123ArticleOnline Logo
Welcome to 123ArticleOnline.com!
ALL >> Technology,-Gadget-and-Science >> View Article

Black Spots Of Common Problems In Injection Molding

Profile Picture
By Author: alvarad982stedk
Total Articles: 17
Comment this article
Facebook ShareTwitter ShareGoogle+ ShareTwitter Share

What is a black spot? Black spot refers to the black spots or stripes on the molded products.
Causes of black spots on injection molded parts:
1. Resin decomposition
As plastic is a chemical, it will decompose gradually when it is heated above the melting point. The higher the temperature, the longer the time and the faster the decomposition. In addition, there are some areas in the barrel that are easy to retain resin, such as check check valve and thread.china mold maker The resin remaining in these parts will be scorched or carbonized and then dropped into the molded product, causing black spots.
2. Insufficient cleaning
The reason for the black spots is that the previously used resin remains in the injection molding machine due to insufficient cleaning. As mentioned above, due to the presence of areas that are easy to hold the resin, such as stop rings and threads, the corresponding strength and cleaning time must be applied to these areas during material change. In addition, cleaning methods suitable for each material must be used. It is relatively easy to clean similar resins, but if different types of materials are cleaned, due to the different melting point or decomposition temperature, there is compatibility between the resins. Despite cleaning, in many cases, it can not be completely removed.
3. Foreign matter mixing (pollution)
Pollution is also one of the causes of black spots. If some particles in the feed hopper are mixed with other resins with lower decomposition temperature, black spots may be easily caused due to resin decomposition. In addition, attention should be paid to recycling plastics. This is because recycled plastics are easier to decompose after multiple heats. In addition, it may be contaminated by metals in the recycling process.
Injection parts black spot solution:
1. Clean thoroughly until no black spots appear.
Black dots tend to stay in the stop ring and screw into the barrel. If there is a black spot, it is estimated that the cause of the black spot is likely to remain in the barrel. Therefore, after the appearance of black spots, it is necessary to thoroughly clean the lens barrel, and then take countermeasures (otherwise, the black spots will never disappear).
2. Try to reduce the resin temperature
Recommended temperature for all resins (also included in product catalog or product packaging). Check whether the setting temperature of the molding machine is out of the range. If so, lower the temperature. In addition, the temperature displayed on the molding machine is the temperature of the sensor area, which is different from the actual resin temperature. If possible, it is recommended to use a resin thermometer, etc., to measure the actual temperature. In particular, areas prone to resin retention (such as check rings) may cause black spots, so pay special attention to the temperature nearby.
3. Reduce residence time
Even if the setting temperature of the molding machine is within the recommended temperature range of various resins, long-term retention may lead to resin deterioration and black spots. If the molding machine provides delay setting function, please make full use of it and select the injection molding machine suitable for the mold size.
4. Is it polluted?
Occasionally mixing other resins or metals can also cause black spots.
Surprisingly, the main reason is inadequate cleaning. Please thoroughly clean and remove the resin used in the last injection process before carrying out the work. When using recycled plastics, check for foreign material in the particles.
About JasonMould Industrial Company Limited
Article Image
china mold factory
Jasonmould is a China mold maker of plastic molds- injection mold, die casting moulds, plastic blow molding, rotational molding, medical plastic injection molding, two shot plastic injection molding, insert molding, overmolding, metal injection molding, micro injection molding, powder injection molding, ceramic injection molding, liquid injection molding, husky injection molding, household mold, casting mold, die mold tool, custom molds, china moulds, rapid prototyping tooling, plastic prototyping tooling, punch press tooling, die and tooling for mobile/ cell phone parts, automotive parts, vacuum cleaners, rechargeable tools, telephones, copiers, computers, multimedia speakers, and many other electronic products and household appliances. And also a plastic product manufacturer, mold manufacturer China– plastic parts, plastic water tank, plastic balls, plastic containers, plastic buckle, plastic anchor, plastic hanger, plastic spoon, plastic pipe fitting, plastic tumble, plastic tableware, plastic cups, plastic bottles, plastic tray, plastic cosmetic container, plastic case, plastic food container, plastic chairs, plastic caps, plastic cap closure, plastic tubes, plastic water pipes, plastic knobs, plastic tubing, plastic utility boxes, plastic racks and so on.
Coupon Code: free shipping coupon code: freeshipping on any order over 2000USD from jasonmolding.com
Person: James Yuan
Company: JasonMould Industrial Company Limited
Add:  LongGang Village,LongXi Town,BoLuo County,HuiZhou City,GuangDong Province, China
Tel: 86-752-6682869
Email: james@jasonmolding.com
Site: https://www.jasonmolding.com/custom-injection-molding/

Total Views: 76Word Count: 781See All articles From Author

Add Comment

Technology, Gadget and Science Articles

1. Nasa's Latest Mission Mars - Developments And Expectations
Author: Chris Greenwalty

2. Google Play Store Optimization
Author: Subhanshu Ranjan Maurya

3. Buy Led Grow Lights Online At Low Price
Author: crecer

4. Advantages Of Having The Best Android Phone
Author: Jakson

5. Information Security Consulting Market Analysis, Size, Growth, Industry Trends, Opportunities, Forec
Author: siddharth mnm

6. Realme 5
Author: ishika

7. Why Call Center Crm Integration Is Necessary For Call Centers?
Author: Zenteno peterson

8. Reasons Why You Should Choose Ionic For Hybrid App Development?
Author: Maria William

9. Get Ready To Take Your Ecommerce Business To Cloud In 2020
Author: Brian Burell

10. Automotive Sensors Market Worth $41.9 Billion By 2025
Author: MarketsandMarkets

11. Artificial Intelligence Facts
Author: zeksta

12. Should You Work For The Nhs Or Enter Private Practice?
Author: Tom Hunt

13. All About Hospital Management System
Author: Shivkumara

14. What It Is And How It Can Help You
Author: Jone Moss

15. Top 5 Reasons To Use Call Center Software
Author: Ethan Jones

Login To Account
Login Email:
Forgot Password?
New User?
Sign Up Newsletter
Email Address: