Sep 22, 2019
The polymerisation of styrene produces the transparent thermoplastic polystyrene (PS).
Polystyrene is crystal clear, hard and impact sensitive in the solid, amorphous form.
As foam (e.g. styrofoam) the material is white and opaque. In this state its strength is lower, but the elasticity is higher.
The foam is often used as packaging material, filler or as insulating material for buildings.
Polystyrene shrinks little during production, so it is preferred for fine contours and straight surfaces in accurate fitting components. For food packaging, shower walls or signs PS is commonly used.
Plastic: Paper trays made out of polystyrene (PS).
Related topics:
This glossary of plastic industry is provided by PLEXPERT Canada Inc.
Oct 21, 2019
The polymerization of the monomer vinyl chloride produces the amorphous thermoplastic polyvinyl chloride (PVC).
PVC is hard and brittle. Therefore it is also called rigid PVC.
Its abbreviation is PVC-U, where U stands for the word “unplasticized”.
Rigid PVC is for example used for pipes, window profiles and records.
Plasticizers provide PVC with elasticity. Therefore it is called soft PVC.
Its abbreviation is PVC-P, where P stands for the word “plasticized”.
A common use of soft PVC is cable sheathing and flooring.
PVC is very durable. Environmental influences, such as sun, sea water and air can hardly harm the material.
Image 1:Plastic: Cable sheathing made of PVC.
Image 2:Floor covering made from PVC
Related topics:
This information and services are provided by:
This glossary of plastic industry is provided by PLEXPERT Canada Inc.
Dec 19, 2018
The inherent cause for the shrinkage, in injection molded parts, is the thermodynamic behavior of the material.
This behavior is shown in the pvT-diagram, in which the specific volume (v) is presented as a function of pressure (p) and temperature (T).
It characterizes the compressibility and thermal expansion of polymers.
There is an essential different pvT behavior between amorphous and semi-crystalline materials.
In the picture there are three different pressure curve shown p0, p1, p2 for each material type.
As a melt, both show a linear dependency of the specific volume on the temperature.
For the solid phase, amorphous materials (green) also have a linear dependency.
While semi-crystalline materials (red), on the other side, show an exponential decrease of the specific volume at decreasing temperatures.
These different behaviors, in the pvT-Diagram, explain the reason for the higher shrinkage of semi-crystalline thermoplastics compared to amorphes materials.
Oct 7, 2019
Molding compounds that contain fully or partly components that have already been been subjected to a processing process for the final product such as semi-finished products, finished parts or sprues have the generic term recyclates.
The name recyclate is a combination of the words recycling and the suffix of many plastics (for example acrylate).
A recyclate may refer to: regrind, regranulate or compound.
Recyclates are no prime material but can substitute prime material in several applications and save CO2 emissions.
Plastic: Power drill housing produced out of
recyclate material.
Related topics:
This information and services are provided by:
This glossary of plastic industry is provided by PLEXPERT Canada Inc.
Oct 7, 2019
With the recycling of industrial production waste, i.e. sorted sprues or rejects are collected, grinded and reprocessed. The reprocessing is a melting process for the production of granules with constant particle size. Without using additives a regranulate is produced, by using additives, i.e. to match specified mechanical properties, a compound is produced. This new regranulate or compound can be used the same way as prime material and is retuned to the circulation. The use of recyclates versus prime material also reduces CO2 emissions, i.e. Polyamide more than 7 kg CO2 emissions per used kilogramm recycled material instead of prime and thus makes an important contribution to environmental protection.
The mechanical recycling of household waste works in principle the same way with additional step of pre sorting one ore more cleaning steps. So collecting, sorting, shredding, wet grinding or washing and reprocessing by melt filtration. Du to impurities of the input raw material, the yield of recyclable granules is much lower.
Plastic: Collected sprues for the mechanical
Recycling.
Related topics:
This information and services are provided by:
This glossary of plastic industry is provided by PLEXPERT Canada Inc.
