5 Tips for Avoiding Injection Blow Molding Defects

Injection Blow Molding

With so many benefits, it’s easy to understand why manufacturing companies of various industries rely on the injection blow molding process. The best equipment produces superior quality injection blow molding products. Some examples include jars for baby food and peanut butter, bottles for water and soda, and containers for biological samples.

When using state-of-the-art injection blow molding machinery, you’ll experience very few problems. However, it’s still possible to end up with a defective product. Considering that flaws slow down production, lead to unnecessary costs, and put your company’s reputation on the line, it’s critical to avoid the most common defects.


Producing Stellar Injection Blow Molding Products

1. Flash
One of the most common defects associated with injection blow molding is flash. This consists of a small flap of thin plastic material that remains on the edges of a finished product. Typically, this occurs when the material ends up on the outside of the mold where it solidifies.

This defect compromises aesthetics. If you experience flash on your injection blow molding products, consider redesigning a worn out or faulty mold. You can also adjust both pressure and temperature and make sure the clamp is strong enough to keep the material contained.

2. Flow Lines
The problem with flow lines is that they stand out from other areas. Usually, these appear near the gate points. As with flash, this defect doesn’t alter the functionality of your injection blow molding products, but it does take away from their appearance.

You can correct this problem by increasing the speed of the molding cycle of your injection blow molding machinery. Other remedies include changing the mold gate locations, adjusting pressure and temperature, and increasing the nozzle size to improve flow rate.

3. Warping
If different areas of your injection blow molding products cool and solidify unevenly, warping can occur. To prevent this from happening, gradually cool the products to eliminate stress on the material. You can also choose raw materials that don’t shrink a lot while cooling, make sure the products have a uniform wall thickness, and when performing mass production, adjust the mold temperature.

4. Discoloration
Another defect is discoloration, which can even happen when using the best injection blow molding machinery. Obviously, you want your finished products to have a uniform color, void of any streaks. Again, this doesn’t alter functionality, only appearance.

After each injection blow molding process, be sure you thoroughly clean the hopper, mold, nozzle, and other components. It’s also essential to purge the machine regularly and always use coloring agents that are properly mixed and have sufficient thermal stability.

5. Air Pockets
Air pockets can also form when using injection blow molding machinery. When bubbles become trapped in a finished product, not only do they alter appearance but they can also weaken the product. Try increasing pressure to force out any bubbles. In addition, have gates close to the thickest part of the mold, thereby preventing the plastic material from cooling too quickly.


It All Starts With Superior Injection Blow Molding Machinery

When you’re in the market for new equipment, contact us at Pet All Manufacturing Inc. As an industry leader, we offer excellent products at competitive prices.


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