When it comes to selecting a sample container for collecting and storing specimens, you’ll need to choose between polystyrene and polypropylene. These common polymers are used to make all manner of plastic lab supplies such as test tubes, petri dishes, beakers and flasks and specimen containers.
While both materials are classed as thermoplastic polymers, they have different qualities which make them most suitable for different applications. Here’s what you need to know about them:
Polypropylene
This polymer is widely used in the manufacture of plastic laboratory supplies. It has several properties which make it ideal for use in the laboratory:
- It’s strong and durable
Polypropylene is a rugged polymer that doesn’t break easily. As it’s so durable, specimen containers made from polypropylene can be used multiple times. This makes polypropylene specimen containers more cost-effective.
- It resists high temperatures
Much depends on the grade of polypropylene, but generally speaking, the melting point of this material ranges from 130°C – 171°C. That means polypropylene is autoclavable.
- It is highly resistant to chemicals
That includes many acids and bases and is one of the biggest reasons why polypropylene is widely used in both laboratory and industrial applications.
Polystyrene
Another polymer that is widely used in a variety of industries, Polystyrene is produced in large volumes. It has its own set of features that make it suitable for a variety of applications.
- It can withstand heat
Although it is not as heat resistant as polypropylene, it can withstand heat up to 100°C. However, if you require a sample container that is good at retaining heat, you should choose one made from polystyrene rather than polypropylene.
- It’s clear and brittle
This makes polystyrene similar to glass but it costs far less to produce. Even if it doesn’t offer the durability of polypropylene, you can easily replace polystyrene lab supplies inexpensively.
- It is resistant to chemicals
Polystyrene offers some resistance to a variety of chemicals, acid and bases. Once again, it doesn’t offer the same level of resistance of polypropylene.
Polystyrene sample containers are best suited to general sample storage and transport. This polymer is also widely used for food grade packaging products and disposable laboratory supplies.
To learn more about the chemical resistance of both polystyrene (PS) and polypropylene (PP), see our Chemical Resistance Chart.
JPlast offers 40ml and 90ml specimen containers in both polystyrene and polypropylene. All our sample containers seal tightly and can be supplied in a sterile bulk pack or individually wrapped. While the 40ml sample container is the most frequently requested size, the additional capacity of the 90ml container makes it ideal for field sampling.
For more information about our specimen containers or to get your quote, please email info@jplast.co.za