Garbage bag

What is the difference between high-density HD and low-density BD bags?

Historically, the polyethylene used to make garbage bags is low-density polyethylene. This doesn't mean it's not strong, but it corresponds to a traditional manufacturing method with a standard PE density.
A high-density bag will have an average molecular density of 0.95, whereas a low-density bag has an average molecular density of 0.92. Hence the notion of "high density".
When the concept of high density emerged, it made it possible to reduce the thickness of garbage bags. The main argument is that an HD bag will have greater tensile strength, but its resistance to punctures or sharp debris will be lower.
The rule is therefore now to use HD bags for loads that can be heavy or bulky without risk of perforation (paper, cardboard...) and to use traditional BD bags for heavy loads but which can cause perforation (kitchen, food, construction work, heavy cleaning...).

How can I be sure of the thickness and dimensions of my bag?

The inspection method can be done using a micrometer , but unless you're a professional garbage bag buyer, very few people have one... The best way is therefore to ask for the bag's measurements and thickness , then weigh it on a letter scale, for example. You can then weigh the bag and verify it using the following criteria:
The calculation formula is as follows:
Weight of your bag = Half perimeter x 2 x Height x Molecular density x Thickness
The molecular density of LDPE is 0.92 on average
The molecular density of HDPE is 0.95 on average
The half-perimeter corresponds to the opening of the bag when fully unfolded, including the gussets.
With this information, you should now be able to truly understand what you are buying and compare...

How to get better prices on garbage bags?

Trash bags, like single-use cotton wool products, are generally sold by the kilo ... So unless your product benefits from a specific system, standard (DASRI for example), labeling (Ecolabel, FSC...) or innovative technology, you should be able to find prices that are consistent with each other, provided you carefully compare the material and dimensions...
As you've probably guessed, garbage bags are a low-cost product for manufacturers and distributors ... Therefore , the best way to get better prices is to buy in bulk, since the biggest expense for a low-cost product is TRANSPORTATION!!