Polyethylene (PE), Technical Properties and Applications

Polyethylene, or PE for short, is a lightweight, durable and versatile thermoplastic material. The material is characterised by very low water absorption, high chemical resistance, good electrical insulation properties and pronounced impact strength.

In industry, PE is used among other things as a plastic sheet, rod, profile, cut piece or fully machined component. Depending on molecular weight and manufacturing process, different PE types are available. Particularly widespread are PE-HD or PE 300, PE-HMW or PE 500 and PE-UHMW or PE 1000.

Martan Plastics supplies suitable thermoplastic semi-finished products and, on request, produces precise cut pieces and components for industrial applications.

What is polyethylene?

Polyethylene belongs to the group of polyolefins and is produced by the polymerisation of ethylene. Different manufacturing processes, molecular structures and molecular weights produce different PE materials, each with its own mechanical and processing properties.

Common to all PE types are low density, very low moisture absorption and good resistance to numerous acids, alkalis, salt solutions and other chemical media. Polyethylene is also electrically insulating and remains comparatively impact-resistant even at low temperatures.

An overview of other engineering materials can be found on our page on plastic materials.

Which PE types are there?

The designations PE 300, PE 500 and PE 1000 are based on the molecular weight of the material. As molecular weight increases, wear resistance, impact strength and sliding properties in particular improve. At the same time, processing by welding, forming or machining becomes more demanding.

PE type	Alternative designation	Characteristic properties	Typical applications
PE 300	PE-HD	High rigidity, good weldability, high chemical resistance	Containers, linings, covers, apparatus engineering
PE 500	PE-HMW	Higher impact strength and wear resistance than PE 300	Cutting boards, guides, machine components
PE 1000	PE-UHMW	Very high wear resistance, very good sliding properties, low friction	Slide rails, chain guides, conveyor systems, wear parts

PE 300 or PE-HD

PE 300 is a high-density polyethylene with comparatively high rigidity and good weldability. The material is often used where chemical resistance, moisture resistance and economical processing are the priority.

Typical applications are containers, tanks, linings, covers, pipework components and structural elements in apparatus engineering. PE 300 can be sawn, milled, drilled, thermoformed and welded using suitable processes.

PE 500 or PE-HMW

PE 500 has a higher molecular weight than PE 300. This improves resistance to impact stress and abrasive wear. The material forms an engineering intermediate stage between the easily processed PE 300 and the particularly wear-resistant PE 1000.

PE 500 is used, for example, for cutting boards, guide elements, machine parts, protective sheets and components in conveyor technology.

PE 1000 or PE-UHMW

PE 1000 is an ultra-high-molecular-weight polyethylene. Due to its very high molecular weight, the material has excellent abrasion resistance, high impact strength and very good sliding and non-stick properties.

PE 1000 is particularly suitable for components that slide, rub or come into contact with abrasive bulk materials on a permanent basis. These include chain guides, slide rails, conveyor screws, linings, rollers, guide profiles and wear plates.

Suitable semi-finished products can be found under PE 1000 or PE-UHMW sheets. Further materials and dimensions are available in our range of plastic sheets and plastic rods.

Key properties of PE plastic

Low density

Polyethylene has a lower density than many other engineering plastics and is significantly lighter than metallic materials. PE components can therefore help to reduce the weight of machines, conveyor systems and technical constructions.

Very low water absorption

PE absorbs practically no moisture. Its dimensions and properties are therefore hardly affected by water or high humidity. The material is accordingly well suited to applications in humid environments and to components with regular water contact.

High chemical resistance

Polyethylene is resistant to many acids, alkalis, salt solutions, alcohols and other chemicals. The specific suitability depends, however, on the type of medium, the concentration, the temperature and the duration of exposure.

For safety-relevant applications, chemical resistance should therefore always be checked against the specific operating conditions.

High impact strength

PE has a high resistance to impact and shock loads. PE 500 and PE 1000 in particular remain comparatively tough even at low temperatures. The material is therefore suitable for components that are subjected to dynamic loads or used in cold environments.

Good sliding and non-stick properties

PE 1000 in particular has a low coefficient of friction and favourable sliding properties. Many bulk materials, foods and sticky materials adhere only slightly to the surface.

These properties are advantageous in guides, chutes, hoppers, linings and conveyor elements.

High wear resistance

PE 1000 is one of the particularly wear-resistant thermoplastics. In applications with sliding or abrasive contact, the material can extend the service life of components and reduce maintenance requirements.

Electrically insulating

Polyethylene conducts electrical current very poorly and is therefore also used as an insulating material. For areas where electrostatic charging must be avoided, antistatic or electrically conductive PE versions are available.

Technical properties of polyethylene

The actual values depend on the respective PE type, the material quality, the colouring and possible additives. The following table therefore serves as a general guide.

Property	Typical rating
Density	Very low
Water absorption	Very low
Chemical resistance	Very good against many media
Impact strength	High to very high
Abrasion resistance	Particularly high with PE 1000
Sliding properties	Good to very good
Rigidity	Lower than POM or PA
Moisture resistance	Very good
Electrical insulation	Good
Bonding	Only with suitable pre-treatment

Temperature resistance of polyethylene

The permissible temperature range depends on the PE grade, the mechanical load and the duration of use. Polyethylene is generally very well suited to applications at low temperatures. As heat increases, however, the rigidity of the material decreases.

For permanently high service temperatures, other engineering or high-temperature-resistant plastics are generally better suited. The maximum service temperature should therefore not be considered in isolation. Load, component geometry, clamping conditions and the desired service life are also decisive.

Chemical resistance of PE

Polyethylene has a high resistance to numerous chemical media. Depending on concentration and temperature, these include among others:

• dilute and many concentrated acids,
• alkalis and alkaline solutions,
• salt solutions,
• alcohols,
• oils and greases,
• water and steam at limited temperatures.

Limitations can occur among other things with strongly oxidising chemicals, certain hydrocarbons and at high temperatures. Stress cracking must also be taken into account with certain media and simultaneously acting mechanical load.

A general resistance statement therefore does not replace application-specific material testing.

UV and weather resistance

Unmodified polyethylene is only suitable to a limited extent for permanent UV exposure. Long-term sunlight can lead to colour changes, surface degradation and a reduction in mechanical properties.

For outdoor applications, UV-stabilised or black-pigmented PE grades are available. Black variants containing carbon black generally have significantly better UV resistance than natural-coloured standard types.

For permanently weathered or safety-relevant components, the intended service life and the specific environmental conditions should be taken into account already during material selection.

Food-safe PE materials

Certain PE grades may be suitable for applications with food contact. They are used, for example, for cutting boards, guide rails, conveyor elements, containers, machine parts and linings in food processing.

The decisive factor is not the material designation PE alone. The specific material grade must meet the respective food-law requirements and be documented accordingly.

Further information can be found on our pages on plastics for the food industry and on the requirements and certifications for food-safe plastics.

Typical applications of polyethylene

Polyethylene is used across industries. The specific application depends above all on the selected PE type.

• Slide rails and guide rails
• Chain guides and curved guides
• Conveyor screws and conveyor elements
• Wear plates and protective strips
• Chutes, hoppers and linings
• Cutting boards
• Containers and tanks
• Covers and cladding
• Rollers, bushes and spacers
• Components for water and wastewater technology
• Components for food machinery
• Electrically insulating components

In mechanical and plant engineering, PE is often used to reduce friction, noise generation and wear. At the same time, the low weight of the material can relieve the load on moving assemblies.

PE sheets, rods and finished parts

Polyethylene is available in various semi-finished product forms. These include in particular:

• PE sheets,
• PE rods,
• profiles and slide rails,
• cut pieces to size,
• machined finished parts,
• welded containers and constructions.

Depending on the PE type, different colours, material thicknesses, formats and special versions are available. These include among others natural-coloured, green, black, blue, antistatic and electrically conductive variants.

Machining of PE plastic

Polyethylene can be machined well with suitable tools. Typical processes are sawing, drilling, milling, turning and waterjet cutting. Martan Plastics handles the complete plastic machining from simple cut pieces to ready-to-install components.

Milling and turning

During machining, the low rigidity, high thermal expansion and low thermal conductivity of the material must be taken into account. Sharp tools, suitable cutting parameters and secure, low-stress clamping improve dimensional accuracy and surface quality.

Rotationally symmetrical components such as rollers, bushes or spacers can be produced by precise CNC turning of plastics.

Welding

PE 300 in particular can be joined well using suitable thermal welding processes. Welding is used among other things in the construction of containers, tanks, pipework systems and apparatus.

Due to its very high molecular weight, PE 1000 is considerably more difficult to weld and is therefore predominantly mechanically fastened or machined into a one-piece component.

Bonding and painting

The non-polar and low-energy surface makes bonding and painting polyethylene difficult. For durable joints, special adhesives and suitable surface pre-treatment are necessary. Possible processes include plasma, corona or flame treatment.

Design notes for PE components

Polyethylene has a significantly higher thermal expansion and lower rigidity than metallic materials. These properties must be taken into account already during design.

For long components, guide rails or large-format sheets, sufficient expansion allowance should be planned. Rigid clamping can lead to deformation or high internal stresses during temperature changes.

Under permanent mechanical load, PE also exhibits pronounced creep behaviour. Point loads should therefore be avoided and forces distributed over as large an area as possible. Bolted connections require sufficiently large contact surfaces and must not be over-tightened.

Advantages of polyethylene

• Very low water absorption
• High chemical resistance
• High impact strength, even at low temperatures
• Low weight
• Good electrical insulation properties
• Very good sliding and non-stick properties with PE 1000
• High abrasion and wear resistance
• Good machinability
• Food-safe versions available
• Antistatic and electrically conductive variants available

Limitations of PE plastic

Despite its versatile properties, polyethylene is not the best solution for every technical application. The following must be taken into account in particular:

• comparatively low rigidity,
• limited load capacity at higher temperatures,
• high thermal expansion,
• tendency to creep under permanent load,
• difficult bonding and painting,
• limited UV resistance with unstabilised types,
• limited dimensional accuracy with tight tolerances.

For highly loaded precision parts, gears or dimension-critical components, materials such as POM or extruded polyamide may be better suited.

PE compared with other plastics

PE or PP?

Polypropylene generally has a higher rigidity and can be used at higher temperatures. Polyethylene, on the other hand, often offers better impact strength at low temperatures and, particularly as PE 1000, is significantly more wear-resistant.

PE is particularly suitable for sliding, impact-loaded and damp applications. PP is often used for more rigid constructions, containers and chemically loaded components with higher temperature requirements.

PE or POM?

POM is harder, more rigid and more dimensionally accurate than PE. The material is therefore well suited to precision parts, gears, bearings and structurally loaded components.

PE, on the other hand, has a lower density, lower water absorption and, depending on the version, higher chemical resistance and impact strength. PE 1000 is also particularly interesting for large-area sliding and wear applications.

PE or PA?

Polyamide offers higher mechanical strength and rigidity. However, it absorbs significantly more moisture, which can change dimensions and mechanical properties.

PE is more dimensionally stable with respect to moisture, chemically resistant and particularly impact-resistant at low temperatures. For highly loaded structural parts, PA is often more suitable, while PE offers advantages with moisture, chemical contact or sliding wear.

Which PE type is suitable for your application?

Requirement	Suitable PE version
Containers, tanks and welded constructions	PE 300
Cutting boards and robust machine parts	PE 500
Slide rails and chain guides	PE 1000
High abrasive wear	PE 1000
Food contact	Compliant special PE grade
Outdoor use	UV-stabilised or black version
Avoiding electrostatic charging	Antistatic or conductive version
Tight tolerances and high rigidity	Consider alternative such as POM

The final selection should be made on the basis of mechanical load, temperature, media contact, component geometry, required tolerances and possible approvals.

PE semi-finished products and finished parts from Martan Plastics

Martan Plastics supplies polyethylene as sheet, rod, cut piece and individually machined finished part. Depending on your application, we support you in choosing between PE 300, PE 500, PE 1000 and suitable special grades.

Based on your drawing, CAD data or technical specification, we produce among other things guides, slide rails, rollers, bushes, linings, wear plates and other structural components.

For applications with special requirements, suitable material certificates and documentation may be necessary. Information on existing quality and company certificates can be found on our Certificates and quality page.

Summary

Polyethylene is a lightweight, chemically resistant and impact-resistant thermoplastic for numerous industrial applications. PE 300 is particularly suitable for containers, linings and welded constructions. PE 500 offers increased wear and impact resistance. PE 1000 impresses with very good sliding and non-stick properties as well as exceptionally high abrasion resistance.

For reliable material selection, temperature, load, chemical contact, moisture, UV exposure and the required dimensional accuracy must be taken into account in addition to the PE type.

FAQ on polyethylene

What kind of plastic is PE?

PE stands for polyethylene. It is a semi-crystalline thermoplastic from the group of polyolefins. The material is lightweight, chemically resistant, moisture-resistant and electrically insulating.

What is the difference between PE 300, PE 500 and PE 1000?

The types differ mainly in their molecular weight. PE 300 is comparatively rigid and easy to weld. PE 500 has higher impact and wear resistance. PE 1000 offers the highest abrasion resistance as well as particularly good sliding and non-stick properties.

Is PE suitable for outdoor use?

Standard PE has only limited UV resistance. For long-term outdoor use, UV-stabilised or black-pigmented PE types should be used.

Is polyethylene food-safe?

Certain PE grades may be approved for food contact. The decisive factor is the specific material grade including the associated declaration of conformity. The general designation PE is not sufficient as proof.

Can PE be milled and turned?

PE can be sawn, drilled, milled and turned well. Due to the low rigidity and high thermal expansion, tools, cutting parameters and clamping must be adapted to the material.

Can polyethylene be bonded?

Due to its non-polar surface, polyethylene is difficult to bond. For durable joints, special adhesives and often pre-treatment of the surface are required.

What advantages does PE 1000 offer?

PE 1000 has a very high abrasion resistance, high impact strength, a low coefficient of friction and good non-stick properties. The material is therefore often used for slide rails, chain guides, linings and other wear parts.

When is POM better than PE?

POM is usually the better choice when high rigidity, strength, dimensional accuracy or precise machining is required. PE offers advantages with moisture, chemical load, low temperatures and abrasive wear.