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Photoes foam sample cut
continuous line polyurethane foam cutting machine foam for sofa mattress, uphostry
What is polyurethane foam (PU FOAM)?
(Soft or foam semi-rigid)
(1) polyurethane
Commonly abbreviated PU is any polymer consisting of a chain of organic units joined by urethane links. Polyurethane polymers are formed by the reaction of a monomer containing at least two isocyanate functional groups with another monomer containing at least two alcohol groups in the presence of a catalyst. Polyurethane formulations cover a wide range of rigid, hardness and density. These materials are low density flexible foam used in upholstery and bedding, low density rigid foam used for insulation heat, soft solid elastomers used for gel pads and rollers, rigid plastics and difficult to use as a tool electronic bezels and structural parts. Polyurethanes are widely used in the seats of high strength flexible foam, rigid foam insulation panels, microcellular foam seals and gaskets, durable elastomeric wheels and tires, electrical potting compounds, adhesives and sealants, high-performance, spandex fibers, seals, gaskets, carpet underlay, and hard plastic parts. Polyurethane products are often called "urethanes". Not to be confused with the specific substance urethane, also known as ethyl carbamate. Polyurethanes are produced from ethyl carbamate, nor do they contain.
Upholstery is the work of providing furniture, especially seats with padding, springs, webbing, and fabric or leather. The word "upholstery" comes from the Middle English words and retained, ie for support. The term is applied to domestic furniture and also for applications in automobiles and boats. A person who works with upholstery is called an upholsterer, a apprentice upholsterer is sometimes called strange or trimmer.
Polyurethane products have many uses. More than three-quarters of global consumption of polyurethane products is in the form of foam, flexible and rigid types being roughly equal in market size. In both cases, the foam is usually behind other materials: flexible foams are behind upholstery fabrics in commercial and domestic furniture, rigid foams are inside the metal and plastic walls of most refrigerators and freezers, or behind paper, metals and other surface materials in the case of thermal insulation panels in the construction sector. His use in garments is growing: for example, lining the tops of the props. Polyurethane is also used for moldings which include door frames, columns, balustrades, window headers, pediments, medallions and rosettes.
The precursors of expanding polyurethane foam are available in many forms, for use in insulation, acoustic insulation, flotation, industrial coatings, packaging materials and even cast-in-upholstery stuffing place. From that adhere to most surfaces and automatically fill in the gaps, they have become very popular in these applications.
Chemistry
Polyurethanes are a class of compounds called reaction polymers such as epoxies, unsaturated polyesters and phenolic compounds. A urethane linkage is produced by reacting an isocyanate group,-N = C = O with a hydroxyl (alcohol) group,-OH. Polyurethanes are produced by the reaction of polyaddition of a polyisocyanate with a polyalcohol (polyol) in the presence of a catalyst and other additives. In this case, a polyisocyanate is a molecule with two or more isocyanate functional groups, R-(N = C = O) n ≥ 2 and a polyol is a molecule with two or more functional hydroxyl groups, R '(OH) n ≥ 2. The reaction product is a polymer containing urethane ratio, RNHCOOR-'. Isocyanates react with any molecule containing an active hydrogen. Importantly, isocyanates react with water to form an urea and carbon dioxide gas, but also react to form polyureas polyetheramines. Commercially, polyurethanes are produced by reacting a liquid isocyanate with a liquid mixture polyols, catalyst and additives. These two components are referred to as a polyurethane system, or simply a system. The isocyanate is commonly known in America North as the "A side" or simply the 'iso'. The mixture of polyols and other additives commonly known as the 'flip side' or 'poly'. This mixture could also be called a "resin" or "resin mixture. In Europe, the meanings of" one side "and" side B " reversed. Mixture of resin additives may include chain extenders, cross linkers, surfactants, fire retardants, foaming agents, pigments and fillers.
The first essential component of a polyurethane polymer is the isocyanate. Molecules containing two isocyanate groups are called diisocyanates. These molecules are also known as monomers or monomer units, since they themselves are used to produce polymeric isocyanates that contain three or more isocyanate functional groups. Isocyanates can classified as aromatic, such as diphenylmethane diisocyanate (MDI) or toluene diisocyanate (TDI), or aliphatic such as hexamethylene diisocyanate (HDI) or diisocyanate isophorone (IPDI). An example of a polymeric isocyanate is polymeric diphenylmethane diisocyanate, a mixture of molecules with two, three, four or more isocyanate groups, with an average functionality of 2.7. Isocyanates can be further modified in part to react with a polyol to form a prepolymer. A quasi-prepolymer is formed when stoichiometric ratio of isocyanate to hydroxyl groups is greater than 2:1. A true prepolymer is formed when the stoichiometric ratio equals 2:1. Features main isocyanates is their molecular backbone,% NCO content, functionality, and viscosity.
The second essential component of a polyurethane polymer is the polyol. Molecules containing two hydroxyl groups are called diols, which have three hydroxyl groups are called triols, etc. In practice, polyols are distinguished of short chain or diluents of low molecular weight glycol chain and cross-linkers such as ethylene glycol (EG), 1.4-butanediol (BDO), diethylene (DEG), glycerine, and trimethylolpropane (TMP). Polyols are polymers in their own right. They are formed by free radical addition of propylene oxide (PO) ethylene oxide (EO) in a hydroxyl or amine containing initiator, or polyesterification of a di-acid such as adipic acid, with glycols such as ethylene glycol or dipropylene glycol (DPG). Polyols extended with PO and EO are polyether polyols. Polyesterification polyols are polyols made up of polyester. The choice of initiator, extension, and molecular weight polyol greatly affect its physical state and physical properties of the polyurethane polymer. Important characteristics of polyols are their structure molecular initiator, molecular weight,% primary hydroxyl groups, the functionality and viscosity.
PU mechanism of reaction catalyzed by carbon dioxide gas tertiary amine and water formed by reaction of isocyanate
The polymerization reaction is catalyzed by tertiary amines, as dimethylcyclohexylamine, and organometallic salts, as dibutyltindilaurate. Moreover, the catalysts can be chosen depending on whether they favor the urethane (gel) reaction, such as diazobicyclooctane, or urea (Blow) reaction, such as bis-dimethylaminoethylether, or specifically lead isocyanate trimerization reaction, such as potassium octoate.
One of the attributes polyurethanes most desirable is its ability to be foamed. Blowing agents such as water, some halocarbons such as HFC-245fa (1,1,1,3,3-Pentafluoropropane) and HFC-134a (1,1,1,2-tetrafluoroethane), and hydrocarbons such as n-pentane, can be incorporated in the next cop or added as an auxiliary flow. Water reacts with isocyanate to create carbon dioxide gas, which fills and expands cells created during the mixing process. The reaction is a three-step process. A water molecule reacts with an isocyanate group to form a carbamic acid. Carbamic acids are unstable and decompose to form carbon dioxide and an amine. The amine reacts with more isocyanate to give a substituted urea. Water has a very low molecular weight, so even if the weight percent of the water may be small, the molar ratio of water can be tall and produces large quantities of urea. Urea is very soluble in the reaction mixture and tends to form separate "hard segment" phases mostly polyurea. The concentration and organization of these phases polyurea may have a significant impact on the properties of polyurethane foam. [11] halocarbons and hydrocarbons are chosen so that have boiling points at or near room temperature. Since the polymerization reaction is exothermic, these blowing agents volatilize into a gas during the reaction process. Fill and expand the extracellular matrix polymer, creating a foam. It is important to know that blowing gas does not create foam cells. Rather, they are formed during the mixing process of nucleation sites that the blowing gas fills and expands. In fact, high-density foam cell micro can be formed without the addition of foam blowing agents or nucleating polyester mechanics before use.
(2) Use of polyurethane
1. Furniture
2. Car Seats
3. Varnish
4. Computer mouse pads
5. Glue
6. Wheels
7. Casas, sculptures and decorations
8. Jetski
9. construction sealants and stop the fire
10. Tennis grips
11. Electronic Components
12. Bookbinding industry
13. Look packing band
1.Furniture
Polyurethane is also used in furniture manufacture for casting soft edges around tables and panel that are stylish, durable and prevent injury. These are used in school tables, hospital furniture and bank and shop counters and sample.
Much of the foam used in chairs, sofas, mattresses and sacks are Comfortable polyurethane foam. This type of foam is mixed polyols, diisocyanates, catalysts, foaming agents and other additives and allowing the resulting foam to rise freely. This can be done in a batch process in relatively small blocks of foam are made in a mold open top or components continuously poured onto a moving inclined belt. The foam is then cut to desired shape and size for use in the manufacture of furniture.
Safety concerns about the flammability of polyurethane foam, especially upholstered furniture, sometimes requires the addition flame retardants in the foam.
Polyurethane is in other countries like the Netherlands used as a soil solution for homes, offices, museums.
2. Car Seats
flexible polyurethane foams and semi-flexible, widely used for automotive interior components, seats, headrests, armrests, roof liners and instrument panels
Polyurethane foam in the bottom half of the mold in which it was made. Once attached to a car seat, this foam makes up the back seat. The forward-facing part of the back seat is the surface of the foam in the mold upside down. The two holes in the foam on top of the image is for the headrest.
Foam after removal of the mold.
Polyurethanes are used to make car seats remarkably. The seat manufacturer has a mold for each seat model. The mold is allowed to close a "shell" type of structure that allows quick wash pad seat, so-called flexible molded foam, which is then trimmed after removal from the mold.
You can combine these two steps, called in-situ Foam on the web or direct molding. In this case, the inner surfaces of the mold with hundreds of small holes that are connected to a vacuum manifold. This creates a constant flow air from the center of the mold to the collector. The operator of the first assembly places a full deck, fully assembled in the mold seat and adjusted so that the manifold vacuum pull the seat cover tight against the mold surface. In some operations, this effect is enhanced by the addition of a thin flexible plastic film as support fabric to help the vacuum work more effectively. When the seat cover is in place, the operator places the steel structure of the seat and closes the mold the mold. At this point the mold contains what could be depicted as an "empty chair", a fabric held up in the correct position of depression Admission and containing a hole in the steel structure in place.
The next step is to inject the chemical mixture of polyurethane in the mold cavity. This is a mixture of two parts that is accurately measured through a mixing head. Then the mold is maintained at a preset reaction temperature until the mixture chemical foam has filled the mold, and formed soft foam stability. The time required is two to three minutes, depending on seat size and the precise formulation and operating conditions. Then the mold is usually opened slightly for a minute or two for additional curing time before the fully upholstered seat removed. The operator cut any seat fabric cover over the finished seat and puts on a conveyor belt.
3 Varnish
polyurethane materials commonly formulated as paints and varnishes for finishing layers of protection or stamp of wood. This results in use on a hard surface, resistant to abrasion and durable coating that is popular for hardwood floors, but considered by some to be difficult or unsuitable for finishing furniture or other items detailed. In relation with oil or shellac varnishes, polyurethane varnish forms a harder film which tends to laminate if subjected to heat or shock, fracturing the film and leave white spots. This tendency is increased when applied over softer woods like pine. This is also partly due to lower penetration of polyurethane on the wood. Various priming techniques are employed to solve this problem, including the use of certain oil varnishes, specified "Dewaxing" epoxy shellac, clear penetrating or "oil-modified" polyurethane designed for this purpose. Polyurethane varnish may also lack the "hand-rubbed" drying oils such as brightness linseed or tung oil, in contrast, however, is capable of much faster and higher "build" of the film, making two layers which may require several applications of oil. Polyurethane can also be applied on a straight oil finish, but due to the relatively slow time healing oils, the presence volatile by-products of curing, and the need for prolonged exposure of the oil with oxygen, care must be taken that the oils are sufficiently cured to accept the polyurethane.
Unlike drying oils and alkyds which cure, after evaporation of the solvent, upon reaction with oxygen from the air, polyurethane coatings cure after evaporation of the solvent by a variety of chemical reactions within the original mixture, or reaction with air humidity. Some products are "hybrids" and combine different aspects of the components of their parents. "Oil changed" polyurethanes, either by water or solvent based, are currently the most widely used wood finish floor.
Exterior use of polyurethane varnish may be problematic because of its susceptibility to deterioration from exposure to ultraviolet light. It should be noted, however, that all transparent or translucent varnishes, and indeed all layers of polymer film (iepaint, stain, epoxy, synthetic plastic, etc) are susceptible to this damage in varying degrees. The paint pigments and stains protect against UV rays, while UV-absorbers are added to polyurethane and other varnishes (in particular, "spar" varnish) to work against UV rays. Polyurethanes are generally more resistant to exposure to water, high humidity, extreme temperatures, and mold or mildew, which also adversely affect varnish and paint performance.
4.Computer mouse pads
Polyurethane is used in the bottom of some T- mouse.
5.Glue
Polyurethane is used as an adhesive, especially as an adhesive for woodworking. Its main advantage over more traditional lines wood is its resistance to water. Was added to the overall market in North America in the 1990s as Gorilla Glue and Excel, but has been used much longer Europe.
6.Wheels
Polyurethane is also used in the manufacture of solid tires. Modern roller skating and skateboarding became economical only with the introduction of hard parts of abrasion-resistant polyurethane. Other constructions have been developed for the tires, and variants of microcellular foam are widely used in tires on wheelchairs, bicycles and other such uses. These types of foam of the latter are also widely found in the wheels direction of the car and the interior and other exterior auto parts, including bumpers and fenders.
7.Houses, sculptures and decorations
The walls and ceiling (not just the insulation) to the futuristic Xanadu House were built with polyurethane foam. vaulted ceilings and other odd shapes are easier to with the foam timber. Foam was used to construct odd-shaped buildings, statues and decorations in the Seuss Landing section of the theme park islands adventure. Specialty foam rigid foam sell manufactured products that replace wood carved sign and industries of the topography in 3D.
8.Watercraft
Some surfboards are made with a solid polyurethane core. A rigid foam blank is molded in the form of specifications, then covered with fiberglass cloth and polyester resin.
The hull of the Boston Whaler boat is made of polyurethane foam sandwiched in a fiberglass skin. The foam provides force, buoyancy, and sound dampening.
9.Construction sealants and stop the fire
Head of Joint Firestop the wall: the presence of penetrating demonstrates the need for both operational support and testing of fire between the joint sealant and mechanical / electrical penetrations. In other words, it is easy to insist on the use of firestops participation can also be used for penetration seals, otherwise they may be run by penetrating subtrades mechanical and electrical inadvertently void the fire-resistance rated wall, which jeopardizes the fire safety plan in place for a whole building.
Head-to-wall Joint Firestop penetrated by both electrical and mechanical services, which demonstrates the need for interoperability and proven fire between the common system firewalls and penetrating, whether electrical, mechanical or structural.
Polyurethane sealants are available in 1, 2 or even 3 party systems, either in the cartridge, the bucket or drum format. polyurethane sealants are also sold for fire applications. Obviously, the seal itself does not offer serious obstacle to the fire because their bonds readily support combustion of hydrocarbons. However, when backed by an inorganic insulation such as wool rock or ceramic fiber, which can act as an effective seal to prevent passage of smoke and blast hose, especially in inorganic joints. It is, however, should avoid direct contact with metal piercing and penetration through cables, and the heat carried by the piercing can compromise the seal. This, however, requires much supervision. Specifically with concrete or concrete masonry joints, however, are free from mechanical penetrating or electric, it works well and reliably. As with all products and passive fire protection systems, the key to the code compliance can be demonstrated constraint.
Fists 10.Tennis
Polyurethane has been used to make several Tennis Overgrips as Supergrap Yonex, Wilson Pro Overgrip Grips and many others. These grips are very flexible to ensure adherence carefully wrapped around the racket handle.
11.Electronic Components
Often, components electronics are protected from environmental influences and impact by enclosing them in polyurethane. Typically polyurethanes are selected for abrasion resistance excellent, good electrical properties, excellent adhesion, impact resistance and flexibility at low temperatures. The disadvantage of polyurethanes is the operating temperature upper limit (usually 250 ° F (121 ° C)). In the production of electronics manufacturing buy a two-part urethane (resin and catalyst) that mixing and pouring onto the circuit assembly (see Resin casting). In most cases, the circuit board mounting end would be irreparable after cured polyurethane. Due to its physical properties and low cost, polyurethane encapsulation (potting) is a popular choice in the automotive manufacturing sector for circuits and sensors in the car.
Industry 12.Bookbinding
In the form of a new tail and better for binders, a new adhesive system was introduced for the first time in 1985. The basis for this system is polyether or polyester, while the polyurethane (PUR) is used as prepolymer. Its special feature is the coagulation at room temperature and reaction to moisture.
Generation 1 (1988 to drupa) – Lower starting strength – high viscosity – Drying time over 3 days
2nd Generation (1996 at the drupa) – Lower starting strength – high viscosity – Drying time of less than 3 days
3 rd Generation (2000 at the drupa) – Good starting solidity – Low viscosity – Drying time between 6 and 16 hours
4 th generation (this) – Good strength starting – Very low viscosity – Drying time is reached in a few seconds due to dual-core Systems
Advantages of polyurethane glue in the bookbinding industry: PUR is real wonder compared to hotmelt and cold glue. Due to lack moisture in the glue, papers with wrong grain direction can be processed without problems. Even paper and paper supercalandered can bind with no problems. It is the most economical glue with a thickness of 0.01 mm theoretical application. But in reality it is not possible applied to less than 0.03 mm. The polyurethane adhesive is weather resistant and stable at temperatures of -40 ° C to 100 ° C.
Banda 13.Watch packaging
Polyurethane is used as a black wrap to watch bands on the main material, which is usually stainless steel. It is used for comfort, style and durability.
