PU4751 is an HMDI based aliphatic polyurethane prepolymer for use as a rubber crumb binder. It has a fast cure speed and as such is ideal for play areas. PU4751 gives excellent UV resistance.PU4751 has been formulated as a flexible moisture curing binder for in situ recycled rubber crumb shock pads and EPDM play surface top coats, which are laid by hand.


Available in:
200L Steel Drum
20L Plastic Pail


  • Rubber crumb shock pads
  • EPDM topcoats
  • TPV topcoats
  • Aquatic waterparks
  • Rubber threshold ramps

See all applications in our Technical Data Sheet

See all applications in our Technical Data Sheet

How to use

  • Application Temperature

    +5°C until +40°C

  • Substrate Preparation

    Ensure the ground to be coated is well prepared. All loose material should be removed. Ensure the surface is free from contamination such as oil and grease. The surface should also be dry.

  • Cure Speed Modification:

    D4861 Rubber Crumb Binder Accelerator (1k) is used to modify the cure time, this is particularly important when PU4751 is being installed below 20°C. Further details are available upon request.

  • Mixing

    Mix rubber granules and binder PU4223CS at desired ratio. Ensure the volumetric ratio of binder addition is considered as the bulk density of rubbers will vary. Rubber granules should be dry in order to stop accelerated cure times and foaming of the binder.
    For adequate mixing, a high torque rotary mixer should be used. Rubber and binder should be mixed for up to 5 minutes ensuring all the rubber is coated.

  • Installation

    The product can then be laid out on a prepared surface and compacted using a hand trowel or weighted roller. Ensure an even compaction of the rubber. A release agent should be used on all tools to avoid adhesion of the binder to the tools. Ensure all equipment is cleaned well after use.



How long does it take for PU4751 to cure?

Cure time is approx. 7-8 hours at 20°C (with 0.01% D4861 accelerator). The cure time will vary depending on the ambient temperature, relative humidity, and accelerator addition %.

Is PU4751 UV stable?

Yes, PU4751 is based on aliphatic polyurethane technology and has excellent long-term UV performance

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