Adhesives sealing applications

Sikaflex -291 One-component, polyurethane-based sealing/adhesive compound All-purpose grade is used for general marine adhesive sealing applications Low viscous, medium modulus. 

In joining reinforced thermosetting pipe it is particularly important that the pipe be cut without chipping or cracking it. It is also important to sand, file, or grind any mold-release agent from the surfaces to be cemented. Joints are built up layer by layer of adhesive-saturated reinforcement by following the manufacturer s recommended procedure. Application of adhesive to the surfaces to be joined and assembly of these surfaces shall produce a continuous bond and provide an adhesive seal to protect the reinforcement from attack by the contents of the pipe. Unfilled or unbonded areas of the joint are considered defects and must be repaired. 

The main use for acrylates is in sealing applications where the improved heat stability over nitrile rubber is the benefit. Automotive transmission seals are probably the major use, other automotive applications include O-rings, hose, tubing, cable covering and spark plug boots. Also used in adhesive formulations. 

It has been found that in the development of EVA polymers for heat seal applications by emulsion polymerization that the concentration of vinyl acetate and ethylene in the polymer is not solely responsible for its use as a heat seal adhesive (2). 

Epoxies can cure in deep sections and are useful in potting and deep-section sealing applications. They adhere well to different substrates and therefore are used in the general assembly of many medical devices. A clear, medical-grade, low-viscosity epoxy adhesive has proved useful in the fabrication of access ports that are implanted beneath the skin of patients who require multiple infusions.21... 

Hot-melt adhesives are usually used for box-sealing applications for coated paperboard products. Migration of mineral hydrocarbons from these adhesives into foods was investigated in a survey. No mineral hydrocarbons were detected but several other substances were present in the adhesives. These were proposed to be natural resins such as polyterpene resins, tall oil rosin esters, and sterol-like natural products.Examples of each of these natural products are described in ref. 13 as being used for hot-melt adhesives. 

C, moisture-crosslinking PUR adhesives are silicone-free sealants and adhesives that can be painted over after appUcation and can be used overhead due to their thixotropy. Rapid skin formation in sealing applications ensures product reliability. 

Beilstein Handbook Reference) AI3-00515 BRN 1889288 CCRIS 6190 DCHP Dicyclohexyl 1,2-benzenedicarboxylate Dicyclohexyl phthalate EINECS 201-545-9 Ergoplast FDC HF 191 Howflex CP HSDB 5246 KP 201 NSC 6101 Phthalic acid, dicyclohexyl ester Unimoll 66. A plasticizer for nitrocellulose, ethylcellulose, chlorinated rubber, PVAc, PVC, and other polymers. Used in formulation of delayed tack heat sealable coatings, it Is a heat activated plasticizer for heat seal applications such as food wrappers/labels, pharmaceutical labels and other applications where delayed heat activated adhesive is required used in manufacture of printing ink formulations for paper, vinyl, textiles, and other substrates. Solid mp = 66° d = 1.383 insoluble in H2O, soluble in EtOH, Et20, CHCI3, Bayer AG Lancaster Synthesis Co. Miles Inc. Morflex Unitex. 

Beilstein Handbook Reference) Benzoflex S-552 Benzoic acid, tetraester with pentaerythritol 2,2-Bis((benzoyloxy)methyl)-1,3-propane-diol dibenzoate BRN 3513249 CCRIS 5971 EINECS 224-079-8 NSC 166502 Pentaerythritol tetrabenzoate 1,3-Propanediol, 2,2-bis( benzoyloxy)methyl)-, dibenz-oate Uniplex 552. Plasticizer for adhesives intended for heat seal applications Solid mp = 102-104°. Unitex. 

Natural rubber adhesive, or latex, is used in self-seal applications, where it makes use of its unique ability to bond only to itself with pressure. Applications include selfseal envelopes, press-to-seal cases, and cold-seal candy wraps. Natural rubber latex is also used in adhesives for lamination of polyethylene film to paper, such as in multiwall hags. 

Figure 3 Application of a sealant automatically extruded onto an oil pan flange. Table 2 Main Adhesive Bonding and Sealing Applications in the Body Shop...

Other differences, both in kind and degree, combine to make the thermosetting resins as a class useful in many industrial applications for which the thermoplastics are chemically unsuited. The thermosetting epoxy resins possess a number of unusually valuable properties immediately amenable to use in the formulation of adhesives, sealing liquids, cold solders, castings, laminates, and coatings. The more important of these properties include ... 

The major use of adhesives for cryogenic applications is for bonding external insulation for both metallic and non-metallic substrates. Adhesives are also capable of acting as sealants. Many wing structures utilize adhesive-sealed tanks and pressure-type bulkheads. Room-temperature-vulcanizing (RTV) silicones have been evaluated as sealants and adhesives for... 

Poly isobutylene, PIB. Applications adhesives, sealing compounds, electrical insulating oils, viscosity improvers. 

Bonds between rubber and substrates can fail for a number of reasons. Section 12.1 deals with some of the causes of rubber to metal bond failures. Section 12.2 examines the type of failures which are adhesion related, in fabric or cord reinforced power transmission belts. Section 12.3 discusses a phenomenon which causes service failures of rubber components, mainly in sealing applications. This phenomenon arises through a bond which is formed between the rubber (nitrile) and the metal mating surface of a valve or similar, which is of sufficient strength to rupture the rubber surface when the valve is opened. 

MlL-A-9117 Adhesive sealing, for aromatic fuel cells and general repair MIL-C-10523 Cement, gasket, for automobile applications MlL-S-11030 Sealing compound noncuring polysulfide base MlL-S-11031 Sealing compound, adhesive curing, polysulfide base MIL-A-11238 Adhesive cellulose nittate... 

Hot-melt systems are usually flexible and tough. They are used extensively for sealing applications involving paper, plastic films, and metal foil. Table 7.29 offers a general comparison of hot-melt adhesives. Hot melts can be supplied as (1) tapes or ribbons, (2) films, (3) granules, (4) pellets, (5) blocks, or (6) cards, which are melted and pressed between the substrate. The rate at which the adhesive cools and sets is dependent on the type of substrate and whether it is preheated. Table 7.30 lists the advantages and disadvantages associated with the use of water-based, solvent-based, and hot-melt thermoplastic adhesives. 

Silicones are synthetic polymeric materials which may be formulated to have a very wide range of properties. All have a basic polysiloxane structure, giving them a combination of organic and inorganic chemical properties. These properties have made them of interest for adhesive and sealing applications. Their main features are ... 

Table 4 further illustrates that the PVOH-protected and the cellulosic emulsion are both excellent bases for adhesives to bond to polyvinyl chloride. The PVOH-protected emulsion is usually chosen for wet laminations and the cellulosic emulsion for heat-seal applications. 

Robots are used to dispense adhesives and sealants throughout the automotive industry today. Automation requirements will be examined for windshield bonding to the vehicle, door manufacturing, passenger compartment interior seam sealing, and the application of sealants during the buildup of the vehicle body. These account for the vast majority of robotic sealant and adhesive dispensing applications in the automotive industry. 

Uniplex 250 is a beat activated plasticizer used in heat seal applications such as food wrappers, food labels, pharmaceutical labels and other applications where a delayed heat activated adhesive is required. 

Uniplex S62 Pentaerythritol Tetrabenzoata CAS No. 4196-86-5 Uniplex 552 is a solid plasticizer that can be formulated into adhesives intended for heat seal applications. It is approved by FDA under 21CFR 175.105. 

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