Bulk Bag Economics 102 - Watch your Weight

When you get your pricing back from a supplier, one of the smartest things you can do is make note of the pallet count.

How can two suppliers quote the same bag, at the same time, then have different quantities per pallet? It's all about the weight, and you need to watch it.

bulk bags

Pictured: Some sad looking bulk bags (not MiniBulk bags, obviously).

As mentioned in our previous Bulk Bag Economics blog, one of the main pricing factors is the cost of resin. Let's look at how much resin is actually used in the production of your bulk bags, and what it means to you.

Your bulk bags are made from woven polypropylene fabric.

Just like the shirt on your back, polypropylene fibers are woven together to make a pliable fabric. The most common methodology to determine the strength of the fabric used to make your bags is GSM (grams per square meter). That is, how much does a square meter of fabric weigh. Heavier fabric weight means you can make a bag with a higher weight capacity. I should also keep our Imperial friends in mind, and note that another way to measure this is ounces per square yard.

The physical weight of your bulk bag can reveal some interesting information.

For example, a typical 1,000 kg bulk bag will have a gsm rating in the area of 170 and weigh around 2 kgs. That is, one square meter of fabric will weigh 170 grams. If the gsm is too low, the bag is at risk of failing and coming apart during transportation. If the gsm is too high, the price of the bag will be out of line with your requirements.

All of the bulk bags MiniBulk Inc. makes have a minimum Safety Ratio of 5:1.

The bags we bring in from overseas are tested to ensure they meet or exceed this critical rating. To give you an idea of how they get his number, let me explain how the testing works. A bulk bag will be filled with a medium (plastic pellets usually) and then the bag is suspended by the 4 corner loops inside a testing rig. A large metal plate is then forced downward into the bag until some part of the bag gives way and the bag comes apart on the rack.

If you are good at math (or even bad at math), you can figure out that a 1000 kg bag with a 5:1 Safety Ratio will not come apart until at least 5,000 kgs of force have been exerted!

Pretty impressive for what is essentially big pieces of plastic sewn together by hand. But you can see, there is some serious engineering involved with making a design that holds up to those kinds of forces.


So what does this 5:1 ratio have to do with bag weight? Well, everything. You can not make a bag that will pass 5:1 if the fabric is too light. There needs to be a minimum amount of material to create a bag that will pass the test. Of course, the more the bag weights, the more resin needs to be used and the price of the bag will go up accordingly.

A common phrase you will hear around the MiniBulk office is "Apples to Apples".

When we quote a custom design for a potential client, we always strive to ensure what we are quoting has the same base-line parameters as what they are using now. If the pricing is off by a large margin, we have to assume something is not right, and we are not quoting apples to apples.

Fabric weight can be dropped to the bare minimum to get the lowest price possible, but that is not the way we like to do things in Calgary. After all, the product in your bags is very important, but not as important as the people on the ground.

Saving a couple dimes up front can cost you a lot of money in the future if you experience bag failures. Not only the loss of product, angry clients, and lost time, but when 1000 kgs of anything is up in the air, you want it to stay there.

So the next time you get a really excellent price on a bag design you are currently using, make sure you take a closer look at what you are really getting.

If you currently get 200 bags on a pallet that weights around 900 lbs, what does is mean if the better price is getting 250 or 300 bags in the same space? If you read this and were paying attention, you know the answer, apples to apples.

Read the rest of the series! The Economics of Bulk Bags: Part 1Part 3 and Part 4

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