Considering a latex crib mattress for your baby? In this guide, we explain what natural latex is, how it’s made, and what the pros and cons are for baby!
What is Natural Latex?
Natural latex (as compared to synthetic latex) is a tree sap that comes from the rubber tree (Hevea Brasiliensis).
Rubber trees are native to Brazil. However, today you can find them throughout SE Asia and Africa. In fact more than 90% of the world’s natural latex comes from Asia.
In sap form, latex is a cloudly white liquid that looks a bit like milk. The majority component of latex sap is rubber particles (30% to 40%) and water (55% to 65%). Proteins, plant sterols, resins, ash, and sugars make up the rest.
Manufacturers first tap the trees to release the sap. They then process the collected tree sap to use across a variety of applications. Baby gear such as crib mattresses and mattress toppers are just some uses for natural latex.
You can also find it in latex pillows, latex mattress toppers, and more.
Making Natural Latex
Collecting Natural Latex
Natural latex starts its life right at the tree. Rubber tappers cut a thin strip of tree bark about halfway around the tree. This causes the tree to release sap for about six hours.
Tappers collect the sap from the tree much as you’d collect maple syrup. They wait for it to slowly drip into cups.
Happily, this process doesn’t harm the tree – tree bark heals quickly when collection is finished. Further, the trees have a fairly long life, yielding latex for 25 years or so.
Processing Natural Latex
From tree sap to latex crib mattress involves processing.
Manufacturers use either the Dunlop Process or the Talalay Process to make finished products natural latex.
Both processes start out the same: workers whip the sap with air in a centrifuge to create a foamy liquid. Both processes also end the same. Workers wash the processed latex to remove additives and dry it at a high temperature to remove excess moisture.
In the Dunlop Process, manufacturers pour the foamy liquid into molds. They then feed the molds into vulcanization ovens and steam bake them.
The Talalay process starts out the same – manufacturers pour the foamy latex into molds. With Talalay latex, however, workers don’t fill the the mold completely. Instead, they seal a partially-filled mold. They then use a vacuum process to expand the liquid latex to completely fill the mold. This difference in processing accounts for the fact that Talalay latex is typically less dense than Dunlop latex. They then flash freeze the mold and contents using Carbon Dioxide, before vulcanizing it at very high heat.
Dunlop Latex vs Talalay Latex: Which is Better?
Dunlop latex and Talalay latex look and feel pretty much the same to the average consumer. That said, there are a few key differences.
Dunlop latex is generally springier and denser. With fewer steps, it’s a more energy efficient production process. Dunlop manufacturers also work closer to the latex plantation. This means the process requires less ammonia as a stabilizing agent.
Talalay latex is more bouncy, softer and more breathable, due to the decreased density. Talalay latex generally requires more additives than Dunlop latex. It’s also thought to be more energy intensive due to the extra step (freezing). Talalay manufacturing plants are mainly based in the Netherlands and United States. This means liquid latex used in the Talalay process needs to be shipped with ammonia to prevent coagulation. Most of this ammonia is removed during foaming, but it’s another environmental con compared to the Dunlop process.
What is Vulcanization?
Vulcanization is a necessary step in processing latex. Vulcanization transforms the foamy, whipped tree sap and allows it to harden.
All natural latexes undergo this process in their journey from tree to final product. And all synthetic latexes undergo vulcanization, too.
During vulcanization, manufacturers add sulfur and zinc oxide to the raw rubber, and then heat the mixture. Heating raw rubber with sulfur facilitates the state change from liquid rubber to solid latex. Zinc oxide plays an accelerator role and prevents early oxidization.
Why Buy a Natural Latex Crib Mattress?
Advantages of a Natural Latex Crib Mattress
- Biodegradable, as compared to materials like petroleum-based foam or PETE / PETE plastic.
- Hypoallergenic (with an asterisk). Natural latex is mold and dust mite resistant.
- Low VOC – Latex may be healthier than petroleum-based flexible polyurethane foam. Petroleum-based foams emit VOCs as they age.
Disadvantages of a Natural Latex Crib Mattress
- Although rare, it’s possible to have an allergic reaction to latex. If you’re concerned or you have a family history of latex or latex-like allergies, talk to your baby’s paediatrician.