EN ISO 15527 Plastics - Compression Moulded Sheets Made of Polyethylene (PE-UHMW, PEHD) - Requirements and Test Methods

The standard "EN ISO 15527 Plastics - Compression moulded sheets made of polyethylene (PE-UHMW, PEHD) - Requirements and test methods", which is based on a European standard and published by the International Standards Organisation (ISO), describes the requirements and test methods for solid flat compression moulded polyethylene sheets (PE-UHMW and PE-HD) without fillers or reinforcing materials. This standard is only valid for thicknesses between 10 mm and 200 mm.

The sheets shall consist of PE-UHMW moulding materials as defined in “ISO 11542-1 Plastics - Ultra high molecular weight polyethylene (PE-UHMW) moulding and extrusion materials - Part 1: Designation system and basis of specifications” or High Density Polyethylene (PE-HD) material selected from polyethylene (PE) moulding materials as defined in “ISO 17855-1 Plastics - Polyethylene (PE) moulding and extrusion materials - Part 1: Designation system and basis of specifications”, without fillers or reinforcements. Materials and additives of unknown identity shall not be used. Legal conditions may require a specific choice of moulding material.

Sheets must have smooth surfaces. Small grooves and resulting irregularities in the thickness of the sheets are acceptable as long as the requirements specified in this standard are met. Sheets must be examined in accordance with this standard.

If agreed upon by the parties involved, sheets with a smooth machined surface can be supplied.

Sheets must be substantially free from bubbles, blowholes and other inhomogeneities which would render them unsuitable for the intended use. Specific requirements regarding this internal integrity must be agreed upon between the parties concerned.

In terms of dimensional tolerances, for any individual sheet metal, the thickness tolerance relative to the nominal thickness should be as specified in the table given in the standard. Testing should be carried out in accordance with this standard. The nominal length and nominal width of the sheets should be agreed upon between the relevant parties.

For any individual sheet randomly selected from any delivery, the rectangularity tolerance expressed as the difference in length of the diagonals must conform to the table given in the standard.

Requirements for physical properties such as density, abrasion, tensile stress at yield point, tensile strain at yield point, modulus of elasticity in tension, impact strength of double-notched samples, Charpy impact strength of notched samples, 190 degree/5 kg melt mass flow rate and 190 degree/21,6 kg melt mass flow rate are given in a separate table in the standard.

For sheets with a thickness between 10 mm and 20 mm and for sheets with a thickness between 20 mm and 200 mm, test samples should be taken as shown in the figures given in the standard.

The surfaces of the test specimens must be free from damage and defects to avoid notch effects. If any burrs occur on the test specimens during machining, they must be removed without damaging the surfaces of the specimens. If necessary, the cut edges must be finished with abrasive paper (grit size 220 or finer), the direction of wear being along the length of the test specimens.

All test specimens shall be conditioned at 291°C plus/minus 16°C for at least 23 hours in accordance with ISO 2 or as specified in the appropriate material standard. If there is no significant difference in the results obtained, shorter conditioning periods may be used by agreement between the parties concerned.

Unless otherwise agreed between the parties involved or otherwise specified in individual test standards, tests are carried out in the 291/23 standard atmosphere specified in the ISO 50 standard or the relevant material standard.

Boards should be visually inspected on delivery to ensure that they are free from mechanical damage or other obvious defects. If necessary, boards may be examined by ultrasonic or X-ray methods.

Where possible, the boards are examined for visual defects by transmitted light using a suitable light source. Otherwise, sufficiently bright reflected light is used. Any defects thus identified are compared with the agreed specification and classified accordingly.

Thickness shall be measured using appropriately calibrated equipment to a minimum accuracy of 0,10 mm. Length and width shall be measured to the nearest 1 mm using appropriate equipment. Measurements shall be made directly across the surface of the sheet and along the cut edge. Rectangularity, expressed as the difference between the lengths of the diagonals as shown in the figure given in the standard, shall be measured to the nearest 1 mm using a graduated ruler or tape measure.

Density is determined in accordance with the relevant section of the ISO 1183 standard.

Preparation of test samples and abrasion testing are carried out in accordance with the standard annex (Annex B).

Yield stress and yield strain are determined using a test speed of 527 mm/min plus/minus 2 mm/min using at least five type 1B test specimens in each direction in accordance with ISO 50-5.

Among the numerous tests, measurements, analyses and evaluation studies that our organization has carried out for businesses in various sectors, it also provides testing services defined in the standard “EN ISO 15527 Plastics - Compression molded sheets made of polyethylene (PE-UHMW, PEHD) - Requirements and test methods” with its trained and expert staff and advanced technological equipment.