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Cement Floor

RIM Tooling

Reaction Injection Mold (RIM) Tooling

We specialize in Reaction Injection Mold (RIM) Tooling. The RIM process produces lightweight, strong, flexible parts which are easily paintable.


Reaction Injection Molding involves the mixture and injection of a 2-part resin into a mold cavity to obtain a final part. RIM molding is most often used for large parts (i.e. machine skins, bumper facia, etc) but is effectively molds smaller parts as well - often in multiple cavity tools.


The RIM process requires lower pressure than traditional injection molding and allows for a variety of urethane resins. The process also allows for the mold-over of preforms. Due to the processes of these molding techniques, the molds are fabricated with several features necessary for end-part success:

  • Temperature control lines

  • Ejector Pins

  • Ejector Sleeves

  • Vents

  • Dump Wells

LMP can also produce your cast or machined temperature controlled production tooling in a variety of materials. Other benefits of partnering with LMP include:

  • LMP provides quick time to market with our CNC five-axis and three-axis routers, and three-axis milling centers.

  • With customer supplied solid surface data, your tooling can be cutting the same day.

  • LMP can help develop your part using state-of-the-art SURFCAM software.

  • Cast or machined aluminum temperature controlled molds are manufactured to meet production, budget and time requirements.

Not only can we make your mold to your exact specifications, we can mount it to create the compatible tooling necessary for your individual machines. Along with manufacturing the molds and tooling in-house, we also tackle mold repairs and modifications.

RIM Tooling

Example Parts


Tooling Features
RIM tooling supports the flow and injection of liquid urethane in various combinations with a liquid catalyst into the mold cavity. LMP creates the tooling features required:

  • Gate

    • Dam Gate

    • Fan Gate

  • Quiet Zone

  • Peanut Mixer

  • Mold Cavity

  • Mold Core

The mold can be single or multiple cavity with features such as:

  • Ejector System

    • Ejector Pins

    • Ejector Sleeves

    • Mechanical Draw Pneumatic/Hydraulic Ejector System

  • Temperature Control

    • Gun Drilled Temperature Control Lines with Inlet/Outlet Connections

    • Two-piece Machined Coolant Plate

    • Cast In Flexible Stainless Steel Lines

  • Vents

    • Dump Wells

    • Popit Vents

Available Part, Pattern, Tooling and Mold Materials
RIM production tooling is fabricated from steel or aluminum billet. It is then CNC machined to size and cavity specification. Larger tools require lap joints between the multiple mold pieces which are assembled using pin and bolt connections.

Cast aluminum molds can provide an economical alternative to fully machined molds.

Short run RIM tooling can be made from laminated epoxy with the cavity being molded off of an existing part if applicable.

Factors Effecting Mold Construction
Construction of Reaction Injection Mold tooling is based on intricacy of the cavity, measurements of platten size for the injection mold, daylight in the press (space when open fully) and the required distance between coolant lines in the tooling.

Machining Tolerances
LMP has the ability to produce your molds with industry tolerances to +/- .005” using conventional and CNC machine tools.

Secondary Operations
On top of providing the tooling for Reaction Injection Molding, LMP can also provide services including:


  • Plumbing Maintenance - for the temperature control line systems

  • Tool Maintenance & Repair

  • Tool Modifications


Besides manual and CNC machining, LMP can perform secondary operations to achieve tighter tolerances, different finish characteristics or geometries that would not be possible with traditional machining methods. These operations include:


  • Wire EDM

  • Water Jet Cutting

  • Framing

  • Sand Blasting

  • Hand Benching

  • Coating Applications


In-House Equipment
Motionmaster 60 x 60 x 30 CNC 5-axis router (2)
Thermwood 60 x 120 3-axis CNC
Freyer 30 X 60 X 30 3-axis Vertical Machining Center
Cintimatic 18 X 30 X 18 3-axis Vertical Machining Center
Wadkins Vertical Turning Center

Preferred Drawing Submission
We support DWG, DXF, IGES, DSN, SCPRT, x_t and other customer files utilizing our Surfcam software and can arrange for file conversion of any program we do not currently support.


LMP uses Surfcam CAD/CAM Software for all tooling design and fabrication.


Production Volume
LMP provides custom built to specification tooling- typically in a single quantity.


Industries Served
Classic Manufacturing
Reaction Injection Molding

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