecules on the surface of the part are dissolved from the resin to create “pockets” that the copper layer can latch onto. Injection molding parameters such as fast injection times (high injection pressure) or lower melt temperatures cause the butadiene molecules to be less prevalent on the surface of the part, reducing the ability for the copper layer to latch onto the plastic and leaving that area unplated.
• Burnt Appearance: The PVD process used to achieve metallic colors like Stainless Steel involves elevated temperatures and process gasses in a low-pressure chamber. These conditions can cause the additives — like colorants and fire retardants — in some plastics to escape. This escaping and burning up of additives is called “outgassing,” and is more common when dealing with 2-shot parts where the first shot is not ABS. The typical remedy is to completely encapsulate the part in electroplating or use only a platable grade of ABS for both the first and second shot.

The picture above shows an unplated area due to high molecular orientation near the gate from high injection pressure.

3. Fail to Specify Plating Performance Levels

Electroplating performance levels indicate how much exposure to the elements your final product can withstand before it starts to corrode. In electroplating, we look at service condition (SC) levels to determine the magnitude of corrosion testing needed. Salt Spray testing, Plating Thickness, and Thermal Cycling are the three most common tests performed to verify plating performance.

Increasing layer thicknesses are a key factor in increasing plating performance. Thicker layers require more processing time, which increases costs. Not specifying the performance requirements of the plating is like not specifying the correct plastic resin for the molded part and could result in increasing the cost of the part.

The table below shows the relationship between performance level and the thickness of the plating layer.

4. Failure to Consider Total Landed Cost

All too often, we’ve seen companies forget to factor in all of their costs. With increased tariffs, saving money is more important than ever. Regardless of whether parts are made domestically or overseas, when choosing an electroplating vendor, you need to consider the costs associated with manufacturing, transportation, warehousing, tariffs/duties, and insurance, often referred to as “Landed Cost”. Increased US tariffs on Chinese products (up to 25%) have increased bottom-line costs of components for OEM’s. The whole point of Section 301 tariffs was to make goods made in China less attractive to companies buying from the USA.

A side-effect is that components made in other Asian countries now look more attractive (and US OEM’s have caught on). When comparing the cost of molding and electroplating in the USA vs. Asia, and factoring in transportation, warehousing, duties and insurance, Asia (outside of China) still holds a significant cost advantage.

Final Thoughts

Let’s end on a completely positive note. All of the mistakes above are 100% avoidable. A mentor once said to me, “learn from other peoples’ mistakes… you won’t live long enough to make them all yourself.” Let us help you overcome any issues that might be holding you back from a successful launch — schedule a call today.