The Lab: PP Woven Rice Bag

One of Singapore's most overlooked waste streams: strong, workable, and almost never recycled.

Waste stream #001 · First researched 2023

What is it?

The bags that rice comes in 10kg and 25kg are made from polypropylene (PP), a plastic woven into fabric. That's why they feel like cloth but are actually plastic. They're tough enough to hold 25kg of rice without tearing, and printed with bold graphics on the outside.

In Singapore, thousands of these bags move through homes, restaurants, hawker centres, and food manufacturers every week. Once the rice is gone, the bag usually goes straight into the bin.

What does it feel like?

PP woven rice bags have a distinct character: slightly glossy on the outside, slippery to the touch, waterproof, and surprisingly flexible. They're stiffer than a fabric bag but softer than rigid plastic — somewhere in between.

This physical quality is what makes them so interesting to work with and well-suited to products like cardholders, pouches, and sleeves that need to hold their shape.

Why can't it just be recycled?

This is the most important thing to understand about this material: PP woven rice bags cannot go into Singapore's blue recycling bin. Even though polypropylene is technically a recyclable plastic (resin code #5), the reality on the ground is very different.

Here's why they fall through the cracks:

  • The woven structure jams standard recycling machinery - it wraps around moving parts and causes equipment to break down
  • The glossy laminated coating on most bags adds a second material layer that complicates processing
  • Food residue from rice means bags need industrial washing before they can be reprocessed
  • There is no dedicated collection or processing infrastructure for this material type in Singapore

So what happens to them? They go to the bin, then to incineration. A material that took energy and resources to produce, that is still structurally intact and fully workable, gets burned.

That's the gap The Interchange is working in.

What we've learned working with it

We started working with PP woven rice bags in 2023, sourcing them from households, food businesses, and our own kitchen. Here's what we found:

  • It sews well. Despite the slippery surface, the woven structure holds a stitch cleanly, finish the edges properly and the seam holds under real use.
  • The waterproof quality carries through. Products made from rice bags naturally resist moisture, useful for cardholders, pouches, and anything that lives in a bag or pocket.
  • The graphics are a feature, not a flaw. Song He, Noble Pine Crane, Jasmine; the branding on these bags is bold and instantly recognisable. We stopped hiding it and started designing around it.
  • Cleaning matters. Bags with rice dust or residue need a wipe-down before working. This affects both the finish of the final product and how long it lasts.

What we've made from it

Our main product from this waste stream is the rice bag cardholder — hand-stitched, made entirely from a single discarded rice bag. We've also explored tote bags, tool pouches, and notebook sleeves.

What's still being figured out

  • Edge finishing at scale: hand-finishing works for small batches but slows production significantly
  • Consistent supply: sourcing enough clean bags from reliable partners is an ongoing challenge
  • Laminated vs unlaminated: the glossy coating affects how bags sew and feel; we're still testing the best product applications for each type

Donate your rice bags

We accept donations of used rice bags; from households, restaurants, caterers, and food businesses. If you go through a lot of rice, we want your bags. Drop us a message at makeit@theinterchange.cc and we'll arrange collection or drop-off at our studio in Bukit Merah.