How to recycle PP raffia efficiently?
Post-industrial recycling of PP raffia, woven sacks, tapes, non-woven/woven could be challenging at times for some producers due to the following reasons:
1) Difficult to process in one single step due to size and strength of the material waste (ex. FIBC and jumbo bags).
When recycling has to be done in several processing steps, it is not cost-effective for the producers in terms of labor, electricity, and occupying too much factory space.
2) Difficult to retain material property (strength and elasticity) after recycling in which the material degrades excessively and therefore, the reusability of the recycled pellets back into the production lines is relatively low.
3) Difficult to process heavily printed woven bags (for example AD*STAR bags) as the degassing and screw design of the recycling machine is not ideal for this type of material with extra amount of ink.
(Comparing to film waste, it is more difficult to cut and feed raffia waste consistently into the recycling machine for its strength and size. Usually, it has to be done in separate steps)
One-step, simple solution for raffia/woven recycling
Polystar’s Repro-One recycling machine provides solutions to the above problems with the following features:
1) One step process with shredder + extruder + pelletizer all integrated into one simple, easy to operate recycling machine.
(instead of having a separate off-line crusher or shredder, POLYSTAR’s Repro-One integrates the shredder with the extruder, allowing a more automated and consistent feeding of the material, which results in stable output and higher quality of recycled pellets)
2) Low processing temperature in the single shaft shredder:
This gentle and short, one-step process ensures minimal material degradation, which allow producers to re-use a higher percentage of the recycled pellets back into the production lines and still meeting the industrial standards (for example, strength and elasticity of jumbo bags for US exports).
(instead of using an agglomerator or a cutter-compactor which processes the material at a higher temperature for a longer period of time, the gentle yet powerful single shaft shredder cuts the raffia waste within a short time at a much lower processing temperature. This helps to maintain the property of the post-industrial waste material as close to new material as possible)
3) Specialized degassing and screw design for processing heavily printed bags:
The optimal screw design can eliminate the problem of material coming out from the degassing (venting) area almost completely, so the machine can operate at full speed with stable production. Efficient degassing is another key factor to ensure the pellets are solid (instead of fluffy and hollow in the middle)
(High efficiency degassing and specialized screw design can process heavily printed woven bags efficiently and obtain good quality pellets)
(heavily printed woven bags are usually more difficult to recycle and reuse in post-industrial applications)
Raffia producers who recycle in-house have many advantages
(plastic packaging in circular economy – Raffia and woven sector)
In general, 8% of production waste is generated during the process (from tape line production, looming and printing). The price of raw material is almost doubled comparing to the cost of having it recycled in-house. It would make sense for medium and large-sized raffia/woven producers (who generate more than 30~40 tones of scraps per month or more) to recycle the production waste internally to reduce production cost.
62 raffia recycling machines installed in India. 257 worldwide.
Many raffia and woven producers have already seen the benefits of doing in-house recycling using the Repro-One, including producers in Argentina, India, Indonesia, Mexico, Philippines, Saudi Arabia, Thailand, Turkey and many others.
Amongst the 62 installations in India, one of the Indian producers has already installed 5 sets of Repro-One at 5 different factory locations, since the first installation back in 2015. “It is cost saving and our operators find it very easy to run and maintain the machines,” said Mr. Kumar, director of Kolkata-based jumbo bag producer, “the shredder integration is definitely the best choice for raffia and woven application,” he added, explaining the reason why they decided to add the second, third, fourth and fifth machine in 2017, 2018, 2019 and 2020. “We produce all types of products with different sizes and shapes, including cement bags, sugar bags, fertilizer bags, mesh bags (for packing onion, ginger, garlic, potato), the machine can handle it all with ease.” “We also recommended the machine to our friends in the industry who produce mosquito and construction net, and they are very happy using the machine as well.”
The high quality pellets ensure easy reuse back again in the production process for raffia, non-woven, and Ad*Star block bottom heavily printed bags. The reusability of the PP recycled pellets is particularly high with the Repro-One recycling machines, raffia producers can use between 20% to 100% recycled pellets back into the production line depending on the final product requirement.
Simple-to-use, automatic pelletizing system for PP
The die face cutting design of the Repro-One is designed specifically to work with PP material:
1) Automatic pelletizing speed adjustment – Prevents pellets sticking due to higher melting index of PP material. Produces more uniform-sized pellets without labor intervention.
2) Automatic blade pressure adjustment – Allows the pressure between the pelletizing blades and the die head to remain constant. As a result there is less machine down time, easier and faster to change blades
(the pelletizing system of the Repro-One prevents PP pellets from sticking to one another, ensuring stable production and output without having to constantly stop the machine for adjustment)
Efficiency and reusability go up. Cost goes down.
In the case of a woven sack producer who used to recycle using off-line shredders and agglomerators before feeding the material into the extruder. Ever since having installed the Repro-One 100, the producer has reduced the operation cost by 30%.
(Raffia producer in Kenya has replaced three of its old recycling machines with a Repro-One, reducing electricity and labor costs while increasing the reusability of the recycled pellets)
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