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Common Materials for Machining Plastic

When manufacturing plastic components, many companies turn to molding techniques to produce the necessary parts and products. However, this method often proves expensive and time consuming.

Machining serves as an alternative to molding that creates small quantities of complex and close tolerance plastic parts quickly. Since the workpiece has to be rigid enough to withstand operations without warping or bending, not all types of plastics are suitable for machining. Despite these restrictions, there remain several plastics of varying costs and performance characteristics that are machinable.

Plastic Material Selection

Machinable plastics are available in many forms—such as sheets, rods, or tubes—and can be broadly classified into two categories: thermoplastics and thermosets.

Thermoplastics

Thermoplastics are the largest category of plastics. They are characterized by their ability to soften and melt under heat multiple times without experiencing any chemical change. Some of the other key properties of thermoplastics are:

• High creep resistance
• Solubility in certain solvents
• Susceptibility to swelling in the presence of some solvents
• Amenability to the use of fillers—such as carbon fibers, glass fibers, graphite, and molybdenum disulfide—for changing material properties

Thermoplastics are available in a wide range of generic and trademarked plastic formulations, each of which demonstrates different material and performance characteristics. Some of the most common types employed include acrylonitrile butadiene styrene (ABS), acetal, acrylic, nylon, polyethylene, polypropylene, polytetrafluoroethylene (PTFE), polyvinyl chloride (PVC), and polyvinylidene difluoride (PVDF).

Thermosets

Unlike thermoplastics, thermosets do not melt or soften under heat for reuse since the polymers in the material form stable, cross-linked bonds once cured. Other significant characteristics of thermoset plastics are:

• Insolubility in most solvents
• Insusceptibility to swelling when exposed to most solvents
• High creep resistance (once cured) and susceptibility to chipping (brittle)
• Amenability to use of fillers for composite materials

Some of the most commonly used thermosets are Bakelite, epoxy, melamine, phenolics, and vinyl ester.

Material Characteristics of Common Machined Plastics

When selecting a plastic material for a machining application, there are two main factors to consider: (a) suitability of the plastic’s properties for the application and (b) its suitability for machining. Some of the characteristics that machined plastic parts can have are:

• Biocompatibility: targeted toward medical and pharmaceutical applications where machined parts must not cause biological reactions in patients
• Chemical resistance: important for parts used in the agricultural, chemical, and food and beverage industries as parts must not dissolve or degrade when they come in contact with chemicals
• Dimensional stability: an important property for outdoor parts that are exposed to varying stress and environmental conditions
• FDA classification: plastics used in food and beverage industry applications must be approved by the FDA
• Impact resistance: some plastics, such as polycarbonate, offer greater impact resistance than glass, making them suitable for use in high impact or stress applications
• Loading strength: the ability of the plastic to withstand compressive and tensile loads
• Temperature resistance: depending on the specifications of the application, the plastic material must be able to perform well under a wide range of temperatures
• UV resistance: an important property for outdoor applications
• Wear resistance: plastic parts used in high speed or high torque applications must have good resistance to wear

Industries and Applications

Machined plastic parts find application across a diverse set of industries as components of cabinets, carts, enclosures and tanks, fume hoods, laboratory equipment, light lenses, point-of-purchase (POP) displays, sign holders, and more. Some of the industries that use machined plastic parts are:

• Biomedical
• Electronics
• Life sciences and animal research
• Lighting
• Marine
• Original equipment manufacturing (OEM)
• Pharmaceutical
• Photonics
• Recreational
• Semiconductor

Plastic Solutions From Plastic Design, Inc.

At Plastic Design, Inc., we have over 40 years of experience designing, prototyping, and manufacturing machined plastic parts for a wide range of industries. We can fabricate parts to standards such as Factory Mutual, Semi, NFPA, and OSHA or custom specifications and maintain ISO 9001:2015, I.P.C.A. 620, and confined space entry certifications. Regardless of whether you need a one-off prototype or a large production run, we can meet your machined plastic needs.

In addition to our design and manufacturing capabilities, we also offer the following services:

• On-site installation
• Support
• Stocking and distribution of plastic materials in various forms, including extruded and molded rods, sheets, and flexible and rigid tubes.

To learn more about our plastic machining and distribution capabilities, contact us or request a quote today.

Plastic Machining Guide

Machining is an umbrella term for the controlled, subtractive manufacturing techniques used to produce parts made from a wide range of materials. Today, many companies employ computer numerical control (CNC) machining to achieve greater precision and accuracy in their end products.

When deciding on a machining method for a part, it is essential to keep in mind the design and construction material as these factors significantly impact the production process and final result. For plastic machining projects, these considerations are especially important due to the greater susceptibility of plastic materials to warping, cracking, and deformation when improperly handled. Further exacerbating the problem is the broad selection of plastics and plastic composites available, with each type exhibiting its own properties and best use cases. Altogether, these challenges necessitate partnering with a supplier who demonstrates a deep understanding of your chosen material.

With over 40 years of experience in plastic fabrication, Plastic Design, Inc. has the knowledge and skills necessary to take on any plastic machining challenge. Equipped with state-of-the-art CNC machining equipment, our expert team has the means to perform several different types of machining processes on a variety of industrial plastics to execute the optimal manufacturing plan for every product.

Additional Capabilities

In addition to our plastic machining capabilities, we also offer:

Original Equipment Manufacturing

Over our years serving customers in the biomedical, pharmaceutical research, and semiconductor industries, we’ve garnered significant knowledge about the requirements expected for the equipment and systems used in the industries. This expertise allows us to serve as an original equipment manufacturer (OEM) of custom-built parts and equipment. With our OEM services, we provide technical guidance to take products from concept to completion.

Specialty Product Manufacturing

Outside of our OEM partnerships, we also manufacture a full catalog of specialty products for customers across a wide range of industries. Some of these past projects have included:

• Automated wet process systems
• Desiccators
• Fume hoods
• Hazardous waste systems
• Tank lines

What Makes Us Different?

At Plastic Design, we are an ISO 9001:2015 certified fabricator. By partnering with us for their plastic machining needs, our customers benefit from our:

• Over 40 years of experience in plastic manufacturing
• Knowledge of specialized fields, including the biomedical, pharmaceutical, and semiconductor industries
• 30,000-square-foot fabrication facility
• OEM manufacturing capabilities

These characteristics allow us to meet some of the most difficult design challenges out there while forming lasting relationships with our industry clients.

Plastic Machining Solutions From Plastic Design, Inc.

Choosing a knowledgeable manufacturer for a plastic machining operation is the key to successful completion of the project. Plastics require specialized expertise to prevent expensive defects or product failures during production, and only a dedicated plastics provider can guide you through the complex material selection and testing process.

At Plastic Design, Inc., we have the technical capabilities and industry knowledge necessary to produce high-quality and cost-effective parts and products from a wide range of plastics. Whether you’re seeking a one-off prototype or a high-volume production run, we’ll work with you to turn your design into a reality.

To learn more about our plastic machining capabilities, contact us or request a quote today.

Choosing a Material for Plastic Chemical Tanks

Plastic chemical tanks are used for holding and storing harsh and corrosive chemicals in a variety of applications across many industries. Plastics are versatile, inexpensive to manufacture, and chemically adaptable—properties that have led to the replacement of expensive stainless steel tanks throughout manufacturing processes for biomedical, pharmaceutical, and semiconductor industries. Because some plastics can react with different chemicals, heat, or pressure, tanks must be designed using materials specifically tailored for the chemicals and processes they need to hold.

Industries for Plastic Chemical Tanks

Biomedical and Pharmaceutical

You will often find plastic chemical tanks used in the biomedical and pharmaceutical industries, where they are employed to store, drain, and mix chemical compounds. The tanks need to be composed of materials that will not interact with or leach into the compounds they are holding. Tanks for pharmaceutical and biomedical use are often constructed using rigorously tested USP Class VI Certified plastics to ensure biocompatibility and prevent toxic interactions with the chemicals in use.

Semiconductor

Plastic chemical tanks used in the semiconductor industry must be highly resistant to corrosion and safe for sterile use in clean rooms. They are useful in harsh environments for the manufacture of circuitry and electronic components for semiconductor equipment. The tanks must be constructed of durable and highly inert plastics to withstand the hot gas, aggressive chemicals, and high-pressure used in the industry, as well as avoid corrosion and a reaction with the materials being used.

Common Materials Used in Plastic Tanks

Depending on their intended use, plastic tanks must be carefully constructed to tolerate various volatile circumstances without risk of corrosion or leaching. As such, a number of different plastic materials are used in their construction.

• Polypropylene is a versatile semi-crystalline material that is highly chemically resistant at low temperatures, but can be less stable at very high temperatures.
• Polyvinylidene difluoride, or PVDF, is a strong fluropolymer that has high chemical resistance, but is less stable at high temperatures.
• High Density Polyethylene, or HDPE, is an opaque semi-crystalline thermoplastic that is highly chemical resistant and impact resistant at low temperatures.
• PVC, or polyvinyl chloride, comes in both rigid and flexible varieties. It is highly resistant to corrosion and has fair to good chemical resistance.

Properties of Each Material

Each plastic material has physical and chemical properties that help determine which is best for a given chemical or application. When choosing a material, consider the tensile strength, dielectric strength, and maximum operating temperature of each material to ensure that the ideal material is being used in each circumstance. Below is a short list of the important physical properties of each of the plastics commonly used in plastic tanks:

Polypropylene

• Tensile Strength (MPa): 33
• Dielectric Strength (MV/m): 28
• Maximum Operating Temperature: (°C): 100

PVDF

• Tensile Strength: 35
• Dielectric Strength (MV/m): 13
• Maximum Operating Temperature: (°C): 150

HDPE

• Tensile Strength (MPa): 32
• Dielectric Strength (MV/m): 22
• Maximum Operating Temperature: 55

PVC

• Tensile Strength (MPa): 20
• Dielectric Strength (MV/m): 30
• Maximum Operating Temperature: (°C): 50

Advantages and Disadvantages of Plastic Materials

Contact Plastic Design for Plastic Chemical Tanks

Plastic Design Inc. is proud to offer high-quality custom plastic tank designs using precise processes and procedures that are fully ISO 9001:2015 certified. We can manufacture products in high quantities that meet and exceed industry specifications, including Factory Mutual, Semi, NFPA, and OSHA. Our knowledgeable and experienced engineers are available to conduct on-site surveys and evaluations of your existing systems, so you can find the best solutions and modifications for your needs.

For more information on our custom plastic tank services and pricing, contact us or request a quote today!