FAQs on Rubber Materials, Manufacturing, and Defect Prevention

Rubber manufacturing is the most integral part of many industrial processes, which offer components for automotive systems, medical devices, electrical devices, consumer goods, and heavy machinery. Unlike metals or plastics, rubber has a different behavior, so it becomes necessary to understand material properties, molding techniques, quality control, and troubleshooting methods, so manufacturers can manufacture rubber parts that conform well and have continual performance.

An excellent rubber manufacturing knowledge base helps engineers, product designers, and procurement make sound decisions concerning material selection, process optimization, and long-term reliability.

 

What are the main types of rubber used in manufacturing, and how do they differ?

Manufacturing rubber can be broadly categorized into two types: natural rubber (NR) and synthetic rubber. Natural rubber is superior in elasticity as well as tear strength, in addition to dynamic performance, which allows mounts and springs to be used in vibration dampers, as well as in moving industrial components. It has limitations and can break down in the presence of heat, oil, ozone, or even some chemicals.

Common synthetic rubbers include:

• EPDM: Excellent resistance to weather, ozone, and steam; typically used in automotive and external applications.
• Nitrile Rubber: Ideally intended for oil and fuel resistance, usually used in seals and gaskets manufacturing, plus O-rings.
• Silicone Rubber: Commonly used due to its excellent thermal resistance--extreme temperatures--biocompatibility and stability; indeed used in medical devices and food-grade parts.
• Neoprene: Balanced oil, weather, and abrasion resistance make it very usable for general-purpose sealing.
• Viton: Best high temperature and chemical environments.

Difference between compression, transfer, and injection molding in rubber manufacturing?

Manufacturing rubber parts is generally carried out using three methods, the selection of which depends on the design of the part and production volume.

• Compression Molding- This method is the simplest and most often the cheapest. Raw rubber is laid directly into an open mold cavity and then compressed between heated plates. It is suited for the manufacture of larger, simpler, or thicker parts. However, the downside to this process is that it may take longer than its other counterparts.
• Transfer Molding- In transfer molding, rubber is loaded into a chamber and forced into the mold cavity by way of small runners. This method minimizes excess material to flash, offers a suitable capability for well-designed geometries, and performs much better than compression molding regarding repeatability. It is mostly used for parts requiring metal inserts.
• Injection Molding- Injection molding is the most advanced technique. Rubber is preheated, plasticized, and injected at high pressure into closed molds. This has the advantage of fast cycle times, good precision, and minimum waste, and therefore is suited for high-volume production. Most benefit from this process are plastic parts that are complex and have tight tolerances.