Plastic vs Styrofoam
Tough plastic propagation trays and containers and Styrofoam propagation trays and containers – there are similarities, but what are the differences?
Proptek trays and containers are all made from black durable injection molded plastic. Except for in exceptional circumstances, all our trays are made from reprocessed material. Using plastic propagation trays provides a great many benefits for growers and can directly help your bottom line and return on investment.
1. Longer Life Design
Typically, a Styrofoam (also known as EPS) tray will only last about 4 seasons. Our injection molded plastic trays will last over 10 years on average – and as long as 20 years if care is taken. Though plastic trays generally have a higher initial price point that Styrofoam, over the course of ten years they are far far more economical in purely cash terms. When you add the benefits of better plants, better sterilization and more plants per square foot, plastic trays become not only financially viable, but financially beneficial.
With a Styrofoam tray the first damage is typically a broken outer wall where a cell has snapped out. This means that the next time you fill this tray the soil, and possibly the seed, falls out. This can get very expensive very quickly as seeds can often be quite a large investment themselves. Eventually it comes to a point that you are losing too much money from broken cells, so you simply throw the tray away. This does not happen with injection molded plastic trays.
2. Improved Sterilization and Disease Reduction
To sterilize injection molded trays or containers all that needs to be done is a simple surface sterilization. This is only possible because plastic trays will not deform or affect plant pulling at temperatures required to clean and kill disease. To sterilize Styrofoam you have to sterilize the whole block of material and this is only practically possible with heat. Even after a single sterilizing you could lose some trays, but certainly after a couple of years a good proportion of trays will become unusable.
Over time a Styrofoam tray will allow roots and disease into the Styrofoam and thus you get tray to tray variation and disease carry over, this never happens with an injection molded tray.
More information can be found on our cleaning and sterilization page.
3. Improved Plant Quality & Air Pruning
Because of the high level of detail that can be created using plastic ribs and holes, exceptional and natural root structures can be grown. An improved and natural root system that isn’t tangled up in itself creates much better, much more consistent plants.
Plastic trays produce a better quality plant as the tray is impervious to roots, water and fertilizer, unlike Styrofoam trays where the roots eventually penetrate the tray. This not only gives a better quality more uniform plant but they also pull a lot easier.
4. Better Integration with Mechanization
As plastic is a more precise material than Styrofoam, injection molded trays better suit automatic transplanting systems. The trays are more durable too, meaning that they survive many more seedings and extractions.
Due to the specialist design of the cells in Proptek plastic trays and containers, plants pull much easier meaning a more reliable extraction using automated machinery.
5. More Plants per Square Foot
As plastic is tougher and stronger than Styrofoam, cell walls can be much thinner and trays no longer need a thick outer rim to keep the tray rigid. This means that more cells can be squeezed into the same space without affecting the spacing of the plants too much.
Find out more about how achieve more plants per square foot on our Improved Plant Density page.
6. Increased Cell Volume
Rather than increasing the number of cells, injection molded trays can also be designed to have a larger cell volume. This is again achieved because of the tough nature of plastic, allowing the cells to share thin cells walls, thereby increasing cell size when it’s required, such as when you require more soil and the water and nutrients it carries.
With our injection molded trays, we can mold your name on the tray for corporate identity. This helps ensure you get all your trays back after they have left the nursery.