Door type

PVC strip curtain

A PVC strip curtain is a curtain of overlapping PVC strips hung from a rail above an opening, which part to the side as people or vehicles pass through. It reduces draughts, cold, dust and noise without a drive, but never closes the opening tightly.

The PVC strip curtain – also called a strip door, plastic strip curtain or industrial curtain – is the simplest form of zone separation in industry, logistics and cold stores. Vertically hanging strips of flexible PVC overlap at the edges so that the opening appears closed. People, pallet trucks and forklifts push the strips apart as they pass through, after which the strips fall back under their own weight. There is no drive, no control unit and no sensor technology.

This simplicity explains why strip curtains are so widespread. A strip curtain is quick to fit, needs no power supply and adapts to almost any opening, because the strips are cut to length and hung in any number. As a first measure against draughts, insects, dust or noise at permanently open passages, it is often the obvious solution.

The limits lie in the principle: because the strips only overlap, a gap always remains, and with every passage the opening is briefly clear. A strip curtain dampens air exchange; it does not stop it. Added to this are contact with vehicles and people, deteriorating visibility, susceptibility to wind and the absence of any safety technology. This page explains, independently of any manufacturer, which industrial strip curtain suits which opening – and when a high-speed door is the better solution.

Key features

• Overlapping strips of flexible PVC, clear, tinted or coloured
• Strip widths typically 100 to 400 mm, thicknesses usually 2 to 4 mm
• Selectable overlap, typically 30 to 100%
• No drive, no power, no control unit
• Wall or ceiling mounting via a hanger rail
• Special strips for freezer areas, welding protection, insect control and ESD

How it works

A strip curtain works purely passively. The strips hang vertically from the rail to just above the floor and overlap at the sides. When a forklift drives through, the front of the vehicle or the load pushes the strips apart; behind it, they fall back under their own weight. The wider and heavier a strip, the more calmly it hangs – but the more resistance it offers to anyone passing through.

The separating effect comes from the overlap. With 50% overlap, each strip covers half the width of its neighbour; with 100%, two layers lie on top of each other across the entire surface. More overlap slows air exchange and draughts more strongly but increases weight and resistance to passage. A strip curtain is never completely tight: gaps remain between the strips and at the floor, and pressure differences or wind lift the strips.

During a passage, the curtain is open to the width of the vehicle and then needs a moment until all strips have settled. With frequent traffic, it is therefore partly open for a considerable proportion of the time. A high-speed door, by contrast, opens only on demand and then closes completely – the PVC high-speed door page shows how this works.

Design and components

The strips are made of plasticised PVC, which is flexible and usually clear. Standard PVC is suitable for buildings at normal temperatures and typically remains flexible down to around −15 to −20 °C, depending on the formulation. For cold stores and freezer areas, there are cold-resistant polar-grade strips that, depending on the material, remain flexible down to around −40 °C and do not become brittle. Ribbed strips have longitudinal ribs that take the abrasion, so the surface between them stays clear for longer.

Special strips are available for particular tasks. Welding strips in red, orange, bronze or green tints filter the radiation from the arc and protect people in the vicinity; the relevant standard here is EN ISO 25980. Yellow or orange tinted strips are intended to attract fewer flying insects. Antistatic strips dissipate electrostatic charge and are used in ESD areas. Coloured, opaque strips provide privacy but block the view of oncoming traffic.

The curtain is carried by a hanger rail made of galvanised steel, stainless steel or aluminium, into which the strips are hung with hooks, clamping plates or quick-release hangers; quick-release hangers allow individual strips to be replaced without tools. For openings that sometimes need to be completely clear, there are swing versions that pivot to the side like a door leaf, and sliding systems on a track.

Criterion	PVC strip curtain	High-speed door
Purchase cost	very low	higher
Tightness	low (a gap remains)	high
Climate separation	limited	very good
Safety	no active protection	light curtain, safety edge
Convenience / appearance	low	high

Technical data

Feature	Guide value
Strip width	typically 100, 200, 300 or 400 mm
Strip thickness	typically 2 to 4 mm, special thicknesses possible
Strip size by opening height	up to approx. 2.5 m: 200 × 2 mm; approx. 2.5 to 4 m: 300 × 3 mm; above: 400 × 4 mm
Overlap	approx. 30% passageways, approx. 50% standard, approx. 66 to 100% cold stores and external openings
Cold flexibility, standard PVC	down to approx. −15 to −20 °C, depending on formulation
Cold flexibility, polar-grade PVC	down to approx. −40 °C, depending on material
Weight per layer	approx. 2.5 kg/m² at 2 mm, approx. 5 kg/m² at 4 mm thickness
Drive, power, headroom	none; only the hanger rail above the opening
Service life of the strips	highly dependent on use, much shorter on forklift routes than at pedestrian doorways

Guide values – exact figures depend on size, curtain and design.

Advantages

• Low purchase cost and quick installation without an electrical connection
• Free passage without waiting time and without activation devices
• Reduces draughts, temperature transfer, dust, insects and noise
• Individual strips can be replaced quickly and easily
• No drive, so virtually no risk of breakdown
• Useful supplement behind cold room doors and high-speed doors

Limitations

• No tight climate separation; a gap remains between the strips
• Strips touch vehicles, loads and people with every passage
• Visibility decreases due to scratches, clouding and dirt
• In external openings, the strips blow open in the wind and tangle
• No active protection; oncoming traffic is hard to see when passing through

Typical applications

• Passageways between areas with a small temperature difference
• Additional screening behind cold room doors and at cold cells
• Inside of loading bay doors that stay open during the day
• Welding workstations as glare and radiation protection
• Doorways between warehouse, workshop and ancillary rooms
• Secondary passages where a door is not worthwhile

What to consider when choosing

Strip size depends on opening height and traffic. For a strip curtain at a doorway with pedestrian and pallet truck traffic, strips 200 mm wide and 2 mm thick are usually sufficient and easy to walk through. For industrial doorways with forklift traffic, 300 × 3 mm is common, and for high or wind-exposed openings 400 × 4 mm. Wider, heavier strips hang more calmly and seal better, but they are uncomfortable at pedestrian-only doorways.

The overlap follows the task: around 30% is enough as dust and visual screening, 50% is the usual standard, and 66 to 100% is recommended for strip curtains in cold stores and at external openings. In chilled areas, cold-resistant polar-grade strips are a must; expect condensate and frost on the strips there. More on the cold chain can be found on the cold storage page.

Before any purchase, ask the key question: should the opening only be dampened, or genuinely separated? A high-speed door is the better choice as soon as there is a significant temperature difference, the opening is passed through very frequently, HACCP or cleanliness requirements apply, wind hits the opening or pedestrians and forklifts share the route. For hygiene-sensitive areas under Regulation (EC) No 852/2004, see the food industry page.

Planning and installation

A strip curtain is usually mounted on the wall in front of the opening; the rail extends slightly beyond the opening at the sides so that no gap remains at the edges. Without a load-bearing wall surface, it is fixed in the reveal below the lintel or to the ceiling, which reduces the clear height by the height of the suspension. The weight is often underestimated: a 4 × 4 m curtain of 4 mm strips with 100% overlap weighs around 160 kg by calculation.

If bulky goods, high forklift masts or crane loads occasionally need to pass through, a swinging or sliding suspension is worthwhile. At the floor, the strips should end just above the driving surface: if they drag, the edges wear; if they hang too high, an air gap remains. Behind a cold room door, the curtain is positioned so that the door leaf and the strips do not obstruct each other.

A strip curtain can almost always be retrofitted, and fitting it is a straightforward job for your own maintenance team or installer. However, consider whether a high-speed door might later follow at the same opening: headroom and side room should then remain free so that the shaft, drive and guides have space. The dimensions required for this are shown on the sizes page.

Typical sizes

Freely sized to the opening – from a doorway to a large drive-through opening. Enter your exact size in the configurator, together with curtain, colour, drive and accessories. Common sizes are listed under High-speed door sizes.

Safety and standards

A strip curtain has no safety devices and, as a passive component, does not need closing force limitation. The risk lies elsewhere: oncoming traffic is hard to see behind cloudy or coloured strips, and pedestrians share the opening with forklifts. Clear strips, separate traffic routes and a separate pedestrian door are therefore the most important measures. A high-speed door, by contrast, is equipped with a light curtain and safety edge in accordance with EN 13241 and EN 12453.

If the opening lies on an escape route, clarify the use of a curtain in advance with your health and safety adviser and in the fire safety strategy for the building. A strip curtain is not a fire-rated closure and does not replace a fire door.

Maintenance and service life

A strip curtain is low-maintenance but not maintenance-free. Check the strips regularly for cracks, torn suspension holes, clouding and deformation, and clean them with a mild cleaning agent and a soft cloth – solvent-based products attack flexible PVC. Scratched or yellowed strips should be replaced promptly, otherwise visibility and separating effect suffer.

As there is no drive, the inspection requirements for power-operated doors do not apply; safe traffic at the opening nevertheless remains the operator’s responsibility. A high-speed door, by contrast, must be inspected by a competent person before first use and at regular intervals, according to the manufacturer’s instructions and the national workplace regulations in the country of installation – more on the delivery and installation page.

Cost and price factors

The cost of a strip curtain is determined mainly by area, strip thickness, overlap and material – 4 mm polar-grade strips with 100% overlap need several times as much material as 2 mm standard strips with 30%. Added to this are the rail, fitting and regular strip replacement. The real calculation, however, is made in operation, because the gap and the open phase with every passage cause ongoing heat or cold losses.

With a small temperature difference and little traffic, the curtain is usually the most economical solution. The higher the cycle rate and the temperature difference, the more likely a high-speed door is to pay off, because it keeps the opening sealed between passages. The factors that determine the price of a door are shown on the page high-speed door cost; you can request a quotation for the tight-closing alternative via the PVC high-speed door configurator.

Compared with other door types

Strip curtain, strip door and industrial curtain essentially mean the same thing. A distinction should be made from the swing door with fixed, swinging leaves, which is smoother and easier to clean and is mainly suited to pedestrian and trolley traffic. The air curtain screens an open doorway with a stream of air but consumes power permanently. All three dampen air exchange; none of them closes tightly.

The PVC high-speed door, by contrast, is a fully-fledged power-operated closure: it opens on demand at 1.5 to 3 m/s and then closes completely. If you want to combine the transparency of a curtain with tight separation, choose a clear curtain door; at sub-zero temperatures, the heated freezer door is the right design.

Criterion	PVC strip curtain	Swing door	High-speed door
Operation	passive, strips are driven through	passive, leaves are pushed open	automatic via radar, induction loop or push button
Contact during passage	yes, strips brush vehicle and load	yes, the vehicle pushes the door leaf open	no, the door opens ahead of the vehicle
View of oncoming traffic	good at first, decreases with scratches	through vision panels	through vision panels and traffic lights
Behaviour in wind	strips blow open	leaves can swing open	wind-resistant with wind bars
Suitable cycle rate	any, wear increases with traffic	low to medium	high, designed for continuous operation
Power and inspection	no power, no inspection as a power-operated door	no power, no inspection as a power-operated door	power supply, periodic inspection as a power-operated door
Space requirement	only the rail above the opening	swing area on both sides	headroom approx. 400 to 650 mm plus side room

Other door types