Office Chair Materials Explained: ABS, PP, PA66 and POM

When choosing an ergonomic office chair, most people begin with the features they can immediately see and feel.

They compare the mesh, seat cushioning, lumbar support, armrests and recline functions. These are all important, but they do not tell the full story.

Beneath the upholstery and visible adjustments are dozens of structural and moving components. Backrest frames, armrest supports, adjustment levers, caster cores, mechanism covers and internal sliders are often made from different types of plastic.

The quality and placement of these materials can influence:

• structural stability
• adjustment smoothness
• resistance to wear
• noise and movement over time
• protection against ageing and cracking
• the overall service life of the chair

This does not mean that every plastic component must use the most expensive material available. A well-designed ergonomic chair uses different materials according to the load, movement and environmental exposure of each component.

In this guide, we explain the most common office chair plastics, how injection-moulding quality affects the finished chair, and what you can realistically inspect before purchasing.ergonomic office chairs

Why plastic components matter in an ergonomic office chair

The word “plastic” is often associated with low-cost furniture, but this is an oversimplification.

Engineering plastics can offer an effective combination of:

• strength
• flexibility
• wear resistance
• precise moulding
• lower weight
• corrosion resistance
• design flexibility

Many high-quality ergonomic chairs use plastic in areas where metal would add unnecessary weight, create noise or limit movement.

The more useful question is not:

Does this office chair contain plastic?

It is:

Has the correct type of plastic been used in the correct part of the chair?

A non-load-bearing cover does not require the same material as a backrest frame. Similarly, a moving internal slider requires different properties from a decorative outer shell.

Understanding this distinction helps buyers evaluate chair quality more accurately.

Common plastics used in office chairs

1. ABS: commonly used for shells and exterior components

ABS, or acrylonitrile butadiene styrene, is widely used in furniture, appliances and consumer products.

In office chairs, it may be used for:

• exterior covers
• decorative housings
• armrest shells
• adjustment covers
• some moderately loaded structural parts

ABS can produce a clean surface finish and consistent colour. It also offers a practical balance of stiffness, impact resistance and mouldability.

Advantages of ABS

• Smooth and consistent appearance
• Good dimensional stability
• Suitable for detailed moulded shapes
• Reasonable impact resistance
• Easy to colour and finish

Potential limitations

ABS can become less resilient after prolonged exposure to heat and ultraviolet light, particularly when the material or stabilising additives are of lower quality.

This is one reason white plastic components sometimes discolour or become brittle after extended exposure to direct sunlight.

However, visible yellowing does not automatically prove that the wrong material was used. Sunlight exposure, additives, pigments and surface treatment can all affect ageing.

Where ABS makes sense

ABS is generally suitable for exterior and lightly to moderately loaded parts. For heavily loaded or repeatedly flexed components, manufacturers may instead use reinforced nylon or another engineering plastic.

2. PP: lightweight and practical for non-critical components

PP, or polypropylene, is another common material used in office furniture.

It is relatively lightweight and resistant to many chemicals and cleaning products. Depending on the design, PP may be used for:

• mechanism covers
• dust covers
• flexible shells
• non-load-bearing trim
• components beneath armrest padding

Advantages of PP

• Lightweight
• Good resistance to moisture and chemicals
• Suitable for parts that need some flexibility
• Efficient to manufacture
• Practical for covers and protective components

Potential limitations

Standard PP generally has lower stiffness and structural strength than materials such as PA66.

For this reason, it may not be the ideal choice for a narrow component that must carry a high load or withstand repeated mechanical stress.

This does not mean PP is automatically a low-quality material. Its suitability depends on the function of the part.

A PP mechanism cover, for example, may be entirely appropriate because the cover protects the internal mechanism rather than carrying the user’s weight.

3. PA66: a high-strength material for structural parts

PA66, commonly known as nylon 66, is an engineering plastic used where greater strength and wear resistance are required.

In ergonomic office chairs, PA66 may be used for:

• backrest frames
• armrest support structures
• caster cores
• reinforced chair bases
• load-bearing brackets
• internal adjustment components

Advantages of PA66

• High mechanical strength
• Good resistance to wear
• Suitable for repeated loading
• Better heat resistance than many standard plastics
• Capable of supporting complex structural designs

PA66 is usually more expensive than standard PP or general-purpose ABS. However, material cost alone does not determine whether a component will perform well.

Its actual strength also depends on:

• material grade
• wall thickness
• internal reinforcement ribs
• moisture conditioning
• moulding accuracy
• component geometry
• the use of glass-fibre reinforcement

A poorly designed PA66 component can still fail, while a well-designed component made from a less expensive material may perform reliably in an appropriate non-critical position.

4. POM: designed for smooth, repeated movement

POM, or polyoxymethylene, is often used for precision mechanical components.

It has a low coefficient of friction and good dimensional stability, making it suitable for parts that slide, rotate or engage repeatedly.

Possible office chair applications include:

• adjustment sliders
• locking teeth
• internal gears
• moving catches
• armrest adjustment mechanisms
• small precision components

Advantages of POM

• Smooth sliding performance
• Good resistance to repeated wear
• Stable dimensions
• Suitable for gears and mechanical interfaces
• Low friction compared with many general-purpose plastics

If an armrest adjustment feels rough or inconsistent, the material may be one factor—but it is not the only explanation.

Adjustment quality is also affected by:

• component tolerances
• lubrication
• assembly quality
• spring tension
• mechanism design
• alignment between moving parts

It is therefore difficult to identify POM accurately from appearance or hand feel alone.

5. Glass-fibre reinforced plastics

Some structural office chair components use plastics reinforced with glass fibre.

These may be described as:

• PA66+GF
• PA+GF
• PP+GF
• glass-fibre reinforced nylon
• reinforced engineering plastic

Adding glass fibre can increase stiffness and help a plastic component resist bending under load.

This type of material may be used in:

• backrest frames
• chair bases
• structural support arms
• seat supports
• heavily loaded adjustment housings

Is more glass fibre always better?

No.

Increasing the glass-fibre content can improve stiffness, but excessive reinforcement may also reduce impact flexibility or make the component more difficult to mould correctly.

The appropriate percentage depends on:

• the shape of the part
• the expected load
• the direction of stress
• required flexibility
• moulding conditions
• long-term fatigue requirements

Some reinforced plastics display faint fibre patterns or silver-like streaks on the surface. These marks are not automatically defects. They may result from fibre orientation, material flow and injection-moulding conditions.

ABS vs PP vs PA66 vs POM: a practical comparison

This table is a general guide rather than a universal specification.

Manufacturers may use different material formulations, blends, reinforcements and proprietary grades. The final performance of an office chair depends on the entire component—not just the material abbreviation printed in a product description.choosing the right ergonomic chair

Injection moulding quality matters as much as the material

Even when two chairs use the same stated plastic, their finished components may differ significantly.

Plastic pellets must be heated, injected into a mould, cooled and removed. During this process, the quality of the mould and the accuracy of the manufacturing controls affect the finished part.

Important factors include:

• mould precision
• material temperature
• injection pressure
• cooling time
• moisture control
• part thickness
• reinforcing rib design
• trimming and finishing
• assembly tolerances

This is why simply stating “PA66” or “ABS” does not provide enough information to judge the quality of an ergonomic chair.

Check the moulding lines

A moulding or parting line is the seam left where two sides of a mould meet.

A well-manufactured component commonly has:

• a fine and controlled seam
• consistent alignment
• minimal sharp edges
• no excessive plastic overflow
• properly aligned assembly holes

A visible seam is not automatically a defect. Many complex components require multiple mould sections.

More concerning signs include:

• sharp or unfinished edges
• obvious mould misalignment
• large areas of excess material
• mounting holes that do not line up
• cracks beginning from the seam
• uneven left and right components
  

Look for flash, sink marks and weld lines

Flash

Flash is a thin layer of unwanted plastic that escapes between mould surfaces.

Minor flash can be trimmed during production. Significant or sharp flash may indicate inconsistent moulding or insufficient finishing.

Sink marks

Sink marks are shallow depressions created as thicker areas cool and contract.

Small cosmetic marks may not affect performance, but deeper sink marks around screw posts, joints or reinforcing ribs can indicate uneven material distribution.

Weld lines

Weld lines appear where two flows of melted plastic meet.

Their presence does not necessarily mean the part is weak. However, a prominent weld line in a highly stressed area deserves closer attention—particularly if it is accompanied by cracking, discolouration or visible separation.

What is two-shot moulding?

Some ergonomic chair arm pads are designed to combine a rigid support layer with a softer contact surface.

This can be achieved through:

• two-shot moulding
• overmoulding
• bonded soft pads
• mechanically fixed padding
• adhesive lamination

In a two-shot or overmoulded component, the hard and soft materials are formed into a more integrated structure.

Possible soft materials include TPU, TPR and other elastomeric compounds.

Why does the manufacturing method matter?

A well-produced arm pad should resist:

• peeling
• bubbling
• edge lifting
• separation between layers
• hardening after repeated use

A bonded or glued arm pad is not automatically poor quality. Its durability depends on the adhesive, surface preparation, material compatibility and manufacturing control.

From appearance alone, consumers may not be able to confirm whether a component is truly two-shot moulded. A reliable brand or supplier should be able to explain the construction of the arm pad and its warranty coverage.

Surface finishes on office chair plastics

Plastic components can receive different surface treatments to improve appearance, grip or comfort.

Painted finish

Paint can create consistent colour and a more refined surface.

The important issue is not simply whether the component is painted, but whether the coating:

• adheres properly
• resists scratching
• tolerates cleaning
• maintains colour over time

Soft-touch coating

Soft-touch finishes may be used on armrests and frequently handled components.

They can improve tactile comfort but must withstand perspiration, skin oils, heat and cleaning products.

Textured moulding

A mould can be engraved or etched to create a textured plastic surface.

This may help:

• reduce visible fingerprints
• improve grip
• conceal light scratches
• create a more consistent finish

A glossy component is not necessarily better than a textured one. The finish should suit the intended function of the part.

The office chair components that deserve closer inspection

An office chair may contain dozens of plastic parts, but a smaller number have a greater influence on long-term performance.

Backrest frame

The backrest frame supports the upper body when the user leans back.

A poorly designed or insufficiently reinforced frame may eventually develop:

• excessive flex
• side-to-side movement
• creaking
• stress whitening
• cracks near curves or joints

A high-quality backrest frame may use reinforced nylon or another engineering plastic, but material alone is not enough.

Its reliability also depends on:

• frame geometry
• rib placement
• wall thickness
• joint design
• load distribution
• fatigue testing

How to inspect it

Hold both sides of the backrest and apply gentle, even pressure.

A controlled degree of flexibility can be normal. Look for:

• excessive looseness
• uneven movement
• sharp cracking sounds
• visible whitening at stress points
• separation around mounting areas

Avoid using extreme force. A consumer inspection should confirm normal stability, not attempt to destroy the chair.

Armrest supports and arm pads

Armrests are frequently touched, adjusted and exposed to perspiration.

They may also receive significant pressure when a person uses them to reposition or stand up.

Check:

• whether both armrests move consistently
• whether each adjustment locks securely
• whether the pad returns after being pressed
• whether the edges are lifting
• whether the soft layer is separating
• whether one side has substantially more movement than the other

A small amount of movement may be normal in a multi-adjustable armrest because the mechanism requires operational clearance.

The more important warning signs are:

• loss of adjustment positions
• significant side-to-side looseness
• cracking around pivot points
• different resistance between the left and right sides
• visible separation between materials

Adjustment levers and internal catches

Seat-height, recline, tilt-lock and armrest functions depend on small internal components.

These parts may experience hundreds or thousands of movements during the life of a chair.

Poorly designed or unsuitable components may result in:

• rough adjustment
• worn locking positions
• excessive free movement
• a lever that no longer engages
• recurring clicking or slipping
• gradual loss of adjustment control

A smooth mechanism is a positive sign, but it does not prove that a particular material has been used.

Mechanism performance comes from the combination of material choice, tolerance, lubrication and assembly.

Mechanism cover

The plastic cover beneath the seat is often misunderstood.

Its purpose may be to:

• protect the internal mechanism
• reduce dust and hair entering moving parts
• cover sharp metal edges
• improve appearance

Because the cover may not carry the user’s weight, PP can be completely suitable for this position.

Rather than judging the material by weight alone, inspect whether the cover:

• fits securely
• has consistent thickness
• avoids contact with moving parts
• covers the mechanism properly
• remains stable during adjustment

Caster cores and wheel surfaces

Office chair wheels combine several materials.

The outer wheel surface may use a softer PU or TPR-type material to reduce noise and protect hard floors. The internal core must carry weight and maintain shape.

Check whether the casters:

• roll smoothly
• rotate freely
• remain aligned
• have cracks around the axle
• show uneven wheel surfaces
• wobble excessively
• produce scraping or grinding sounds

Soft outer wheels do not necessarily have low strength. Performance depends on the wheel core, axle, outer material and connection to the chair base.

Five-star chair base

An ergonomic office chair may use a base made from:

• reinforced nylon
• aluminium alloy
• steel
• another engineered composite

A reinforced plastic base is not automatically weaker than a metal base.

A well-engineered nylon base can provide strength while reducing weight and avoiding corrosion. The relevant questions are:

• What material is used?
• Is it reinforced?
• What is the rated chair capacity?
• Has the base completed appropriate load and durability testing?
• How long is the structural warranty?

Inspect the base for:

• consistent leg thickness
• clean reinforcement ribs
• cracks near the centre hub
• whitening at high-stress points
• uneven moulding
• damage around the caster sockets

ergonomic chair for long hours

Can you identify good plastic by smell or weight?

Not reliably.

Online buying guides sometimes suggest that consumers can identify plastic quality by:

• smelling it
• scratching it
• tapping it
• bending it
• comparing its weight

These methods may reveal obvious manufacturing problems, but they cannot accurately confirm whether a component is ABS, PP, PA66 or POM.

For example:

• new material may still have an odour from packaging or additives
• recycled material does not always have a strong smell
• stress can cause plastic to whiten
• glass fibre may create visible surface patterns
• hollow structural design can reduce weight
• component thickness changes the tapping sound

A more reliable assessment combines:

• visual inspection
• functional testing
• published material information
• product certifications or testing
• rated weight capacity
• warranty terms
• availability of replacement parts

How to inspect an ergonomic office chair after delivery

You do not need laboratory equipment to identify obvious quality problems.

A short inspection after assembly can help confirm that the chair has been manufactured and assembled consistently.

Step 1: Check for unusual odours

A mild “new product” smell may occur when plastics, foam, adhesives and packaging have been enclosed during transport.

Ventilate the room and observe whether the smell reduces.

Contact the seller if the chair has:

• an intense chemical or solvent-like odour
• a smell that causes noticeable irritation
• an odour that remains very strong after ventilation
• one particular component with a concentrated, unusual smell

Odour alone cannot identify the exact plastic or prove the use of recycled material.

Step 2: Inspect seams and edges

Turn the chair carefully and inspect:

• the backrest frame
• armrest brackets
• seat underside
• mechanism cover
• chair base
• caster sockets

Look for:

• sharp edges
• heavy flash
• cracks
• misaligned holes
• uneven seams
• missing fasteners
• left-to-right inconsistencies
• whitening around stressed screw points

Fine mould lines are normal. Sharp, misaligned or cracked parts are not.

Step 3: Test each adjustment

Use each adjustment several times under normal conditions.

Check the:

• seat-height lever
• recline control
• tilt lock
• armrest height
• armrest pivot
• armrest depth
• headrest adjustment
• seat-depth adjustment, where available

The movements should feel predictable, and the chair should return to the same adjustment positions consistently.

Report:

• repeated slipping
• uneven locking
• excessive looseness
• grinding
• significant left-to-right differences
• controls that disengage under normal use

Step 4: Check overall stability

Sit in the chair and move gently from side to side.

Some movement is normal in an adjustable chair. It contains multiple joints, pivots and moving mechanisms.

However, investigate:

• a sudden shift in the seat
• excessive wobbling
• metal-on-metal impact sounds
• a backrest that moves independently from its mounting
• a caster that repeatedly lifts or catches
• visible movement around screws or structural connections

Questions to ask before buying an office chair

Instead of asking only whether an office chair uses “premium plastic”, ask more specific questions.

Useful questions include:

1. What material is used in the backrest frame?
2. Is the frame glass-fibre reinforced?
3. What material is used in the five-star base?
4. What is the tested or rated weight capacity?
5. Are the arm pads overmoulded, bonded or mechanically attached?
6. What materials are used in the armrest adjustment mechanism?
7. Has the chair completed load, impact or fatigue testing?
8. How long are the structural components covered by warranty?
9. Are replacement armrests, casters and mechanisms available?
10. What cleaning products are safe for the plastic and soft-touch surfaces?

Avoid relying only on marketing terms such as:

• aerospace-grade plastic
• premium polymer
• imported nylon
• military-grade material
• advanced composite

These phrases have limited value unless the brand explains the actual material, component application and testing.

compare Shappa office chairs

Does a more expensive office chair always use better plastic?

Not necessarily.

The price of an ergonomic office chair may also reflect:

• research and development
• adjustment mechanisms
• mesh or upholstery
• metal components
• assembly quality
• certification and testing
• local warehousing
• after-sales support
• warranty coverage
• availability of spare parts

A higher price does not automatically guarantee better materials.

At the same time, extremely low-cost chairs may need to reduce costs through simpler mechanisms, thinner components, lower material grades, limited testing or shorter warranties.

The most useful comparison is not price alone. Compare the complete specification and after-sales support.

What makes an office chair durable?

A durable ergonomic office chair does not use the most expensive material in every location.

Instead, it uses:

• structural materials in load-bearing areas
• wear-resistant materials in moving mechanisms
• softer, stable materials in contact areas
• lightweight materials in protective covers
• accurate moulding and assembly
• appropriate reinforcement where required
• components tested for repeated use

Material selection, design and manufacturing must work together.

PA66 printed in a specification does not compensate for poor geometry. A metal base does not compensate for an unreliable tilt mechanism. A thick plastic cover does not necessarily improve structural safety if the cover carries no load.

Durability is the result of the complete chair system.

Final thoughts

When comparing ergonomic office chairs, it is easy to focus on visible features.

Mesh, cushioning, lumbar support and adjustment range affect immediate comfort, but the less visible structural components influence how the chair performs after months and years of daily use.

Before buying, look beyond the number of adjustments.

Inspect the frame, armrest supports, mechanism housing, base and casters. Test the controls. Ask what materials are used in important load-bearing and moving components.

Most importantly, consider whether the chair is supported by a clear warranty and access to replacement parts.

A good ergonomic chair should not only feel comfortable on the first day. It should remain stable, predictable and functional throughout years of regular use.

At Shappa Australia, we believe office chair specifications should help customers understand how a chair is built—not simply provide more marketing terminology. Our ergonomic chair range is selected for Australian home offices and workplaces, with attention to adjustability, structural support and long-term ownership.

Explore Shappa ergonomic office chairs and compare the features that matter for your workspace.

FAQ

What is the best plastic for an ergonomic office chair?

There is no single best plastic for every part of an ergonomic chair. PA66 and glass-fibre reinforced nylon are commonly suited to loaded structures, while POM can be useful in moving mechanisms. ABS and PP may be appropriate for shells, covers and non-critical components.

Is a plastic office chair base safe?

A reinforced nylon office chair base can be safe and durable when it is properly engineered, manufactured and tested. Buyers should check the chair’s rated weight capacity, warranty and relevant testing rather than judging the base by material alone.

Is PA66 better than ABS for an office chair?

PA66 generally offers higher mechanical strength and wear resistance, making it more suitable for some loaded components. ABS can provide a better cosmetic finish and may be appropriate for shells and covers. The better material depends on the function of the component.

What is POM used for in an office chair?

POM is commonly used for small mechanical parts that slide, rotate or lock repeatedly. These may include internal catches, gears, sliders and adjustment components.

What does glass-fibre reinforced nylon mean?

Glass-fibre reinforced nylon is nylon combined with short glass fibres to improve stiffness and structural performance. It may be used in office chair frames, bases and supports, although performance still depends on component design and manufacturing quality.

How can I tell whether an office chair is well made?

Check the consistency of seams, edges and mounting points. Test every adjustment, inspect the backrest frame and base, and look for cracks, sharp flash, abnormal looseness or uneven operation. Also review the rated capacity, testing information and warranty.

Does a heavier office chair mean better quality?

Not necessarily. Weight can come from thicker materials, metal components or inefficient design. A lighter chair may still be strong if it uses appropriate engineering materials and structural reinforcement.

Why do white office chair parts turn yellow?

Discolouration may result from UV exposure, heat, material formulation, pigments or ageing. Keeping a chair away from prolonged direct sunlight can help reduce colour change.