POROPLAST – microporous polyethylene
The name POROPLAST stands for microporous polyethylene from the house of DURST filter technology. The polymeric material is divided into exactly-defined grain fractions, in order to achieve a specified pore size.
The field of application of the porous material is very large. A significant weight reduction is achieved by the hollow spaces in the material. For improvement of the filtration properties, additives can be enclosed in variable concentration.
Special properties, such as for example:
- Antistatic characteristic behavior
- Increase of the strength and stiffness
can thus be achieved.
In the raw state, POROPLAST has hydrophobic properties, it is statically chargeable and has a white color. Without additions, POROPLAST e.g. in case of plates, has little inherent stability. POROPLAST of low-molecular polyethylene is employed mainly with open-pore parts, while ultra-high-molecular polyethylene is employed for very fine-pore applications. It is to be noted that, with increasing molecular weight, the resistance also increases with respect to mechanical, chemical and thermal actions.
With the manufacture of porous parts, it must be noted that the sinter material is subject to more or less shrinkage through its thermal processing, according to its composition.
In general, all usual mechanical cutting processes, such as rotating, milling and drilling are feasible.
Plates and pipes which cannot be sintered from one piece are composed from part segments and welded.
Toxicology and combustion characteristics
The material POROPLAST ignites with a flickering, yellowish flame. The material does not have any self-extinguishing properties and also does not extinguish on dripping off.
In case of UHMW-PE types, the material is decomposed with temperatures of approx. 350°C, with the development of inflammable gases and liquids. Carbon dioxide and water result, as well as mainly soot.
All specifications are non-binding and correspond to the present state of the art. We reserve the right to changes.
GENERAL CONSTRUCTION REGULATIONS
The following regulations apply for the construction of special fittings of sinter plastic:
- Sharp corners should be avoided.
- Bores and undercuts perpendicular to the pressing direction are realizable only through reworking.
- Bores should have at least 2 mm diameter.
- The „length/diameter ratio“, dependent on the height of the workpiece, is not to be selected too extreme. Case by case, several parts can be correspondingly placed.
- Dependent on the material, thickening and edge spacing should be selected as far as possible greater than 2 mm.
- If it is desired to round off external edges, it is recommended to form these as bevels (30° – 45°) with run-out slopes. In case of two front-sided opposing bevels, a mold partition is required.
- Generally, parts with one or several partitions require an increased tool and manufacturing-technical expenditure outlay. The step height and the part thickness should not fall below 1.5 mm.
Generally, parts with one or several partitions require an increased tool and manufacturing-technical expenditure outlay. The step height and the part thickness should not fall below 1.5 mm.
You will be provided with tolerances on special fittings on request.