Paper Shipping Sacks Today
Multiwall paper shipping sacks originated in the 1920s when sack makers supplied hand-tied sacks to Portland cement plants. Since then, the paper sack industry has developed to become a packaging leader, and sacks have been extensively transformed.
This evolution has allowed the kraft paper sack to take shape using an unlimited array of constructions, such as carefully selected papers, films, foils, special coatings, laminations and surface and other treatments. The construction materials specified in each case are determined by the product itself and the degree of product protection required to safeguard its quality.
Thousands of people are directly involved in the production of paper shipping sacks in America, with many in addition who work in sales, accounting, customer service and other supporting or related functions.
From a modest beginning, the paper shipping sack and consumer bag industry has emerged into a billion dollar a year industry with shipments of over three billion sacks annually. Today, paper shipping sacks are used to package a wide variety of food, agricultural building material and industrial purpose products.
Advantages of Using Paper Shipping Sacks
Paper shipping sacks are flexible containers made from one or more walls of specification papers and other materials. They are custom-designed to meet the exact requirements of individual shippers and provide the highest degree of product quality protection at the lowest cost that meets normal handling, shipping and service requirements.
Multiwall sacks are frequently used as master containers (balers) for consumer bags.
Current specifications for sack papers, constructions and various types of closures have been developed by scientific evaluation of the performance of paper shipping sacks over a long period of time. This continuous, long-term research has led to evolutionary improvements in materials and closures over the period.
The package engineer is virtually unlimited in the choice of constructions available in paper shipping sacks. Walls of the sack and treatments used can be precisely specified to provide types and degrees of product protection required for whatever the distribution system and handling characteristics dictate. Sack designs and constructions can be adapted to existing or new filling and handling equipment.
Paper shipping sacks offer excellent printing surfaces. Today’s sack manufacturing plants are equipped to print product graphics on the outer ply of a sack with the clarity and detail that approach magazine and other fine paper printing technologies.
- Basic raw material is a renewable resource
- Protects contents from the absorption of moisture
- Prevents loss of essential moisture from contents
- Permits top-icing of fresh produce
- Prevents the escape of oils or flavors from products
- Protects against chemical action of contents
- Prevents seepage or penetration of products packed “hot”
- Provides a gas or vapor barrier for volatile products
- Prevents sifting of finely ground products
- Provides low-cost protection against contamination
- Permits stacking for better utilization of warehouse space
- Serves as a degradable package under certain conditions
- Has the FDA approval for food packaging
- Provides excellent graphics for improved “buy appeal”
- Permits free-standing use as a point-of-purchase display
Sizes and General Types
Paper shipping sacks are made in many sizes as specified by the shipper, consistent with the suppliers’ manufacturing capabilities and product requirements. Multiwall sack capacities usually range from 20 pounds to 110 pounds of product. Self-opening style sacks holding less than 20 pounds of contents are referred to as consumer bags. Sack constructions usually are of two general types and designated according to the filling method to be used:
- Open mouth: filling is done by gravity or compression
- Valve: filling is done through a filling tube or spout
Valve sacks are usually fabricated entirely in the sack plant, except for a corner opening to allow filling at the customer’s packing plant. Open mouth sacks are fabricated in the sack plant except for the top which is closed in a variety of ways at the packing plant.
Originally used for packing low-cost, bulk-type commodities, paper shipping sacks are now used for the delivery of thousands of different types of products. In value, these products typically range from a few cents to several dollars per pound. As improvements in materials, constructions and distribution systems continue to develop, more products with a greater value-per-pound are being packaged in shipping sacks.
The paper shipping sack industry is one of growth, innovation and service to its customers. Significant advancements in sack packaging are continuously being made to better serve current customers and develop new package uses for the versatile multiwall paper sack.