We recommend using two kinds of adhesives for sealing of the cells. One is the permeable adhesive tape and the other is completely impermeable. The permeable tape should be placed on the end which is higher, usually the one at the walls or the roof.
For building a winter garden you should use a least 16 mm thick X structure sheets. Thinner materials (e.g. 4/10-6 10 mm Makrolon multi UV) should only be applied if the bending radius of the planned roof is less as of the 16 mm thick material’s. Ideally it is recommended that we plan our winter gardens with 25 or 32 mm thick sheet, due to the constant increase in energy prices. While choosing the color we should take into consideration that white sheets are the most comfortable to live with, while clear sheets might let through too many light and sunshine, whereas bronze causing disturbing brownish tint.
It is usually recommended to use sheets of 10 mm thickness. Thinner sheets are not significantly cheaper, but their load ability is less, so they need a stronger structure. Thicker – 16 mm – for instance sheets should only be applied if you would like to have an airy understructure. In our opinion for terraces every day (e.g. dining room, living room etc.) the most suitable is to use white colored sheets, due to its better thermal insulation values but still letting in the daylight.
Despite the fact that our company is dealing with materials with double sided UV protection we are of the opinion that apart from a few applications there is no real need for it. In case of a terrace covering, a winter garden or a roof light it is completely redundant. The double sided UV protection only plays a role if we are planning to build a usually vertical surface where the sunlight has an effect on both sides (e.g. car washes at petrol stations) or if for economic reasons we are preparing a fan shaped cover consisting of triangle shaped parts cut out of a standard sheet.
▼ What are the most common construction mistakes, how can I avoid them, how can I assess the failure?
Before, during and after building in polycarbonate sheets we might face the following typical mistakes:
1, The sheets are built in “upside down” – the UV protected side facing down – not facing the sunshine. Polycarbonate sheets without UV protection or improperly fixed are yellowing rapidly and changing color – unlike the correctly built sheets – due to the effect of the UV radiation. It is very typical that in some cases the wrongly built sheets are yellow, while the correctly fixed ones keep their original color. If you find, that some sheets change their color to yellow faster than the others, furthermore their surface is damaged by even a light hail, you can be sure that they were built in upside down.
What is the solution?
The only thing we can do posterior is to change the incorrectly built sheets. This is the reason why we should pay attention during the construction, that the UV protected sides are built in facing the sunshine. On the protection film of Makrolon UV polycarbonate sheets distributed by our company there is a clear indication (inscription and illustration) which of the both sides is UV protected. Please do not forget, that the protection film should be removed at the very end of the construction process, when you can double check by standing underneath the roofing and seeing any inscripted film.
2, The plastic sheets are sensitive to the aggressive dissolvents in painting colors. During the drying process the disengaged gases can damage the already built-in material. If this is the case, the material looses all its mechanical resistivity and breaks or fractures without any reason, its surface turns matt or blow holes appear on it.
What is the solution?
If you are using chemicals persistently in the close environment of plastic materials, you should ask for information before starting the construction regarding the resistance of the materials. Our suppliers provide us with wide and exact data about the chemical resistance of their products, which makes us possible to give information which chemicals might harm the materials. If you are working with a chemical which has not yet been tested, the producing company will test their effect in their own laboratory.
The simplest case is, when we only have to count with the paint used for the frame. We should wait a few days after the painting, to let it dry and then we can start working with the polycarbonates. Later, when we are repainting the frames it is recommended to at least partly remove the polycarbonate sheets. It can be easily assembled thanks to the universal profile system. Please remember to mark the UV protected side of the disassembled pieces, in order to avoid any mistakes later.
3, Defective sealing of the cells, or no sealing at all. This problem can only appear in case of multi skin sheets and will result in steam formation and contamination in lower cell parts.
What is the solution?
Always use a permeable closure tape to seal the cells. These adhesive tapes are protection the cell from water, insects and dirt, but they are vulnerable and unaesthetic, so we recommend using polycarbonate U profiles to protect them. If we are looking for a professional solution it is absolutely necessary to use an aluminum U profile.
4, The plastic sheets crackle in the morning and in the evening. Polycarbonates and acrylics are materials with high heat expansion grades, for this we have to avoid tights fixing points and we always have to make sure that the material has enough room to expand. In general we can say, that 1 mm of polycarbonate or acrylic expands about 4-5 mm (dilates), so the only professional way to build them is fixing them with cramp sections and rubber gasket profiles which let them dilate. If your roof is mounted without a significant gap between the sheets or the material is fixed with screws, than it is firm that crackling is caused because the material has no room to expand.
What is the solution?
Although it is not the cheapest solution, always use the necessary cramp sections and rubber gaskets and please remember that the screw holes should have a bigger diameter then the screw itself, as they have a heat expansion as well.
The polycarbonate (both solid and multiwall structures) and Plexiglas sheets should be stored horizontally and in a closed space as far as possible. If it is for some reason inextricable (e.g.: sheet size), than try to find an open space with the least sunshine and shady as possible for storing the material. In case of outdoor storage please cover the string with a weather resistant white foil, and ensure that the material is properly fastened, because in case of stormy or windy weather, due to the light weight and relatively great surface the sheets can easily be damaged which can result in property damage.
Does PLEXIGLAS® form a lot of smoke when it burns?
No, as compared with many other plastics, and especially with several types of wood and other natural materials, PLEXIGLAS® develops almost no smoke.
Does PLEXIGLAS® emit toxic combustion gases?
No, the smoke gases emitted by PLEXIGLAS® were examined in detail by a specialized institute. The combustion gases generated by PLEXIGLAS® are toxicologically inoffensive according to DIN 53436 and do not impede escape from fire.
Does PLEXIGLAS® emit corrosive combustion gases?
No, the combustion gases generated by PLEXIGLAS® do no attack the surfaces of other materials.
Which combustion gases are formed when PLEXIGLAS® burns?
PLEXIGLAS® burns with a bright flame, virtually without smoke. Under normal circumstances, combustion only gives rise to carbon dioxide and water.
Is burning PLEXIGLAS® particularly difficult to extinguish?
PLEXIGLAS® can be extinguished with water or any other extinguishing agent. Small fires can usually be blown out!
Does PLEXIGLAS® give off sparks while it burns?
No, burning PLEXIGLAS® gives rise to no burning sparks whatsoever.
Does PLEXIGLAS® form burning melt or burning droplets?
Like all thermoplastics, PLEXIGLAS® melts in the event of fire.
Do all grades of PLEXIGLAS® behave in the same way?
Not in every detail. Compared with extruded PLEXGLAS®, cast PLEXIGLAS® burns more slowly, for example.
However, all grades usually form little smoke in the event of fire, and the smoke is toxicologically inoffensive.
Do colored grades of PLEXIGLAS® behave just like crystal-clear ones?
In principle, yes. Depending on the colorant and filler content, colored grades generate a little more smoke, but according to our findings this is always toxicologically inoffensive.
What is the fire rating of PLEXIGLAS® according to DIN 4102?
PLEXIGLAS® is rated in Class B2, normally flammable, according to DIN 4102, Part 1, without burning droplets, and in Class E according to DIN EN 13501.
Optical properties Since PLEXIGLAS® GS is manufactured by cell casting between two sheets of mirror-like glass, it has excellent surface quality. PLEXIGLAS® XT is manufactured in a special extrusion process and therefore cannot always match the high optical quality of PLEXIGLAS® GS.
Machining PLEXIGLAS® GS offers greater scope for fabrication, which means the machining conditions do not have to be observed with such accuracy. Less scope is available with PLEXIGLAS® XT, and care must be taken to ensure the correct tools are used in order to obtain clean cuts and drill holes, if necessary using cooling lubricants.
Thermoforming PLEXIGLAS® XT allows more economical solutions during thermoforming because the forming cycles are shorter and contours can be more accurately reproduced.
Permanent service temperature The permanent service temperature of PLEXIGLAS® GS is 80°C, about 10°C higher than PLEXIGLAS® XT.
Chemical resistance Owing to its higher molecular weight, PLEXIGLAS® GS shows better chemical resistance.
What are the mechanical properties of PLEXIGLAS® GS?
Mechanical properties / Standard / Value
Density / ISO 1183 / 1.19 g/cm3
Tensile strength / ISO 527-2/1B/5 / 80 MPa
Elongation at break / ISO 527-2/1B/5 / 5.5%
Modulus of elasticity / ISO 527-2/1B/1 / 3300 MPa
Flexural strength / ISO 178 / 115 MPa
Compressive yield stress / ISO 604 / 110 MPa
Shear modulus / ISO 537 / 1700 MPa
Impact strength / ISO 179/1fu / 15 kJ/m²
Notched impact strength / ISO 180/1 A / 1.6 kJ/m²
Admissible material stress / - / 5 - 10 MPa
Poisson’s ratio / ISO 527-1 / 0.37
Ball indentation hardness / ISO 2039-1 / 175 MPa
Scratch resistance / ISO 9352 / 20 - 30% haze
Minimum cold-bending radius / - / 330 x sheet thickness
How does PLEXIGLAS® behave towards water?
PLEXIGLAS® absorbs about 1.2 percent (%) water in humid ambient air and about 2% when stored in water. That means a one-meter-long (m) sheet of PLEXIGLAS® expands by about 1 to 2 mm, depending on how it is stored. The increase in volume due to water absorption is taken into account in the recommended expansion allowance of about 5 mm/m sheet length for PLEXIGLAS®.
Down to which sub-zero temperatures can PLEXIGLAS® be used?
Even at extreme temperatures of - 40 degrees Celsius (°C), PLEXIGLAS® shows no self-destruction. The tensile strength increases from 80 megapascals (MPa) at 23°C to 110 MPa at - 40°C, which suggests an increase in brittleness.
Is PLEXIGLAS® permeable to gas?
PLEXIGLAS® is permeable to gas. The permeation coefficient (g cm / cm2 h Pa ) for the following media is:
Water vapor 2.3 x 10-10
Nitrogen 4.5 x 10-15
Oxygen 2.0 x 10-14
Carbon dioxide 1.1 x 10-13
Air 8.3 x 10-15
How does PLEXIGLAS® behave towards chemicals?
PLEXIGLAS® shows good resistance to inorganic substances, acids and alkalis at low concentrations, salts and salt solutions.
PLEXIGLAS® is not resistant to organic compounds, chlorinated hydrocarbons, ketones and esters.
Plastics normally become statically charged and attract dust as a result. Out of doors this is usually prevented by air and moisture, whereas in closed rooms this phenomenon is promoted by mechanical friction at the plastics surfaces, air currents and dry air.
Subsequent polishing of stressed surfaces (especially of PLEXIGLAS®) can be performed easily and effectively using the right cleaning and polishing agents.
Dirt can hardly cling to the smooth surfaces of PLEXIGLAS®. Dust is removed with water and some dishwashing liquid, using a soft, non-linting cloth or sponge. Never wipe the sheets dry and use only non-scouring agents for more intensive cleaning, e.g. ANTISTATIC PLASTICS CLEANER. 'Post-treatment' of the smooth and glossy PLEXIGLAS® plastic surfaces is very simply done – even by hand – using polishing liquid or paste.
Should there ever be scratches on a sheet of PLEXIGLAS®, these can be eliminated from the smooth surface without any problem. Treat the scratched area first with wet sandpaper of, say, grit 240, and then go over it with 400- to 600-grit paper. Finally polish the sheet with a soft cloth and ACRYLIC POLISHING PASTE or commercially available car polish, or else use a buffing wheel and polishing wax.
Large glazed areas or facades are often cleaned mechanically, using rotating brushes, squeegees and the like. No such methods are suitable for PLEXIGLAS®: Even if brushes are used with copious amounts of water, there is no way to exclude scratching of the sheet surfaces. On the other hand, outward-facing PLEXIGLAS® surfaces can conveniently be cleaned with high-pressure/hot-water cleaning units. The recommended pressure is 50 to 100 bar and the water temperature should be between 50 and 80°C.
Removal of Graffiti
Spray paints on PLEXIGLAS® GS and XT can be removed with water-soluble brush cleaner. To this end, cover the paint with a soaked cloth for up to 20 minutes, depending on type and layer thickness and then wash it off with plenty of water. Pre-treatment with paint-repellent substances is not recommended for acrylics.
Can PLEXIGLAS® be painted with glass paints?
PLEXIGLAS® can be painted with conventional glass paint pens with excellent results. Solvent-based colour pens are to be avoided.
Can PLEXIGLAS® be polished with solvents or acids?
Polishing with chemical substances like solvents and acids is not recommended, since it dissolves PLEXIGLAS® to a considerable depth or corrodes it. This usually provides a polish with optical distortions and involves the risk of stress cracking, on top of the other risks presented by using such substances.
How is the range of application of ACRIFIX® 2R 0190 and 1R 0192 defined?
ACRIFIX® 2R 0190 and 1R 0192 are preferably used for bonding PLEXIGLAS® GS to PLEXIGLAS® GS and PLEXIGLAS® XT to PLEXIGLAS® XT, but also for other materials such as ABS, CAB, PS, PVC, SMS, UP and wood.
The cured joints are virtually colourless.
How can bubbles be avoided when bonding PLEXIGLAS®?
- Bubbles due to stirred-in air Degas adhesive compound.
- Bubbles introduced during bonding Apply adhesive without bubble formation; if necessary, enhance wetting-out by pre-treating the surface with ACRIFIX® TC 0030, scrape cut surface, remove bubbles using a paintbrush and ACRIFIX® TC 0030.
- Bubbles caused by excessive heat development during polymerization Reduce layer thickness, slightly reduce hardener quantity, add ACRIFIX® MO 0070, apply adhesive in several steps.
- Bubbles due to uneven adhesive joint Treat adherents mechanically to make them plane, space them more accurately.
- Bubbles due to adhesive shrinkage or elastic recovery due to indrawn air Apply a thicker or more even layer of adhesive if necessary, apply growing contact pressure during the pot life until curing is completed.
- Bubbles due to soiled adherent surfaces Thoroughly clean the surfaces to be bonded.
Can PLEXIGLAS RESIST® be cold line-bent?
PLEXIGLAS® cannot be cold line-bent.
PLEXIGLAS RESIST® 75 or 100 can be “bent” cold at a radius exceeding twice the sheet thickness, but this is not advisable because it leads to deterioration of the mechanical and optical properties.
What is to be borne in mind when line-bending PLEXIGLAS®?
For this, PLEXIGLAS® sheets are heated linearly, then bent and held in place in the desired shape until the parts have cooled down. Bending is performed with the aid of a jig or over an edge. When bending over an edge, the material must be clamped on one side only in order to avoid stretching and thus a pronounced thickness reduction in the bend area. Moreover, the edge of the clamping device must be rounded in such a way that it does not touch the heated sheet area so as to avoid unwanted mark-off.
The bending radius should be at least twice the sheet thickness. Smaller radii cause excessive stress or even creasing on the inside.
The required bending angle determines the width of the heated area. Normally it should be at least three to five times the sheet thickness. If the heated area is too narrow, the material may be over expanded or stretched.
How can the minimum cold-curving radius of PLEXIGLAS® be calculated?
The minimum cold-curving radius of PLEXIGLAS® depends on the product grade. The following values apply:
PLEXIGLAS® GS and XT: Sheet thickness x 330
PLEXIGLAS RESIST® 45: Sheet thickness x 300
PLEXIGLAS RESIST® 65: Sheet thickness x 250
PLEXIGLAS RESIST® 75: Sheet thickness x 210
PLEXIGLAS RESIST® 100: Sheet thickness x 170
PLEXIGLAS RESIST® SDP 16: Sheet thickness x 150
Which PLEXIGLAS® grade offers the best UV protection for picture glazing?
PLEXIGLAS Gallery® is the best UV blocker among picture glazing materials. Unlike conventional picture glass, e.g. float glass, PLEXIGLAS Gallery® filters out all damaging UV rays. The UV protection offered by PLEXIGLAS Gallery® UV 100 is at least 99.7 percent (%) in material of 3mm thickness.
Which grade of PLEXIGLAS® is best suited for noise control?
PLEXIGLAS SOUNDSTOP® and PLEXIGLAS SOUNDSTOP® GS CC with integrated sliver retention meet these requirements. Transparent noise barriers made of PLEXIGLAS SOUNDSTOP® are
- highly transparent and clear - extremely resistant to weathering and aging - easy to form and machine - lightweight - and come with a 10-year guarantee - as well as being recyclable, - colourless and available in seven transparent colours
Is PLEXIGLAS® suitable for rink shields around ice hockey rinks?
PLEXIGLAS® GS and XT are suitable as the protective shield material above the dasher boards from a material thickness of 12 mm. A scratch-resistant coating further enhance this functionality.
Is there a grade of PLEXIGLAS® that lets in light, but keeps out the heat?
PLEXIGLAS HEATSTOP® solid and multi-skin sheets meet this requirement in the ideal manner. PLEXIGLAS HEATSTOP® is an infrared-reflecting grade of PLEXIGLAS®. Depending on the version, this sheet is equipped with a coextruded layer or colored in the mass. This functional layer contains special pearl-gloss pigments that are free from heavy metals.
Like PLEXIGLAS HEATSTOP®, PLEXIGLAS® XT can be cold-curved and thermoformed.
What are the typical applications for PLEXIGLAS® GS?
PLEXIGLAS® GS 0Z09: With higher chemical resistance, e.g. for boiler covers
PLEXIGLAS® GS 0Z18: UV-transmitting, e.g. for light guides
PLEXIGLAS® 245 and PLEXIGLAS® 249: With high optical quality for aircraft glazing
PLEXIGLAS® Blöcke 0F00: e.g. for aquariums
PLEXIGLAS® GS: Colours for illuminated signs and items for points of purchase (P.O.P)
PLEXIGLAS truLED®: Special colours for illuminated signs with LEDs
PLEXIGLAS RESIST® HP: For windshields and protective glazing
PLEXIGLAS SATINICE® SC and DC: For furniture, displays, signage
PLEXIGLAS SOUNDSTOP®: For transparent noise barriers
PLEXIGLAS SUNACTIVE®: For tanning beds
PLEXIGLAS® GS 235: With better formability for sanitary ware
PLEXIGLAS® GS SW: For sanitary applications
PLEXIGLAS® MULTICOLOR: For applications with cut-outs and edge effects
PLEXIGLAS® Struktur Trend Line: e.g. for balcony guards
What must be borne in mind for cutting PLEXIGLAS® correctly with jigsaws and bandsaws, and when scoring and breaking?
The jigsaw blade must be fine-toothed and slightly side-set. The jigsaw blade packaging must state that the blades are suitable for machining hard plastics. The following points should be taken into account when working with jigsaws:
- Adjust stroke action to zero for sheets up to 4mm thick, and to 1 to 2 for thicker sheets; select an average feed rate - Set saw to high cutting speed - Always turn on saw before starting to cut - Place shoe firmly on the masking film - Cool the material with water or compressed air from 3mm thickness onwards - When cutting recesses, holes should be predrilled at the corners to avoid notch effects and thus possible breakage of the workpiece.
For contour cuts and trimming moulded parts made of PLEXIGLAS®, fabricators often use the bandsaws commonly used in the wood and metal industry. Their blades are always slight side-set, thus providing somewhat rougher edges than those obtained with circular saws, independent of the material. Post-treatment of edges is normally required. The width of the band blade, between 3 and 13mm, depends on the desired contour cut and the type of saw used. The number of teeth should be between 3 and 8 per cm of band length. The band speed (= cutting speed) can vary from 1,000 and 3,000m per min. As a rule of thumb, the lower the cutting speed, the greater the number of teeth. While sawing, care must be taken that the sheets are secured against flutter and vibration.
Sheets of PLEXIGLAS® up to 3mm thick can be scored with a scribing knife along a ruler or a curve template with not too narrow radii, and then neatly broken. This generates little internal stress in the surfaces of fracture, which do not need to be annealed. The broken edges should be deburred by means of a scraper.
PLEXIGLAS RESIST® is not suitable for scoring and breaking.
What must be borne in mind when flame polishing PLEXIGLAS®?
Flame polishing is one option for polishing PLEXIGLAS® edges. The best results are obtained if the cut edge is deburred with a scraper beforehand and then polished to a matte finish with a fine abrasive, grit size 400 to 600. The high surface stresses generated by flame polishing make subsequent annealing essential to avoid stress cracking during subsequent use, especially if the material enters into contact with adhesives and paint thinners or cleaning agents.
Flame polishing of intensely colored sheets may be difficult and can lead to a matte finish or discoloration. Unless work is skillfully performed, it involves the risk of “flashover,” i.e. the flames may lick over the cut edge onto the sheet surface, generating thermal stress and optical distortion.
What must be borne in mind when drilling PLEXIGLAS®?
Twist drills cannot be used for PLEXIGLAS® unless the point angle is reduced from normally 120° to 60 to 90°. The rake angle must be ground down to between 0 and 4°. If the drill is to work correctly, the principle is to scrape rather than cut, so that chipping at the exit side of the hole is avoided. The clearance angle should be at least 3°.
Thin sheets should be clamped onto a flat, solid support to prevent chipping at their bottom surface.
From a material thickness of 5mm onwards, use a cooling lubricant or a drilling (oil in water) emulsion compatible with acrylic. The drill should be lifted several times to avoid overheating.
Step drills and conical drills can be recommended as special drills. Step drills leave no chatter marks and guarantee clean cylindrical bores. With each subsequent drilling step, the hole is simultaneously chamfered, thereby increasing the economy of the work process. Conical drills with a triple-edge design produce slightly conical drill holes but there is no chipping on the exit side of the hole.
Why does PLEXIGLAS® become electrically charged?
Owing to its very good insulation properties, PLEXIGLAS® has high surface and volume resistivity. That is why PLEXIGLAS® may become statically charged. Negative side effects are dust attraction and (rarely), sparkover.
Static charges may be due to:
- mechanical friction in contact with solid objects, dry clothes or polishing agents - friction produced by dry air currents - removal of the masking film from the sheet
How can static charging of PLEXIGLAS® be avoided?
Static charging is most easily prevented by wiping the material with water or an antistatic cleaning agent.
Another very economical method is blowing the sheet or parts of it down with ionized air. The effect, however, is of fairly short duration.
Static charging can also be durably prevented by applying thin metallic surface layers.
What must be borne in mind when machining PLEXIGLAS® RADIANT?
PLEXIGLAS® RADIANT can be machined using the same parameters and appliances as standard acrylic sheets.
What is annealing and what has to be borne in mind?
Annealing involves the storage of plastic components with inherent stresses in a drying oven with subsequent slow cooling to room temperature.
The following conditions apply for annealing PLEXIGLAS® to remove inherent stresses:
- temperatures: PLEXIGLAS® GS approx. 80°C PLEXIGLAS® XT approx. 70°C - annealing time for PLEXIGLAS® GS and XT: The material thickness in mm divided by 3 corresponds to the annealing time in hours. This should not be less than two hours in any case. Cooling: For PLEXIGLAS®, the cooling time in the drying oven in hours corresponds to the material thickness in mm divided by 4. The cooling speed should never exceed 15°C per hour. The temperature upon removal from the oven should be less than 60°C.
What must be borne in mind when sawing PLEXIGLAS® with circular saws?
- The saw blade should protrude only slightly beyond the sheet. - Never work without a stop. • Switch on the saw before carefully starting to cut. - Make sure the blade is guided accurately. - Do not tilt the material. - Secure the sheet against fluttering. - Work at an average feed rate. - From 3mm sheet thickness onwards, cool the material with water, cooling lubricant or compressed air.
Which circular saw blades provide the best cutting results with PLEXIGLAS®?
Only unset circular saw blades are suitable for cutting PLEXIGLAS®. This is the only way to ensure smooth, clean cut edges. We recommend using only carbide-tipped saw blades with the largest possible number of teeth. Blunt and incorrectly ground blades cause chipping on the underside of the sheet. The teeth of the saw blades should be alternately beveled, i.e. have alternating angles of 15° and 45°. We also recommend
- a clearance angle of 10° to 15° - a rake angle of 0° to 5° - cutting speeds of up to 4,500m/min - a tooth pitch of approx. 13mm
The extruded and cast materials differ in the manufacturing process. The extruded sheets are produced with an extruder (roller) machine, which results in more even thicknesses and more rigid material. The cast acrylic is produced from liquid methyl - methacrylate. During the process, the liquid is poured between two glass sheets and reaches its final shape after polymerization. Cast acrylics have higher tolerances on thickness and are more sensitive to environmental effects (heat, humidity), but due to the material structure it is suitable to all kinds of work processes. In general we can say, that extruded material is recommended for flat building (all kinds of advertising – light boxes, letters etc.), while cast acrylic can be used for more complicated processes, like heat bending etc.
Acrylic – also known as polymethyl metacrylate – is a highly transparent (light transmission 92%), weather resistant plastic material which offers a wide range of applications for the user. Plexiglas® was invented by Otto Röhm, and has been produced since 1933.