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Molded Polyurethane Components

Our custom, cast polyurethane formulations are known for:

polyurethane molded

  • Advantages over metal, rubber, and plastic
  • Wide range of part applications and industries
  • Compatibility to various molding methods
  • Ability to be finished in numerous ways
  • Low to mid volume production
  • Diversity in part size

Outstanding Physical Properties

  • Wide range of hardness
  • High load-bearing capabilities
  • High abrasion resistance
  • Low coefficients of friction
  • Good resistance to gas, oil, alkali and acid
  • Tear resistance and toughness

The two main types of cast polyurethanes, Polyester and Polyether, offer specific properties:

Ester
  • Solvent, Oil and Fuel Resistance
  • Abrasion Resistance
  • Excellent Mechanical Properties
  • Dry Heat Resistance to 200F
  • Vibration Dampening
  • Higher Split Tear Strength
Ether
  • Superior Rebound Properties
  • Low Temperature Flexibility
  • Excellent Hydrolytic Stability
  • Excellent Mechanical Properties
  • Resistance to Dynamic Heat
  • Reduced Frictional Properties

Typical Applications

Rollers
Rollers

Scrapers
Scrapers

Gears
Gears

Liners
Liners

Couplings
Couplings

Wheels
Wheels

Deflector
Deflector

Bumpers
Bumpers

Seals
Seals

Plugs
Plugs

Grippers
Grippers

WearPlates
Wear Plates

Wipers
Wipers

  • Impellers
  • Insulators
  • U Cups
  • Plates
  • Cams
  • Fans
  • Mounts
  • Guides
  • Isolators
  • Guide Rings
  • Bushings
  • Cushions
  • Gaskets
  • Springs
  • Squeegees

Key Advantages of Cast Polyurethane

Typical material competitors for cast polyurethane applications are metal, rubber and plastic. Cast polyurethane is tougher, stronger and has many other advantages as well.

vs. Metal

  • Less Weight
  • Less Noise
  • Better wear
  • Corrosion resistance
  • Cheaper fabrication
  • Non-sparking
  • Non-conductive
  • Impact resistance

vs. Rubber

  • Abrasion resistance
  • Cut and tear resistance
  • Higher load bearing
  • Harder durometer range
  • Clarity, Translucence
  • Non-marking, non- staining
  • Pourable, castable
  • Ozone resistance
  • Micro organism resistance
  • High dampening

vs. Plastic

  • Non-brittle
  • Abrasion resistance
  • High elongation
  • Elastomeric memory
  • Impact resistance
  • Lower tooling cost

Part or Product Size

Precision mechanical PU components range in size from 50 grams to over 60 pounds. In-house production utilizes a range of hot table and oven sizes for open cast molding, with our largest ovens measuring 10′ square, and presses up to 24″ square for compression molding.

Molding Technologies

Polyurethane (PU) can be molded in a variety of ways — open cast, compression, spin cast and low pressure injection. PU tooling is lower cost due to the simplicity of the tooling, the ability to gravity feed individual cavities, and the constant temperature processing, requiring no cooling lines. •Open Cast Molding — Because of the liquid nature of the uncured resin, PU parts are often molded using an open cast process. The polymer and curative agents are premixed and poured into an open cavity of a mold. After the parts reach “green strength” or are partially cured, they are demolded and moved to a secondary post cure oven. Open cast molded parts are subject to a looser tolerance on the open cast surface, and may require a secondary cutting or machining operation if a tighter tolerance is needed.

  • Compression Molding — PU can be cast using a compression or closed mold process. The polymer and curative are premixed and poured into the open mold. The mold is overfilled with raw material, helping to drive out air as the mold is closed and placed under pressure. After the parts reach “green strength”, they are demolded and moved to a secondary post cure oven. In this process, all surfaces are controlled by the closed mold.
  • Spin Casting — The polymer and curative are premixed and poured into a spinning, closed mold. This process is designed to remove air that can be trapped during casting. After the parts reach “green strength”, they are demolded and moved to a secondary post cure oven. Like the open cast molding process, a secondary machining process may be needed to remove the risers or gates.
  • Low Pressure Injection Molding — The polymer and curative are premixed and injected under low pressure into a closed mold. Bleeder vents are used to allow the excess air to escape during the injection process. After the parts reach “green strength”, they are demolded and moved to a secondary post cure oven.

Additional Capabilities

Insert Molding

When additional mechanical structure is needed in a component, cast urethane is easily overmolded onto a substrate. A variety of metals including carbon steel, aluminum, stainless, brass and bronze can be used. Non-metallic, rigid materials, such as fiberglass and glass-filled nylon, are also candidates.

Urethane may be either mechanically or chemically bonded to an insert. Mechanical bond is the encapsulation of the substrate without the use of a secondary adhesive. A chemical bond utilizes an adhesive system to ensure an unyielding bond between the substrate and urethane.

Finishing Operations

  • Deflashing – During the molding process uncured PU can seep between plates causing excess material extending from the part. After the parts are cured, the thin flash or excess material is removed in a batch process called cryogenic deflashing. The parts are frozen using liquid nitrogen, tumbled and blasted with media to remove the flash while retaining the part integrity.
  • Machining and Grinding — Machining or grinding can be used to achieve tighter tolerances than molding alone can create.
  • Die Cutting — Die cutting can be used to create a smooth, clean-cut edge as is often required for squeegee blades.
  • Knifing – Knifing is a manual operation whereby excess, unwanted material like flash or overpour is removed from the part by removal with a blade.
  • Kitting – Products may be special packaged, labeled or assembled per customer requirements.
  • Inventory Programs — Flexible systems, including KANBAN, are set up to hold raw, WIP and/or finished goods inventory depending on customer need.

Annual Volume Sold

Low to mid volume PU production capabilities. Some of our customers, including military, often only require small production runs, while other customers require weekly releases and a supporting KanBan program to keep them in supply. The systems and methodologies we learn from larger, more structured companies can be applied to benefit customers across the board.

Quality/Certifications

  • ISO 9001:2008
  • WBENC (Woman Owned Business)