The process and application advantages of PMMA lampshade products

What is an acrylic lampshade

PMMA, also known as acrylic, is commonly known as "plexiglass", which has excellent optical properties and weather resistance. The penetration of white light is as high as 92%. It has room temperature creep characteristics, and as the load increases and the time increases, it can lead to stress cracking. PMMA has good impact resistance properties. PMMA lampshade products have very low birefringence and are especially suitable for making video discs.

Injection mold process conditions

Drying treatment: PMMA is hygroscopic, so drying treatment before processing is necessary. The recommended drying condition is 90C, 2~4 hours.

Melting temperature: 240~270C.

Mold temperature: 35~70C.

Injection speed: medium

The characteristics of acrylic PMMA lampshade

1. Transparency: PMMA is an amorphous high polymer, and the arrangement of its internal molecules will not interfere with the speed of light entering it when it passes through various parts, so that the light can advance at the same speed (that is, uniform refractive index), It will not make the light scattered in all directions and interfere with each other. Therefore, PMMA has excellent optical properties and high light transmittance (90-92%, related to wavelength).

A sheet or rod with an extremely smooth surface can reflect all the light incident from one end inside it and advance from the other end after being bent to a certain limit, just like water flowing through a pipe (certainly Curvature refers to the angle formed by the bent position and the original position, which cannot exceed 42°; when the bend is arc-shaped, the radius of the arc must be greater than 3 times the diameter of the rod or the thickness of the sheet). But when a certain part of its surface is roughened, light can escape from here and show light. This characteristic can be used to manufacture edge-lit devices, surgical and medical instruments, and the like.

2. Mechanical properties: The mechanical strength of PMMA lampshade products is more than 10 times higher than that of ordinary glass, but compared with other plastics, the strength can only be considered medium. Its disadvantages are light and brittle, easy to crack (or silver streaks), low surface hardness, easy to scratch and lose luster; poor wear resistance, the coefficient of static friction between them is 0.8, and the coefficient of dynamic friction against steel is 0.8. 0.45 to 0.50, so it is easy to scratch the sanding.

3. Electrical properties: The electrical properties of PMMA lampshade products are good, especially under low frequency working conditions. However, some of its electrical properties are unique: the dielectric loss tangent decreases with increasing frequency. Temperature and frequency have an effect on the dielectric constant, while climate and humidity have little effect on electrical properties. But the electrical performance is worse than PE, PS and so on.

4. Thermal properties: The heat resistance of PMMA is not good enough, and the service temperature is only 80°C. The heat resistance can be improved by copolymerizing and cross-linking its monomers with diester-based ethylene glycol acrylate or methacrylate, etc. The specific heat of PMMA is lower than that of most thermoplastics, which is conducive to its rapid thermal plasticization. In addition, it also has a certain degree of cold resistance, and the impact strength changes little at a low temperature of -50 to -60 °C.

5. Chemical properties; PMMA has a certain chemical corrosion resistance, but it weakens with the increase of temperature. It has strong chemical corrosion resistance to gas, and has not been corroded when it has been in contact with ozone and sulfur dioxide for a long time; chlorine gas can corrode its surface. It can be dissolved in ethyl acetate or butyl ester, glacial acetic acid, chloroform and benzene, etc.; it can absorb various alcoholic organic compounds, causing the volume to expand and the surface to be rough and hairy, but it is insoluble in aliphatic compounds.

6. Weather resistance: PMMA lampshade products have excellent weather resistance, and there is little change in transparency and color after years of exposure in tropical climates.

What are the materials of the lampshade? Choice of lampshade material:

1. Material of lampshade

The first type of shade:

Milky white lampshades, milky white lampshades are divided into transparent PMMA+toner, transparent PC+ribs, transparent PC+frosted powder, glass+phosphor powder, transparent PC+light diffuser, the following is their detailed introduction:

1. Transparent PMMA+toner: The lampshade made of this material is low in cost, slightly transparent, and the light source can be seen, but its light transmittance is low and the light diffusion is uneven. the

2. Transparent PC+ ribs: The lampshade made of this material has high mechanical strength and good light transmittance, but it will cause light loss and the effect of light diffusion is also very general. After covering the lamp, the light will not be enough soft. the

3. Transparent PC + frosting powder: The lampshade made of transparent PC + frosting powder can cover the lamp beads, so the light transmittance will be greatly enhanced, but the haze is low, the light loss is very serious, it will reach 40%, and the diffusion of light General effect. the

4. Glass + phosphor: it has the characteristics of low cost and good light-gathering effect, but it is easy to break and inconvenient to transport. the

5. Transparent PC + light diffusing agent: The light diffusing agent itself has the effect of softening the light. The lampshade made of it will make the light of the lamp softer and the appearance is also very beautiful. However, its weather resistance Generally, the degree of light loss reaches 30%.

The second type of shade:

Transparent lampshade, this lampshade is mainly made of glass, PC and PMMA. the

1. Glass: The lampshade made of glass has very strong light transmittance and basically no light loss. If the wattage of the lamp is high, the light diffused by the glass lampshade will be more dazzling and easier to break. the

2. PC and PMMA: The light transmittance of the lampshade made of this material is very high, and the light loss rate is small, but the diffused light will be more dazzling. the

This kind of lampshade, the appearance is very European-style furniture manufacturing style, the frame of the lampshade is made of high-grade steel, which is not easy to deform, and then the lampshade is made of transparent PC and frosted powder, the transparency is low, and it is tender enough to cover the lamp beads. The appearance design of the lampshade In the form of petals, with hand-drawn patterns, it has a strong sense of art.

2.the choice of lampshade material

The replacement of the lampshade is relatively fast, and most of the lamps are carefully designed by the designer. For the lamp, it is not necessary to replace the entire lamp, but only the outer lampshade of the lamp. Therefore, it is a good choice to change the lampshade if you want to change the environment. the

First of all, let`s first understand the decorative effects brought by different materials of the lampshade. The lampshade on the cloth surface gives people a simple and elegant impression, the lampshade on the paper surface can create a hazy and dreamy atmosphere, and the lampshade made of metal material has a cool tone. Temperament and modernity, while the drum-shaped lampshade brings a nostalgic feeling. In the bedroom, we can choose silk lampshades, especially hand-stitched and hand-painted lampshades, which can bring softness to the room and add an intimate atmosphere; living room can choose linen or parchment lampshades. the

Secondly, you only need to pay a little attention to the color. The white lampshade has better light penetration and can be matched with the crystal base to create a crystal clear effect; the black and colored lampshades are relatively poor in light penetration. Some, can radiate the light downward, so that the local light is stronger, and can be matched with the bronze base. the

Finally, choose the lampshade according to the shape of the lamp holder. If the lamp holder is curved, then the lampshade should choose a style with some curves. If the lamp holder is flat and straight, choose a more regular lampshade. If the lamp holder looks Thick, you can choose a tapered lampshade to reduce the heavy feeling. the

After the lampshade is used for a period of time, not only is it covered by dust, but also the long-term exposure to light causes the color to fall off. We can use these small methods to clean the lampshade in details to prolong the service life of the lampshade.

3. DIY lampshade

Tools: soft pencils, old oil paint brushes, clean old toothbrushes, soft cloth. the

Step 1: Find a transparent white lampshade as the main material, draw the outline on the lampshade with a pencil, and mark the boundaries of different colors. the

Step 2: Color with an oil brush, leaving uncolored dividing lines for different colors. If you are right-handed, color in the counterclockwise direction, otherwise, use clockwise. This prevents staining of painted areas. the

Step 3: After filling all the colors, use a clean old toothbrush to apply oil paint and repaint it again, so that the colors can fully penetrate into all parts of the lampshade. the

Step 4: After repainting the color, use a soft cloth or drawer cloth to gently wipe off the excess paint on the lampshade, and place the lampshade in a warm place to dry overnight. the

Step 5: When the base color of the lampshade is completely dry, use the oil paint brush used the day before to draw dot patterns on the base color of the lampshade. The color of the dots should be the opposite of the base color, then let the lampshade dry in a warm place and use it the next day.

4. Acrylic lampshade

Acrylic lampshade is a lampshade made of acrylic as the main raw material. It has outstanding optical transparency, excellent insulation performance, good weather resistance, mechanical strength, electrical properties and chemical resistance, high hardness, and fast burning speed. It is slow and does not generate sparks, so it is often used to make equipment panels, automotive lenses, lampshades, etc. the

Acrylic is transliterated from English Acrylics. Acrylic is a general term for acrylic and methacrylic chemicals, including monomers, plates, pellets, resins and composite materials.

Advantages of acrylic lampshades:

1. Excellent transparency: colorless and transparent, with a light transmittance of over 92%. the

2. Excellent weather resistance: strong adaptability to natural environment, good anti-aging performance, can be used indoors and outdoors,

3. Good processing performance: suitable for mechanical processing, easy to heat form, dyeable, and the surface can be painted, silk screen or vacuum coated. the

4. Excellent comprehensive performance: various varieties and rich colors provide diversified creative choices for lampshade designers. the

5. Safe and non-toxic: It is harmless for long-term contact with people, and does not produce toxic gas when burned. the

6. Sturdy and durable: the acrylic lampshade has a hardness of 85-105HRM, is not fragile, and has a certain ability to resist pressure.