Common protective screen material analysis

Polycarbonate

Polycarbonate (abbreviated as PC) is a high molecular polymer containing a carbonate group in its molecular chain. According to the structure of the ester group, it can be classified into various types such as aliphatic, aromatic, and aliphatic-aromatic. Among them, due to the lower mechanical properties of aliphatic and aliphatic-aromatic polycarbonates, their use in engineering plastics is limited. At present, only aromatic polycarbonates have been industrially produced. Due to the special structure of polycarbonate, it has become the fastest growing general engineering plastic among the five engineering plastics.

Physical properties

Density: 1.20-1.22 g/cm Linear expansion rate: 3.8×10 cm/cm°C Thermal deformation temperature: 135°C

Polycarbonate is a colorless, transparent, heat-resistant, impact-resistant, and flame-retardant BI grade. It has good mechanical properties at normal use temperatures. Compared with polymethyl methacrylate, polycarbonate has better impact resistance, higher refractive index, better processing performance, and UL94 V-0 flame retardant without additives. However, polymethyl methacrylate has a relatively low price relative to polycarbonate and can produce large devices by bulk polymerization. With the ever-increasing scale of polycarbonate production, the price difference between polycarbonate and polymethyl methacrylate is shrinking.

Not resistant to strong acid, not resistant to alkali, modified to acid and alkali

Polycarbonate has poor abrasion resistance. Some polycarbonate devices for wear-resilient applications require special treatment of the surface.

The application development of polycarbonate is developing towards high compounding, high functionality, specialization, and serialization. At present, CDs, automobiles, office equipment, cabinets, packaging, medicine, lighting, films, and other products have been introduced. Grade grade.

(1) For the building materials industry. Polycarbonate sheet has good light transmittance, impact resistance, UV radiation resistance and dimensional stability of the product and good molding processing performance, making it has obvious technical performance advantages over the inorganic glass traditionally used in the construction industry. At present, China has more than 20 hollow board production lines for polycarbonate building materials, and it is required to use about 70,000 tons of polycarbonate annually, and it is expected to reach 140,000 tons by 2005.

(2) For the automotive industry. Polycarbonate has good impact resistance, thermal distortion resistance, and good weather resistance, high hardness, so it is suitable for the production of various parts for cars and light trucks, mainly in the lighting system, dashboard, heating plate, in addition to Froster and polycarbonate alloy bumper. According to the statistics of developed countries, the proportion of polycarbonate used in electronics, electrical and automobile manufacturing is between 40% and 50%. At present, the proportion of China's use in this area accounts for only about 10%. The electronic and electrical and automobile manufacturing industries are rapidly developing in China. In pillar industries, the demand for polycarbonate in these areas in the future will be enormous. It is expected that the total number of vehicles in China will reach more than 3 million units in 2005, and the demand will also reach 30,000 tons by that time. Therefore, the application of polycarbonate in this area is extremely promising.

(3) For the production of medical devices. Since polycarbonate products can withstand steam, cleaning agents, heating, and high-dose radiation sterilization without yellowing and physical degradation, they are widely used in artificial kidney hemodialysis equipment and others need to operate under transparent and intuitive conditions. Need repeated sterilization of medical equipment. Such as the production of high-pressure syringes, surgical masks, disposable dental appliances, blood separators and so on.

(4) Used in aviation and aerospace fields. In recent years, with the rapid development of aviation and aerospace technology, the requirements for various components in aircrafts and spacecrafts have been continuously improved, making the application of PCs in this field increasingly increasing. According to statistics, there are 2,500 polycarbonate parts used on only one Boeing aircraft, and about 2 tons of polycarbonate is used for a single aircraft. On the spacecraft, hundreds of different configurations of fiberglass-reinforced polycarbonate parts and astronauts’ protective equipment were used.

(5) Used in the packaging field. In recent years, new growth points in the packaging sector have been the repetitive disinfection and use of various types of water bottles. Because polycarbonate products have the advantages of light weight, good impact resistance and transparency, and the advantages of using hot water and corrosive solutions for washing without deformation and maintaining transparency, PC bottles in some fields have completely replaced glass bottles. It is predicted that with the increasing emphasis on the quality of drinking water, the use of polycarbonate in this area will increase at a rate of more than 10%, and it is expected to reach 60,000 tons in 2005.

(6) Used in the field of electronic appliances. Due to its good and constant electrical insulation over a wide range of temperature and humidity, polycarbonate is an excellent insulating material. At the same time, its good flame retardance and dimensional stability make it a broad application field in the electronic and electrical industries. Polycarbonate resin is mainly used for the production of a variety of food processing machinery, power tool housing, body, bracket, refrigerator freezer drawer and vacuum cleaner parts. In addition, polycarbonate materials also show extremely high use value for important components such as computers, video recorders and color televisions with high parts accuracy requirements.

(7) Used in the field of optical lenses. Polycarbonate occupies an extremely important position in this field because of its unique characteristics of high light transmittance, high refractive index, high impact resistance, dimensional stability and easy processing and molding. Optical lenses made of optical grade polycarbonate can be used not only for cameras, microscopes, telescopes, and optical test instruments, but also for film projector lenses, copier lenses, infrared auto-focus projector lenses, laser beam printer lenses, and each The prisms, multi-faceted mirrors and many other office equipment and home appliances have a very wide application market. Another important application area of ​​polycarbonate in optical lenses is as a lens material for children's eyeglasses, sunglasses and safety glasses and adult eyeglasses. In recent years, the average annual growth rate of polycarbonate consumption in the world's optical industry has been maintained at more than 20%, showing great market vitality.

(8) Base material for optical discs. In recent years, with the rise of the information industry, optical discs made of optical grade polycarbonate have become a new generation of audio and video information storage media, and are rapidly developing at an extremely fast pace. Due to its excellent performance characteristics, polycarbonate has become the main raw material for the world's optical disc manufacturing industry. At present, the amount of polycarbonate consumed by the world's optical disc manufacturing industry has exceeded 20% of the total consumption of polycarbonate, and its average annual growth rate exceeds 10%. The output of optical discs in China has grown rapidly. According to figures released by the State Press and Publication Administration, there were 748 optical disc production lines across the country in 2002, which consumed about 80,000 tons of optical grade polycarbonate and were all imported. Therefore, the application prospect of polycarbonate in the field of optical disc manufacturing is extremely broad.

acetate fiber

Acetate, also known as cellulose acetate, cellulose acetate. Cellulose acetate Man-made fibers obtained by esterification of acetic acid and cellulose as raw materials. The structural formula can be expressed as: (C6H7O2)(OOCCH3)3n.

use

Acetate fibers are not easy to ignite and can be used in the manufacture of textiles, cigarette filters, film bases, and plastic products.

performance

1. The physical and mechanical properties of cellulose acetate

Acetate fibers have a lower density than viscose fibers and are relatively close to polyester fibers; strength is the lowest among the three fibers, and the strength loss is greater in the wet state, the remaining strength is about 70% of the dry strength, and the viscose The wet strength is almost the same. Therefore, be sure to take a gentle approach in the stretching and wet processing of cellulose acetate. However, the elongation at break of the cellulose acetate is higher than that of the viscose and the elongation in the wet state is greater. Therefore, the elasticity of cellulose acetate is relatively good, similar to silk, wool. The boiling water shrinkage is low, but the high temperature treatment will affect the strength and gloss of the fiber, so the temperature should not exceed 85 °C. The moisture regain is lower than viscose fiber, but much higher than polyester fiber, between viscose and polyester. In other words, cellulose acetate not only has a certain degree of water absorption, but also has the property of quickly removing after absorbing water. The softening temperature and melting point of the cellulose acetate are similar to those of the polyester, and have thermal properties similar to synthetic fibers; dry heat treatment under relaxed conditions does not affect the properties of the fiber.

2, the chemical properties of cellulose acetate

Acetate fiber has good acid stability, common sulfuric acid, hydrochloric acid and nitric acid will not affect the strength, gloss and elongation of the fiber within a certain concentration range; however, it can be dissolved in concentrated sulfuric acid, concentrated hydrochloric acid, and concentrated nitric acid. Acetate fibers are very sensitive to alkaline agents, especially the diacetate fibers, which are prone to deacetylation after encountering strong alkalis. Blank t-shirts cause weight loss, and strength and modulus also decrease. Therefore, the pH of a solution treated with cellulose acetate should not exceed 7.0. Under standard washing conditions, it has strong chlorine bleach resistance and can also be dry cleaned with perchloroethylene.

3, the dyeing performance of cellulose acetate

Although cellulose acetate is derived from cellulose, in the course of esterification, a large part of the polar hydroxyl groups on the cellulose glucose ring is replaced by an acetyl group to an ester. Therefore, the dyes commonly used for the dyeing of cellulose fibers have almost no affinity for cellulose acetate. , difficult to dye. Theoretically speaking, cellulose acetate can also be dyed with direct, reactive dyes, etc., after reduction of the original hydroxyl group by partial saponification. However, this is not feasible. In addition, because the carbonyl oxygen atom on the cellulose acetate and the residual hydroxyl group have a certain amount of negative charge, it was also experimentally dyed with a cationic dye for the diacetate fiber, but the result showed that only a light color can be obtained. The dyeing performance of acetate fiber is similar to that of polyester or nylon. Only the finely dispersed water-insoluble dye can enter the interior of cellulose acetate at a certain temperature and dye the fiber. The most suitable dyes for acetate fibers are disperse dyes with low molecular weight and similar dye uptake rates. In fact, the birth of the first disperse dye was also due to the need for cellulose acetate dyeing. Acetate fibers or fabrics dyed with disperse dyes are bright and bright, with good level dyeing effect, high dye exhaustion rate, high color fastness, and complete chromatograms. Culture shirt manufacturers

The dyeing process of cellulose acetate has a great influence on the dyeing effect, especially the control of temperature. The lower the temperature, the easier the dyeing is. The higher the temperature, the worse the dyeing due to the fast dyeing. The following dyeing process is given for the acetate fabrics produced therewith:

Auxiliaries: chelator 0.33 g/L at 27°C, sodium dihydrogen phosphate 0.08 g/L, anionic detergent 0.07 g/L;

pH: 6.5-7.0

Temperature: 71°C Add dye, slowly warm up to 82～88°C

Time: 60 min

Draining, cleaning

Acetate fibers can be cross-linked with a variety of natural or man-made fiber blends to produce a two-color effect in one bath dye. For acetate textiles, they should be dyed on a wide jigger or atmospheric dyeing machine to reduce fabric breakage.

Cellulose acetate is a natural fiber derived from nature, but a man-made fiber with special properties, whether it is used alone or blended with other natural, synthetic, synthetic yarns or fibers, is a kind of clothing that can bring beautiful and practical clothing. And comfortable fabrics. Culture shirt custom

Acetate yarns also give fabrics the following properties:

-Natural luxury

- Silky feeling

- Comfort

- Elegant drape

- Breathability

- Reduces allergic reactions

- Biodegradation

- Bright colors do not fade

- Cross dyeing

-stable structure

3, the use of cellulose acetate in the lining

According to the GAMA (Global Cellulose Acetate Manufacturers Association), more than 40% of the cellulose acetate consumption worldwide is used in linings. This is because cellulose acetate increases the value and quality of the lining. The value of cellulose acetate used in lining includes: Wuhan Advertising Shirt

a Improve the appearance of the interior of the garment

- Covering interior accessories (pads, ties, welts)

- Hide sewing details (seams, loose threads)

- Increased fashion and luxury

b Improves wearer comfort

- Help the garment "breathe" by providing a hygroscopic layer

- Rough and fluffy fabric use this lining to increase the sense of smoothness

- Makes the wearer easy to stretch freely

c Improve the drapery of the garment

- Eliminating electrostatic adsorption causes the garment to droop naturally

- Take away moisture and greasy make the fabric absorb the body

- Resisting external forces to make garments resistant

d Extend the life of apparel fabrics

- Good dirt resistance

- Good resistance to external forces

e Increased visual and thermal isolation

- Elimination of perspective

- Add a warm layer

f Feel

-Soft, smooth, dry, smooth, elastic

g Comfort

- Breathable, hygroscopic, fast drying, no static and no adsorption

- Drape

- Clothing aptamer, good drape

h color

- The color fastness is required to satisfy the printing and dyeing of bright colors and artistic patterns

i glossy

- Form a special appearance effect under solar reflection

Acetate is also environmentally friendly because it is made from wood pulp that reconstitutes trees. Advertising shirt production

The use of cellulose acetate in clothing

Cellulose acetate has been used for a limited number of years in linings, but it has become very popular as people increase their interest in using man-made fibers in clothing.

The main end-use customers of cellulose acetate in the apparel industry focus on women's clothing. The use of cellulose acetate in the apparel industry began in the 1960s, when cellulose acetate was mainly used in blends with silk to increase strength and reduce costs. In the late 1970s, cellulose acetate was used to blend with viscose fibers to produce the famous "CADY", a dry silk crepe that was mainly used for formal dresses.

Today, cellulose acetate can be used in almost all apparel fabrics, from premium garments to high fashion. It is used in blends with natural fibers, synthetic or synthetic fibers or yarns to produce countless woven fabrics such as: Chinese crepe, georgette, satin, Shandong silk, gabardine, and velvet. In knitwear, there is also a fine-textured acetic polyamide knitted fabric that incorporates Lycra's stretch knits and stretch jacquard. Designers chose these fabrics because of their feel, excellent drape, comfort, gloss, and more. Its main uses: evening dresses, dresses, bridal gowns, everyday clothes, etc.

Cellulose acetate can decorate people from head to toe. Looking at many designer's clothing series, we can easily find out from it how it can be used and where it is used.

Cellulose acetate has a natural soft luster, it can perfectly absorb a variety of colors, give the fabric quality and corporate promotion and cultural jersey, so that the fabric to obtain different effects: flash, rough, bright, bump and so on.

Cellulose acetate and knitted fabrics

Due to the special properties of cellulose acetate yarns (drapability, coolness, comfort) and some properties of other yarns (toughness, elasticity), it makes it untreated or dyed yarns, pure spinning or other natural Synthetic yarn blends have achieved great success in the knitting industry.

PETG material

PETG material is a kind of transparent plastic and is a kind of amorphous copolyester. PETG's commonly used comonomer is 1,4-cyclohexane dimethanol (CHDM), which is called polyethylene terephthalate. Alcohol ester-1,4-cyclohexanedimethanol ester. It is a product of polycondensation of terephthalic acid (TPA), ethylene glycol (EG) and 1,4-cyclohexanedimethanol (CHDM) with transesterification. - Cyclohexane dimethanol comonomer, compared with PCT, has more ethylene glycol comonomer. Therefore, PETG performance is very different from that of PET and PCT. With its uniqueness, currently only the United States Eastman and South Korea SK two companies have relatively mature technologies.

PETG is an amorphous copolyester. With the increase of CHDM in the copolymer, the melting point decreases, the glass transition temperature increases, and the crystallinity decreases. Finally, an amorphous polymer is formed. The content of CHDM in PETG is generally 30%-40%. Has good viscosity, transparency, color, chemical resistance, and resistance to stress whitening. Can be thermoformed or extruded blow-molded quickly. The viscosity is better than acrylic (acrylic). Its products are highly transparent and have excellent impact resistance. They are particularly suitable for forming thick-walled transparent products. They have excellent processing and forming properties. They can be designed in any shape according to the designer's intention. They can be used for traditional extrusion, injection molding, blow molding and suction. Plastic molding methods, can be widely used in sheet and sheet, high-performance shrink film, bottle and profiled materials and other markets, while its excellent secondary processing performance, can be routine machining modifications. PETG is an amorphous copolyester, its products are highly transparent, excellent impact resistance, especially suitable for forming thick-walled transparent products, its excellent processing and molding properties, can be designed according to the designer's intentions of any shape, can be used Traditional molding methods such as extrusion, injection molding, blow molding, and blister molding can be widely used in the market of sheet and sheet, high-performance shrink film, bottle and profile, and cosmetic packaging. At the same time, its secondary processing performance is excellent and can be carried out. Conventional machining modifications.

The main characteristics of PETG

Outstanding thermoforming performance

PETG sheet is easy to produce products with complex shapes and high draw ratios. Moreover, unlike PC boards and impact modified acrylics, this board does not require pre-drying prior to thermoforming. Compared with PC board or acrylic, the molding cycle is short, the temperature is low, and the yield is higher.

Toughness

Extruded sheets of PETG sheets are generally 15 to 20 times tougher than general acrylic and 5 to 10 times tougher than impact modified acrylic. The PETG sheet has sufficient capacity during processing, transportation and use to help prevent cracking.

Weather resistance

PETG sheet provides excellent weather resistance. It can maintain the toughness of the product and prevent yellowing. It contains a UV absorber that can be co-extruded into a protective layer that protects the panel from the harmful effects of UV light.

Easy processing

PETG sheet can be sawed, die cut, drilled, punched, cut, riveted, milled and cold-bent so that it will not break. Slight scratches on the surface can be eliminated with a hot air gun. Solvent bonding is also a routine operation. It is easier to process than general acrylic, impact modified acrylic or PC board, and can be flocked, electroplated, static electricity and other processing.

Excellent chemical resistance

PETG sheet can withstand many chemicals and commonly used cleaning agents.

Environmental protection

PETG sheet substrates are environmentally friendly materials and meet food contact management requirements.

Economical

It is cheaper than PC board, durable than acrylic.

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