Manufacturers often use a variety of finishing processes to improve their products. These range from cleaning and etching to plating and chemical/electrochemical conversion. Without finishing, the lifespan of parts and products would be reduced due to corrosion and wear, and their function would be diminished. Finishing helps achieve a range of desired characteristics.
In the metal finishing industry, businesses that manufacture and finish products are classified based on the products they specialize in. Captive shops perform metal finishing as part of a larger operation or work with a single customer, while job shops are independent facilities that provide coating operations for various customers. Laszeray Technology, LLC is unique in that we specialize in various types of design, manufacturing, and finishing.
What Is the Finishing Process?
Virtually all finishing processes involve the same basic steps. During surface preparation, the workpieces are cleaned by platers. This removes greases, oils, and oxides. Solvents and detergents may be used before the item is dipped in acid to further remove any oxide material.
Surface treatment involves physical and chemical modification of a workpiece. The item then undergoes a series of baths and rinses. Plating helps improve the adhesion of materials, after which the process solution is rinsed off and the item is dried. Post treatment can involve other finishing operations to further improve a workpiece’s properties or appearance. Heat treating is a common type of post treatment.
One of the greatest concerns during finishing is pollution prevention. To reduce or prevent pollution, manufacturers may substitute raw materials, modify the process to use less toxic substances, redesign the product, and/or install upgraded more-efficient equipment. In addition to providing opportunities to reduce waste and pollution, finishing can:
- Increase hardness
- Enhance electrical properties
- Provide additional forming and shaping
- Strengthen bonding of adhesives or coatings
- Improve solderability
- Increase chemical resistance
- Give an item color or brightness
Types of Finishing Manufacturing
Finishing, which occurs after a part is made and secondary processes have been completed, takes many forms. The types of finishing operations that Laszeray offers include:
An electric current is applied to create a bond between metal and a chosen conductive surface. To accomplish this, both are submerged in a solution that consists of dissolved metal ions. The metal attracts the ions. While controlling voltage, amperage, temperature, and other variables, producers can plate ferrous and non-ferrous objects with aluminum, copper, brass, iron, nickel, silver, gold, zinc, chromium, and other metals. The process of depositing additional material on a workpiece is called electrodeposition.
Electroplating can be used to:
- Add properties the base material doesn’t have
- Increase part thickness
- Form objects via electroforming
A concentrated acid or alkaline solution is used to provide an anodic effect, or reverse the current of a part. As a result, a film of material forms around the primary contours. If there are tiny micro-projections, the film forms a thinner layer; for micro-depressions, it is thicker, effectively smoothing out the part. This is due to the lower resistance-to-current flow at the micro-projections that causes the finish to dissolve more rapidly. A wide range of electropolishing solutions exist to accommodate many types of substrates.
Using a specialized machine, manufacturers can create marks and designs on metal or plastic parts with high precision. Laser marking equipment does not come into contact with the material, so there is no abrasion damage. Whether used to create a logo, bar code, part number, or QR code, it is permanent and fraud proof.
Laser engraving is also adjustable to accommodate for different types of stainless steel, aluminum, and other materials, including rubber, graphite, and composites. It is environmentally safe, as marking does not release waste products or toxic fumes. No consumables are required, as the laser beam itself creates micrometer-thin depressions in the surface.
Material is exposed to a free-flowing batch of powder, which is adhered using an electrostatic process. The part is then cured in an oven. This allows the powder to form a thick, solid, durable coating. A solvent is not required, as the binder and filler can be kept in a liquid suspension, reducing or eliminating Volatile Organic Compounds.
Powder coating can be accomplished via electrostatic spraying, an electrostatic fluidized bed process, or an electrostatic magnetic brush. To cure a thermoset powder, the workpiece must be exposed to elevated temperatures to allow the powder to melt, flow, and harden and dry; known as crosslinking, this requires high-temperature exposure for a specific amount of time, depending on the desired properties and material.
Metal parts have natural oxide layers. Increasing their thickness helps create a hard, corrosion-resistant surface layer. Anodizing is often done on aluminum parts but may also be applied to titanium, magnesium, and zinc. It is an electrolytic process that can allow paint or glue to better adhere to a material; aesthetic properties can be enhanced as well.
Thinner than paint or powder, an anodic film is abrasion-resistant, provides electrical resistance, and won’t peel, chip, or fade.
Other Types of Finishing Operations in Manufacturing
The processes described above are not the only methods of finishing. Others include cladding, in which a metal coating is bonded to a part via heat and pressure. A metal surface may also be modified via case hardening, sand blasting, vibration, brushing, buffing, or grinding. Hot blackening is when black oxide is spread over a product surface to increase abrasion resistance. For porous materials such as textiles, paper, and packaging, dying might be used to add color.
Choosing the right production process depends on material characteristics and desired properties, as well as production speed, cost, and metal hardness.
Contact Laszeray Technology
We specialize in a variety of finishing processes that are performed at our state-of-the-art facility. Serving numerous markets, we employ a team of experienced engineers and use the most advanced finishing equipment in the industry. Whether you need a product coated, polished, anodized, plated, or engraved, request information online or call 440-582-8430.