Vacuum Injection Molding

Inox Cast Vacuum Injection Molding

Inox Cast is a professional manufacturer with expert engineers who can provide vacuum injection molding styles and designs. We have been manufacturing such high-quality vacuum injection molding with advantageous quality.

We are sure of your gratitude when considering our offered vacuum injection molding for your business or even for your processing plants. Inox Cast started manufacturing almost 20 years ago and counting. Knowing that can also develop your trust in Inox Cast.

Additionally, all of our customers appreciate the qualities and the services of Inox Cast worldwide. Secure packaging and safe delivery are what you can assume in Inox Cast. We have a complete guide for the exact installation and operation of vacuum injection molding, and it may be videos or manuals.

Manufacturing even large designs of vacuum injection molding is our expertise. Considering our long-time experience, we can also successfully give you satisfying features of our presented vacuum injection molding. The competitive cost of vacuum injection molding is what you can get on us.

Inox Cast operates 24/7 of services. Choose the best one for you. We can offer you customized vacuum injection molding. Just let us know your desired style and specifications by drawings or 2D and 3D samples, and we will perfectly provide your aimed vacuum injection molding.

Contact us now for more inquiries right here!

Vacuum Injection Molding: The Ultimate FAQ Guide

Let’s look at some of the fundamental aspects you should know about vacuum injection molding.

Take a look:

1.  What Is Vacuum Injection Molding?

This refers to a high-volume production process through which plastic resins are transformed into desired shapes using a vacuum pressing machine.

vacuum injection molding

The process is done through dry-reinforcement between a rigid airtight mode and a flexible film.

2.  What Are The Benefits Of Vacuum Injection Molding?

Vacuum injection molding has several advantages which are;

The process requires low capital investment to set it up when compared to other molding methods.

It gives room for use of pre-existing molds rather than going for new ones.

Highly versatile as it gives room for a wider range of sizes for various components, including the larger ones.

The compression effect applied in this process plays a significant role in improving the improvement of the physical properties of the components.

You can easily merge changes when it comes to component designs.

The fill-in time is usually short and quick.

3.  How Does Injection Molding Vs Vacuum Forming Compare?

Their Processing Abilities.

Injection molding is a versatile procedure that gives room for detailed work of your components.

This involves the addition of small parts which comprise metal inserts, side cores, ribs, bosses, screwthread, and the use of several molding materials.

The procedure is not limited to a specific shape as it involves the injection of the plastic material into the mold.

injection molding

With the correct selection of the injection molding machine, materials, and proper design & manufacturing, you will always have the best results.

Vacuum injection molding on the other hand is a brief procedure.

Shaping of the stretched plastic sheet over a mold is limited to one direction resulting in a limited number of shapes.

To attain the desired shapes and sizes, secondary procedures and finishing is usually done.

This method is more suitable for laminates with a thinner wall.

A perfect tool design is a key determinant to getting the best results which involve a range of special features.

Their Tolerances And Precision.

Injection molding can endure small tolerances resulting in quality, exact and accurate products.

Vacuum injection on the other hand endures moderate tolerances with minimal control of the stretching material.

vacuum forming

Materials Used In Production.

The vacuum injection molding process is compatible with a variety of standard materials.

They include; thermoplastic rubber, bio compostable, chemical resistant, and antistatic plastic.

In addition, the process is not restricted to certain specific colors. This includes masterbatch coloring and color compounding.

On the contrary, vacuum injection has limited options when it comes to material options.

The process is more effective with ABS, Fire Retardent ABS, HDPE, HIPS, Conductive HDPE & HIPS, PP, PVC, Clear HIPS, Ultra Violet Stable HIPS & PETG.

Similar to injection molding, it can capacitate a wide range of colors.

Product Finishing & Waste Materials.

Injection molding uses a mold tool that has runners.

The runners work together with the core and cavity in the shaping of the final product.

They can be removed from each mold, from time to time grounded again, and thereafter re-used.

Both cold and hot runners are effective in making this process successful.

For this reason, no waste materials will be produced during the entire molding process since the final product comes in perfect shape and size.

For vacuum injection, things are slightly different.

The product is highly dependent on finishing and secondary procedures which involves cutting and the use of effects.

Cutting is done using a roller cutter or a CNC machine.

Based on the desired shapes and sizes, some parts are left out summing up to form waste products.

However, these waste materials are not discarded but rather used in other processes.

4.  How Does Vacuum Injection Molding Work?

Vacuum injection process functions in the following steps.

Step 1: Mould preparation

Prepare the mold by applying a chemical release agent or gel over its surface.

Leave it for a few seconds until it dries off.

Step 2: Application of the sealing tape

Apply a sealing tape around the perimeter of the mold, preferably a vacuum bagging tape.

Step 3: Laying a Reinforcement into the mold

Use a tape to hold the reinforcement into place

The mold could be a modified lay-up mold.

Use cool materials as they are easily accommodated while the mold ensures the flow of resin around them.

Step 4: Cutting and positioning of the peel-ply layer.

This is significant as it prevents the bagging stack from sticking into the pot.

Moreover, it allows easy removal of the infusion mesh once the molding process is complete.

Step 5: Position the infusion mesh using tape.

Use a plastic mesh to ensure resin flow and quick distribution across the mold surface.

It also ensures resin take-up at the end of the experiment.

Make slits around the corners to help press down the mesh from running off.

Step 6: Positioning of the infusion spiral.

Connect the infusion spiral on top of the infusion mesh using a resin feed silicone connector.

Extra infusion mesh is cut and positioned to ensure flow balance

Additionally, it helps to spread the vacuum ensuring there is an even pour off the resin across the pot.

Step 7: Position the vacuum line silicone connector around the mold.

Step 8: Cutting of the bagging film.

Cut it oversize to give room for pleating.

Fix the film to the gum tape while adding pleats.

Pleats are made to ensure there is no bridging of the bagging film.

Step 9: Cutting of the PVC hose. This is used for resin feed, add a gum tape seal on it.

This is done above the connector.

Alternatively, you can use a galvanized metal coil to create this pass-through channel.

Step 10: Slit the film and attach the hose with a seal to the socket connector.

Repeat this on the opposite end.

Step 11: Connect the vacuum pump and the catch-pot

Step 12: Close the feed using an infusion line clamp.

This prevents air from being drawn into the bag.

Step 13: Check for leaks by evacuating the vacuum bag using a leak detector machine.

Step 14: Clip the resin feed line to the resin pot.

Release the clamp to start the infusion.

The resin is fed from the feedline through the channel line with a vacuum of 0.6-0.8 being pulled from the central point (Connector feed socket).

Clamp the resin feed line when the resin reaches the catch pot for about 10seconds.

Thereafter, clamp the vacuum line to stop the flow.

Step 15: Remove the bagging material and de-mold the part.

This is inclusive of the peel-ply and the infusion mesh.

Finish by carrying out the secondary operations which include trimming the edges, cutting the part into required shapes, and application of other filters.

5.  Which Are The Best Material For Vacuum Injection Molding?

Thermoplastics are known to be the best materials when it comes to vacuum injection molding.

We have several thermoplastics which are very effective, even though some may be locked out.

Their uses and application vary from one to another.

The most suitable thermoplastics include;

Acrylonitrile butadiene styrene (ABS)

Acrylic (PMMA)

Polyvinyl chloride (PVC)

Polycarbonate (PC)

Polypropylene (PP)

High Impact Polystyrene (HIPS)

Polyethylene terephthalate glycol (PETG)

High-density Polyethylene (HDPE)

In summary, these materials are known to be hard, rigid, and possess a high impact resistance.

They can be cut, trimmed, and machined easily.

Besides being durable, they also give room for easy fabrication.

Additionally, the materials are cost-effective which is why they would make the best choice for you!

6.  Where Can You use Vacuum Injection Molding?

Transportation Uses

Automotive manufacturers are in a position to create parts for buses, cars, boats, etc using vacuum injection molding.

They include mats, bumpers, and truck beds among others.

Vacuum injection molding has also made it possible to produce them in colors and gives a variety of options to consumers.

Additionally, designers have an easy time trying out new inventions towards development.

Industrial Uses

Through injection molding, industries can produce various items including machinery contoured containers and crates.

The process also aids in the production of other parts, majorly used on the outer parts acting as UV-resistant or flame retardants.

Examples include flame-retardant polyvinyl chloride and UV-filtering acrylic.

All of them are formed through a vacuum injection molding process.

Used as displays and packaging for house-holds and appliances.

A larger percentage of the packages into which products are sealed are made of plastic material.

This comprises electronics, makeup, razors, toothbrushes, and detergents amongst others.

Most of these packages are made through vacuum injection molding.

We also have various displays used by marketers and POPs, grocery aisles, etc. are components of vacuum injection molding.

Packaging Of Foodstuffs.

Food-grade plastic is one of the materials well suited for vacuum injection molding.

Packages made out of this material can be sanitized easily making them safe for food storage.

Some of the food storage parts and components made through this procedure include cracker trays, fruit, and plastic egg containers.

Other consumer products made through vacuum injection molding include; travel accessories, home decors, toys, etc.

They have medical uses.

Anti-microbial and contaminant-resistant components are products of vacuum injection molding.

This comprises hospital bed components, medical and pharmaceutical try packages amongst o

7.  How Do You Determine Vacuum Injection Molding Cost?

You can determine the cost of the vacuum injection folding using several factors.

These are material selection, design, prototype, mold making, labor used, and the secondary operations performed.

Summing up the costs applied here gives you the total price.

8.  How Can You Increase Efficiency Of Vacuum Injection Molding Process?

To compete effectively, there must be efficiency in the production process which is why machinery and raw materials are very key.

This efficiency is based on a combined effort of the manufacturer concerning the factors that make production efficient.

Some of the factors you need to work on are;

Production technology to apply

Products to use

Raw materials in use

Production management by the manufacturer.

For best machinery selection, focus on the technology used, Economical use, and customer service related.

9.  How Does Vacuum Injection Molding Vs Thermoforming Compare?

Thermoforming is a process through which a plastic sheet is heated, and shaped using a mold, and the resulting component is trimmed into the desired shape.

vacuum injection molding

Thermoforming is of two types which are; vacuum injection molding and pressure forming molding process.

Vacuum forming is a less detailed procedure that requires a vacuum pressure and a single piece of mold to obtain the required part.

Thermoforming

This, therefore, makes it suitable for electronic and food packages.

10.  Which Are The Common Vacuum Injection Molding Defects?

Some of the commonly encountered defects during this process are;

Sharp corners, are perceived to be vertical and offer fewer draught angles.

The base area is located way too below the tool/mold.

Availability of the production material in large sizes.

The proximity of the deep male molds as opposed to the female counterpart.

Here are the possible solutions to these defects.

We recommend the addition of a draught angle to enable the material to run over the mold or tool.

Smaller-sized sheets would make the best choice as they allow the material to be stretched easily using the mold or tool.

In addition, the setting of angle blocks at the corners makes use of the extra material.

Attach steel blades or wires to the clamping frame. Their role is to hold the sheet in place while moving the mold into the sheet.

The use of frames on plugs helps in pulling down the material and reduction of web formation.

Consider the use of female mold in case of webbing occurs.

To minimize webbing occurrence, ensure that the vacuum slows down while increasing the tool height to use the extra material responsible for webbing.

11.  How Do You Choose Mould For Vacuum Injection Molding?

Speed To Build

Construction of molds has longer lead times especially those used to run high-volume production.

Usually, the period taken is 12-18 weeks.

Alternatively, use prototype molds since they take a shorter period of 3 to 6 weeks as you wait for your high-volume order to be ready.

Choosing molds with shorter lead times saves you time as well as cost.

Cost Of The Initial Mold Build

The cost of the mold to be used in vacuum injection molding is after the quality of the mold.

Usually, prices range from 5,000$- 10,000$.

This price range is not fixed as some may exceed this range.

The mold for designing simple parts will cost you less as opposed to the multi-cavity.

For durability reasons, go for high-quality molds even though the prices might be high.

Project Development Stage

This is broken down into design, prototype, pre-production, production, and high-volume.

Therefore, mold selection depends more on which stage you have progressed to.

For instance, early stages like design and prototype cost less which is subject to making low-quality mold.

The reason is we have a high number of design reviews and changes.

On the contrary, mature stages like high-volume, usually cost more especially repairs and mold replacement thus leading to prototype degradation.

A better understanding of which stage you lye helps you save on money and time.

Do not risk skipping some stages as this waste of time and money.

This is because the cost of changes and modifications for these molds will keep increasing.

Complexity And Geometry Of Your Parts/Components.

This comprises the structure, features, and shape concerning the mode of making the mold.

Approaches used may differ from one to another based on their properties.

For this reason, some parts are made of hard materials like steel whereas others are made of softer materials like aluminum. (R&D tooling)

Moreover, the making of the mold also plays a significant role when it comes to material selection.

Since quality attracts quality, you realize that some plastic materials are not compatible with certain molds.

Therefore, there is a need to ensure that these materials interface with each other in the most appropriate ways possible.

Also, consider the overall functionality, this guides you on the best mold to go for.

Production Quantity.

How many parts do you intend to produce from the mold?

For small-scale production, you will go for moderately small quantities as opposed to large-scale production which requires massive purchases.

The design of your parts also matters when it comes to quantity.

Simple designs with no changes will consume a lower quantity whereas detailed designs where changes may apply consumes more.

Molds made of hard steel would make the best choice are they are highly flexible and can tolerate changes.

12.  Is Vacuum Injection Molding Suitable For Large Parts?

Yes, vacuum injection molding is a versatile process that gives room for application to larger components.

For this reason, this process is considered useful in a variety of manufacturing applications.

The production ranges from small custom parts to larger components which are done over automatic industrial machines.

13.  What Is The Recommended Temperature And Pressure For Vacuum Injection Molding?

The recommended temperature and pressure at which vacuum injection molding should be maintained is 194°C and 14.7 pounds/inch^2.

This temperature is equivalent to 380 °F.

14.  Is There Recommended Tolerance And Wall Thickness For Vacuum Injection Molded Parts?

When carrying out vacuum injection, it is advised you allow larger tolerances which help reduce speed up delivery and cost.

For instance, aluminum tools have a tolerance of 0.25mm for 25mm preceded by 0.1 for every 100mm.

However, this varies for various materials and designs as the materials are formed at different contraction rates.

Vacuum injection molds have a thickness of 0.0127-12.7 mm.

Prototype applications use molds with a minimum thickness of 0.0127 and a maximum of 6.35 mm.

The resultant components will always shrink resulting in thickness variations.

15.  What Determines The Cost Of Tooling In Vacuum Injection Molding?

The cost of tooling is based on the type of materials used in construction.

For instance, cooling made of hardened steel tends to cost more as opposed to that made of soft materials like aluminum.

Equally applies to those made of plastic or wood as they are cheaper.

Size is also a factor as far as quality is concerned.

16.  How Do You Choose Vacuum Injection Molding Machine?

Selection of the vacuum injection molding material is a very crucial step.

It is done based on different factors which include;

Size- We have these machines in different sizes, those that are small and larger industrial machines.

Complexity- This is more of designs that are applied to the vacuum injection molding machines.

Cost- Pricing of the machines is a key determinant when it comes to quality as far as size is involved.

Small sizes will cost less whereas the larger ones cost more.

Similarly, substandard quality machines tend to cost less while those of standard quality are costly.

Capability- This is simply the production ability of the machine.

Quality- Cost will help you distinguish poor quality from the good one, with less attention to the size.

Speed- The efficiency, reliability, and effectiveness of the machine.

Vacuum injection molding machine

17.  Do Vacuum Injection Molded Parts Require Finishing And Secondary Operations?

Yes, finishing and secondary operations are mandatory.

A finishing operation is significant to attain the final product.

We have secondary operations which follow thereafter.

For instance, if you require the product in certain shapes and sizes, then cutting has to be done based on the requirements.

You can use a roller cutter to reduce it to the required sizes.

18.  Is Vacuum Injection Molding Similar To Blow Molding?

No, these two procedures differ even though both processes involve the incorporation of different materials for a specified design.

Vacuum injection mold uses flat plastic sheets while the blow molding process works with hollow plastic parts.

Blow molding

More Resources:

Vacuum Die Casting

Thermoplastic Injection Molding

Die Casting

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