DACELLFLEX^®

Insulation sheet

The same closed-cell formulation in sheet form — plain, self-adhesive, or faced with reinforced aluminium foil for ducts, vessels and large-bore equipment.

Thickness 3/8″–1″ standard, up to 50 mm to order
Rolls 1.0 or 1.2 m wide × 10 m, 15 m or custom
Adhesive backing optional
Duct and vessel cladding

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Products — Insulation sheet

Property	Class B	Class 0 same values
Cell structure	Closed cell	—
Material	NBR / EPDM	—
Density	65 kg/m³ standard · 55–90 kg/m³ to order	—
Thermal conductivity λ at −20 / 0 / +40 °C	0.030 / 0.032 / 0.037 W/(m·K)	0.030 / 0.032 / 0.037 W/(m·K)
Water vapour permeability	1.96 × 10⁻¹¹ g/(m·s·Pa)	—
Moisture resistance factor μ	≥ 10,000	—
Oxygen index	≥ 32 %	—
Flammability / smoke density	Self-extinguishing / smoke density 25–50	—
Water absorption	≤ 5 %	—
Service temperature	−57 °C to +125 °C	—
Flexibility / ozone resistance	Excellent / no crack	—
Standard thickness	3/8″ · 1/2″ · 3/4″ · 1″ (10 / 13 / 19 / 25 mm)
Other thickness	up to 50 mm to order
Roll	1.0 or 1.2 m wide × 10 m long
Other lengths	15 m or any length to order

Values are nominal production figures, tested per batch. Density, wall thickness and colour are produced to the customer's specification.

— means the value is identical for Class B and Class 0.

Batch test — black and coloured sheet

Test	Value	Method
Apparent density	64.4 kg/m³	GB/T 6343
Tear strength	1,400 N/m	JIS K6767 § 8.7
Compression set	15 %	GB/T 6669, method B

Tensile strength (GB/T 6344) and dimensional stability (GB/T 8811) are tested on the same sheet by the GB method; those figures are in the batch report and sent on request. Values refer to the last tested batch — every batch is sampled before packing.

Inner diameter 6–89 mm (1/4″–3-1/2″) · wall thickness 6–50 mm (1/4″–2″). Intermediate sizes produced on request.

Where the sheet is used

Sheet exists for the places a tube cannot reach: flat duct faces, vessel walls, large-bore equipment and anything with a shape of its own. Same closed-cell formulation, same thermal and moisture data as the tube.

Rectangular ductwork and AHU casings

Cut to size and glued or taped over the duct face. The plain sheet is used where a finish will be applied over it; the foil-faced version is used where the sheet is the visible surface and has to take a wipe-down.

Vessels, tanks and large-bore pipe

Above roughly 89 mm outside diameter there is no standard tube size that slips over the pipe, so the sheet is wrapped and seamed instead. The seam becomes the critical detail — it is the only place vapour can get in.

Cold rooms and refrigeration plant

Closed cells with a moisture resistance factor of μ ≥ 10,000 and water absorption of 5 % or less, which is why the sheet is used on cold surfaces where an open-cell product would waterlog.

Duct and vessel cladding with aluminium foil

The reinforced foil facing gives a wipeable surface and some protection against mechanical damage and ultraviolet. It is the usual choice for outdoor or plant-room equipment where nobody is going to paint the insulation afterwards.

Self-adhesive sheet for overhead work

The adhesive backing exists for one reason: holding the sheet in place on a ceiling or a duct underside while it is being seamed. It is not a structural adhesive and should not be sold as one.

How to specify thickness, width and length

Same logic as the tube — the thickness is an output of the duty, not a preference. Give us these and we come back with a thickness and a roll size:

Surface temperature and the coldest duty — The sheet has to keep its surface above the dew point at the coldest operating condition, exactly as the tube does.
Ambient temperature and relative humidity — Sets the dew point. This is the pair that turns 'one inch everywhere' into a wrong answer.
Flat area to be covered — Decides the roll format. Standard is 1.0 m or 1.2 m wide × 10 m long; 15 m and custom lengths are produced to order.
Finish required — Plain for a covered surface, self-adhesive for overhead, reinforced aluminium foil where the sheet is the finished surface.

Standard thicknesses are 3/8″, 1/2″, 3/4″ and 1″ (10 / 13 / 19 / 25 mm) with up to 50 mm produced to order. If a project needs a thickness outside that list, say so at quotation stage — it is a production parameter, not an exception to be negotiated after the order.

How the wall thickness is calculated →

Installation points that decide whether it works

Butt the edges tightly and tape or glue every seam. On a flat surface the seam is the weak point, not the middle of the sheet.
On vessels and large pipe, stagger the seams between layers if more than one layer is used, so a single line of leakage never runs through the full thickness.
Foil-faced sheet: fold and tape the facing, do not leave a bare cut edge exposed to moisture and air.
Self-adhesive sheet still needs its seams sealed. The adhesive holds the sheet up; it does not close the joint.
Do not stretch the sheet round a corner. Cut and fit, or the material thins exactly where the radius is.
Outdoors, protect the surface — foil facing or a coating — the same as the tube.

Questions buyers ask before ordering

Should I use tube or sheet for a duct?

Tube follows pipes; sheet covers flat and irregular surfaces. For ductwork, vessel walls and large-bore equipment the sheet is the correct product because it can be cut to the shape and seamed, where a tube would have to be slit and would leave a long compressed seam.

What does the aluminium foil facing do?

It gives a wipeable, mechanically tougher surface, reflects radiant heat, and protects the foam from ultraviolet and minor damage. It is the usual finish for outdoor equipment and plant rooms where the insulation stays visible.

What thicknesses and roll sizes are standard?

3/8″, 1/2″, 3/4″ and 1″ (10 / 13 / 19 / 25 mm), with up to 50 mm produced to order. Rolls are 1.0 m or 1.2 m wide × 10 m long as standard; 15 m and custom lengths are produced to order.

Is the self-adhesive version suitable for cold rooms?

The adhesive is there to hold the sheet in place during installation — it is not a vapour seal. On cold rooms the seams and edges still have to be sealed, and the adhesive has to be applied to a clean, dry, above-dew-point surface or it will not bond.