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Engineering Plastics to Use in Precision Machined Parts

Precision machining is a controlled manufacturing process used to manufacture high-precision parts out of various materials, such as plastics. Precision machined plastic parts are found in nearly every industry, valued for their lightweight and versatile properties. Here we’ll discuss the most common materials used in precision plastic machining and their respective benefits.

Popular Plastics for Precision Machined PartsEngineering plastics

Precision machining, specifically computer numerical control (CNC) machining, is compatible with a wide range of plastics. CNC machining is an automated, computer-controlled manufacturing process. Here is an overview of the best types of plastics to use for precision machining.

Acetal

Acetal has a slippery surface and impressive wear resistance. It is common in valve components, bearings, and gears.

Nylon

Nylon is a type of low-friction engineering thermoplastic with excellent chemical resistance, abrasion resistance, and high impact strength.

Polyetheretherketone (PEEK)

PEEK is a lightweight, durable thermoplastic valued for its unique combination of mechanical properties. It is resistant to wear, liquids, fatigue, creep, chemicals, and high temperatures up to 260 °C. 

Polycarbonate (PC)

PC is a tough, lightweight plastic that can withstand high heat and has good electrical insulation properties. Polycarbonate sub-types include:

  • Abrasion-resistant PC
  • Glass-filled PC
  • Static dissipative PC
  • Bullet-resistant PC

Polytetrafluoroethylene (PTFE)

PTFE—also known as Teflon®—is a high-performance polymer with impressive physical and mechanical properties, including resistance to chemicals, water, UV, light, high temperatures, moisture, fatigue, and weathering. PTFE is also popular for its low coefficient of friction and corrosion resistance. 

Polyphenylene Sulfide (PPS)

PPS is a high-temperature engineering thermoplastic that can withstand up to 200 °C for extended periods of time. It is the best material choice for complex parts with tight tolerances because of its dimensional stability under temperature and humidity fluctuations.

Benefits of High-Precision Machined Plastic Parts

Each plastic type stands out for its distinct mechanical and physical properties. They each have applications for which they are best suited when precision manufacturing parts. Below are the benefits of these commonly used plastics.

Acetal

  • Wear resistance
  • Good stiffness
  • Dimensional stability
  • Heat resistance
  • Chemical resistance

Nylon

  • High impact strength
  • Chemical resistance
  • Abrasion resistance

PEEK

  • High resistance to chemicals, wear, fatigue, and high temperatures
  • Lightweight
  • Recyclable
  • Biocompatible
  • Insoluble in most solvents

PC

  • Lightweight
  • Clarity
  • Tough 
  • Good electrical insulation
  • Transparency; excellent light transmissivity

PTFE

  • Anti-adhesive
  • Chemical resistance
  • High-temperature resistance
  • Light and UV resistance
  • Wear resistance
  • Fatigue resistance
  • Water resistance 
  • Creep resistance  

PPS

  • High-temperature resistance
  • Good electrical insulation
  • Dimensional stability
  • Chemical resistance
  • High tensile strength

High-Precision Machining at National Plastics and Seals

At National Plastics and Seals, we pride ourselves on our in-depth expertise with polymeric materials and high-precision machining. We work with a wide range of plastics, including nylon, PTFE, PEEK, polycarbonate, PPS, and acetal. We are uniquely equipped to partner with you on material selection based on your specifications. Contact us to discuss your project, or request more information to learn more about our products and services. 

Choosing the Right Heat Shrink Tubing

Heat shrink tubing provides added protection and is a common choice for securing wires and electrical connections. Choosing the right heat shrink tubing is the key to a smooth project. Some of the best ways to ensure you’re making the right choice is to:

  • Consider the application environment, such as temperatures, weather, potential contaminants, and more.
  • Ensure it meets the right certifications and standards for your industry.
  • Based on your application’s needs, decide the color, expanded ID, recovered ID, recovered wall thickness, and material.

In this guide, we’ll go over the various factors to keep in mind when choosing the best heat shrink tubing, as well as their common materials.

Heat Shrink Tubing Considerations

Because heat shrink tubing protects wiring and electrical lines from the environment, it needs to be able to keep all potential environmental hazards at bay. The exact conditions can vary from location to location, so it’s important to keep these heat shrink tubing considerations in mind:

Abrasion or Flex Damage

Electrical lines and wiring will shift over time. Above-ground installations may be bumped, moved, or pushed against; even below-ground installations may encounter some flex as the ground expands and compresses in the weather. The right heat shrink tubing material will be able to handle the physical hazards in your intended application environment. 

Arc Flash

An arc flash occurs when an electric current leaves its path and travels through the air to the ground, or from one conductor to another. In this case, the proper heat shrink material would encase the wiring and provide sufficient resistance to ensure electrical current stays on course.

Exposure to Chemicals

Almost no locations are free from the risk of chemical contaminants. Assess the likely chemicals, including solvents, chemical salts, oils, and greases, present in your application environment. You may need specialized materials or multiple/thick layers of protection to ward away particularly caustic or pervasive substances.

Exposure to the Elements

In outdoor or partially enclosed environments, protection against harsh temperatures isn’t enough. The material must also be strong enough to withstand rain, snow, abrasive winds, and direct or indirect UV exposure.

Exposure to Temperature Extremes

Very cold or very hot climates present different risks to the effectiveness of heat shrink tubing. Even if the line is buried and out of direct exposure, temperatures can reach deep into the ground. Make sure you choose a heat shrink tubing material that can withstand extreme heat and cold, or large variations in temperature. 

Fire Risks

The heat shrink tubing you choose needs to both halt the spread of a fire and mitigate the risk of an external flame from reaching and damaging the wires; this is also referred to as flame-retardancy.

Moisture

Virtually every environment will have moisture, ranging from ambient humidity to rainfall or even proximity to marine spaces. Determine the amount of water, frequency of exposure, and duration of exposure the heat shrink material needs to be able to protect the wiring against.

Common Heat Shrink Materials

Now that you know what to look for, consider the properties of commonly used heat shrink materials to find the right fit for your needs. Common material options include:

  • Fluoroelastomers. This material is flexible, even at cold temperatures. It can also resist diesel and fluid damage.
  • Fluoropolymers (PTFE). PTFE has multiple grades, including a medical grade variation. This material can also operate reliably across hot and cold temperatures.
  • PET. Polyethylene terephthalate is strong, clear, and comes in food-safe options.
  • Polyolefins. This material is well-regarded for its insulative ability. It can be used in a wide range of manufacturing and industrial use cases.
  • PVC. PVC is flexible, easy to work with, and can handle physical impact without degrading. However, it does have a relatively low-temperature resistance.

Choose Heat Shrink Tubing From National Plastics & Seals, Inc.

Choosing the right thickness, material, and characteristics of your heat shrink tubing can make all the difference for protecting electrical wiring long-term. At National Plastics & Seals, we specialize in formulating and producing high-quality heat shrink tubing that can work in a variety of conditions. We excel at customer service and meeting the needs of clients with custom projects and specifications. Contact us today to learn more about our products or request a quote to get started.