Application of plastic molds in cosmetics industry

1. Plastic mold manufacturing process

Plastic molds are tools used to make plastic products including cosmetic bottles, boxes, tubes, sprayers, etc. The process of making plastic molds includes several steps. First, you need to determine the 

size and shape of the mold 

according to the design drawings, then use CAD software to design the model, then make the mold parts and perform fine processing and assembly, and finally conduct mold testing and adjustment with 

professional equipment. 

The entire process requires experienced technical personnel and advanced production equipment.

2. Advantages of plastic molds in the cosmetics industry

01. High production efficiency: The plastic mold manufacturing and molding process is simple and can achieve large-scale and efficient production; 

02. Stable product quality: Products made by plastic molds have a high degree of accuracy and consistency, which can ensure the quality and consistency of cosmetic packaging. Consistency in 

appearance; 

03. Low cost: Compared with other molds, plastic molds have lower manufacturing costs, are relatively lightweight to use, and are easy to maintain and replace.

3. The scope of application of plastic molds in the cosmetics industry

Plastic molds are widely used in the cosmetics industry, such as lotion bottles, sprayers, perfume bottles, lipstick tubes, lipstick shells, plaster boxes, medicine jars, hair dye bottles, etc. Among them,

the manufacturing of cosmetic bottles requires the most types of molds, including push-button bottle caps, dripper bottle caps and other types.

4. The impact and future development of plastic molds on the cosmetics industry

The widespread application of plastic molds has had a significant impact on the cosmetics industry. Using plastic molds to manufacture cosmetic packaging can greatly improve production efficiency 

and product quality, and reduce costs. As the demand for cosmetics market continues to grow, the scope of plastic mold applications is also expanding. In the future, with the advancement of 3D printing and material technology, the 

manufacturing of plastic molds will be more refined and intelligent, and its application fields will be broader.

The main function of the plastic mold bottle cap core is to ensure that the threaded part of the bottle cap can be accurately formed, thereby improving the sealing and durability of the bottle cap. ‌ 

The bottle cap core plays a vital role

in the mold. It determines the accuracy and shape of the bottle cap thread, which directly affects the sealing performance and service life between the bottle cap and the bottle.

Generally speaking, the design and manufacturing of plastic mold bottle cap cores need to consider many aspects:

‌Tightness‌: The design of the plastic mold bottle cap core must ensure a tight fit between the cap and the bottle to prevent leakage of liquid or gas. Through precise manufacturing processes, the core 

can ensure the sealing performance of the bottle cap and extend the shelf life of the product.

‌Durability‌: The material and structural design of the plastic mold bottle cap core should take its durability into consideration to ensure that the bottle cap will not be easily damaged during use. For example,

the use of high-strength materials and reasonable cooling systems can extend the service life of the mold and improve production efficiency.

‌Production efficiency‌: The design of the plastic mold bottle cap core also needs to consider production efficiency. By optimizing the cooling system and reducing friction, the production cycle can 

be shortened and overall production efficiency improved.

To sum up, the plastic mold bottle cap core plays an important role in ensuring the sealing, durability and production efficiency of the bottle cap, and is an indispensable part of the bottle cap 

manufacturing process.

Summary of the functions of various parts of plastic molds

1. Nozzle (sprue sleeve): It is in direct contact with the nozzle of the beer machine. When the beer machine injects glue, it must pass through the nozzle before entering the mold core.

2. Positioning ring (ring): used for easy alignment when using the mold loading machine (mold base);

3. Template: together with the bottom plate, it supports the entire set of molds;

4. Ejector protection switch: When the ejector plate is not retracted in place, the switch is not turned on. At this time, the circuit is disconnected and the front and rear molds cannot be closed. 

This ensures that the front mold will not hit the ejector pin due to the ejector pin not being retracted in place. This avoids Damage to the mold;

5. Ejection pin hole: After the forming is completed, the ejector pin pushes the ejector plate, and the ejector pin plate advances to eject the product;

6. Nozzle tie rod: used to pull the nozzle plate apart when opening the mold, so that the nozzle can be easily removed;

7. Guide pillars: play a guiding role when the front and rear molds are closed (4 in total);

The "guide pillar" in the mold is also called "guide pillar", and its function is to guide. The function of the mold guide device is to guide the upper mold and the lower mold to align in the correct position. The most common guide device is the guide post guide bushing.

8. Waterway interface: When the mold is in production, the mold temperature continues to rise, and transporting water allows the mold to be produced at a constant temperature, thereby ensuring the stability of the product;

9. Inclined guide post: If the spring of the row position does not work when the mold is opened, the inclined guide will drive the row to exit backward (the inclined guide is fixed on the front mold), 

also called the hypotenuse or bent pin: Used as a moving slider to perform repeated movements;

10. Shovel: When closing the mold, the shovel relies on the slope to push the rows forward, and the shovel is fixed on the front mold (the mating surface between the shovel and the rows is a slope);

11. Row position: installed on the rear mold;

12. Row spacers: used to increase the wear resistance of the rows; (the product has buckles, so the rows need to be done)

13. Back pin: It plays a guiding role when the ejector pin is ejected and retreated, and ensures that after the front and rear molds are closed, the back pin is in contact with the front mold base, so the ejector plate can be retreated to the position (4 in total); (The product is in When ejecting, it relies on the thimble, inclined ejection, and cylinder.)

14. The cylinder needle: fixed on the bottom plate. When the ejector plate is ejected, the cylinder needle remains stationary; lock a headless screw at the cup head of the cylinder needle. The diameter of the headless screw depends on the size of the mold. For small molds, the distance is 5MM, and for large molds, it is 10MM.

15. Skewer: When there is an annular bone position on the product, and the depth of the bone position is relatively high, and it is easy to stick to the mold when the mold is released, you should consider making a spool; the spool has an ejection function and is fixed on the ejector plate. on.

16. Inclined roof: When the mold is ejected, the inclined roof pushes upward along the oblique direction (angle 90°). After the inclined roof is ejected from the mold, the distance between the inclined roof and the product buckle must be more than 0.5MM to ensure that the product cannot be ejected from the mold. It will buckle to the sloping roof;

17. Ejector (pipe ejection): ejects the product from the mold core. Its function is the same as the ejection pin, but it is generally used for demoulding of cylinders with fine holes in the center of the product;

18. Sleeve needle: used for molding the column hole of the product, used with the spool, not for demoulding;

19. Support column (support head): supports the B board, which is deformed due to pressure during injection molding; lock the screw from the bottom of the panel to the bottom of the B board;

20. Garbage nail: supports the ejector plate. Due to its small area, it can prevent garbage from accumulating on it and making the ejector plate uneven or deformed; start from the bottom of the ejector plate;

21. Water carrying hole: used for effective cooling of the mold to keep the mold temperature within a certain range;

22. Throat nozzle: It is installed on the water carrying hole of the mold and is used to connect the cooling water pipe of the beer machine. It is generally made of copper;

23. Pulling rod:

A. Split channel pull rod: Because the plastic stored in the split channel is not easy to fall off, it is convenient for the cold material to fall off when opening the mold;

B. Gate pull rod: When opening the mold, pull out the main channel condensate from the sprue sleeve to facilitate separation from the nozzle of the injection molding machine. Generally, it is at the end of the cold material cavity. The diameter of the pull rod is equal to the diameter of the large end of the gate inner diameter. , in order to trap the cold material;

24. Slider: It is an important part to complete the side core pulling. It is used in conjunction with the guide chute and is driven by an inclined guide post to perform side core pulling;

25. Row position (slider groove): It is a sliding transverse mold, generally used when the side of the product has concave and convex shapes. It is divided into rectangular rows (T-shaped groove) and dovetail shape, so that the slider drives the molding core to pull the core smoothly and accurately. Width tolerances can be relaxed;

26. Spring: plays a reset role;

27. Small tie rod: It has the same function as the tie rod and plays a limiting role. It is the main accessory of the double parting surface mold (thin nozzle);

28. Limiting nail (stop block): It plays a limiting role and is often used to limit the top plate in the formwork (on the back of the B board or the front of the top plate);

Limit pin: limits the ejection stroke of the ejector plate;

29. Exhaust slot: used to discharge the air in the mold itself and the gas generated by the heating of the plastic. Common processing is in parting molds, surfaces and hot runner plates. There is also a ventilation groove for the guide post, which is generally processed on the upper plywood and the square iron close to the guide bush;

30. Positioning steel balls: mainly used to stop the slider (row seat);

31. Lifting ring: also called ring head screw vertebra; used for hanging molds;

32. Middle support: installed on the ejector assembly plate, used to guide the ejection system;

33. Resin opener (nylon rubber plug): mainly used to increase the mold opening resistance between the fixed and movable molds to ensure that the flow channel plate, panel and fixed template are opened before the fixed and movable templates are opened;

Design considerations:

⑴ The nylon plug of the resin opening and closing plug should be embedded in the movable template 3 mm;

⑵ The opening of the fixed template should be rounded R and polished to prevent scratching the nylon plug. If it is made into a bevel chamfer, the surface of the nylon plug will be easily scratched and the service life of the nylon plug will be reduced.

⑶ An exhaust device should be installed at the bottom of the fixed template hole;

⑷ The holes in the fixed template matching the nylon plug should be polished;

⑸ Do not add oil to the nylon plug, because adding oil will reduce its friction;

⑹ The product itself has been trimmed by a precision automatic machine, and the roundness can reach within 0.01 MM, thus increasing the contact area of the nylon plug;

⑺ There is no need to lock the screws too tightly when using;

⑻ Determination of the number of nylon plugs: If the mold mass is less than 100 kg, use 12 * 4 pieces in diameter; if the mold mass is less than 500 kg, use 16 ;

34. Heat insulation board: Since the mold temperature is higher than that of the injection molding machine, the main function of the heat insulation board is to prevent heat dissipation;

35. Inserts: save materials, molds and labor;

A. Generally speaking, if the bone position is higher than 8 mm, inserts should be considered to facilitate mold saving and exhaust;

B. The insert should be 0.05 ~ 0.1 MM away from the edge to prevent excessive saving in material;

C. Make inserts for the convenience of mold saving;

D. If the product has a seam, make a large insert, and do not set the insert through; (0 ~ 1 degree bevel)

E. Inserts should be considered for cylindrical and round holes to facilitate processing. For pin and circular inserts, if the top glue level is uneven or the shape is asymmetrical, positioning and anti-rotation are required;

36. Screw pull rod: fixes the mold opening stroke of the upper fixed plate and stripper plate;

37. Pulling nozzle plate: fixing the pulling needle;

38. Front and rear mold inserts: fixed runner plate and front and rear mold cores;

39. Pulling needle: pull the nozzle;

40. Back mold pin inlay: mainly used for product cup mouth molding;

41. Ejector: Ejects the material strip to separate it from the mold; it is part of the ejection glue position;

42. External tie rod: used to open the cavity and limit the mold opening distance of the cavity;

43. Flat thimble (flat pin): It is mainly used to eject the ribs of plastic products, as well as long strips of glue. Flat thimbles are used where the dome needle cannot be lowered; it is used to eject the glue position from a relatively deep place. ;

44. Tonggong: For places that cannot be processed, use copper tungsten to make its shape and process it;

The purpose of making copper pins is to prepare parts of the glue position (such as bone position) that cannot be processed. It is made into the shape of the glue position, and then the electric spark is used to process the glue position that cannot be processed with current. The undercut requires The inclined guide pillar is manufactured;

45. Pillow position: the partial shape of the formed product;

46. Tiger's mouth: positioning the front and rear mold cores;

47. Pin setting: It is part of the local glue position;

48. Supported setting pin: used for ejecting products with holes below 2 MM;

49. Shovel: Installed opposite the slide block and behind the inclined guide column. Generally, the angle of the locking module is 3~5° larger than the angle of the inclined guide column. When the slider is in the moving mold, the locking module is on the fixed mold. When closing the mold, the locking module resists the slider behind the slider to prevent the slider from retreating due to the pressure of the injection molding during injection molding, thereby affecting the size of the injection molded part. The locking module plays the role of locking the mold slider. When the mold is opened and the fixed mold is separated, the lock module is also separated from the slider at the same time. At this time, the slider will be driven backward by the inclined guide column or the hydraulic core pulling mechanism to complete the core pulling process.

50. Lock module: It prevents the movable and fixed mold from opening during the lifting, loading, unloading, and transportation of the mold and protects the mold. Be sure to open it when producing injection molding. Generally, one installation is enough for small molds, and two or more for large molds.