Plastic chips are small, engineered abrasive media primarily utilized in mass finishing processes to grind sharp corners, deburr, radius, and refine the surface of various manufactured parts. They are a gentle yet effective solution for surface treatment, particularly for softer materials where ceramic or metallic media might be too aggressive.
Function and Applications
The core function of plastic chips is to facilitate controlled material removal and surface refinement. They are specifically designed for applications requiring a smoother finish or precise corner radiusing without excessive material loss or damage to the workpiece.
Plastic chips are highly effective across a range of materials, including:
- Non-ferrous metals: This category includes copper, zinc, nickel alloys, bronze, aluminum, and zamak. Their gentler abrasive action is ideal for these metals, preventing nicks, scratches, or excessive wear.
- Composite materials: For parts made from various composite blends, plastic chips offer a consistent finish.
- Plastic materials: They are particularly suitable for deburring and smoothing plastic components, where other media could cause damage or unwanted surface textures.
These chips excel in achieving a high-quality finish and are chosen for their ability to deliver a maximum abrasive-grinding ratio, ensuring efficient material removal with desirable surface characteristics.
Composition and Characteristics
Plastic chips are typically composed of a polyester or urea formaldehyde resin base, impregnated with a specific abrasive grit, such as aluminum oxide or silicon carbide. The type and concentration of abrasive determine the chip's cutting ability and the final surface finish.
They are generally classified and coded based on their abrasive level, allowing manufacturers to select the most appropriate media for their specific needs:
| Classification | Abrasiveness Level | Typical Applications |
|---|---|---|
| Low | Gentler | Light deburring, surface smoothing, polishing |
| Medium | Moderate | General deburring, radiusing, pre-finishing |
| High | More Aggressive | Heavy deburring, grinding sharp edges |
How Plastic Chips Work in Mass Finishing
Plastic chips are integral to various mass finishing techniques, such as vibratory finishing and tumbling. In these processes, parts, plastic chips, and a specialized finishing compound (liquid or paste) are placed into a machine that creates motion (vibration, rotation). This motion causes the media to rub against the parts, performing the desired surface modification.
The process typically involves:
- Loading: Parts, plastic chips, and a liquid finishing compound are loaded into a vibratory bowl or barrel.
- Motion: The machine's motion causes the media and parts to abrade against each other.
- Abrasion: The abrasive embedded within the plastic chips slowly grinds away sharp edges, burrs, or surface imperfections.
- Rinsing & Separation: After the desired finish is achieved, the parts are separated from the media, rinsed, and dried.
Advantages of Using Plastic Chips
Choosing plastic chips for finishing operations offers several significant benefits:
- Gentle Processing: They are less aggressive than ceramic media, making them ideal for delicate parts or materials prone to damage.
- Versatile Application: Suitable for a wide array of materials, from various non-ferrous metals to plastics and composites.
- Controlled Finish: Allows for precise control over the material removal rate and desired surface texture.
- Cost-Effective: Often a durable and economical choice for achieving consistent quality finishes.
- Improved Part Quality: Reduces manual labor for deburring, ensures consistent part quality, and enhances functional and aesthetic properties.
Choosing the Right Plastic Chip
Selecting the appropriate plastic chip involves considering several factors:
- Part Material: Match the chip's abrasive strength to the hardness of the workpiece material.
- Desired Finish: Determine if the goal is heavy deburring, light radiusing, or a high-luster polish.
- Part Geometry: The size and shape of the chip must allow it to access all areas of the part without lodging.
- Machine Type: The specific mass finishing equipment (vibratory tumbler, centrifugal disc, etc.) will influence media choice.
By carefully selecting the right plastic chip, manufacturers can optimize their finishing processes, resulting in high-quality, consistently finished components.
