Semi-rigid plastic

Plastic, semi-rigid See semi-rigid plastic. 

Disposable ear-plugs are made from glass down, plastic-coated glass down and polyurethane foam, while re-usable ear plugs are made from semi-rigid plastic or rubber. Re-usable ear-plugs need to be washed frequently. 

In the preceding sections, our discussion has been limited to softer grade elastomer-plastic vulcanizates. Commercial interest, however, also centers on another major family of polymer blends, semi-rigid impact resistant polyolefins. Thus, we report some of our findings on PRP triblock copolymer and EVA rubber blends without... 

Gas-filled plastics are polymer materials — disperse systems of the solid-gas type. They are usually divided into foam plastics (which contain mostly closed pores and cells) and porous plastics (which contain mostly open communicating pores). Depending on elasticity, gas-filled plastics are conventionally classified into rigid, semi-rigid, and elastic, categories. In principle, they can be synthesized on the basis of any polymer the most widely used materials are polystyrene, polyvinyl chloride, polyurethanes, polyethylene, polyepoxides, phenol- and carbamideformaldehyde resins, and, of course, certain organosilicon polymers. 

We also use semi-rigid polyurethane foams to package irregularly shaped objects. Liquid reactants are injected into a plastic bag, which swells to form a custom fit that immobilizes items within an outer box. 

Rigidity or plasticization rigid or unplasticized PVC (PVC-U), semi-rigid PVC, flexible or soft PVC. 

The compressive strain is given at 10 % compression, since for semi-rigid foamed plastics there is no sudden rupture of the cell structure. In the characteristic compressive force-compression set line for foamed PS material, the curve rises linearly at the beginning. Here foamed PS material behaves elastically. As the strain increases, an irreversible deformation occurs (compressive set). The limit of elasticity lies in the range 1.5-3.5% compression. This limit is shifted toward lower compression levels as the temperature increases. The compressive strain at 10% compression depends on the degree of fusion of the pre-foamed beads. Compressive set increases linearly with increasing density (Figure 9.16). 

For enviromnental testing, specimens were wrapped inside a semi-rigid multilayer plastic bag filled with detergent solution. To allow the specimen to bend freely during the test, a folded section was introduced into the central portion of the bag (Fig. 3). Testing was conducted at 50°C and 70°C in air and at 50°C in detergent solution respectively. 

Gamma-ray plastic sources The semi-point source is deposited in the leak-proof cavity of a rigid plastic holder. 

This standard covers the apparent core density of rigid cellular plastics and the bulk density of semi-rigid and flexible cellular plastics and rubbers. 

FDA approved under 21CFR178.2010 for use in acrylonitrile-butadiene-styrene copolymers at levels not to exceed 0.6% by weight of the copolymer. Section 177.1010 for use in semi-rigid and rigid acrylics at levels not to exceed 0.1% by weight of the plastic, and Section 175.105 as a component of food packaging adhesives. Also, approved by the FDA as an antioxidant in the preparation of rubber articles at a level not to exceed 5% by 21CFR177.2600. 

The ionomer which was isolated from the neutralization of sample SBD-2 was a brown-colored elastic network of moderate strength. Ionomer samples SBD-1 and SBD-2, neutralized to the stoichiometric end point using KOH, were compression molded at 140°C and examined for tensile properties. The results, as shown in Figure 16, illustrate the profound influence of crystallinity on the elastomeric inner block. The semi-crystalline material (SBD-1) behaves much like a rigid plastic, while the amorphous sample (SBD-2) is an elastomer of moderate strength. 

BULK Intermediate Bulk Container (rigid, semi-rigid, or flexible) Steel, aluminum, plastic, wood, fiber, textile and paper. 

Baker P-8 EINECS 202-935-1 Glyceryl triacetyl ricinoleate 9-Octadecenoio acid, 12-(aoetyloxy)-, 1,2,3-propanetriyl 1,2,3-Propanetriyl 12- aoetyloxy)-9-octa-decenoate Rioinolein, tri-, triacetate, A plasticizer for vinyl polymers and GR/S, neoprene GN, ethyl cellulose, and perbunan. Used for vinyl wire jacketing and semi-rigid vinyls as an emollient and stabilizer for anhydrated... 

The first commercial blend of this type is Cylon . Here PVC is the matrix, and PA (that melts below 215°C ) the dispersed phase. The two resins were compatibilized using the well known PVC plasticizer — Elvaloy (a terpolymer of ethylene, carbon monoxide and acrylics). These soft to semi-rigid alloys were commercialized for wire coating, automotive applications and blow molding [Grande, 1997 Hofmann, 1998]. They are flame, abrasion and chemicals resistant, easy to process, and tough. 

Plasticizers are the most voluminous additives of semi-rigid and flexible PVC formulations. Their properties, mechanisms of action, and effect on properties of plasticized materials have been extensively discussed in a specialized monographic source, and data on different grades are included in the plasticizer database. ... 

Use of esters of cyclohexanone polycarboxylic acids, such as di-(2-ethyl-hexyl) cyclohexanoic acid ester, enables production of materials having comparable mechanical properties with less PVC. It also increases UV stability, improves low temperature properties, and reduces smoke on burning. Highly flexible and semi-rigid goods can be manufactured with these plasticizers. This film is specially suitable for production of blood bags. 

Plastics in the form of rigid TSs, flexible elastomers and TPs, and semi rigid elastomer-modified TS materials have thus acquired a new function in the engineering world, namely, that of providing thermal protection. As reviewed this mode of heat protection is now known as the ablation or ablative process, and the fimctional materials employed are commonly referred to as ablators. ... 

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