View the complete, original article at: constructioninformer.com
By Edward Manning
Latex gloves are popular options for industrial and medical services. It is hard to imagine a world without this multi-purpose, durable, and affordable handwear. As popular as the product is, few among us might not know “How are latex gloves made?”
This critical question can give us knowledge about different types of latex gloves to ensure that they are the ideal choice for our duties. Here’s what to know about the latex gloves manufacturing process:
1. Tapping the Rubber Trees
The rubber trees must be around for 7 years until they can be tapped to collect latex. The critical tool for this process is a steel taping knife with a sharp edge. Workers use a sharp and strong knife to remove the thick bark strips off the tree. They have to make sure that the barks stripped off form a curve downward.
There must be cups or bowls at the end of the curve attached to the trees to get the latex. The cups must be held securely to not spiral away from the straps when they are filled with the white latex sap. Usually, the worker will put two bowls or cups lining straight so the spilling drops from the upper one can fall into the lower one.
One interesting fact about this process: as the latex sap coagulates quickly when the temperatures are high, tapping should be done in the early morning. And from that moment, the sap will flow into the cups for around six hours before stopping.
In such a period, one rubber tree can offer us a gallon of milky white fluid. Workers can carry out the same process the following day until they decide the collected amount is enough. They, then, take care of the open parts of the rubber with ammonia.
2. Concentrating and Stabilizing the Rubber Sap
The collected milky latex from the rubber trees has other contents, which we do not need for the manufacturing process. The fluid mostly contains water, sterol glycosides, protein, resins, sugars, and ash.
To concentrate and stabilize this mixture, the latex sap must be processed with chemicals. This step involves accelerators, sulfur, zinc oxide stabilizers, pigments, antioxidants, and de-webbing agents. After around 24-36 hours, the formulated compound is ready for the next process.
3. Shaping and Leaching Latex Gloves
Hand-shaped formers are required for shaping latex gloves. These molds are often made of aluminum or ceramic washed for a prolonged time in chlorine and hot water. This step is to eliminate all residues from the batches before.
All the hand-shaped molds are attached firmly on a moving chain, one by one. They will be soaking in the mixing agent, which has calcium carbonate and calcium nitrate. This solution releases the gloves from those molds.
When the molds are dry, they are dipped again into the concentrated latex compound. And the dipping period will determine how thick the gloves are going to be.
As those formed gloves are still fresh on the mold, they are leached one by one in chlorine and hot water. This time, it is to eliminate residues of chemicals and proteins in the latex, ensuring safer use for allergic people.
4. Drying, Curing, and Vulcanization
After that, the leached gloves are dried and cured for the following process of vulcanization. It adds elasticity to all formed latex gloves by causing a reaction between the chemicals and rubber molecules. With that, the latex gloves will resist tear and ripping better for work with sharp tools.
5. Drying, Rinsing, and Cuff Rolling
The next stage is drying and rinsing to remove more proteins. After this, it’s time to bead and roll the cuffs for convenience, so putting on and taking them off are quick.
The last drying process happens after one cornstarch dipping. Then, the pneumatic air jets or workers get the dried and complete gloves away from the molds. Finally, they are tumbled in hot air to eliminate all leftover powder.
6. Checking the Quality of Manufactured Gloves
Powder-free latex gloves are often used as non-sterile gloves for medical and other industrial use. They have to go through testing before they are qualified to be released into the market. Latex gloves must meet standards set by the US Food and Drug Administration (FDA) and the American Society for Testing and Materials (ATSM).
In the acceptable quality limit (AQL) test, the whole batch of new gloves is tested to find out if they have pinholes, which can lead to leaking and fluid transferring. For non-sterile latex gloves, the required AQL is 1.5 – 2.5. This requirement means the amount of failed gloves in the batch must be at most 2.5 percent.
Such a test will determine if the batch of gloves is qualified for industrial or medical service. For medical duties that require a higher level of hygiene, the gloves continue to be tested with a more rigorous process.
The Story of Latex Gloves
The first latex gloves were manufactured in 1883, and only a decade after the first appearance, they became essential gear for surgical procedures.
Afterward, an issue arose as latex gloves got stuck to doctors’ and surgeons’ hands due to their designated tight fit. The new process was born to add lubrication to the latex gloves, making it easier for users to take them off.
At the beginning of the 21st century, latex gloves with powder were reported to have severe health effects on people with allergies. And once more, the making process was changed to provide powder-free gloves for the medical sector. Due to their convenience and approved safety, latex gloves have become familiar gear in various fields.
Reaching the end of this piece, we now know the step-by-step process of “How are latex gloves made?” It is important to be aware of how latex gloves made of rubber are finished and tested to meet the strict requirements of different fields.
With this knowledge, we can feel at ease using this type of gloves for our work and daily life tasks. If you know any fun facts about this essential gear, feel free to share with us here!