Plastic furniture is a kind of furniture with new properties. There are many types of plastics, but they can basically be divided into two types: thermosetting plastics and thermoplastic plastics. The former is our common radio receiver, car dashboard, etc.; while the latter is various household appliance plastic parts, hoses, films or cabernet, etc. In modern furniture, this new material is pressed into a chair seat through a model, or pressed into various films as a cover fabric for soft furniture. There are also plastic hoses of various colors wrapped around steel pipes to form a soft chair.

Classification

Classify plastics according to usage characteristics

According to the different usage characteristics of plastics, plastics can generally be divided into three types: general-purpose plastics, engineering plastics and special plastics.

¢ÙGeneral-purpose plastics

Generally refers to plastics with large output, wide application, good formability and low price. There are five major types of general-purpose plastics, namely polyethylene (PE), polypropylene (PP), polyvinyl chloride (PVC), polystyrene (PS) and acrylonitrile-butadiene-styrene copolymer (ABS). They are all thermoplastics.

¢ÚEngineering plastics

Generally refers to plastics that can withstand certain external forces, have good mechanical properties and high and low temperature resistance, good dimensional stability, and can be used as engineering structures, such as polyamide, polysulfone, etc.

Engineering plastics are divided into two categories: general engineering plastics and special engineering plastics.

General engineering plastics include: polyamide, polyoxymethylene, polycarbonate, modified polyphenylene ether, thermoplastic polyester, ultra-high molecular weight polyethylene, methylpentene polymer, vinyl alcohol copolymer, etc.

Special engineering plastics are divided into cross-linked and non-cross-linked types.

Cross-linked types include: polyaminobismaleamide, polytriazine, cross-linked polyimide, heat-resistant epoxy resin, etc. Non-cross-linked types include: polysulfone, polyethersulfone, polyphenylene sulfide, polyimide, polyetheretherketone (PEEK), etc.

¢ÛSpecial plastics

Generally refers to plastics with special functions that can be used in special application fields such as aviation and aerospace. For example, fluoroplastics and silicones have outstanding special functions such as high temperature resistance and self-lubrication, and reinforced plastics and foam plastics have special properties such as high strength and high cushioning. These plastics all belong to the category of special plastics.

a. Strong plastics: Reinforced plastic raw materials can be divided into three types in appearance: granular (such as calcium plastic reinforced plastics), fibrous (such as glass fiber or glass cloth reinforced plastics), and sheet (such as mica reinforced plastics). According to the material, they can be divided into three types: cloth-based reinforced plastics (such as rag reinforced or asbestos reinforced plastics), inorganic mineral-filled plastics (such as quartz or mica-filled plastics), and fiber-reinforced plastics (such as carbon fiber reinforced plastics).

b. Foam plastics: Foam plastics can be divided into three types: hard, semi-hard and soft foam plastics. Hard foam plastics have no flexibility, and the compression hardness is very large. They will only deform when a certain stress value is reached, and they cannot return to their original state after the stress is released; soft foam plastics are flexible, have a very small compression hardness, are easily deformed, can return to their original state after the stress is released, and have a small residual deformation; the flexibility and other properties of semi-hard foam plastics are between hard and soft foam plastics.

Classification of plastics according to physical and chemical properties

Based on the different physical and chemical properties of various plastics, plastics can be divided into two types: thermosetting plastics and thermoplastic plastics.

(1) Thermoplastic plastics

Thermoplastic plastics: refers to plastics that melt when heated, flow into a mold and cool to form, and melt again when heated again; that is, they can be heated and cooled to produce a reversible change (liquid ¡û¡ú solid), which is the so-called physical change. The continuous use temperature of general-purpose thermoplastic plastics is below 100¡ãC. Polyethylene, polyvinyl chloride, polypropylene, and polystyrene are collectively known as the four general-purpose plastics. Thermoplastic plastics are further divided into hydrocarbons, vinyl containing polar genes, engineering, cellulose, and other types. They become soft when heated and harden when cooled. They can soften and harden repeatedly and maintain a certain shape. They are soluble in certain solvents and have the properties of being fusible and soluble. Thermoplastics have excellent electrical insulation properties, especially polytetrafluoroethylene (PTFE), polystyrene (PS), polyethylene (PE), and polypropylene (PP) have extremely low dielectric constants and dielectric losses, and are suitable for high-frequency and high-voltage insulation materials. Thermoplastics are easy to form and process, but have low heat resistance and are prone to creep. The degree of creep varies with the load, ambient temperature, solvent, and humidity.

In order to overcome these weaknesses of thermoplastics and meet the needs of applications in space technology, new energy development, and other fields, countries are developing heat-resistant resins that can be melt-formed, such as polyetheretherketone (PEEK), polyethersulfone (PES), polyarylsulfone (PASU), polyphenylene sulfide (PPS), etc. Composite materials with them as matrix resins have high mechanical properties and chemical corrosion resistance, can be hot-formed and welded, and have better interlaminar shear strength than epoxy resins. For example, composite materials made of polyetheretherketone as a matrix resin and carbon fiber have fatigue resistance that exceeds epoxy/carbon fiber. It has good impact resistance, good creep resistance at room temperature, good processability, and can be used continuously at 240-270¡æ. It is an ideal high-temperature resistant insulating material. The composite material made of polyethersulfone as the matrix resin and carbon fiber has high strength and hardness at 200¡æ, and can still maintain good impact resistance at -100¡æ; it is non-toxic, non-flammable, has minimal smoke, and has good radiation resistance. It is expected to be used as a key component of spacecraft, and can also be molded into radar antenna covers, etc.

Formaldehyde cross-linked plastics include phenolic plastics and amino plastics (such as urea-formaldehyde-melamine-formaldehyde, etc.). Other cross-linked plastics include unsaturated polyesters, epoxy resins, phthalic acid diallyl ester resins, etc.

(2) Thermosetting plastics

Thermosetting plastics refer to plastics that can be cured or have insoluble (melting) characteristics under heat or other conditions, such as phenolic plastics, epoxy plastics, etc. Thermosetting plastics are divided into two types: formaldehyde cross-linked and other cross-linked. After hot processing and molding, a solidified material with infusibility and insolubility is formed, and its resin molecules are cross-linked from linear structures to mesh structures. Further heat will decompose and destroy.

Typical thermosetting plastics include phenolic, epoxy, amino, unsaturated polyester, furan, polysilicone and other materials, as well as newer polypropylene phthalate plastics. They have the advantages of high heat resistance and not easy to deform when heated. The disadvantage is that the mechanical strength is generally not high, but its mechanical strength can be improved by adding fillers to make laminated materials or molded materials. Thermosetting plastics made of phenolic resin as the main raw material, such as phenolic molded plastics (commonly known as bakelite), have the characteristics of being strong and durable, dimensional stability, and resistance to other chemical substances except strong alkali. Various fillers and additives can be added according to different uses and requirements. For varieties requiring high insulation performance, mica or glass fiber can be used as fillers; for varieties requiring heat resistance, asbestos or other heat-resistant fillers can be used; for varieties requiring earthquake resistance, various appropriate fibers or rubbers can be used as fillers and some toughening agents to make high-toughness materials. In addition, phenolic resins modified by aniline, epoxy, polyvinyl chloride, polyamide, polyvinyl alcohol acetal, etc. can be used to meet the requirements of different uses. Phenolic resin can also be used to make phenolic laminates, which are characterized by high mechanical strength, good electrical properties, corrosion resistance, easy processing, and are widely used in low-voltage electrical equipment. Amino plastics include urea formaldehyde, melamine formaldehyde, urea melamine formaldehyde, etc. They have the advantages of hard texture, scratch resistance, colorlessness, translucency, etc., and can be made into colorful products by adding colorants, commonly known as electric jade. Because it is oil-resistant and not affected by weak alkali and organic solvents (but not acid-resistant), it can be used for a long time at 70¡ãC and can withstand 110-120¡ãC in a short time, and can be used for electrical products.

Melamine formaldehyde plastics are harder than urea formaldehyde plastics, have better water resistance, heat resistance, and arc resistance, and can be used as arc-resistant insulating materials. There are many types of thermosetting plastics made with epoxy resin as the main raw material, of which about 90% are based on bisphenol A epoxy resin. It has excellent adhesion, electrical insulation, heat resistance and chemical stability, small shrinkage and water absorption, good mechanical strength and other characteristics. Unsaturated polyester and epoxy resin can be made into FRP, which has excellent mechanical strength. For example, FRP made of unsaturated polyester has good mechanical properties and low density (only 1/5 to 1/4 of steel and 1/2 of aluminum), and is easy to process into various electrical parts.

The electrical and mechanical properties of plastics made of dipropylene phthalate resin are better than those of phenolic and amino thermosetting plastics. It has low hygroscopicity, stable product size, good molding performance, acid and alkali resistance, boiling water and some organic solvents. Molding plastics are suitable for manufacturing parts with complex structures, both heat resistance and high insulation. Generally, it can be used for a long time in the temperature range of -60 to 180¡æ, and the heat resistance grade can reach F to H, which is higher than the heat resistance of phenolic and amino plastics.

Organic silicone plastics in the form of polysiloxane structure are widely used in electronic and electrical technology. Silicone laminated plastics are mostly reinforced with glass cloth; silicone molded plastics are mostly filled with glass fiber and asbestos, which are used to manufacture parts of high temperature, high frequency or submersible motors, electrical appliances, and electronic equipment. The characteristics of this type of plastic are that the dielectric constant and tg¦Ä value are small, and the frequency is less affected. It is used in the electrical and electronic industries to resist corona and arc. Even if the discharge causes decomposition, the product is silicon dioxide instead of conductive carbon black. This type of material has outstanding heat resistance and can be used continuously at 250¡ãC. The main disadvantages of polysilicon ether are low mechanical strength, low adhesiveness, and poor oil resistance. Many modified silicone polymers have been developed, such as polyester modified silicone plastics, which are used in electrical technology. Some plastics are both thermoplastic and thermosetting plastics. For example, polyvinyl chloride is generally a thermoplastic plastic. Japan has developed a new type of liquid polyvinyl chloride that is thermosetting and has a molding temperature of 60-140¡ãC; a plastic called Lendex in the United States has both the characteristics of thermoplastic processing and the physical properties of thermosetting plastics.

¢Ù Hydrocarbon plastics. They are non-polar plastics, which can be crystalline or non-crystalline. Crystalline hydrocarbon plastics include polyethylene, polypropylene, etc., and non-crystalline hydrocarbon plastics include polystyrene, etc.

¢Ú Vinyl plastics containing polar genes. Except for fluoroplastics, most of them are non-crystalline transparent bodies, including polyvinyl chloride, polytetrafluoroethylene, polyvinyl acetate, etc. Most vinyl monomers can be polymerized using free radical catalysts.

¢Û Thermoplastic engineering plastics. They mainly include polyoxymethylene, polyamide, polycarbonate, ABS, polyphenylene ether, polyethylene terephthalate, polysulfone, polyether sulfone, polyimide, polyphenylene sulfide, etc. Polytetrafluoroethylene. Modified polypropylene, etc. are also included in this range.

¢Ü Thermoplastic cellulose plastics. They mainly include cellulose acetate, cellulose acetate butyrate, celluloid, cellophane, etc.

Classification of plastics by processing methods

According to the different molding methods of various plastics, they can be divided into various types such as film pressing, lamination, injection, extrusion, blow molding, casting plastics and reaction injection plastics.

Mold pressing plastics are mostly plastics with physical properties and processing properties similar to those of general solid plastics; laminated plastics refer to fiber fabrics impregnated with resin, which are combined into a whole material through superposition and hot pressing; injection, extrusion and blow molding are mostly plastics with physical properties and processing properties similar to those of general thermoplastics; casting plastics refer to liquid resin mixtures that can be poured into a mold without pressure or with a little pressure and can be hardened into a certain shape of products, such as MC nylon; reaction injection plastics are plastics that use liquid raw materials, pressurized into the film cavity, and react and solidify into a certain shape of products, such as polyurethane.

Advantages

Compared with other furniture, plastic furniture has the following advantages:

1. Colorful and smooth lines

Plastic furniture has bright colors. In addition to the common white, there are red, orange, yellow, green, blue, purple...all kinds of colors are available, and there are also transparent furniture. Its bright visual effect brings people visual comfort. At the same time, because plastic furniture is processed by molds, it has the remarkable characteristics of smooth lines. Every fillet, every arc, every grid and interface is naturally smooth and without any traces of handwork.

2. Diverse, casual and beautiful shapes

Plastics are easy to process, so the shape of this type of furniture has more randomness. The random shape expresses the designer's highly personalized design ideas, and embodies a kind of casual beauty through the shape that is difficult to achieve with ordinary furniture.

3. Lightweight and compact, easy to carry

Compared with ordinary furniture, plastic furniture gives people a feeling of lightness. You don't need to spend a lot of effort to carry it easily, and even plastic furniture with metal brackets inside, its brackets are generally hollow or have a small diameter. In addition, many plastic furniture have the function of folding, so it saves space and is more convenient to use.

4. Diverse varieties and wide application

Plastic furniture is suitable for both public places and ordinary families. In public places, you see the most various chairs, and there are countless varieties suitable for families: dining tables, dining chairs, lockers, hangers, shoe racks, flower racks.

5. Easy to clean and easy to protect

If plastic furniture is dirty, it can be directly washed with water, which is simple and convenient. In addition, plastic furniture is also easier to protect, and the requirements for indoor temperature and humidity are relatively low, and it is widely used in various environments.

Maintenance Methods

1. PVC furniture is easy to age and crack, and can only be used indoors, not outdoors. It should be kept away from direct sunlight and near stoves and radiators. If there is a crack, it can be softened with an electric soldering iron and then glued, or it can be glued with glue made from banana water and PVC powder.

2. Polypropylene furniture is resistant to light, oil, and chemical solvents, but has poor hardness. It should be prevented from collision and scratches by hard objects with knife tips. If there is a crack, it can be repaired by hot melt method, and no glue can be used.

3. FRP furniture has excellent performance and is suitable for indoor and outdoor applications. It has a long life, is sturdy and durable, but it is not easy to repair damage. It can be connected and repaired with screws and gaskets. When using it, it should be prevented from overloading and accidental fracturing and scratching.

4. Plastic furniture can be washed with ordinary detergents, be careful not to touch hard objects, and do not use metal brushes to wash. Frequent washing and sun protection can keep plastic furniture new for a long time.

5. Artificial leather, synthetic leather, and soft leather furniture are afraid of heat, sunlight, cold, and oil, and cannot be placed in the bathroom or kitchen. Clean soft cloth should be used frequently for cleaning. If the dirt is heavy, wipe it with a cloth dipped in neutral detergent, then wipe it with a wrung wet cloth, and then wipe it with a dry cloth. Covering the artificial leather and synthetic leather furniture with a cloth cover, such as a sofa cover and a chair cover, can extend the service life.

6. Plastic veneer furniture should not be exposed to direct sunlight, local vertical pressure, or heat to prevent the veneer joint from expanding and degumming. It is also necessary to prevent local hammering and cutting cracking. The substrate of the veneer furniture is mostly fiberboard, which is very easy to swell and separate due to moisture. Pay special attention to waterproofing and moisture-proofing. You can apply 1 to 2 layers of varnish on the substrate, that is, the reverse side of the veneer to prevent moisture. If the veneer is found to be detached from its substrate, the joint should be cleaned with banana water or xylene first, and then restored with universal glue. After the glue is dry, seal the joint with varnish. White latex is not water-resistant and should not be used to paste boards.

Plastic Industry Video