Plexiglass Primer and History of Plexiglas

ePlastics

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4/10/2018 2:42 pm

What is Plexiglass?



At ePlastics we feel this information will be a valuable tool in your search for knowledge about Plexiglas® and techniques for working with this exciting material. If you have any questions you might have about this material, please email us at Info@ePlastics.com and we will respond quickly.


Ridout Plastics - Authorized Distributor of Plexiglas Sheet



We stock and sell Plexiglas sheet and shapes from our San Diego location. We ship worldwide and we are easy to do business with. Call today.

For Plexiglas sheet - please click on the Plexiglass link on the navigation bar above

PLEXIGLAS® SHEET: GENERAL RECOMMENDATIONS FOR MACHINING

Use only properly sharpened tools.
Fabricate at constant feed rate.
Insure that processing equipment is well maintained and capable of machining with accuracy.
Sand edges only with a wet sander, orbital sander or by hand.
Polishing edges is best accomplished by buffing, if feasible.
When flame polishing edges, utilize an oxygen-hydrogen flame source.
Limit stack cutting to 1".
Keep solvents (paints, adhesives, cements, strip heated and dry belt/disk sanded areas.
Use only air, water, or soap and water as machining coolants.
Dampen tight masking paper with mineral spirits or clean kerosene to aid in the removal of tight masking paper.
Use isopropyl alcohol to remove any adhesive residue. Wash the sheet with detergent in clean water immediately afterwards.
Clean only with detergent in water using a soft cloth or brush and dry by wiping with a damp clean chamois.

Remove static build-up by lightly wiping one surface with a damp clean chamois. Minor scratches can be masked with a light coat of wax or polished out using a mild abrasive wax.

Brief History of Plastics - specifically Plexiglas acrylic sheet



Before going on to the next topic, we would like to briefly illuminate on the history of plastics and their introduction into the industrial and consumer society. As we mentioned, the definition of the word plastic is to form or model something. In this light you can understand that wood, clay, glass and vegetable fibers were the plastics of early man who shaped and baked these materials to his own needs. With the coming of the Industrial Revolution came man's exploitation of natural resources and scientists in western civilization began to experiment with these resources and organic chemicals.

The first important date in our history books shows us that a compound called urea was discovered and isolated in the urine of mammals and other higher forms of animal life. This event took place in the year 1773, but it was not until 1828 that urea was synthetically produced and the foundation for phenol-formaldehyde plastics was laid. In 1843 an acrylic acid preparation was reported and in 1901 Dr. Otto Rohm published the results of his researches with acrylic resinoids. By 1909 the first patent for phenol- formaldehyde plastics was secured by Dr. Leo Baekeland. he found that phenol and formaldehyde when combined formed a resinous substance, a phenolic plastic which he called "Bakelite". It was a plastic -- it could be softened with heat and then molded into shape and set into final form by continued heating under pressure while in the mold. Baekeland's discovery triggered the creative imagination of organic chemists and research began the world over more intensely than ever before.

Yes, in 1914, the founding company that became Ridout Plastics began selling those small numbers and letters made from cellulose plastic.

Acrylic resins were first prepared in this country in 1931 for industrial coatings and laminated glass binders. The better known derivative of methacrylic acid, polymethyl methacrylate, was not introduced until 1936 as a transparent sheet and in 1937 as a molding powder. Thus the beginning of the acrylic era and Plexiglas. Acrylic sheet played an important role in World War II as bullet resistant glazing in our warplanes. It was found to be light and very strong and could be easily formed to fit into the structural designs of the aircraft. To this day, the Plexiglas windows in those planes are still clear and free from yellowing; weatherability of Plexiglas is one of its most well known traits, something no other plastic glazing can match. Plexiglas soon found its way into homes and factories for safety glazing, electrical and chemical applications, skylights and windscreens and hundreds of other beneficial applications.

Introduction to Plexiglas, Lucite, Perspex acrylic sheet



Plastics have come of age over the last 75 years. The material has evolved from a synthetic "substitute" for other materials to a valuable new raw material. It now occupies a permanent place in out technology and may be the basic material of the future.

This primer is designed to familiarize you with the possibilities of plastics; most particularly acrylics.

Two hundred years ago, when the pioneers and early settlers were building shelters and towns, they used to use the material resources of the land; as structural materials, as furniture, and as ornamentation to what they built. They chose their materials carefully with an eye to the purpose the finished product would serve. Wood, for instance, came in different strengths and hardness. Some stone could be quarried and cut more easily than others. Various metals were formed for different purposes. These early builders and craftsmen learned which type of available raw materials would be most suitable for specific tasks. Technology has come of age, and now we have access to materials offering a variety of use beyond those basic needs of shelter, furniture and decoration. One of the most important of these materials is plastic, and plastic is what this primer is all about.

If we take a look at the definition of the word plastic, it can help us to understand what is so exciting and unique about this material. One finds the term used in an artistic sense as sculptural and characterized by modeling or molding of the surfaces. Therefore, an object of art could be described as being plastic or as having a great deal of plasticity. Webster ties the word plastic to the creative forces in nature and the adaptability of animals in their environment. Looking to the Greek root of the word plastic, plastikos, we find the definition as being to mold or form something. You will agree then that the word plastic is an ideal word for describing this valuable material that has found permanent home in our lives.

There are two basic kinds of plastics: Thermoset, which, when formed, remain in the formed shape and cannot revert to a liquid state, the final shape is set during the manufacturing phase, and thermoplastics which, when heated to forming temperatures, are pliable and can be reshaped.

Examples of thermoset plastics can be found in your home, in your car, even in some of the sporting goods you use. One of the earliest plastics discovered and put into commercial service were phenolic resins. This was a material which could take not only heavy impact, but was both heat and chemically resistant. Modern day usage of phenolics can be seen in the PC boards of your solid state TV, the handle of your buck knife, as well as your coffee pot, and even the pulleys and cleats of your racing yacht.

The use of thermoplastics is by far the leader in today's industrial society. The packaging industry requires more plastics at an ever increasing rate. Take another look at that soft drink bottle next time you pour from it. Thermoplastics are playing an important part in saving energy for America.

Plexiglas storm windows have been in service for several decades and new glazing materials like Twinwall sheets are giving its users insulation benefits of up to 40% better thermal retention than plate glass alone. Plastics will enhance the beauty of our future automobiles while shaving off hundreds of pounds of excess weight per car. In the model year 1979, Detroit has used nearly one million tons of combined types of plastics in their efforts to reach these energy goals.

So we find that acrylics fall into the thermoplastics category, which means they can be formed when heated to the proper temperature. Their chemical composition is that of a clear, water-white, transparent liquid substance of monomer that can be polymerized into sheets, rods, tubes, molding pellets and additives. Additives are primarily used in the production of other materials, e.g., multi-grade oils, other plastics, paints, and floor polishes. So think of acrylics as a new "raw" material. A material as basically important as the traditional resources of wood, metal stone, etc.

Acrylic is a derivative of natural gas: see chart below.

(Natural Gas)-->>(Propane) -->>(Propylene)-->>(Isopropyl Alcohol) -->>(Acetone)

+ hydrogen cyanide -->>(Acetone Cyanohydrin)

+ sulfuric acid -->>(Methacrylamide)

+ methanol -->>(Methyl Methacrylate)-->> (Acrylic Plastic) Plexiglas, Lucite, Acrylite!


Physical Properties of Plexiglas, Lucite, Perspex Acrylics



Acrylic plastic sheet is produced in several formulations to provide specific physical properties required for various types of applications. Generally speaking, however, the physical characteristics of acrylics are:

Transparency - In colorless form acrylic plastic is as transparent as the finest optical glass. Its total white light transmittance is 92%, the highest transmittance physically possible of any material.

Breakage Resistance - Acrylic sheet has from 6 to 17 times greater impact resistance than ordinary glass in thicknesses of .125" to .250". When subjected to blows beyond its resistance, acrylic sheet reduces the hazard of injury because it breaks into large relatively dull edged pieces which disperse at low velocity, due to the light weight of the material.

Weather Resistance - The many years of actual outdoor exposure of acrylics in a wide variety of applications, proving its weather resistance, cannot be matched by any other transparent plastic material.

Chemical Resistance - Acrylic plastic has excellent resistance to most chemicals, including solutions of inorganic alkalis and acids such as ammonia and sulfuric acid, and aliphatic hydrocarbons such as hexane, octane and VM&P naphtha. It is attacked by the following chemicals:

Gasoline

Chlorinated hydrocarbons such as methylene chloride, a solvent cement widely used, and carbon tetrachloride.

Aromatic solvents such as turpentine, benzene, and toluene.

Ethyl and methyl alcohol.

Organic acids such as acetic acid, phenols, and lysol.

Lacquer thinners and other esters, ketones, and ethers.

Light Weight - Acrylic sheet is less than half as heavy as glass: it is 43% as heavy as aluminum and 70% as heavy as magnesium.

Dimensional Stability - Acrylic sheet is notable for its freedom from shrinking and deterioration through long periods of use. Many drawing instruments requiring exact dimensional stability have been fabricated from Plexiglas.

Combustibility - Acrylic sheet is a combustible thermoplastic and should be treated as an ordinary combustible material such as wood. The self ignition temperature (spontaneous combustion) of acrylic is between 850 degree F and 869 degree F. The temperature at which the material will ignite in the presence of a flame is between 550 degree F and 570 degree F. While the ignition temperatures of acrylic are higher than that of most woods, it burns vigorously and generates heat rapidly when involved in fire. The primary products of acrylic combustion are carbon monoxide and carbon dioxide, however, burning acrylic plastic does not produce either excessive quantities of smoke or gasses more toxic than those produced by burning wood or paper. Observe fire precautions appropriate for comparable forms of wood and paper products.

Heat Resistance - The maximum "continuous service temperature" of acrylic is between 180 degrees F and 200 degrees F depending on the particular use. This means that while the material can withstand higher temperatures for very short periods of time, it will soften and lose its form or shape if subjected to these higher temperatures for any period of time. While acrylics respond to heat, they are not affected by cold, and will not become cracked or brittle in cold weather.

Electrical Properties - Acrylic plastics are affected only a minor degree by weathering or moisture. Its surface resistivity is higher than that of most other materials, and makes an ideal insulator.

U-Factor - heat transfer through .187" thick acrylic is approximately 20% less than through equivalent thickness of glass.

(0.187" acrylic = 1.09 BTU's/hr./sq. ft./ degree F with 15 MPH and 0 degree F air on one side and 0 MPH and 70 degree F air on the other. 0.187" Glass = 1.23 BTU's/hr./sq. ft./degree F under the same conditions).

Ease of Fabrication - It can be sawed, drilled, and machined like wood or soft metals. When heated to a pliable state, Plexiglas can be formed to almost any shape.


Formulations of Plexiglas acrylics



Ridout Plastics is proud to be a distributor for Plexiglas, the registered trademark or brand name for acrylic plastic sheet, molding powder, and mirror manufactured by Arkema Group of North America Company. (Acrylic is the generic name for this type of thermoplastic. Just as the different automobile manufacturers make several different models of each automobile, Arkema Group of North America manufactures several formulations of Plexiglas sheet and Plexiglas molding powder.) The different formulations for sheet are listed below:

Remember, when acrylic sheet is heated to forming temperature (325 F), it will shrink 2.2 percent!

Extruded and Melt Calendered - the commodity sheet that is sold in most plastics companies is extruded material. This process involves heating the molding compounds until a clear viscous material can be forced between large, polished rollers that can precisely control the thickness of the material that is extruded. Thickness from .060" to .942" are made in this process in sheets up to 108" wide. By changing the rollers, different surface textures can be applied, such as non-glare, or patio table top textures. This grade is suitable for most applications - except skylights, aircraft, and fish tanks due to a lower molecular composition. Use solvent cements such as Weld On #3, #4 and #16. For special application a polymerizable 2 component cement, Weld On #40 can be used.

Continuous Casting - Lucite International has a unique process in the manufacture of Lucite XL acrylic sheet. They employ a pair of highly polished steel belts that allow the sheet to form on a continuous basis, hence the name, and allow for a higher molecular weight. This material is limited to use for spa, bath and kitchen applications

Cell Casting - This is the classic and traditional method of making acrylic sheet. Plexiglas G is the general purpose grade material used for most applications except those requiring a special combination of physical properties. Use solvent cements such as Weld On #3, #4 and #16 with Plexiglas G for a high quality bond. For special application a polymerizable 2 component cement, Weld On #40 can be used.

Cell Casting - Preshrunk/UVA - Plexiglas II UVA (ultra-violet absorbing) sheets have the same excellent weathering characteristics and the same physical properties as Plexiglas G, but are manufactured to military specifications and is used primarily for aircraft glazing, plotting boards and other scientific equipment.

Reflective Acrylic - Plexiglas mirror is transparent acrylic plastic sheet for indoor use, vacuum metallized with aluminum on its back surface. A tough opaque back-coat protects the metallized surface. The image reflecting sheet, available in various sizes up to 48" x 96" , is unique in comparison with glass mirror and other reflecting materials in flexibility of design, installation and assembly. It is light weight, breakage resistant and can be installed more easily and safely than glass mirrors. Plexiglas mirror can be cut with conventional saws and routers, and can be drilled and machined. It can also be formed by strip heating and bending, and can be surface decorated by silk-screening, spray painting or other artist's techniques. Plexiglas mirror requires slightly different fabrication techniques. To bond Plexiglas mirror to another surface, an acrylic contact cement, white silicone cement, or double faced foam tape should be used. Solvent cements will dissolve the backing of the mirror.

Extruded & Cell Cast - UltraViolet Filtering Plexiglas UF was designed to block the destructive UV transmissions in sunlight, reflected sunlight, and from fluourescent lighting. The degrading wavelengths are in the 280 - 400 nanometer area. This material blocks 98% of the transmissions. Available in clear and non-glare. Check our library page (above) to see the specifics.

Design Considerations for Plexiglas acrylic sheet



The reason acrylic plastic is widely used in so many applications is because it has a better combination of properties for certain types of jobs than other materials such as metals, woods, and glass. It also has properties which must be considered in design and installation. All materials have limitations - metals rust, woods warp, and glass breaks - yet each is a basic material in industry because these limitations are taken into account in product design, installation and use. Similarly, the characteristics of acrylic sheet must be understood for the most effective use of the material. Taking into account these factors in design, fabrication and installation will insure success in the finished product or part.

Stress Limits - Acrylic sheet offers good tensile, impact, and flexural strength properties as shown in the table below; however, stress considerably below the test values shown will produce light surface checking or fractures known as crazing. To avoid crazing, loads should not exceed 1,500 psi.

Tensile Strength 10,500 psi (Tensile strength is a measure of the force required to pull a specimen apart.)

Flexural Strength 16,000 psi (Flexural strength is a measure of the force required to break a specimen by bending it.)

Compressive Strength 18,000 psi (Compressive strength is a measure of the compressive load required to cause failure.)

Modulus of Elasticity 450,000 psi (Modulus of elasticity is a measure of the force required to produce a given change in dimension. A high modulus is associated with rigidity and a material's ability to hold its shape under momentary loading.)

Thermal Expansion and Contraction - All materials expand and contract to a greater or lesser degree due to changes in temperature and humidity. Allowances must be made for these changes in the construction and fabrication of products; for example, the expansion joints in cement sidewalks and on steel bridges. Acrylic sheet is subject to greater dimensional change, due to thermal expansion and contraction, than other materials with which it is used in construction.

Comparison of Co-Efficient of Thermal Expansion

Acrylic Sheet vs. Other Materials



Inches/Inch/F

Acrylic Sheet .0000410

Aluminum .0000129

Plate Glass .0000050

For indoor applications where temperature normally remain the same (+/- 20 degrees F), acrylic sheet does not generally require special considerations for expansion and contraction other than providing for a snug rather than tight fit since its movement is approximately 1/32 of an inch per foot length for each 20 degrees of temperature change. In outdoor use where temperature varies widely, acrylic sheet should be handled in accordance with the following recommendations:

1. Sheets or panels should be installed in a channel frame engaging the edges of the material so that it is free to expand and contract without restraint.

2. The channel frame depth should be sufficient to allow for thermal contraction of the sheet without withdrawal of the edges of the frame.

3. Through-bolting or other inflexible fastenings which do not provide for expansion and contraction may cause failure of the installation.

4. Before installation in the channel frame, the sheet or panel should be cut sufficiently shorter than the channel frame dimensions to allow for thermal expansion.

5. Sealant compounds and tapes should be types which are sufficiently extensible to accommodate thermal expansion and contraction of the material and which adhere to both sheet and frame. A practical rule to follow in outdoor installations is that the frame depth should be 1/4" plus 1/8" per running foot of acrylic sheet in length and width to provide for contraction. To provide expansion clearance, the flat sheet should be cut 1/16" per running foot shorter than the frame depth in both dimensions.

Rigidity - Acrylic sheet is not as rigid as many other materials such as metal, wood, and glass. This can cause the material to deflect under load and foreshorten as a result of the deflection. Observation of the following recommendations will contribute to the good performance of the finished part.

1. Channels engaging the edges of the sheet must be sufficiently deep to allow for foreshortening of the sheet due to deflection under load, as well as thermal expansion and contraction.

2. Thermoforming the sheet into dome-shaped or corrugated sheets increases its rigidity. Wherever practical, formed panels should be used in large unsupported area usage, where wind loads or snow loads are involved.

3. If it is not practical to form the sheet, increasing the thickness of a flat sheet will impart greater rigidity to the panel.

4. Another possibility is to insert a curved wedge under a Plexiglas skylight to give it a convex shape.

5. As a general rule, any horizontal outdoor glazing for skylights, etc., should be 1/4" thickness for minimum deflection with maximum unsupported span of 36".

Notch Sensitivity - Like glass and many other materials, acrylic plastic is notch sensitive. Notches and chipping along the edges of the sheet, at drilled holes, and inside corner cuts are potential points of cracking or breaking. Scraping, sanding or joining the rough cut edges will eliminate these notches and insure the maximum impact resistance of the part. Inside corner cuts should be avoided whenever possible or at least be designed to have a slight radius.

Surface Hardness - The surface hardness of acrylic sheet is approximately equal to that of copper or brass. Abrasives will scratch the surface of acrylic. This is not ordinarily a handicap in the use of colored or patterned sheet but may be one in the use of clear sheet where scratch-free appearance is desired. The exercise of reasonable care in cleaning colorless acrylic sheet will minimize scratching.

Combustibility - Acrylic plastic must be used with an appreciation for the fact that it is a combustible material. The fire precautions observed to protect wood and other ordinary combustibles should be used to protect acrylic plastic from ignition sources and involvement in fire. Applications subjected to high heat sources of flame such as high wattage incandescent light bulbs, radiators, heaters, fire places or candles, etc. should be avoided. Items normally made from non-combustible materials should be considered carefully before making them in acrylic as an unknowing user might assume they are safe when they might, in fact, present a hazard.

Service Temperature - The maximum temperature at which acrylic plastic can be subjected to for any period of time is 180 degrees F to 200 degrees F. The material softens when heated to temperatures above 260 degrees F which is 40 degrees below the temperature used in thermoforming, and 300 degrees below its ignition temperature. Applications subjected to high heat sources should be avoided or temperatures checked to allow for an adequate safety factor. An alternative clear plastic to use would be Tuffak Polycarbonate with a service temperature of 270 degrees F.

Proper Storage of Plexiglas sheet



Plexiglas G sheets are covered or "masked" on both sides with a tough Kraft paper or polyethylene film coated with a pressure sensitive adhesive that does not attack the surface of the Plexiglas. (Note: Plexiglas may be ordered unmasked and some patterns do not come with masking.) The masking helps prevent scratching during normal handling and fabrication operations, and should be kept in place for most cutting and machining procedures. If the sheet is thermoformed, however, or if it is installed outdoors the masking must be removed. The masking will protect the Plexiglas during normal handling, but sheets should not be slid against one another or across rough or dirty surfaces.

Storage Rooms - In general, the fire precautions that are observed in connection with the storing of ordinary combustibles such as wood and paper should be observed when storing Plexiglas. In addition, storage rooms should be well ventilated. Air should circulate freely and should be relatively moist and cool. The temperature should no exceed 125 degrees F. Storing Plexiglas sheet in a hot, dry environment may eventually cause the adhesive used on the masking to dry out, making it difficult to remove from the Plexiglas. Excessive moisture may cause the masking paper to deteriorate and reduce its effectiveness for protecting the Plexiglas.

Storage Racks - Masked sheets of Plexiglas are best stored on edge in "A" frame storage racks. These racks give full support to the sheets yet permit easy removal of individual sheets from any rack. If masked sheets must be stored flat, care should be taken to avoid trapping chips and dirt between the sheets. Such chips and dirt may scratch or press into the surface of the material. Piles of Plexiglas sheet should not be over 18" high. Small sheets should be stacked on the larger ones to prevent unsupported overhang.

Use of Plexiglas acrylic sheet for Lighting Applications



Lighting Diffusers Using Fluorescent Lamps - Lighting can be built into ceilings and overhangs by installing panels of white translucent Plexiglas below fluorescent lamps, as shown below. The Plexiglas panels rest on the projecting edges of the wood moldings or metal framing. If diffuser is outdoors, cut material 1/4" smaller than the opening to allow for thermal expansion of the material. For service access to the lighting, the diffusing panels are pushed up, tilted and removed. Plexiglas in 1/4" thickness is recommended for installations with areas larger than two square feet. For uniform diffusion of light, the distance from the Plexiglas to the fluorescent lamps should not be less than two-thirds of the distance between rows of lamps. All surfaces above the diffusing panels should be given at least two coats of high-reflectance white paint, with white enamel as a finish coat.

Lighting Diffusers Using Incandescent Light Bulbs - When using Plexiglas in an incandescent lamp, you must provide sufficient space for ventilation between the light bulb and Plexiglas to prevent overheating and softening of the Plexiglas. For best results - even illumination and no hot spots - use show-case bulbs. The formula for determining the minimum distance between a given wattage bulb and Plexiglas:

Minimum Distance, Bulb to Plexiglas = 1/2 the square root of the bulb's wattage.

Note: The minimum distance can be reduced by providing ventilation for heat to escape, however there is no general formula to determine the reduction.

A general rule of thumb for indoor applications of Plexiglas lighting white is to use:

Thickness Unsupported Horizontal Span

1/8" 0" - 24"

3/16" 24" - 36"

1/4" 36" - 48"

Assembly and Fastening of Plexiglas acrylic sheet


Through Fastening - Plexiglas may be easily attached to other surfaces using round head wood screws, round head bolts, sheet metal screws, oval head screws or bolts used in conjunction with finishing washers, and threaded rod used with cap (Acorn) nuts. Flat head screws, bolts and other fasteners which require countersinking should not be used, because a countersunk hole is almost the same as a notch and a potential fracture point. The countersunk fastener also does not provide freedom of movement for expansion and contraction. Holes for fasteners should be drilled oversized to allow for thermal movement of the Plexiglas. Remember, acrylic and metal have different expansion rates. Always, use a Plexiglas Drill Bit or regrind your steel bit to a 60 degree included tip angle. A minimum oversize for each drilled hole is recommended in the table below in accordance with the size of the Plexiglas part and the temperature range to which the part is exposed:

OVERSIZE HOLE RECOMMENDATIONS FOR THROUGH-BOLTING PLEXIGLAS

Degree of Size of Temperature Change for Plexiglas
 10 15 20 30 40 50 60 

12" 1/16 1/16 1/16 1/16 1/16 1/8 1/8 24" 1/16 1/16 1/16 1/16 1/8 1/8 1/8 36" 1/16 1/16 1/16 3/8 1/8 3/16 1/4 48" 1/16 1/16 1/8 1/8 3/16 1/4 1/4 60" 1/16 1/16 1/8 1/8 1/4 1/4 3/8 72" 1/16 1/8 1/8 1/8 1/4 5/16 3/8 84" 1/8 1/8 3/16 3/16 5/16 5/16 1/2 96" 1/8 1/8 3/16 1/4 5/16 3/8 1/2


Whenever possible locate holes to provide at least 1/4" of material from edge of hole to edge of Plexiglas sheet. If possible smooth inside of hole by wrapping 320 grit wet or dry sand paper around a wood dowel and sanding until smooth. Bring fastener up snug and then back off 1/4 turn, again to provide for natural movement of the material as it expands and contracts. Again, the types of recommended fasteners: round head screws or bolts, oval head screws or bolts used in conjunction with finishing washers, and threaded rod used with cap (Acorn) nuts

SKYLIGHTS & PATIO WINDBREAK FENCING

1. Always use 1/4" thickness of Plexiglas for all skylight applications. Thinner grades will deflect due to gravity and may cause water puddles to collect. When covering lath type structures with shading type framework, thinner grades of Plexiglas may be used, but are not recommended. Through-fastening is not advised but with proper drilling techniques with oversize holes and Plexiglas bits, it can be used satisfactorily.

2. With patio wind break fencing spans of more than 2' x 4' must 1/4" Plexiglas due to wind load deflection. Spans of more than 4' should have a top cap of wood to enclose the upper portion of the Plexiglas panel. This may be left off, but the top of the Plexiglas panel will have a slight curvature. Be sure to allow for this movement in the framing. Patio glazing must be framed in other wood or metal channel frames.

Care and Cleaning of Plexiglas acrylic sheet



You are now the proud owner of a fine piece of ACRYLIC. All of us at Ridout Plastics would like to offer these bits of wisdom to help you get the most value out of your purchase.

The Number 1 Problem with acrylic is the use of incorrect cleaners. Yes, we said "cleaners". Please... never, ever, use cleaners containing ammonia. Cleaners such as Windex or 409 will harm your new piece of acrylic. Use only products specifically recommended for cleaning acrylic such as Novus #1, or Brillianize, and a soft cloth. (All are available in our showrooms). Never use a dry cloth or your hand to clean your acrylic! This rubs the dirt and dust INTO the acrylic as much as it rubs it OFF. First, blow the dust or dirt off, or use water and a soft cloth to float the dirt off. Then use a recommended cleaner to complete the job. Note: a mild solution of dish detergent and warm water takes off stubborn dirt easily without harming the acrylic if you've run out of Novus #1 or Brillianize.

The Number 2 Problem with acrylic is SHOCK. Dropping your acrylic can cause cracking: From large cracks that deal a death blow, to small chips that can turn into mortally wounding cracks. Acrylic is incredibly resilient, but flying off the top of your car was not part of our stress testing. However, cracks in an acrylic sheet can be HALTED by drilling a small (1/8" diameter) hole at the end of the crack. This will keep your sheet in 1 piece while you call us for a replacement.

The Number 3 Problem with acrylic is children. Yes, just as with any other fine article in your home, children should be properly instructed on its care. Acrylic should be treated like fine furniture. Please note that Acrylic is the number 1 protector of children! When used as a safety barrier on balconies, or in windows that have a high probability of being broken, we encourage its use near children!

Scratch Removal: In the event that, after taking meticulous steps to prevent it, your fine piece of acrylic becomes scratched, HAVE NO FEAR. Fine scratches can be removed with a mild abrasive polish such as Novus #2, or Novus #3. Heavier scratches, such that you can feel with your fingernail, will require some elbow effort to remove with a bit of sanding and buffing. A series of grits (150,400,600) followed by a buffing wheel and available buffing compound, will restore the luster of your acrylic!

We Want You To Be Satisfied.

We have offered these basic rules to guide you to years of satisfaction. If you experience any problems with your acrylic, have questions regarding cutting, drilling, buffing or are curious as to new materials available, please call our customer service representatives for prompt and courteous service, or visit our showroom.