# Block-Bottom Valve Bags for Cement and Building Chemicals

> Square-bottom woven PP valve bags with heat-seal or internal valves help cement and dry-mix producers fill faster, cut dust and ship stable pallets through wet construction sites.

Published  by Evergreen Packaging (Yantai Evergreen Packaging Co., Ltd.). Canonical: https://www.egpbags.com/projects/cement-valve-bags-construction/

**Summary:** Paper cement sacks burst and soak up rain. Laminated woven PP block-bottom valve bags fill on the same packers, close dust-tight, stack square and survive wet sites.

## The challenge

Cement, white cement and dry-mix producers fill tens of thousands of bags per shift on rotary valve packers. Paper sacks are cheap but fragile: they burst during palletising, tear in transit and absorb rain on open construction sites. Every broken bag is lost product, dust and a complaint.

## The specification

- **Fabric:** woven polypropylene, **PE-coated or BOPP-laminated** for moisture resistance.
- **Construction:** **square block bottom** at both ends for brick-shaped, stable stacks.
- **Valve:** internal valve for standard cement; **heat-sealable valve** for premium and export products that must stay dust-tight.
- **Fill:** 25 kg and 50 kg formats sized to the packer spout.
- **Print:** brand, product grade, weight and safety information on all faces.

## Why it works

1. **Fewer breakages.** Woven PP is many times more tear-resistant than paper at a similar weight.
2. **Weather resistance.** Coated and laminated fabric sheds rain on site.
3. **Same filling line.** Bags are designed to run on existing valve packers.
4. **Stable pallets.** Block bottoms stack square, reducing collapsed loads in trucks and containers.

## Products used

[Custom Logo Square Bottom Laminated PP Woven Waterproof](https://www.egpbags.com/products/valve-bags/custom-logo-square-bottom-laminated-pp-woven-waterproof-cement/), [Heavy Duty Heat Seal Bottom Gusset Bag Valve Pocket 25KG](https://www.egpbags.com/products/valve-bags/heavy-duty-heat-seal-bottom-gusset-bag-valve-pocket-25kg-capacity/) and [Square Bottom Gusset Bag with Valve Pocket Durable 25KG](https://www.egpbags.com/products/valve-bags/square-bottom-gusset-bag-with-valve-pocket-durable-25kg-chemical-raw/). See [valve bags vs open-mouth bags](/blog/valve-bags-vs-open-mouth-bags/).

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