The Importance of Chemistry in Vibratory Finishing

The Importance of Chemistry in Vibratory Finishing

The Importance of Chemistry in Vibratory Finishing

The Importance of Chemistry in Vibratory Finishing

How the Right Chemistry Can Transform Your Vibratory Finishing Process

Vibratory finishing equipment, or mass finishing, provides batch finishing processes for a multitude of parts such as descaling, deburring, polishing, cleaning, surface preparation, and other applications. These systems reduce labor and cut down on the total processing time spent on parts. There is a variety of vibratory equipment, media and chemistry utilized in the process. Each of these play a role in the final outcome of the part which is why it’s important to learn about each to ensure it’s the best fit for your process. This article will break down chemistry and how it affects the vibratory finishing process.

Types of Vibratory Chemistry

Vibratory finishing chemistry is engineered for specific applications to provide the best surface finish. These compounds ensure that your media and equipment continue to run at high production levels to meet your surface specifications. There are multiple types of chemistry for vibratory finishing processes:

  • Burnishing Compound – creates a highly polished and bright surface finish. Can also develop additional colors to the part.
  • Cleaning Compound – enhances the feed and roll of the mass as well as cleans the parts.
  • Deburring Compound – assists in removing burrs and provides smooth and refined surfaces while providing lubrication and reducing impingement.
  • Descaling Compound – removes tough oxide and carbonized oxide films.
  • Inhibiting Compound – protects parts from oxidation, corrosion, and tarnishing.

Why Vibratory Chemistry Is Important

Chemistry improves the vibratory finishing process through a variety of factors. It’s important to dial in each aspect of your process. Here are a few ways the chemistry will affect the process:

  • Cleaning and degreasing – The chemistry acts as a lubricant and surfactant, facilitating the breakdown and suspension of oils, greases, and other contaminants. This prevents them from redepositing on the parts and ensures thorough cleaning.
      • pH Control – Depending on the type of contaminants and workpiece material, the pH of the solution can be adjusted for optimal cleaning. Alkaline compounds are effective for greasy soils, while acidic solutions might be used for rust removal. Balanced pH also protects against corrosion.
  • Preventing media wear – the chemistry will keep the media clean and sharp, reducing the ‘glaze’ effect that can happen to tumbling media. The chemistry will also act as a lubricant, reducing friction between media and parts.
  • Process Control – Foam build up can hinder the finishing process by reducing the cutting action of the media. The chemistry can be formulated with anti-foaming agents to maintain appropriate foam levels.
  • Corrosion – Protecting parts from corrosion by utilizing rust inhibitors in the chemistry formula.

Improper use of chemistry or ratios can result in severe quality issues. If the chemistry is not suited for your process, or you don’t have the ratio correct, there can be inadequate contaminant removal, surface staining, corrosion, or pitting. There will also be a decreased life on your media, longer cycle times, and extra waste generated.

Best Practices for Utilizing Chemistry In Your Vibratory Finishing Process

Chemical Composition – There are many pre-mixed chemistries on the market. However, your process may need an engineered solution. It is recommended to run tests based on the part and the contaminants to create the most optimal solution for your cleaning process.

Concentration – Finding the best ratio for your finishing process in crucial. During testing, you will have an opportunity to develop the ratio of media, chemistry, and water. If your concentration is too low, there will be a drop in effectiveness and increase in cycle time. If the concentration is too high, there may be corrosion and damage done to the surface of the parts.

pH – The acidity or alkalinity of the solution can affect its cleaning power and compatibility with different materials. For example, acidic solutions might be ideal for removing rust but could damage delicate surfaces.

Temperature – Higher temperatures can increase the cleaning effectiveness by accelerating chemical reactions. However, certain materials can be damaged if the temperature is too high. It’s important to understand how the substrate will react with the chemicals.

Foam control – Excessive foaming can hinder the cleaning process by reducing contact between the solution and the surface. Anti-foaming agents are often used to control foam levels.

Rinsing Chemical Residue – Improper rinsing or residue build-up from the cleaning chemistry can affect subsequent finishing steps, like polishing or coating, requiring additional cleaning or rework.

Cycle Time – Controlling the amount of time the chemistry is in contact with the parts will affect the overall results of your finishing process. Some contaminants may require longer exposure times to be removed.

Other considerations for your vibratory finishing process are whether agitation or ultrasonics are needed, the type of surface you are cleaning, the contaminants, water quality, waste removal capabilities, and health hazards.

It is important to regular test and monitor your cleaning bath and waste. Not only will this ensure you are operating an effecting cleaning process, but will help create a safe work environment for your whole team.

The Right Chemistry Can Transform Your Vibratory Finishing Process

In the realm of vibratory finishing processes, the role of chemistry cannot be overstated. As discussed, the right chemistry is pivotal in achieving efficient, high-quality results across various applications, from deburring to polishing and beyond. Understanding the nuances of vibratory finishing chemistry empowers manufacturers to optimize their processes, enhance productivity, and uphold stringent quality standards.

vibratory finishing chemistry

Refine Your Mass Finishing Process

Testing your vibratory finish components is vital for refining your finishing process. Send us your parts and our processing lab will determine the right media and chemistry combination for your finishing application.

Why Tumbling Media Shape Matters

Why Tumbling Media Shape Matters

tumbling media shape

Why Tumbling Media Shape Matters

A Media Shape Resource Guide

Tumbling media comes in many sizes, compositions, and shapes. Each of these factors are a crucial decision within your finishing application. We’re going to breakdown the various shapes of tumbler media in this article. Here is a list of various shapes:

  • Spheres and Balls
  • Triangles
  • Pyramids
  • Pins
  • Arrowheads
  • Wedges
  • Ellipses
  • Nuggets
  • Cylinders
  • Quadrants
  • Cones
  • Ball Cones
  • Ovals
  • Stars
  • Four-pointed stars
  • Diamonds
  • Tetrahedrons
  • Random Shapes

Importance of Tumbler Media Shape

The various shapes of tumbler media all have different advantages for specific tumbling applications. The main items you need to consider when selecting a size are:

  • The ability for the media to cover the full surface area of the part being tumbled.
  • Media will not lodge in any holes or recesses.
  • Speed and smooth flow through the tumbler.
  • Allow for easy separation of media from the parts at the end of the cycle.

There are times when using a combination of media shapes is the best process for an application.

ceramic tumbling media
tumbling media

Triangle Media

Triangular tumbler media is ideal for harder to reach corners and slots on parts. The flat parts of the triangles are effective on straight edges while the edges provide coverage into the smaller areas. Triangular media consists of triangles, arrowheads, and angle-cut triangles, often used in cleaning and deburring applications.

Cone Media

Conical tumbling media is effective for entering holes and passageways on parts without lodging. Typically used in applications that require aggressive action, ball cones are often used for burnishing.

Sphere Media

Spherical tumbling media is ideal for blending and smoothing surfaces. The round shape creates good flow and movement through the tumbler.

Wedge Media

Wedge-cut tumbling media, or often referred to as V-cut cylinders, is a versatile shape that can be effective for many applications.

Cylinder Media

Cylindrical media is ideal for deburring holes and contours. The angled ends are effective at reaching into recesses on parts. Cylinders are also very efficient at removing rust from parts.

Oval Media

Oval tumbling media provides a larger surface-to-surface coverage than spheres, while still providing good flow and motion through the tumbler. Ovals are often used in barrel tumbling applications.

The composition of the media will have an affect on the available media shape options. Stainless steel media can’t be made into all of the same shapes as ceramic and plastic.

stainless steel tumbling media

Process Testing

Testing your tumbling process is vital for selecting the right media. Send us your parts and our processing lab will determine the right media shape and type for your finishing application.

Mass Finishing Ammunition

Mass Finishing Ammunition

Midvale offers Hammond Roto-Finish machinery designed for mass finishing ammunition.  Hammond Roto-Finish equipment has been used with calibers of small arms ammunition up to 20 mm, as well as several sizes of ordinance.  Spiratron®, Multi-Pass® and Roto-Max® machines are capable of processing a vast size range of product.

The leading question we are often asked is “How many and how fast?” Our answer to that is “How many and fast would you like?” Hammond Roto-Finish and Midvale Industries have a wide range of machine and finishing processes to meet your needs for mass finishing ammunition. Choose from: Vibratory Batch FinishingVibratory Continuous Finishing or Centrifugal Batch Finishing methods.  Below are videos of the mass finishing process in action, along with a related video on the automated polishing of barrels (another process Midvale and Roto-Finish is familar with).

Tumbling Media Composition Matters

Tumbling Media Composition Matters

tumbling media composition

Tumbling Media Composition Matters

A Media Composition Resource Guide

The composition of tumbling media plays an important role in your finishing process and determines whether the media is for cutting or finishing. Cutting media will contain abrasives within the composition while, finishing media will either contain no abrasive or very fine abrasive. The main materials used for tumbler media include ceramic, steel, plastic, urethane, or corn cobs.

Ceramic Tumbling Media

Ceramic media is typically made up of a combination of abrasive and clay. The curing time and oven temperatures determine the hardness of the ceramic. A softer ceramic will provide better cutting as the media wears away revealing fresh abrasive under the top layer. There are various cutting speed options available to meet specific finishing requirements.

Applications: Deburring, Deflashing, Burnishing, Polishing, Brightening, Radiusing

Available Shapes: angle cut cylinders, stars, cones, triangles, wedges, pyramids, and specialty shapes upon request.

ceramic tumbling media

Stainless Steel Tumbling Media

Steel media provides shape uniformity, short cycle times, and long-lasting durability. Often used in cosmetic finishing, steel tumbling media does not scratch or damage the parts, but provides a clean surface. Steel media does not cause wear to the machine lining, reducing maintenance costs.

Applications: Stress Relieving, Strengthening, Brightening, Preplate

Available Shapes: pins, ball cones, oval cones, diagonal cylinders, and specialty shapes upon request.

stainless steel tumbling media

Plastic Tumbling Media

Plastic media has a lower density than ceramic and is typically softer. The composition is made of abrasive, bonded with various types of plastic or resins. Plastic is commonly used in applications with softer metals or fragile parts. There are various cutting speed options available to meet specific finishing requirements.

Applications: Deburring, Deflashing, Surface Metal Removal, Fine Finishing, Radiusing

Available Shapes: angle cut cylinders, stars, cones, triangles, wedges, pyramids, and specialty shapes upon request.

Plastic tumbling Media

Urethane Dry Finishing Media

Urethane media eliminates the need for compound in the tumbling process. It has a long-life cycle and reduces many typical use costs. It also eliminates the messy residue often associated with plastic media formulations.

Applications: Deburring, Deflashing, Burnishing, Polishing, Brightening

Available Shapes: angle cut cylinders, stars, cones, triangles, wedges, pyramids, and specialty shapes upon request.

urethane tumbling media

Corn Cob Tumbling Media

Corn cob media is typically used to dry metal parts after tumbling or parts washing cycles. The starch helps absorb water, oil and grit. This reduces the chance for watermarks or stains on the parts. It can also be infused with various buffing and polishing compounds for enhanced finishes.

Applications: Deflashing, Burnishing, Polishing, Brightening

Available Shapes: crushed corn cobs, multiple sizes available

Corn Cob blasting Media

Selecting the Right Media Composition

The desired finishing process or final outcome is a large factor in determining the composition as some media types are more suitable for certain applications than others. When selecting your tumbling media composition, as well as shape/size, the part and desired outcome are major factors. The type of metal is a factor when selecting composition as softer metals need a specific blend for ceramic, as an example.

Process Testing

Testing your tumbling process is vital for selecting the right media. Send us your parts and our processing lab will determine the right media shape and type for your finishing application.