---
title: "Free-Casting Polyurethane Technology: Features, Advantages, Applications"
description: "Learn about free-casting polyurethane technology for industry: advantages, comparison with rubber and steel, hardness selection, custom part orders."
lang: "en"
date: "2026-08-02"
canonical_url: "https://timol.com.ua/en/statti/tehnologiya-vilnogo-littya-poliuretanu"
---
# Free-Casting Polyurethane Technology: Features, Advantages, Applications

When you repeatedly replace rubber or steel parts that fail faster than the warranty on the unit expires, finding an alternative becomes critical. Cast polyurethane allows for the production of wear-resistant parts with specified properties tailored to specific units and operating conditions. Let's explore how free-casting polyurethane technology works, its manufacturing and operational advantages, and why dozens of industrialists choose it for quickly wearing parts.

## What is Free-Casting Polyurethane Technology?
Free-casting polyurethane technology is a process where a two-component reactive mixture (isocyanate and polyol) is poured into an open or semi-open mold without using pressure. This approach allows for the creation of products of any complexity, even with undercuts and internal channels, without further mechanical finishing. Unlike pressing or injection molding, there is no rigid attachment to mold geometry or high tooling costs for small and medium series.

The technology is particularly suitable for producing single items or small batches on demand when standard solutions are not suitable. The quick transition from drawing to finished part is a key advantage for companies that value flexibility and downtime. After mixing the components, the mixture is quickly poured into the mold, where it polymerizes and acquires its final properties.

## What are the Advantages of Free Casting over Pressing or Machining?
Free-casting polyurethane provides an integral microstructure of the part without the internal stresses that occur during pressing or machining. The absence of mechanical tool impact eliminates the appearance of microcracks and edge defects. As a result, products can withstand impact, pressure, and abrasion without early degradation.

When a complex shape is needed in a unit, such as a conical seal or lining with grooves, pressing is often impossible, and machining polyurethane does not provide the same uniformity and tightness. Free casting allows for varying thickness, reinforcing specific areas, and combining inserts. Manufacturing according to individual drawings allows for exact size and fit replication, even for old or worn-out units.

For serial products like elevator buckets, screens, or scrapers, the technology allows for flexible size changes to suit each line's specifics. This is especially important for units that are constantly operated in abrasive or chemically aggressive environments, as polyurethane adapts to the task.

## Hardness Range: How to Choose the Optimal Solution?
Choosing the hardness of polyurethane is key to the part's longevity. For parts working with abrasives (screens, linings, scrapers), the optimal range is 80-95 Shore A. This hardness provides a balance between absorbing abrasive impact and resisting wear. Elasticity allows the material to not break under dynamic loads, repelling particles and preventing deep scratches.

For seals, gaskets, rings, 70-90 Shore A is used. Here, elasticity and the ability to restore shape after deformation are important. If structural, load-bearing, or support parts are needed in the unit (e.g., support plates, bands), hardness up to 70 Shore D is used, but this is not for abrasive wear, rather for working under constant pressure.

> **Engineer’s Tip:** For linings, scrapers, and screens under abrasive conditions, we always recommend polyurethane 80-95 Shore A. Order with surface preparation for adhesion to ensure reliable installation even under dynamic loads. For seals and gaskets, choose 70-90 Shore A to maintain elasticity and tightness.

## How is a Typical Polyurethane Part Manufactured?
A typical cycle for producing a polyurethane part begins with creating a three-dimensional model or drawing of the product. The mold is made individually for each task, which can be metal, silicone, or composite tooling. Technologists are involved in selecting the optimal pouring and polymerization parameters for the given thickness and geometry.

The reactive mixture is prepared immediately before pouring: components are thoroughly mixed, controlling temperature and humidity. Pouring takes place in the prepared mold, followed by polymerization, which lasts from a few minutes to several hours depending on the product's mass. The finished part is removed from the mold and checked for geometric and property compliance. If necessary, machining of seating or mounting areas is performed.

In the case of linings or scrapers, the metal base is often additionally prepared: cleaned, degreased, and an adhesive layer is applied for reliable polyurethane fixation. This ensures long service life and minimal risks of delamination even in vibrating or wet environments.

## Comparative Table: Polyurethane and Main Materials for Wear Parts
| Material | Abrasion DIN 53516, mm3 | Working Temperature, °C | Tensile Strength, MPa | Hardness | Density, g/cm3 |
|------------------------|-------------------------|------------------------|------------------------|--------------------|---------------|
| Polyurethane (PU, TIMOL) | 20-45 | -60...+100 | 25-60 | 50A - 70D | 1.05-1.25 |
| SBR Rubber | 100-200 | -40...80 | 8-20 | 40A - 80A | 0.94-1.1 |
| NBR Rubber | 80-150 | -30...100 | 10-25 | 40A - 90A | 1-1.3 |
| Natural Rubber | 60-130 | -50...70 | 20-30 | 30A - 80A | 0.92-1 |
| Caprolon (PA6/PA66) | 30-90 | -40...100 | 60-85 | 75D - 85D | 1.13-1.15 |
| Wear-resistant Steel |, | -40...250 | 1250-1600 | 370-540 HB | 7.8-7.85 |

Polyurethane abrasion (20-45 mm3) is 4-10 times lower than SBR rubber (100-200 mm3), and 2-4 times lower than caprolon (30-90 mm3). At the same time, polyurethane has a density of 1.05-1.25 g/cm3, which is 6-7 times lower than steel, and its working temperature range (-60...+100 °C) covers most standard tasks. The tensile strength of polyurethane (25-60 MPa) is higher than most rubbers, and its rebound elasticity (35-65%) provides effective impact damping.

## Where is TIMOL Cast Polyurethane Used?
Free-casting polyurethane covers 12 main industries: from mining and metallurgy to the oil and gas sector, railway transport, and even the food and light industries. In each of these industries, wear parts such as elevator buckets, conveyor belt scrapers, screens, gaskets, bushings, rollers, sheets, hydrocyclones operate in harsh conditions and often require quick replacement.

In the [TIMOL polyurethane products catalog](/katalog), parts for process lines, equipment for transporting bulk and liquid materials, surface protection elements, seals, and support parts are presented. All products are manufactured according to drawings or customer samples, and adapting geometry and hardness to the unit's specifics is standard practice at the factory.

Importantly, polyurethane is equally effective in units with dynamic loads (scrapers, drum linings) and for static seals or elements where abrasion resistance and chemical inertness are key. This allows for quick modernization even on old lines without changes to equipment design.

## Installation, Operation, and Maintenance of Cast Polyurethane Parts
Polyurethane parts are installed in standard locations of existing units, often using bolted, flanged, or adhesive connections. For drum and conveyor linings, preparing the metal base is critically important: it is cleaned, degreased, and coated with an adhesive compound for maximum fixation. Seals, gaskets, rings are mounted in standard seating places without the need for equipment adaptation.

Polyurethane retains its properties in a temperature range from -60 to +100 °C, does not crack in the cold, and does not soften when heated within this corridor. Thanks to its high wear resistance (10 times higher than rubber), parts last much longer, reducing the number of repair stoppages. Maintenance generally involves checking fastenings and, if necessary, cleaning the surface from deposits.

In case of damage to individual elements, most parts can be replaced separately without disassembling the entire unit. This is especially beneficial for complex products like hydrocyclones or screen linings, where downtime is very costly.

## Economics and Customization Opportunities
Thanks to free-casting polyurethane technology, standard rubber, steel, or thermoplastic elements can be effectively replaced without making changes to the design. Manufacturing to drawings allows for considering all seating dimensions, undercuts, and technological holes. For production launch, expensive molds or multi-stage tools are not required, as the mold is made for each product based on the batch or even a single item.

Selecting hardness for the task (from 50 Shore A to 70 Shore D), controlling thickness, and locally reinforcing specific areas allow for optimizing resource use and reducing maintenance costs. The customer receives a part that not only fits the geometry but also surpasses the original in wear resistance and reliability. This is especially noticeable in units where standard rubber or steel fails within weeks.

## Conclusion: When is it Advisable to Switch to Cast Polyurethane?
If you have a unit with regularly failing wear parts, and standard rubber or steel elements do not meet the required resource, free-casting polyurethane technology is a practical solution. TIMOL factory produces parts according to drawings or samples with a guarantee of material quality and adaptation to your operating conditions. Leave a request through the [contact form](/contacts) or view [reference information](/informatsiya) to get a calculation for your task. By choosing TIMOL polyurethane, you ensure long-lasting unit operation, reduced downtime, and a personalized approach to each technical task.