Plastic Electroplating

From our company's inception, our foray into Plastic Electroplating has sparked a trail of remarkable triumphs!

Compared to their metal counterparts, electroplated plastic parts offer not only a superb metallic texture but also the benefit of reduced product weight. This process not only enhances the aesthetic appeal of plastic, catering to decorative needs, but also improves its electrical, thermal, and corrosion-resistant properties. However, the choice of material for electroplating hinges on several factors, such as the material's processing characteristics, mechanical properties, cost-effectiveness, precision of dimensions, complexity of processing, and other considerations. Thanks to its advantageous structural properties, electroplated plastic not only boasts excellent overall performance but is also easy to shape. This ease of shaping allows for high coating adhesion, as seen in chrome-plated plastic and electroplating on ABS plastic, making it highly sought-after in electroplating applications.

In designing plastic parts for electroplating, it's crucial to ensure that their appearance and functionality are not compromised while meeting these specific requirements.

For advice or more information call us today on +44(0)1827 712910 or email us at sales@coler.co.uk

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Understanding Plastic Electrocoating at Coler Supply Solutions

Plastic electrocoating, often known as electroplating on plastic, is a unique process that involves adding a metal coating to a plastic object. This technique allows for the creation of products that combine the lightweight and versatile nature of plastic with the strength and aesthetic appeal of metal. It’s a popular method used in various industries, especially for items where the look and feel of metal are desired, but the weight and flexibility of plastic are beneficial.

The process of plastic electrocoating begins with preparing the plastic surface. Since plastic is not naturally conductive, it needs to be treated to adhere to the metal coating. This is typically done by cleaning the plastic thoroughly and then applying a layer of conductive material, often a special paint or a thin layer of metal. Once the plastic is prepared, it is submerged into an electroplating bath. This bath contains a solution of metal ions, such as gold, silver, or nickel. When an electrical current is applied, these metal ions are attracted to the plastic surface, forming a thin and even metallic layer.

This metallic coating can then be further treated to enhance its appearance and durability. For example, it might be polished to increase its shine or coated with a clear lacquer to protect against scratches and corrosion. The final product is a plastic item with a luxurious metal finish, often indistinguishable from solid metal at first glance.

Plastic Electroplating Requirements

Plastic electrocoating, also known as electroplating on plastic, is a fascinating process where a thin layer of metal is applied to a plastic surface. This technique combines the lightweight nature of plastic with the desirable properties of metals, such as shine, durability, and conductivity.

Here's a simple breakdown of how it works:

Preparation of Plastic: The first step is to prepare the plastic surface so that it can hold the metal coating. This involves cleaning and sometimes etching the surface to make it slightly rough. This roughness helps the metal adhere better to the plastic.

Conductivity: Unlike metal, plastic doesn't conduct electricity, which is necessary for electroplating. So, the plastic is coated with a conductive material, often a thin layer of metal, making it ready for electroplating.

Electroplating Process: The prepared plastic part is then submerged in a solution containing metal ions (like gold, silver, or chrome). An electrical current is passed through this solution, which causes the metal ions to stick to the plastic's surface, creating a thin, even metallic coating.

Final Touches: After electroplating, the plastic part might receive additional treatments for enhancing its appearance or protective features, such as polishing or applying a protective clear coat.

The result is a plastic item that looks, feels, and behaves more like a metal part. This method is popular in various industries, especially in automotive manufacturing (for car parts), consumer electronics (like fancy casings for gadgets), and decorative items.

The benefits of plastic electrocoating are quite impressive:

Lightweight: The end product remains lightweight as the base is still plastic.
Aesthetically Pleasing: It gives a high-end metallic finish to otherwise ordinary-looking plastic parts.

Versatile: It can be used on various types of plastics.

Enhanced Properties: The metal coating can add desirable properties, such as improved electrical conductivity or resistance to corrosion.

In summary, plastic electrocoating is a clever way of enhancing plastic parts with the benefits of metal, giving them a sleek, durable finish without significantly increasing their weight or losing the advantages of using plastic.

 

Mould Design

The material for the mold should not be beryllium bronze alloy; instead, high-quality vacuum cast steel is recommended. The mold cavity surface should be polished in the direction of mold release to achieve a bright mirror finish with a smoothness variance of less than 0.2mm. Ideally, this surface should also be coated with hard chromium for optimal results.

Since the surface of the plastic part is a direct reflection of the mold cavity's surface, ensuring a smooth mold cavity is vital for a quality finish. The surface roughness of the mold cavity should be 1 to 2 grades finer than that of the final part's surface.

The design should avoid placing parting lines, welding wires, or core inlay wires on the surface to be electroplated, as these can affect the quality of the finish.

The ideal location for the gate is at the thickest part of the workpiece. To prevent premature cooling during the filling process, the gate size should be larger than usual (about 10% more than a standard injection mold). A gate and runner with a circular cross-section are preferable, and the runner's length should be as short as possible.

Adequate vent holes should be included in the design to prevent the formation of defects like vent marks or bubbles on the surface of the finished part.

The selection of an ejection mechanism is crucial to ensure smooth demolding of the parts without damaging the electroplated surface.

Main Points

Solving the Floating Challenge in Electroplating: A common issue we faced was with electroplating parts like lampshades, which tend to float due to their low specific gravity. Initially, we used a copper wire to secure the lampshade for electroplating, but this method had its flaws. The release of gas during the process could cause the lampshade to detach, and the lightweight copper wire wasn't sufficient to keep it submerged. Our innovative solution involved attaching a heavier object to the copper wire to counteract the floating issue. However, this led to another problem: poor conductivity at the contact points, resulting in burns and exposed plastic. To tackle this, we designed a unique fixture that ensures the lampshade stays submerged without burning at the contact points, thanks to the use of wide conductive sheets that distribute current evenly.

Overcoming Bubbles in Electroless Copper Plating: Bubbles in the electroless copper plating of lampshades posed a significant challenge, often worsening post-processing. The comprehensive process flow of plastic plating includes multiple stages: degreasing, water washing, roughening, sensitization, activation, and several washings, each of which could potentially cause blistering if not executed correctly. One of the main issues was poor adhesion, often due to inadequate degreasing or roughening. We addressed this by optimizing the chemical degreasing process and carefully controlling the temperature and agitation of the workpiece. The roughening process, particularly for ABS plastic, needed precise control to avoid over-coarsening, which could damage the adhesion. Sensitization and activation steps also required careful attention; imbalances here could result in ineffective coating deposition or reduced adhesion. Furthermore, we paid close attention to the drying of ABS particles, adhering to guidelines that required less than 0.1% moisture content before injection and thorough drying in a controlled environment.

Why Choose Coler Supply Solutions?

To ensure that your manufacturing plan operates efficiently and with the flexibility required to maintain high-quality standards, it's crucial to implement strict project flow management. Here's a concise guide to achieving this:

Product DFM Analysis

Mould Design

Mould Making

Mould Trial

Sample Approved

Large Volume Production

Quality Control

Packing

Delivery

Customer Aftercare