It may be interesting to know that all sign holders, brochure holders and other p.o.p. displays are injection molded using polystyrene sheet or pellets. So what is the origin of this process? It all began in 1868. At that time, John Wesley Hyatt injected hot celluloid into a mold and produced billiard balls. As the first one to do it, he patented an injection molding machine, which remained the used process until 1946, when James Hendry built the first screw injection molding machine. This new process revolutionized the plastics industry. Today, almost all molding machines now use screws to efficiently heat, mix and inject plastic into molds.

Barrels, Source: Complete Plastics

Using thermoplastic material, Injection Moulding is a manufacturing technique for making thousands of unique parts for millions of unique products, from tiny transistor radio parts to car parts. To facilitate elementary understanding, molten plastic is injected at high pressure into a mold; the mold is the inverse of the desired shape. Made from either steel or aluminum, the mold is precision-machined to form the features of the desired part. Sometimes brochure displays, racks, counter displays, donation / suggestion boxes and point of purchase (p.o.p) displays are made through the injection molding process.

Injection Molding, Source: Zone

Key facts:

• Molds are carefully designed to ensure that parts are not trapped in the mould
• Molds need to be completely filled before the molten resin solidifies to compensate for material shrinkage
• Molds separate into at least two halves so that extraction can occur
• A part needs to be shaped in such a way so that it will not be locked into the mold.• Parts that are “bucket-like” tend to shrink onto the core while cooling and, after the cavity is pulled away are typically ejected using pins.
• More complex parts are formed using different types of molds, which may require moveable sections or “slides”.
• Slides are inserted into the mold to create features that cannot be formed using only a core and a cavity.

The Injection Process

• First, heated plastic is forced under pressure into a mold cavity. It is then clamped together and begins to take the shape of the mold.

Resin Pellets, Source: RJM International

• Resin pellets are poured into a “feed hopper”, a large open bottomed container which distributes the granules down to the screw.
• The screw is operated by a motor that turns the screw, feeding the pellets into the screws grooves.
• Next, the depth of the screw’s flight decreases toward the end of the screw nearest the mold.
• As the screw rotates the pellets are moved forward
• They undergo extreme pressure and friction which generates most of the heat needed to melt the pellets.
• The screw “travel limit switch” sets the distance the screw moves.
• The hydraulic system pumps oil from the oil tank to firmly close the male and female mold parts that run along the tie bar
• Liquid resin is then injected into the mold.
• Water cools the mold and the heated plastic solidifies into the part.
• The mold opens and the part is ejected.If you are looking for a brochure display, rack, counter display, donation / suggestion box or point of purchase (p.o.p) display, we can assist!

Have you ever looked at something made of plastic and wondered how it was made? It’s obviously not a metal, wood or plant based derivative. To the educated person, it could be assumed that it’s made by a chemical process, but not much more about it is as easily surmised. Clearly, acrylic thermoplastics have some very interesting characteristics and properties. Of course, they are well known for their crystal clarity and outstanding weatherability. But did you also know they are available in cast sheet, rod, and tube, extruded sheet and film, and compounds for injection molding and extrusion? Acrylic can be used to manufacture brochure holders, racks, counter displays, donation / suggestion boxes and point of purchase (p.o.p) displays among other products.Below are some general properties of acrylic sheet:

Acrylic Sheets, Source: Acrylics in China

* Strong and resists weathering
* Flexible when compared with glass
* Less breakable than glass
* Abrasion resistant
* Can withstand sunlight for long durations
* Resistant to most chemicals and industrial fumes
* Can transmit or filter ultraviolet light
* Can be cleaned easily
* Can be cut by various methods
* Corrosion resistant
* Good insulator.

Other general properties include the ability to transmit and control light. They are also stable against discoloration, and have superior dimensional stability, as you would notice if you have an acrylic brochure display, counter display, donation / suggestion box or point of purchase (p.o.p) display. Possessing an excellent combination of structural and thermal properties, clear acrylic plastic is as transparent as the finest optical glass:

* Possess a light transmittance of 92%
* Low haze level of approximately 1%
* Index of refraction of 1.49
It also has the ability to be injected with color, producing a full spectrum of transparent, translucent, or opaque colors depending on your needs. This process does no harm in terms of long-term durability; colored acrylics can be used outdoors for a long time. Why? They are formulated to filter ultraviolet energy in the 360-nm and lower band. Other acrylic formulations are opaque to UV light or provide reduced UV transmission.

Colour Spectrum, Source: Photoinf

And how about mechanical properties? Although not known for having many, acrylics can be used for short-term loading. If the intended use is long-term, stresses must be limited to 1,500 psi to avoid surface cracking and deterioration.

Acrylic does well in the cold, as the impact resistance of standard formulations is maintained in these conditions. It should be noted that high-impact acrylic grades have greater impact strength than standard grades at room temperature, but impact strength decreases as temperature drops. Some types of acrylic are even known to resist bullets!

Acrylic plastics are highly scratch resistant, especially among other thermoplastics. It’s a good idea, however, to ensure proper maintenance and cleaning. Keep in mind that abrasion-resistant acrylic sheet is available and has the same optical and impact properties as standard grades. You will see this in many of our brochure displays, racks, counter displays, donation / suggestion boxes and point of purchase (p.o.p) displays.

Jet, Source: Wayfaring

This brings up a good point – its versatility and adaptability. Are you aware that Jet-aircraft cabin windows are made from acrylic sheet? They do this by inducing molecular orientation during forming. This proves the potential strength of acrylic sheet. How do they react to other chemicals and compounds? Acrylic sheet and moldings resist solutions of inorganic acids and alkalies and aliphatic hydrocarbons such as VM&P naphtha, as well as most detergent solutions and cleaning agents. They are attacked by chlorinated and aromatic hydrocarbons, esters, and ketones.