Box manufacture process

Packaging engineers design corrugated boxes to meet the particular needs of the product being shipped, the hazards of the shipping environment, (shock, vibration, compression, moisture, etc), and the needs of retailers and consumers.

The most common box style is the Regular Slotted Container (RSC). All flaps are the same length from the score to the edge. Typically, the major flaps meet in the middle and the minor flaps do not.

The manufacturer’s joint is most often joined with adhesive but may also be taped or stitched. The box is shipped flat (knocked down) to the packager who sets up the box, fills it, and closes it for shipment. Box closure may be by tape, adhesive, staples, strapping, etc.

The size of a box can be measured for either internal (for product fit) or external (for handling machinery or palletizng) dimensions. Boxes are usually specified and ordered by the internal dimensions.

Manufacturing

Boxes can be formed in the same plant as the corrugator. Part of the scoring and cutting takes place in-line on the corrugator. Alternatively, sheets of corrugated board may be sent to a different manufacturing facility for box fabrication; these are sometimes called “sheet plants”.

The corrugated board is creased or scored to provide controlled bending of the board. Most often, slots are cut to provide flaps on the box. Scoring and slotting can also be accomplished by die-cutting.

The “Flexo Folder Gluer” is a machine that in one single pass prints, cuts, folds, and glues flat sheets of board to convert them to boxes for any application, from storing old family pictures to shipping the biggest of plasma TV sets to the global market. The most advanced of FFG’s can run at speeds of up to 26,000 boxes per hour (about 433 per minute).

When talking about Corrugated protection, Flute is one of the things you might hear to describe the type of corrugated, to you it might sound like an musical instrument, but rather, it means a fluted corrugated sheet with flat linerboards on either side of it. The most commonly used Flute, is the C Flute, see below the measurement are for all the flute sizes.  Corrugated sheets are widely used to manufacture corrugated boxes and protective sheets or rolls.

Manufacture of Corrugated Board

Corrugated board is manufactured on large high-precision machinery lines called corrugators, usually running at 500 lineal feet per minute or faster. These machines over time have become very complex with the objective of avoiding some common problems in corrugated board production, such as warp and washboarding.

The manufacturing process begins with pulping, the separation of wood (hardwood and sapwood) into individual fibers, as accomplished by mechanical methods or chemical treatment.

In the classical corrugator, the paper is softened with high-pressure steam. After the board is formed it is dried in the so-called dry-end. Here the newly formed corrugated board is heated from the bottom by hot plates. On the top, various pressures are applied by a load system on the belt.

The corrugated medium is often 26 lb/1000 sq.ft basis weight in the U.S. At the single-facer, it is heated, moistened, and formed into a fluted pattern on geared wheels. This is joined to a flat linerboard with a starch based adhesive to form single face board. At the double-backer, a second flat linerboard is adhered to the other side of the fluted medium to form single wall corrugated board. Linerboards are test liners (recycled paper) or kraft paperboard (of various grades). The liner may be bleached white, mottled white, colored, or preprinted.

Common flute sizes are “A”, “B”, “C”, “E” and “F” or microflute. The letter designation relates to the order that the flutes were invented, not the relative sizes. Flute size refers to the number of flutes per lineal foot, although the actual flute dimensions for different corrugator manufacuturers may vary slightly. Measuring the number of flutes per lineal foot is a more reliable method of identifying flute size than measuring board thickness, which can vary due to manufacturing conditions. The most common flute size in corrugated boxes is “C” flute.

Corrugated fiberboard can be specified by the construction (single face, singlewall, doublewall, etc), flute size, burst strength, edge crush strength, flat crush, basis weights of components (pounds per thousand square feet, grams per square meter, etc), surface treatments and coatings, etc. TAPPI and ASTM test methods for these are standardized.

The choice of corrugated medium, flute size, combining adhesive, and linerboards can be varied to engineer a corrugated board with specific properties to match a wide variety of potential uses. Double and triple-wall corrugated board is also produced for high stacking strength and puncture resistance.

(Thanks WikiPedia for you help)

Welcome to the new blog for the Boxery, where you will be able to find all your packaging needs at great prices.

We will update this blog regularly with information about corrugated packaging and boxes, mailers for any item, protective bubble wrap or anything packaging related.