Polypropylene (PP)
Properties:
• Low density compared to other materials (0.91 g/cm3)
• Minimum water absorption (< 0.01%)
• Excellent chemical resistance, also to solvents
• High corrosion resistance
• Relatively high surface hardness
• Very good electrical insulator
• Physiologically safe
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Sliding properties
PP-H is subject to strong sliding abrasion and is thus not suitable for use in sliding applications.
Chemical resistance
PP-H is resistant to acids, alkaline solutions, salts and salt solutions, alcohols, oils, fats, waxes and
many solvents. Aromatics and halogenated hydrocarbons cause swelling. PP-H is not resistant to
strong oxidising materials (e.g. nitric acid, chromic acid or halogens) and there is a danger of stress
corrosion cracking.
Behaviour in fire
PP-H is rated as normal flammable. When the source of ignition is removed PP-H continues to burn,
forming droplets. However, apart from carbon dioxide, carbon monoxide and water, only small
quantities of carbon black and molecular constituents of the plastic develop as conflagration gases.
The oxygen index (the oxygen concentration required for combustion) at 18% is low compared to
other plastics.
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Weathering effects
PP-H is not resistant to UV rays. UV rays, in combination with atmospheric oxygen, oxidise the
surface and discolouration occurs. If the material is exposed to the effects of UV rays for a longer
period, this will cause irreparable damage and decomposition of the surface.
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Machining
In addition to its good welding properties, PP-H can also be machined on machine tools. The
semi-finished products can be drilled, milled, sawed, planed and turned on a lathe. It is also possible
to cut a thread into the material or insert a threaded element. Generally no cooling or lubricating
emulsion is necessary.
During cutting, it is very important to ensure that the tools that are used are always adequately
sharp. Blunt tools cause the surface to heat, which can cause “smearing” and consequently
unacceptable surface finishes.
Polypropylene is a semi-crystalline thermoplastic with high rigidity and very good chemical resistance. Characteristic for polypropylene is a CH3 side-group in the monomer structural unit, which can be aligned in various spatial positions during polymerisation. The various spatial alignments are significant for the physical properties and differ according to the following:
• Isotactic (regular, one-sided alignment in the macromolecule),
• Syndiotactic (regular, double-sided alignment in the macromolecule),
• Atactic (irregular, random alignment in the macromolecule).
Standard Colours: White / Grey
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Fields of Application:
• Pump parts
• Component parts in chemical apparatus construction
• Fittings
• Valve bodies
• Product holders for electroplating processes
• Punching plates
​• Electroplating industry
• Chemical industry
• Machine engineering
• Stamping/punching plants