月度归档： 2022年5月

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Blog

What are Jigs and Fixtures?

Fixtures

If you are someone belonging to the manufacturing industry or have even an iota of interest in the manufacturing world, then you must have surely come across the terms Jigs and Fixtures. Jigs and fixtures are essential tools deployed in the manufacturing process to develop different pieces of CNC machined parts. Though their roles are different, though they are created using different manufacturing techniques, essentially jigs and fixtures essay the role of producing products with great precision. Jigs and Types of Jigs

Jigs are devices that hold the workpieces and guide the various CNC machining tools to perform their specific tasks.

Jigs serve the major purpose of providing products with the features of modification, interchangeability and precision.

Jigs are lightweight, cost-effective products used extensively in QBH technology and automation tools to carry out various processes such as drilling, cutting, etc.

Types of Jigs:

Drill Jig: One of the most common types of jig, the drill jig is used to drill holes at specific locations.

Template Jig: Template jigs have holes in them through which the cutting tool is guided. These can be easily mounted onto the workplace.

Wooden Jig: As the name suggests, wooden jigs are specifically used to create wooden work profiles.

Plate Jig: Apart from having holes to guide the cutting tool, plate jigs are also braced with drill bushes. Angle plate jig, which is a type of plate jig is used to make diagonal holes.

Leaf Jig: Leaf jigs have a hinged leaf that comes with a provision for opening and closing them. This feature facilitates faster loading and unloading of products.

Diameter Jig: A unique type of jig made specifically to enable the drilling of rounded workpieces.

Fixtures and Types of Fixtures

While jigs serve as the guiding factor for tools, fixtures are holding devices that firmly hold and support the workpiece at a certain position to carry out the manufacturing process. The CNC machined fixtures are accurate, improve the speed of manufacturing and give the desired output. Fixture finds its application in multiple CNC machining processes such as grounding, turning, and cutting to name a few.

Types of Fixtures

Drilling Fixture: Drilling fixtures have both bushes and holes and are often paired with jigs.

Turning Fixture: These fixtures are mounted on the machine table in such a way that they can rotate and thus are used to make comparatively complex products .

Milling Fixture: As the name suggests, milling fixtures are used to perform a number of milling operations and are secured on the work table with fasteners.

Grinding Fixture: Another kind of fixture which is used majorly to support and hold the parts during grinding operations.

Components of Jigs and Fixtures

The cnc machined fixtures and jigs are composed of several components or sections such as follows:

1) Body: The body of jigs and fixtures is generally strong to withstand strong force.

2) Clamping Devices: Both the jigs and fixtures have clamping devices to hold the workpiece securely and to carry processes such as cutting.

3) Locating Devices: These are in the form of pins to locate and place the jigs and fixtures easily.

4) Bushings: Bushings are present in both jigs and fixtures and they facilitate the holding and cutting process.

While the components of jigs and fixtures are more or less the same, individually they can be made using different materials as per the requirements and desired outcome.

Materials Used for Jigs and Fixtures

With the advent of QBH technology and other automation tools, the same material can be used to produce jigs and fixtures. Different materials bring their own characteristics and properties to the produced jigs and fixtures.

1) Hardened Steel: These are used to make water-resistant and non-shrinking jigs and fixtures.

2) Cast Iron: Jigs and fixtures made with cast iron can be self-lubricated and are used to build odd-shaped materials.

3) Nylon and Fiber: Nylon and fiber are used for jigs and fixtures to provide them with a soft lining for clamps so that there is no damage caused due to clamping pressure.

4) Phosphor and Bronze: Used majorly to form durable nuts and screws used in jigs and fixtures.

Apart from these materials jigs and fixtures are also made with alloys, plastic, mild steel, nickel, etc.

Fixtures

Designing Considerations for Jigs and Fixtures

Since cnc machined jigs and cnc machined fixtures essay a very significant role in the manufacturing world, it is imperative that they adhere to certain design considerations. Following these design considerations ensure the large-scale production of products with accuracy and precision.

Position: The workpieces should not be positioned in a plane that has more than 3 points. This helps to protect the workpiece from getting deformed. Furthermore, the workpiece should be placed such that it is easily located, thus saving time, effort and overall cost of production.

Well-maintained Equipment: A well-maintained equipment, should be deployed so that the production is smooth without any interruptions and delays.

Precise Design: For precise and accurate results, it is necessary that the jigs and fixtures are designed in such a manner that apart from the correct option, there is no other option or way for the tool and operator to handle it.

Streamlined Process: Less time translates to more output. Jigs and fixtures must be designed so that all the processes such as loading, clamping, cutting, are streamlined thereby reducing the time to a great extent.

Weight: Use jigs and fixtures that are low weight, so that they become easy to handle and operate. At the same time, make sure the material is a good one that offers rigidity and sturdiness.

Coolant: Designing jigs and fixtures with a provision to cool them is very useful to reduce the time in manufacturing the final product.

Hardened Materials: The tools, locating surfaces and mounting tables should all be hard and stable to provide much needed support during the process and ensure accurate results without any deformity and breakage.

Clamping Device: There can’t be any compromise in the effectiveness that jigs and fixtures bring to the workpiece. Thus, it becomes important that the clamping devices should be able to hold the workpiece firmly and at the same time ensure there is no breaking or disorientation caused.

Interchangeable Parts: Interchangeability is one of the highlighting and fundamental properties of jigs and fixtures. Thus, the locating and supporting surfaces should be standardized so that there won’t be any problem in producing them with tweaks or as it is in the near future.  

Safety is a Key: Safer the jigs and fixtures, less is the worry and the better it is for the tools and operator to get the most out of the manufacturing process.

Difference Between Jigs and Fixtures

In the manufacturing industry,  “Jigs” and “Fixtures” are often termed together since they are made up of the same material and are also equally used for mass production. However, there are a good number of ways in which a jig is distinguished from a fixture.

Fixtures

Jigs and fixtures in unison, increase the efficiency, quality, and output of CNC machining. Being easy to use and easily modifiable, Their unparalleled features find great application in the automotive, electrical and manufacturing industries.

So to conclude, jigs and fixtures are the backbones of the manufacturing industry as together they guide various cnc machining tools and at the same time also support them to carry out their functions precisely, ensuring accurate, large scale and cost-effective production.

But to get the most out of the jigs and fixtures, the operators should ensure that the several design aspects and considerations are in place and the type of material used is specific to the desired output.

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Blog

Which Material is Best for Your Medical Prototypes?

Prototypes

Prototyping is a huge part of medical research and development. While general-purpose prototypes can be manufactured using any number of materials, medical devices are limited to biocompatible materials. Choosing the suitable materials for your medical prototypes can be a challenging endeavor.

So here is a detailed guide on material selection for medical prototypes.

What is Biocompatibility?

The biocompatibility of a material is its ability to exist in harmony with living tissue. The material must not degrade upon interaction with the tissue or damage the tissue. Biocompatible materials are often used for medical implants, like knee replacements.

Biocompatible materials can be both metallic and non-metallic in nature. However, materials must pass a biocompatibility test to get a biocompatibility certification. ISO (International Organization for Standardization) is responsible for a majority of global biocompatibility certifications.

Different Biocompatible Materials

Any material that passes the biocompatibility test is safe to use for internal medical implants. Here are some common biocompatible materials used for medical prototypes.

Metal

  • Titanium
  • Stainless Steel

Non-Metal

  • PC (polycarbonate)
  • PEEK (polyetheretherketone)
  • PEI (polyetherimide)
  • PPSU (polyphenylsulfone)
  • Acetal
  • Nylon

Liquid 

  • ABS-Like Resin
  • Silicone Rubber
Prototypes

Manufacturing Medical Prototypes

The fabrication of medical prototypes is primarily dependent on material choice. Some materials are very restrictive and only compatible with one type of manufacturing process. 

Here are some of the most commonly used manufacturing processes for medical prototypes.

1.CNC Machining Medical Prototypes

CNC machining is an incredibly versatile and flexible prototype manufacturing method. It has near-universal compatibility with all sorts of metal and plastic materials. CNC allows for quick and precise machining of prototypes. However, different materials come with their own compromises.

Plastic Materials

Plastics like PEEK, PC, Nylon, etc., are generally well regarded for medical prototypes. They are ideal for the prototyping phase, due to their lower cost and lighter weight. Additionally, they are creep and temperature resistant, resulting in easy sterilization.

Metal Materials

Metals are considered premium materials for medical implants but are poor choices for prototyping. Titanium is a highly resilient metal and won’t degrade or react with body tissue. Stainless steel is a low-cost alternative to titanium and is particularly favored for medical equipment and surgical instruments.

Titanium is an expensive raw material that requires expensive tooling and machining to work. This is no issue for final medical implants, but prototypes typically undergo several iterations and changes. So the prototyping costs can add up quickly.

Prototypes

2.Injection Molding Medical Prototypes

Injection molding is a quick and reliable method suitable for large-volume productions. Ideally, you should not use this method for prototyping, as the tooling costs for the molds are incredibly high. Standard prototyping practice dictates you use CNC or 3D printing for your early prototypes and only use injection molding for the final prototype before commercial production.

Plastic Materials

Injection molding is pretty much incompatible with metallic materials, with only a few exceptions. Plastics like PC, PEEK, PEI, and PPSU are commonly used for medical prototypes. Injection-molded plastics are used for mass production parts, while CNC machining is used for patient-specific parts.

Liquid Silicone

Silicone rubber is often used to overcoat rigid plastic medical implants with a softer material. You will commonly see liquid silicone-coated parts in external medical devices, like prosthetics.

An alternative method for liquid silicone coating is vacuum sealing.

3.3D Printing Medical Prototypes

3D Printing is an additive manufacturing technique that can encompass several manufacturing sub-categories. 3D printing is a slower manufacturing process but more versatile than CNC machining.

For medical prototypes, there are only a couple of viable 3D printing processes.

Plastic 3D Printing – FDM

FDM (Fused Deposition Modeling) uses molten plastic extruded through a nozzle to create intricate and complex shapes. Nylon is the only commercially used biocompatible material that is also compatible with FDM.

Metal 3D Printing – SLS

SLS (Selective Laser Sintering) uses a high-powered precisely-controlled laser to selectively sinter (melt) metal powder to create the desired shape. Metal 3D printing is the most expensive manufacturing technique for medical prototyping. 

Titanium is currently the only real choice for this method of medical prototyping.

Resin 3D Printing – SLA

SLA (Stereolithography) uses a  high-powered precisely-controlled laser to cure (harden) photosensitive resin. This is a very rare method of medical prototyping as it is expensive and very limited in material choices. 

Sterilization of Medical Prototypes

Medical equipment is generally non-reactive and safe to use. But over time, germs and microbes will accumulate on the surface. So it is necessary that medical equipment be sterilized before use. Here are some standard sterilization methods for your medical prototypes.

  • Gamma Irradiation (GI)
  • Autoclave (AC)
  • Dry Heat (DH)
  • Ethylene Oxide (EtO)
  • Oxygen Plasma (OP)
  • Ultraviolet (UV)
  • Chemical Sterilization (CS)
Prototypes

Cost of Medical Prototypes

Prototyping medical parts is an expensive endeavor. However, some methods are more expensive than others.

Manufacturing Costs

CNC is the most cost-effective method for prototyping. 3D Printing, on the other hand, is excellent for rapid prototyping but can be more expensive than CNC. Injection molding is not recommended for prototyping and is better suited to mass production.

Material Costs

Metals are obviously the more costly option for prototyping. But CNC machined metal prototypes will be cheaper than 3D printed metal prototypes.

Prototypes

Conclusion

Selecting the right materials for your medical prototypes might seem daunting. However, once you have a good grasp of the process details, it becomes much more manageable. Consider both the manufacturing process and cost impact when selecting the best material option. Some materials are locked into specific manufacturing processes, adding unintended costs to your prototyping phase.

For experienced and skilled prototype manufacturing, look no further than QBH Technology. We offer a diverse range of machining services for the medical industry. Our CNC Machining and Quality Assurance are second to none. As a bonus, we have low MOQ and quick turnaround times.

Don’t miss out on your excellent prototyping services, and Contact us Now!