The Benefits of AD*STAR® Block Bottom Woven Valve Sacks

November 25, 2020

AD*STAR® Block Bottom Woven Valve Sacks

What is an AD*STAR Block Bottom Woven Poly Valve Bag? 

A woven poly “block bottom” or “valve” bag is a common industrial packaging style designed to package a wide variety of dry flowable products. Valve bags are packed on equipment that deposits material into the bag via horizontal filling spout. After filling, forces generated by the product inside the bag allow the valve opening to self-seal. 

Valve bags can be made with paper, woven poly, or poly film. AD*STAR® block bottom woven valve bags are made by extruding polypropylene resin into sheets, cutting the sheets into tapes, and weaving the tapes into tubular fabric. The tubular fabric is then laminated, cut, and converted into a finished bag. AD*STAR® valve bags offer several functional advantages over traditional multi-wall paper bags.

What is AD*STAR®?

The trade name AD*STAR® is a registered trademark of Starlinger & Co GmbH. Starlinger Company is a world-renowned manufacturer of woven packaging and textile machinery. The name is protected around the world. Today over 10 billion AD*STAR woven black bottom valve bags are produced each year. 

What can AD*Star® Block Bottom Woven Valve Sacks be used for? 

Poly woven valve bags can be used for all types of free-flowing goods including:

  • Cement
  • Building materials
  • Fertilizer
  • Chemicals
  • PVC Resin
  • Masterbatch
  • Seeds
  • Mortar
  • Gypsum
  • Lime
  • Flour 
  • Sugar
  • Animal feed
  • Ready mix
  • PP Resin
  • PE Resin
  • Corn
  • Sand

AD*STAR® Block Bottom Woven Valve Sacks

How are AD*STAR Woven Poly Bags Manufactured? 

Starlinger Company supplies integrated bag converting machinery to produce the woven valve bag from start to finish. Production steps include:

Tape Extrusion: High-strength tapes are produced by stretching after the resin extruding process.

Weaving: Tapes are woven into tear-proof fabric in circular looms. 

Coating: A thin layer of PP film is laminated to the woven fabric. 

Printing: Up to 8 colors, including photorealistic quality graphics can be printed on the bag fabric

Slitting: Top, bottom, and valve patches are pre-cut for the converting line.

Converting: Using Starlinger machines, sacks are assembled by forming the block bottom and applying patches and the valve using hot air sealing technology. No glue is used to seal the bag. 

Baling: Bags are palletized and baled. Up to 7,000 bags can be baled in a single pallet

AD*STAR® Block Bottom Woven Valve Sacks


AD*STAR® Bag Specifications and Sizes



Block Bottom Valve


Coated Woven PP Tapes


Single Ply Woven Poly

Two Ply: Woven Poly

Two Ply: Woven Poly + Paper

Tape Width:

2.5mm - 5mm

Fabric Weight

50 - 80 gsm

Coating Weight:

17 - 25 gsm

Valve Material:

Woven PP, PE Film, Non-Woven Spunbond


Adjustable Levels of Perforation

Valve Type: 

Standard Internal, Tuck-in, and Sonic Seal

Bag Size Min. & Max.


10.25 - 23.625 Inches


12.25 - 47.25 Inches

Bottom Width:

3.15 - 7.00 Inches 

Need Woven Poly Valve Bags Now?

ON-DEMAND Bag Inventory – We currently stock over 300,000 woven poly valve bags in multiple sizes and bag colors. Bags are baled 5,000 – 6,500 per pallet and are available for immediate shipment. 


CUSTOM Orders - Custom orders can be manufactured to your exact specifications. MOQ is generally 20,000 per size or print. Lead time is typically 14 – 16 weeks. 

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