Questions about plastic sheets

NUDEC PET plastic sheets have a pH that is slightly lower than 7 (6,4), which means it is slightly acidic.

The minimum cold-bending radius is 150 times its thickness (the minimum radius would be 450 mm for a 3 mm sheet). Cold-bending is not recommended for plastic sheets with thicknesses exceeding 3 mm.

NUDEC PET plastic sheets can be correctly heat-transformed, although sheet thickness will be reduced as in all heat-transformation processes. If the heat-transforming is uniform, meaning that the entire sheet increases uniformly in height (bubble type), the thickness reduction effect will also be uniform and there will be no critical points anywhere in the sheet.

It is considered to be sufficient to protect the exterior activated 50 μm layers. However, layers of up to 80 μm are produced for heat-transformation (layer stretching). Therefore, providing thickness reduction is less than 1.5 times the original thickness, the sheet will be correctly protected (for example, the thickness of a 3 mm sheet of NUDEC PETG can be reduced to approximately 2 mm and will continue to provide protection against UV).

Our plastic sheets can be printed (with different techniques: offset, digital, screen printing, hot stamping), painted and lacquered quite easily using a wide range of products. We have carried out internal digital printing tests and the results have been satisfactory. It is recommended to check with the paint supplier in order to guarantee that the solvents in the paints and lacquers will not attack the sheets. Soft, damp cloths can be employed to remove any dirt and particles without scratching the surface.

Yes, NUDEC PMMA clear is suitable for coming into contact with foodstuffs.

In general, our NUDEC SANuv plastic sheets have a ten-year guarantee against ageing, although this will depend on the geographical location of the product.

After installation, NUDEC PS plastic boards should be cleaned with neutral detergent and water solution in order to ensure good maintenance. To accomplish this, clean them and then always dry them with a soft cloth with very little pressure. Do not use any form of cleaner or aggressive products, such as alcohol or household bleach solvents or cleaning pads.

This refers to light passing through the plastic sheet.

The plastic extrusion process consists in moulding products continually, as the plastic material is pushed by a worm screw through a cylinder ending in a nozzle, and this produces a strip (sheet) of indefinite length and constant thickness. On the contrary, casting consists in pouring the plastic material in a liquid state into a mould, where it sets and solidifies, producing a sheet with a greater molecular weight, but a non-uniform thickness (the thickness at the ends is not the same as the thickness in the centre of the sheet).

Our polystyrene sheets are very resistant to visible light, but not to UV light over a long period. Although the light from fluorescent tubes emits a small amount of UV radiation, the polystyrene has been used for a long time for this type of application. In order to prevent it from deteriorating as quickly as normal, it is important to consider the location of the plastic sheet and the cleaning products used, as they can deteriorate the NUDEC PS sheet more quickly.

In order to delay the yellowing of the material when exposed to the light from fluorescent tubes, the NUDEC PS Opal with UV protection could be used. This does not disregard the fact that the NUDEC PS can be used outdoors or that its colour can be guaranteed to be kept constant throughout the useful life of the sheet.

All 3 materials are suitable for use in lighting, although the NUDEC PC and the NUDEC PS should include UV protection to prevent them from deteriorating too quickly. Out of the 3 polymers, the most fire-proof one is the NUDEC PCuv (the NUDEC PS and the NUDEC PMMA have a poor fire rating).

The way to remove the electrostatic charge is to clean them, before use, with a static air gun. If the protective film is adhesive, there may be a greater electrostatic charge when the film is removed, but this should have reduced after changing to the non-adhesive film.

We have data that relates the frequency of sound to the acoustic reduction of PETG, while we can analyze PMMA based on the thickness of the sheet.

All our polymers can be recommended, as none of them is an electrical conductor. Also, other characteristics should be taken into consideration, which make affect this condition:

– The NUDEC PMMA is a good electrical insulator with high electrostatic charges.

– As for fire resistance, the ones with the best ratings are the NUDEC PET and the NUDEC PETG.

– If the material is to be impact resistant, the NUDEC PET, the NUDEC PETG and the NUDEC PC could be used, with the latter being the most resistant.

– If chemical resistance is required, the NUDEC PET and the NUDEC PETG must be recommended, as they are the most resistant in this aspect.

– If the sheet is to withstand high temperatures, it must be considered that the maximum working temperature of the NUDEC PET and the NUDEC PETG is 60^o C, whereas that of the NUDEC PC is 150^o C.

Therefore, it is important to study other factors, and consider the the features and specifications of the standards, before choosing the product that is considered most suitable.

Since the continual usage temperature of the NUDEC PET is 60^o C, it is not advisable to use it for the roof of a bus, as certain conditions may arise (breakdown in air-conditioning system, accident, etc.) where this temperature is exceeded. Also, the type of join between the sheeting and the roof may be a critical point, because if the sheeting is in direct contact with the profile section, this will behave like a source of heat, and therefore in this contact area the NUDEC PET can exceed 60^o C and either crystallise or bend. Other materials should be studied that withstand a higher temperature, such as the NUDEC PC, the NUDEC PMMA and the NUDEC SANuv.

The most characteristic differences between the two are as follows:

– Since the density of the NUDEC PMMA is 1,20 g·cm^-3 and that of the NUDEC PS is 1,05 g·cm^-3, with a sheet of the same dimensions, the NUDEC PMMA version would weigh more than the NUDEC PS sheet.

– The NUDEC PMMA sheet has greater tensile, bending and impact strength. It also has a greater hardness rating than the NUDEC PS.

– The chemical resistance of the NUDEC PMMA is less than that of the NUDEC PS.

– The NUDEC PMMA has greater transparency (TL = 92 %) than the NUDEC PS (TL = 89 %).

– The NUDEC PS dilates more than the NUDEC PMMA, as the linear thermal expansion coefficient (α) of the NUDEC PMMA is less.

Yes. As the NUDEC PMMA allows UV radiation to pass through the plastic sheet, the inner NUDEC PS sheet can be attacked (virtually as if the NUDEC PMMA sheet were not there).