Laser Engraving Plastics
Laser Engraving Plastic
Laser engraving machines for plastic are an extremely flexible technology that can be used for different plastic types, such as ABS, polyamide, or polycarbonate. Owing to the versatility and reliability of the technology, more and more companies have started to offer laser marking plastic services.
Before plastics, the traditional materials used were metal or wood. Plastics quickly gained popularity for being cheaper, lighter, more versatile, and easier to manufacture. Nowadays, plastics are found in practically every industry, from food and healthcare to automobiles and infrastructure. In many of these applications, laser engraving plastic parts has been a handy tool.
Plastic and Laser Technologies
Laser engraving plastic uses a high-intensity laser to raise the temperature of an incredibly thin layer of the plastic, causing it to melt and form a modified surface upon solidification. An even higher intensity laser can be used to alter the surface of the plastic. Localised evaporation of the material causes carbonisation and a change in colour to the surface of the object.
A low-intensity laser is used for laser marking plastic. The foaming method uses low energy laser to induce the polymers in the plastic to form a walled foam structure, which stands out from the material with its elevated surface and lighter colour. The most common method for laser marking plastic is basic colour change, where a high-frequency laser causes a molecular change in the polymer, resulting in a change in colour. The contrast of marks made by colour change can be further enhanced by the application of additives in a process called bleaching.
Uses of Laser engravings with Plastics
Prior to laser marking, ink printing was the technique of choice for plastic marking. However, the numerous advantages of laser marking meant that ink printing was soon pushed to the background. The ink printing process was carried out by having an image placed directly on the plastic surface using inks, which can be erased by solvents or by long-term abrasion. On the other hand, the marks made with lasers are indelible and permanent.
Laser marking is also much faster than ink printing, capable of producing up to 1,000 alphanumeric characters per second. The detail in laser marking of plastic parts can be at the level of several microns, allowing it to produce highly intricate designs.
Laser Engraving Plastics in Manufacturing
Laser engraving is a highly modular technology which can be easily integrated into any existing manufacturing process using plastics. It needs minimal human intervention to operate, allowing it to produce at a fast rate without interruption.
As a non-contact technology, laser marking plastic and laser engraving plastic does not cause secondary damage to the object being marked. Compared to traditional engraving methods, the material does not undergo stress in laser marking, allowing it to retain its integrity throughout the whole manufacturing process.
The parts of laser marking equipment do not undergo wear and tear as heavily as traditional ink printing and engraving equipment. Aside from enabling it to produce consistent results, this also reduces the need for regular parts replacement. Combined with the fact that it does not use any consumables in the form of ink cartridges, laser marking can be considered the most cost-effective option for the permanent marking of plastic surfaces.
What is Plastic?
The term ‘plastic’ can be used to refer to a number of synthetic or semi-synthetic materials, commonly organic compounds. They are usually made of organic polymers. Polymers are composed of long molecular chains of repeating units, called ‘monomers’, which in this case are composed primarily of carbon atoms.
Connected to the main backbone of the polymer are various ‘pendant’ groups, which may be composed of other elements (such as sulphur or oxygen) or other carbon-based molecules. The nature of the molecular bonds and pendant groups, as well as the length of the polymer chain, play a significant role in determining the properties of the resulting plastic.
Why Laser Mark
Plastics have become the material of choice versus more traditional materials (such as wood or metal) due to some fundamental properties. Manufacturing and working with plastics is much cheaper and easier. Plastics are lightweight but can exhibit comparable strength and durability. They are impervious to the effects of moisture and organic decay.
With the wide variety of plastic products, the range of applications available for laser etching plastic items is virtually endless. Plastic etching has been used to label housings of electronics, tools and tool parts, various forms of packaging, automotive parts, electronic components, printed circuit boards, identification and product tags, buttons, keyboards and sensors.