How is coffee ground fiber made?
The raw material required for the manufacturing of S.Cafe fiber is coffee ground and recycled polyester and the process is patented by Singtex. The process involves converting these coffee grounds into yarns at a temperature of about 160 for carbonisation. When compared with the conventional carbonisation process, the temperature required is 600 thus making the Singtex process more energy efficient.
The whole process can be understood in a nutshell as combining coffee residue with recycled plastic which is then repolymerised and spun into coffee yarns. Singtex claims that a single cup of coffee can make two T-shirts. Thus, this composite fiber is basically utilising the waste by various methods such as extraction and grinding. While coffee fiber has the ability to be blended with other synthetic fibers such as polyester and nylon.
The steps involved in the production of coffee ground fiber are as follows:
• Preparation material with coffee residue: This step involves the preparation of microcapsules. Microcapsules are miniature capsules consisting of certain substances. Microencapsulation is a technique in which chemicals are released in a controlled manner over a long period from the microcapsules. In the case of coffee ground fiber, firstly microcapsules are prepared consisting of coffee residue, coffee essential oil (extracted from the coffee bean) and fragrance organic substance.
• Cleaning or sieving of coffee residue or raw material:
The coffee residue having an initial particle size of 20-100 microns is washed in clean water and dried. This is followed by sieving the mixture so as to attain a particle size of about 80-100 microns.
• Removal of organic contents from material with coffee residue:
The mixture is then dissolved in a solvent to get rid of organic matter. This is followed by the removal of fatty acid.
• Preparation of carbonized particles:
This step involves carbonisation of the coffee mixture obtained from the above step using chemicals such as zinc chloride, magnesium chloride, calcium chloride or phosphoric acid.
• Mixing of material with carbonized material to form a mixture
• Blending the mixture with the polyester chip:
The final step involves mixing and blending of coffee ground particles and polyester chips in the weight ratio of 1:9. Or 75% of carbonised particles and 25% of fragrance material is mixed with polymer chips.