At Northwest Rubber Extruders, we make all our extrusion dies and tooling in-house to provide total control over quality, reliability, and accuracy. Our in-house processes enable us to maintain tight tolerances and accurate profiles, to ensure that the rubber extrusions you receive meet your design requirements. We can deliver custom rubber extrusions in sizes from 1/16” around to 14” wide, in straight lengths up to 20’ and coiled lengths up to 200’.

Custom rubber extrusions, extruded rubber aircraft seals, and extruded rubber tubes are produced using a wide range of standard and specialty materials. These include natural rubber, chloroprene, and a variety of unique blends. Each material offers different benefits, and your decision should be based on your performance and application requirements.

Size requirements for your custom rubber extrusion are based on the application. Weatherstripping and gaskets, for example, are typically in longer lengths with the width or diameter depending on the size of the door, window, or component being sealed. To meet the needs to various applications, we provide rubber extrusions in a wide range of sizes and lengths.

A primary benefit of extrusion is the ability to create custom rubber shapes with tight tolerances. In addition to standard tube, rectangular and square extrusions, this process cane be used to create custom rubber seals including “P” shapes, “J” seals, “T” shapes, and oddly-shaped extruded rubber products.

Custom rubber extrusions are produced in a range of shapes and configurations ranging from tubes and pipes to custom rubber shapes with intricate designs. Though every project we work on is different, some products are more common than others, such as:

Universal jointexamples

Northwest Rubber Extruders can deliver custom rubber extrusions that meet our quality control standards a variety of industry specifications, including:

Northwest Rubber Extruders, Inc. produces custom extruded rubber products for customers in all markets. We specialize in extruded rubber aircraft seals, extruded rubber tubes, and custom rubber shapes for all applications.

Universal joint BearingSize Chart

Extruded products are often left unvulcanized prior to extrusion, which leaves the rubber in a softer, more pliable state post-extrusion. If this is the case, rubber extruded products generally need to be vulcanized before they can be used. Depending on the type of rubber being extruded, the vulcanization process will cause the material to either swell or shrink, both in its cross section and its length. In most cases, a length of rubber extrusion will experience greater dimensional reduction or expansion across the center than at its ends.

In rubber extrusion, the term “shape” and “profile” are more or less interchangeable. When discussing an extruded rubber shape or profile, you are talking about its cross section—essentially, the “shape” of the die or tooling through which it is extruded. This can be anything from a simple “U” shape to more complex, multifaceted shapes with intricate edges and interior details. Some of the various custom rubber shapes include:

By using the maintenance-free bearing for the universal joints of commercial vehicles (fig. 2), the manufacturer comes one important step nearer to his ultimate goal – the maintenance-free truck.

The maintenance-free universal joint differs from current models in another aspect. The cross itself is without the internal lubrication ducts and there is no grease nipple. Instead, the end faces of the cross have relatively shallow depressions which are intended as grease reservoirs. The absence of the through-going inter-connected lubrication ducts means that production costs are reduced.

The propeller shafts used today must be relubricated at regular intervals if they are to attain acceptable service life. The greater part of the used and surplus grease is ejected from the propeller shaft and ends up in the environment. In Germany, it is estimated that several hundred tonnes of grease pollution come from this source alone.

SKFuniversal jointCatalogue pdf

Rubber extrusions are similar to molded rubber products, in that both are created by forcing heated rubber in a near-liquid state into a specially made mold or die under pressure. The extrusion process begins with an unvulcanized rubber compound being fed into an extruder. Revolving screws within the extruder carry the rubber toward the die; temperature and pressure increase as the material is forced through the opening. As it passes through the opening, the material generally swells to a certain extent, based on its chemical makeup and hardness. Plus/minus tolerances in the design of the extruded part’s cross section are often required to account for this swelling.

Universal JointCoupling

The internal secondary axial sealing lip (4) which runs against the secondary seal presents a further barrier to any dirt which may have penetrated. The efficiency of this lip’s function is supported by rotation of the propeller shaft. All sealing positions and the intervening spaces are filled with lubricating grease. This further enhances sealing efficiency.

With our innovative, lean production processes and highly trained staff, we manufacture custom rubber extrusions that match our customers’ exact design specifications. We can produce the custom rubber extrusions you need in short runs or high quantities, all with quick turnarounds and at competitive prices.

By using the maintenance-free bearing for the universal joints of commercial vehicles (fig. 2), the manufacturer comes one important step nearer to his ultimate goal – the maintenance-free truck.

The spring-loaded primary sealing lip (1) enables sealing performance (against grease loss) to be kept constant throughout service life. The special design of the lip ensures that an adequate lubricant ‘wedge’ can be built up under the lip to prevent wear.

The operating conditions for universal joint bearings on commercial vehicle propeller shafts have always been associated with heavy specific loads in the rolling contact. Because of the kinematic conditions, the roller set of a universal joint bearing ‘only’ performs oscillating movements. Both these factors place extremely high demands on the grease.

Ujoint bearingcaps

The rubber extrusion process is ideal for creating seals for any number of uses. An extruded rubber seal can provide a barrier against water/moisture, fluids, gases, dirt/dust/particulates, and much more, so long as the correct material is used for the application at hand. Our expert team can help you determine which material is best for your sealing needs, based the environmental and application.

The secondary seal (2), which has a sheet steel reinforcement, serves to exclude dirt. It has an interference fit on the pin where it prevents penetration of water and all other forms of contamination. The steel insert enables this tight fit to be maintained and provides protection even against loose stones. The sealing lip edge (3) contacts the outside surface of the drawn cup and acts as a dynamic seal at this position.

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The universal joint for commercial vehicle propeller shafts is essentially a specially-designed grease-lubricated needle roller bearing. This new maintenance-free universal joint bearing is now in production.The present design of a drawn cup bearing incorporates a kind of plain bearing at the closed end and integral seals at the open end (fig. 1).

Another design feature of the maintenance-free universal joint is that considerable attention was paid to the design and performance of the sealing system (primary and secondary seals). Figure 2 shows the patented SKF sealing concept.

The concept of a maintenance-free propeller shaft has brought the use of a high-performance grease even more into focus since, if there was no relubrication whatsoever, fresh grease could not be supplied to the system at any time.

Performance testing of the SKF maintenance-free universal joint bearings, which involved extensive rig tests at SKF and potential customers, has been successfully completed. Endurance testing of the joints are underway, but due to the long time scale required, they have not yet been completed.

Universal joint bearingcatalogue

This grease loss was the starting point for the innovative development work. Before a new concept could evolve however, extensive system analysis of existing relubricable universal joints was carried out. This study was based on years of field experience and data from in-house dynamic relationships between the universal joint (cardan cross) bearings, seal design and grease movement. The SKF universal joint bearings produced so far have achieved satisfactory service life in terms of fatigue. The fatigue life of a universal joint bearing is determined by the macro-geometrical dimensions, component micro-geometry and the materials used.

Northwest Rubber Extruders is a leading custom rubber extrusion manufacturer. We can deliver short runs or products with quantities in the tens of thousands, with unparalleled service and on-time deliveries to meet your schedule. Request a quote on custom rubber extrusions, or contact us to discuss your project.

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