What is a block bottom valve bag?

A block bottom valve bag is a PP woven sack with a square (block) base formed by side gussets, enabling the filled bag to stand upright and stack neatly on pallets. A valve at the top or side connects to automatic filling machines, suited to high-volume cement, chemical and dry-powder packing lines.

What products are typically packed in block bottom valve bags?

Block bottom valve bags are used for cement, lime, gypsum, dry chemicals, construction aggregates, fertiliser and other free-flowing powders and granules filled on automated lines.

What capacities are available for block bottom bags?

Adpack manufactures block bottom valve bags in capacities from 20 kg to 50 kg, with fabric weights of 90-120 GSM. Custom dimensions are available on request.

Can block bottom bags be printed with company branding?

Yes. Adpack prints block bottom bags in up to 6 colours using flexographic printing, or with BOPP lamination for premium photographic-quality branding.

Do block bottom bags require a special filling machine?

Yes. Block bottom valve bags are designed for valve-filling machines that inject product through the valve inlet. The valve self-seals after filling and is compatible with standard rotary and impeller filling equipment.

Does Adpack supply block bottom bags to cement manufacturers in Kenya?

Yes. Adpack supplies block bottom valve bags to cement, lime and chemical manufacturers in Kenya and across East Africa including Uganda, Tanzania, Rwanda, Ethiopia and the DRC.

Block Bottom Bags Kenya — Square-Base Woven Bags Manufacturer

Adpack Limited manufactures block bottom bags — also known as SOS (self-opening square) bags or valve bags — for industries that require a flat-based, free-standing package that fills efficiently on automated lines and presents well at the point of sale. Our block bottom bags are constructed from PP woven fabric with an integrated square base, allowing the filled bag to stand upright without support. Available 5 kg to 50 kg in plain, printed, or BOPP laminated finishes. MOQ 5,000 bags. Lead times 12–20 working days.

Standard Specifications

Parameter	Detail
Base construction	Block bottom (square base, self-standing)
Base material	PP woven fabric, 80–120 gsm
Lamination	Unlaminated or BOPP laminated outer surface
Printing	Up to 6-colour (unlaminated) or 10-colour (BOPP laminated)
Standard fill sizes	5 kg, 10 kg, 20 kg, 25 kg, 50 kg
Top closure	Open top (sewn), pinch top, or valve top
Valve type	Paper or PP film valve insert
Inner liner	PE liner available
MOQ	5,000 bags
Lead time	12–20 working days

Product Types

Open-Top Block Bottom Bags

Flat square base allows stacking on pallets without tipping. Open top accommodates hand filling or semi-automated filling spouts. After filling, top is sewn closed. Available plain or BOPP laminated.

Valve-Top Block Bottom Bags

Sealed top with small fill valve through which product is injected under pressure. After filling, the valve self-seals. Standard for cement, lime, plaster, and fine powders on high-speed rotary filling lines.

BOPP Laminated Block Bottom Bags

Full-bleed photographic printing on all four faces plus the base panel. Premium appearance combined with the structural advantage of the square base — ideal for retail flour, sugar, pet food, and branded grain.

Flour Bags (5 kg – 50 kg)

Block bottom construction is standard for branded milling products in East Africa. The flat base allows retail display in supermarkets and dukas without bags slumping. PE liner standard for flour. Sizes 2 kg, 5 kg, 10 kg, 25 kg.

Cement Valve Bags (50 kg)

50 kg block bottom valve bags for OPC cement, gypsum, lime, and tile adhesive. Fabric 110–120 gsm. Valve top for rotary packer compatibility. UV-stabilised yarn for outdoor palletised storage.

Industries Served

Milling — maize flour, wheat flour, ugali, rice, fortified blends
Sugar industry — retail branded sugar
Cement & construction — OPC cement, lime, gypsum, tile adhesive
Seeds — certified seed retail packs
Animal feeds — pet food, aquafeed, poultry starter
Chemicals — fine industrial powders requiring valve-top filling

Frequently Asked Questions

What is a block bottom bag and how does it differ from a standard woven sack?

A block bottom bag has a sewn and folded square base (SOS base) that allows the filled bag to stand upright without support. Standard tubular woven sacks have a flat bottom and tend to lean when filled. Block bottom bags are preferred for retail display, automated filling, and neat pallet stacking.

What is the difference between a valve bag and an open-top block bottom bag?

An open-top bag is filled through the open top and stitched closed — suitable for hand or semi-automated filling. A valve bag has a pre-sealed top with a small fill valve through which product is injected. The valve self-seals after filling, giving a cleaner, dustless fill. Valve bags are standard for cement and fine powders on rotary filling lines.

What fill sizes are available?

Standard: 5 kg, 10 kg, 20 kg, 25 kg, 50 kg. Custom dimensions available for non-standard fill volumes — provide required fill volume and product bulk density and we calculate appropriate bag dimensions.

Can block bottom bags be used on automated filling machines?

Yes. Valve-top block bottom bags are designed for rotary and impeller filling machines. Valve diameter and material must be specified to match your filler head type. Contact us with your filling machine make and model for compatibility confirmation.

Can you print all six panels of a block bottom bag?

With BOPP laminated bags, all four side panels plus front and back faces can carry full-colour printing. The base panel can also be printed. We recommend BOPP lamination for any application requiring all-round branding.

What is the minimum order quantity?

5,000 bags per specification. For ongoing supply requirements, we can hold agreed stock quantities at our Athi River facility under a blanket purchase order arrangement.

Request a Quote for Block Bottom Bags

Tell us your fill product, required capacity, filling method, and branding requirements. We will provide a detailed specification and quotation within one business day. Request a quote now or email info@adpacklimited.com.