Demands on furniture glides

Furniture glides face the constant challenge of integrating into the design concept of furniture while at the same time meeting the requirements of the application environment and furniture use. Often they should remain inconspicuously functional over the entire life of the furniture.

Furniture designers and manufacturers develop new furniture as part of comprehensive design and functional studies. Furniture glides are already an integral part of the design. In addition to sometimes very elaborate in-house developments, furniture glides are often used as bought-in parts from the ranges of corresponding suppliers. Furniture that is moved little or subjected to heavy loads is not critical when selecting a furniture glider, whereas chairs require the careful selection of a suitable glider.

Tension between chair – floor covering – use

The furniture glides should be made in such a way that

• the floor covering is not damaged
• the floor covering does not damage the glider excessively -> soiling, sealing with hard substances, etc.
• there is little noise when the chairs are moved
• moving the chairs is pleasantly easy, but not too easy -> slipping when sitting down
• misuse (tipping, falling, etc.) is tolerated and the floor remains undamaged in the process

Design types of furniture glides

In the last few decades the following varieties of gliders have become widespread:

1. Singel-part glides

They are usually inexpensive and allow for rather flat and less conspicuous designs. In most cases, the quality of the attachment to the chair determines the size. They are offered in the following materials

• Polyethylene (PE),
• Polypropylene (PP)
• Polyamide (PA)
• Polyoxymethylene (POM)
• Polycarbonate (PC)

Here are some examples from our range:

2. Two-part or multi-part glides, fabric-locking with

• very firmly glued
• welded on or
• overmoulded sliding insert

These offer a more precise adaptation to given floor coverings, but are more complex to manufacture and therefore often more expensive.

Examples from our product range:

3. Two-part or multi-part glides, form-fitting with

• Mounted sliding insert

With mounted gliders, the insert can be replaced if necessary. As a result, the gliders are usually somewhat larger, more complex to manufacture and more expensive than the first variant. Examples:

Sliding inserts

The following forms and materials have become widespread for the sliding inserts or inserted or applied sliding inserts:

1. Felt punched parts
   • presse in
   • with plastic frame overmoulded mounted or snapped in place
   • glued on
   • welded on by means of friction welding
2. One-piece hard plastic mouldings (PE, PP, PA, POM, PC, etc.)
   • overmoulded
   • glued
   • welded on by means of friction welding
   • pressed in
   • mounted
   • snapped in
3. Stainless steel bowls
   • flanged around the glider
4. Chrome or nickel-plated steel shells
   • flanged around the glider
5. One-piece soft plastic mouldings (elastomers and thermoplastic elastomers)
   • overmoulded
   • glued
   • welded on by means of friction welding
   • pressed in
   • mounted
   • snapped in
6. Materially bonded composite moulded parts made of soft-elastic carrier and lubricious film (elastomer or thermoplastic elastomer [TPE] with film made of polytetrafluoroethylene [PTFE, brand name e.g. ™Teflon], ultra-high molecular weight PE or radiation-crosslinked ultra-high molecular weight PE).

What can chair glides do?

Chair glides or glide inserts of chair glides are wearing parts and require maintenance and, in the case of sensitive floors, preventive inspection. There are no universal floor glides for all floor coverings. There are glide surface materials that can be used on all floor coverings, but with the conflicting aims of the

• durability
  • e.g. PTFE
  • felt
• Functional incompatibility
  • e.g. TPE/U, PUR = excellent adhesion
  • PTFE = extremely low frictional or adhesive resistance

The durability depends first and foremost on the right choice of chair glider:

• Footprint of the chair glider or glider insert in relation to the payload
  • weight of person + weight of chair
• Correct choice of glide insert material to match the floor covering
• Usage behaviour or type of use
• Colour of the sliding insert

For various reasons (design, cost, weight, etc.), round steel tubes with small diameters or even tapered, hydraulically pressure formed steel tubes with small diameters are often installed in tubular steel chairs. The expectation of furniture manufacturers is then often that the chair glides do not have conspicuously large gliding surfaces in relation to the steel tube diameter.

With regard to the wear of the sliding inserts, it must be taken into account that this increases quadratically with decreasing diameter. In addition, the pressure load on the floor increases quadratically. The fastening and firm hold of chair glides also becomes increasingly difficult as the diameter of the chair tubes decreases. This is less critical for cantilever chairs or tubular steel chairs without upright chair legs with smaller tubular steel diameters (18-22 mm) if the gliding surface can be sufficiently long.

The choice of glide insert material depends on the requirements of the floor covering and the desired comfort. Floor covering manufacturers should list the suitable or compatible glide materials and the minimum glide area per chair in their products. With regard to the comfort requirement concerning low noise, it should be taken into account that soft materials (felt, elastomers, thermoplastic elastomers) wear significantly faster with decreasing hardness. With regard to the comfort requirement of particularly easy displaceability, it must be taken into account that the materials PTFE and ultra-high molecular weight PE or radiation-crosslinked ultra-high molecular weight PE cannot be thermoplastically processed into moulded parts in standard processes, but are usually available as semi-finished film products or sintered pressed parts for further processing into a materially bonded composite moulded part. The wear resistance of the available and processable films is limited, so that despite the low friction and the resulting low abrasion, only a medium durability can be expected with intensive use.

Extreme demands by users or the type of use usually arise in schools and in mass seating with stacking chairs. The only thing that helps here is good floor cleaning in conjunction with regular maintenance. Very often there is also vandalism. Chair glides cannot meet these requirements with a long durability.

On delicate floors, natural coloured glide inserts can ensure that the abrasion can be removed without a trace, whereas coloured glide inserts or glides can leave traces that are difficult or impossible to remove.

Furthermore, the following criteria must then be taken into account:

• Care and cleaning of the floor
• Type of flooring
• Quality of the floor design

Floor cleaning and floor care depending on the degree of dirt and wear are essential. Small hard grains settle in all sliding surfaces and then scratch the floor when the chairs are moved and additionally erase the sliding surface of the chair glider.

This creates sharp-edged grooves in steel or stainless steel shells, which in turn work on the floor. Some flooring manufacturers seal their flooring with a top coat containing corundum to protect the flooring against scratches.

However, corundum is a very hard abrasive and erases the glides and glide inserts in a very short time.

The type of flooring already determines the level of friction and adhesion to be expected when moving the chairs and the noise level when moving the chairs. Accordingly, more gliding or more stopping chair glides and, if necessary, additional noise-dampening chair glides can be chosen.

A floor with seating should be level and have no protrusions. Coarse floor tiles with protruding edges or abrupt floor thresholds/impacts can render chair gliders unusable in a short time. With regard to the comfort feature of low noise, a suitable floor covering can already make a decisive contribution.

In many cases, the durability of furniture glides exceeds the furniture service life. Often a simple straight plug of our type GL in natural colour or adequately an inclined glider of our type RS in natural colour is a simple and satisfactory solution and very easy to replace once wear has progressed too far -> see also “Information on plastics“.

Non-public and public invitations to tender for seating

If specific chair glides are specified in tenders, the floor design/floor covering, chair glides and type of use must match in such a way that the intended realistic durability with specified floor care (floor cleaning and maintenance/inspection of floors and chair glides) is given. The tender text essentially determines the service life of the building materials, objects and components to be procured.

In many cases, the chair glider is the weakest link and can cause damage to the floor covering due to defects caused by overuse.

With regard to the type of use, the use of stacking chairs in schools and large rooms used for school purposes, as well as at large events, is likely to place the highest demands on chair glides.
It should be carefully considered which chair glides are suitable for the type of use.
If articulated glides are chosen, it must be taken into account that they can also be turned in the opposite direction according to the supported chair leg angle. In this case, the staff responsible for seating must make absolutely sure that the articulated glide surfaces are aligned as flat as possible to the floor and that the chairs are not thrown onto the floor when lifted from the stack, but are set up.
Otherwise, it is inevitable that the joint gliding surface will be cut off or the joint gliders will be damaged in some other way when the chairs are set up or subsequently used. The choice of a natural-coloured slanted plug made of PE (our groups SRS or RS) may be the less elegant but safer solution (if necessary sufficiently soft, colourless, possibly somewhat higher abrasion wear).

We offer all common sliding surfaces

• EPDM
• Felt (various quality, natural od dyed)
• PA (natural od dyed)
• PE (natural od dyed)
• POM (natural)
• PP (natural od dyed)
• PTFE (natural od dyed)
• PVC-P (soft; natural or dyed)
• Stainless steel
• Steel (nickel- or chrome-plated)
• TPE-U/-V/-E (natural or dyed)

TPE-U has the greatest stopper effect and at the same time a very long service life across many different types of floor. PTFE has the greatest sliding effect (static and sliding friction) over a wide range of floor types.

Some mounted glide inserts can be exchanged for new ones with little effort. It is often cheaper or more sensible to replace the glide than to replace the glide inserts in glides designed for interchangeable glide inserts. With a view to universal use, natural-coloured glide surfaces are recommended. This also eliminates the problem of colour migration if the floor and/or glides contain vinyl (PVC, EVA, etc.). When cleaning the floor wet, it is recommended to remove furniture with glide inserts made of felt or steel (nickel or chrome-plated) until the floor is completely dry. Glide surface material and floor cleaner must be compatible or should not interact.

Depending on regular cleaning and care of the floor covering at sufficiently short intervals and careful use of the chairs, the following pairings with different durability of the glide inserts can be considered without any guarantee (varying comfort):

• Laminate floors (not sealed with hard materials): Depending on sensitivity and anti-slip factor, soft to medium-hard felt, TPE, PE, PP or PVC-P (natural)
• Parquet (not oiled or sealed with hard materials): Depending on sensitivity and anti-slip factor, soft * to medium-hard felt, TPE or PVC-P (natural)
• Elastic flooring for sports halls and similar: Depending on sensitivity and anti-slip factor, stainless steel and each natural colour (not coloured) medium-hard felt, PA or POM
• Linoleum: Depending on sensitivity and anti-slip factor, soft * to medium-hart felt, TPE or PVC-P (natural)
• Soft, smooth natural stone: Depending on sensitivity and anti-slip factor, soft * to medium-hard felt, PTFE, TPE or PVC-P (natural)
• Soft, raw natural stone: Depending on sensitivity and anti-slip factor, TPE or PVC-P
• Hard, smooth natural stone: Depending on sensitivity and anti-slip factor, medium-hard felt, PTFE, PA, PP, PE, POM or PVC-P (natural)
• Hard, raw natural stone: Depending on sensitivity and anti-slip factor and each natural colour (not coloured) POM, PA, PP, PE or PVC-P
• Hard, smooth ceramic tiles: Depending on sensitivity and anti-slip factor, medium-hard felt, PA, POM, PVC-P or TPE
• Carpet/textile floors: Depending on sensitivity and type, stainless steel, PTFE or PVC-U (hard PVC)
• Vinyl floors: Depending on sensitivity and anti-slip factor, stainless steel, felt and each natural colour (not coloured) TPE, PA, PP, PE or POM
• Composite concrete, exposed concrete: POM (natural), PA (natural) or stainless steel

*) soft felt has a short shelf life – look at “Information on industry felt“

Legal notice

This article has been written and researched in good faith. However, the views and recommendations of Walter Bethke GmbH & Co. KG presented here are for informational purposes only and are in no way legally binding.

Walter Bethke GmbH & Co. KG is therefore not liable for any damages that may result from implementation into practice. Further we would like to point out the required coordination between soil material, sliding surface material, colouring of the sliding surface material, surface area of the sliding surface (pressure load) and the floor cleaning agent. This isiues are subject to be clarified by the customer in cooperation with the manufacturer of the soil material or/and the architect in charges of the task.

Copyright © 2023 Walther Bethke GmbH & Co. KG