Packaging cushion

Compressive Behavior. The most kiformative data ki characterising the compressive behavior of a flexible foam are derived from the entire load-deflection curve of 0—75% deflection and its return to 0% deflection at the speed experienced ki the anticipated appHcation. Various methods have been reported (3,161,169—172) for relating the properties of flexible foams to desked behavior ki comfort cushioning. Other methods to characterize package cushioning have been reported. The most important variables affecting compressive behavior are polymer composition, density, and cell stmcture and size. 

M.E. Gigliotti, Design Criteria for Plastic Package-Cushioning Materials , PLASTEC Rept 4 (1961) 3)M.C. StCyr, State of the Art,... 

Cellular Polymers II. Conference proceedings. Edinburgh, 23-25th March 1993, paper 21. 6124 PREDICTION OF PACKAGING CUSHION CURVES AND HELMET LINER RESPONSES... 

Details are given of the change in cell structure of a closecell foam due to multiple impacts and the range of application of cushion curves as they relate to reusable packaging. Cushion curves and stress-strain curves for up to 15 compressions were generated for three different moulded closed-cell PE foams. 

Polyethylene foam sheet is used mainly in package cushioning, and also in roof insulation and extruded profile is also used as construction sealants and pipe insulation. It is made mainly by tandem extrusion. The first extruder melts the polyethylene and blends in liquid volatile organic foaming agent. The second extruder cools it to the optimum foaming temperature, and pumps it through a die into room-temperature air, where it expands into foamed sheet. 

Molded foam for package cushioning, flotation devices, and sports equipment is made from foamed pellets. Polyethylene pellets are foamed with volatile organic liquid and cross-linked by peroxide or electron beam. The foamed pellets are poured into a... 

ASTM D 1596-91 Standard Test Method for Shock Absorbing Characteristics of Package Cushioning Materials, 6 pp (Comm D-10)... 

MIL-HDBK-304B NOTICE 1 Package Cushioning Design, 28 November 1988, 3 pp Notice + 536 basic hdbk) (Area PACK) (69)... 

U.S. Department of Defense, Military Standardization Handbook MIL-HDBK-304B, Packaging Cushioning Design, (31 October 1978), 518 pp. 

Durability of container, adequacy of interior packaging, and protection given to contents by packaging (cushioning, clearances, support, positioning). The most nearly noncombustible suitable containers should be used. 

Antistatic protection is an important consideration within the electronic industry and various antistatic agents are used commercially to aUeviate this problem in cushion packaging materials. 

Steam-Chest Expansion. In steam-chest expansion the resin beads in which gas is already present are poured into molds into which steam is injected. The steam increases the temperature close to the melting point and expands within the stmcture to create beads with food cushioning and insulating properties. Expanded polystyrene is widely used in this process for thermal insulation of frozen food packaging. 

But high stiffness is not always what you want. Cushions, packaging and crashpadding require materials with moduli that are lower than those of any solid. This can be done with foams - composites of a solid and a gas - which have properties which can be tailored, with great precision, to match the engineering need. 

Very popular is plastic cushioning material used in packaging, usually laminated thermoplastic films that incorporate air bubble pockets. 

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