Glass containers are one of the most commonly used packaging materials for cosmetics, in addition to plastic products and paper products. Glass containers are easy to form, provide good customer experience, and have a variety of post-processing methods, which can present different characteristics to the brand. Therefore, they are very popular in the cosmetics industry! However, the mouth, body, bottleneck and other parts of glass containers are prone to quality problems caused by factors such as materials, molding process, and molds, which is also a big problem for brands to choose. In this article, we share the common quality problems of glass containers:

1. Serious Defects

   Danger to personal safety, such as broken mouth, broken glass inside the bottle. Customers cannot use the bottle normally. Such as: severe deformation, insufficient mouth.

   Glass wire inside the bottle: Also known as making a telephone call: There is a glass wire in the bottle.

   Glass foreign matter adheres to the outside of the glass bottle: The glass sticking to the outer surface of the bottle is usually quite sharp. That is, after the hot end is formed, the bottle is at a high temperature, and the two bottles come into contact with each other and stick together. After reaching the cold end, separate.

   Glass inside the bottle: The three defects of punch sticking and bottle spikes are all produced during hot end molding. Glass sticking in the bottle means that when the bottle is at high temperature, the glass block falls in and sticks to the inner surface of the bottle, but it may appear on the bottle body. Punch sticking means that there is a small sharp glass protrusion on the inner wall of the bottle head. A bottle spike is a sharp protrusion of glass on the inner surface of a glass bottle, usually near the bottom of the bottle.

   Cracks in the inner wall of the bottle (inner cracks): Cracks of any length and width on the surface of the bottle, wide enough for a fingernail to enter. It has the same shape as the crack line. It is classified as a serious defect because cracks appear inside the bottle when some products require high-temperature sterilization or are filled with inflatable materials, resulting in broken glass and endangering human safety.

   Burrs on the inside of the bottle mouth (bottle mouth burrs): The inner diameter edge of the bottle mouth is protruding, and a piece of ring-shaped glass is often accompanied by an increase in bottle height or unequal bottle mouth when it belongs to the outer double mouth. Burrs on the inner edge of the bottle mouth: A very small piece of glass protrudes upward on the edge of the inner diameter of the bottle mouth. These two defects affect the sealing of the cap and cause crushed glass to fall into the bottle.

   Thin skin bubbles (broken bubbles): The bubbles inside and outside the bottle or on the sealing surface of the bottle mouth are too soft and will burst when the bottle is used normally. They can be penetrated by scraping with your fingernails.

   Spiked protrusions on the surface: A raised spur on the seam line of the bottle.

2. Bottle Mouth Defects

   Bottle mouth flanging (convex mouth) and damage: A piece of glass that protrudes horizontally outward from the outer edge of the bottle mouth. Mouth mold damage: A small piece of glass protrudes from the mouth seam line and the sealing surface as well as the place where it fits with the primary mold. Use a vernier caliper to measure the defective part. Usually, the outer diameter of the mouth exceeds the standard or affects the smoothness of the automatic capping.

   Cracks at the bottle mouth (deep explosion), fine cracks on the sealing surface of the bottle (shallow explosion): Deep bursts are different from shallow bursts. They are deeper and the cracks often extend from the inner edge to the outer edge. Shallow bursts are shallow cracks on the top edge of the bottle mouth. The reflection of the cracks can only be seen through the refraction of light. Therefore, it is easier to miss detection. For products with high sealing requirements, such as beverage bottles, chicken essence bottles, bird’s nest bottles, etc., after filling and capping, bottles with shallow bursts will be found to have raised vacuum safety buttons and leaks after being placed for three to five days, and the contents of the bottle will deteriorate.

   Depression (notch) in the mouth of the bottle: The inner diameter of the bottle mouth is too large. Teeth-through: The glass on the inner wall of the bottle mouth is obviously unevenly distributed and deformed. If you touch the inside of the mouth, it will obviously feel concave in an arc shape. The inner diameter of the bottle mouth is too large: The inner diameter of the bottle mouth is larger than the design requirements. Two defects will cause leakage when some internal plugs are required.

   The drum mouth and bottle ring are too large: Bulging mouth means that the bottle mouth bulges outward. Too large bottle mouth ring: the bottle head size exceeds the upper limit of the standard. The drum mouth will also cause the bottle head to exceed the standard size. The cause is improper operation, while too large a mouth ring is caused by the mold.

   Bottle mouth is cracked or damaged: The flange of the bottle mouth is defective, and the thread of the bottle mouth is defective, both of which collapsed due to impact. Just the location where it appears is different.

   The mouth of the bottle is rough: The rough surface of the bottle mouth due to poor finish of the mouth mold is not allowed for some products with strict quality requirements, such as milk bottles and beer bottles.

   Disc-shaped bottle mouth, uneven bottle mouth, tilted bottle mouth: The inner edge of the bottle mouth is sunken due to the incomplete mouth edge, which looks like a cleft lip, and is often accompanied by insufficient or uneven mouth. Uneven bottle mouth: The difference between the highest point and the lowest point of the bottle mouth surface exceeds the standard requirements. This defect must be detected by a vernier caliper. Bottle mouth tilt: that is, the parallelism exceeds the standard, and the difference between the maximum and minimum values ​​of the bottle mouth surface to the bottle bottom exceeds the standard requirements.

   Insufficient threads and small bottle mouth ring: The thread forming of the bottle mouth is insufficient. In severe cases, the outer diameter of the thread will be too small and the bottle mouth will not be too small: the dimensions of the bottle mouth will be smaller than the standard lower limit.

3. Bottleneck Defects

   Clamp cracks (clamp burst) and bottleneck cracks (neck burst): The cracks caused by bottle clamps are crescent-shaped and appear at the bottom of the bottle. Neck bursts are cracks in the neck of the bottle, usually horizontal cracks.
   
   Bottle neck folding, neck grabbing, bottle shoulder/neck collapse: Obvious deep creases on the glass surface usually appear at the neck of the bottle. Grabbing the neck means bottleneck deformation, and shoulder and neck collapse means insufficient air blowing into the bottleneck or shoulders.

   Wry neck, crooked body: Neck crookedness means that the bottle neck is not straight, which affects the parallelism index. The height of the bottle can be measured with a height gauge. The difference between the lowest point and the highest point can determine the degree of neck crookedness. Body crookedness refers to the deviation between the center line of the bottle mouth and the mid-vertical line of the bottle bottom. The vertical axis turntable can detect body crookedness, but a height gauge cannot be used.

4. Bottle Body Defects

   Cracked Body: A short and deep crack, caused by the hot bottle surface coming into contact with a cold object such as metal after molding, and the crack reflects light. Shallow crack: A shallow crack on the surface of glass, the length of this crack is uncertain, it does not penetrate deep into the glass, and it does not reflect light.

   Bottle crack line: Open cracks on the outer surface of the bottle. Scratchy to the touch.

   Cold mold: Due to the overcooling of the mold temperature, the outer surface of the glass becomes rough, the glass is unevenly distributed, and it feels bumpy when touched by hand.

   Wrinkles: The bottle’s exterior has fine horizontal wrinkles that are denser in the transverse direction.

   Creases: A slight crease in the surface of glass. Usually the crease is nearly horizontal.

   Bottle is dented: After the bottle is formed, the bottle wall is squeezed to form an obvious or inconspicuous depression. As a result, the out-of-roundness of the bottle exceeds the standard or the diameter of the bottle is too small at some point.

   Bottle body is small: The overall diameter of the bottle is smaller than the standard lower limit, which may result in unqualified capacity or inability to affix a label.

   Crack seam line: Cracks usually appear on the bottle body at the mold seam line.

   Bottle shoulder crack: Vertical crack on the shoulder of the bottle.

   Deep cracks in bottle root: Deep cracks at the base of the bottle.

   Cracks in positioning: Cracks around the positioning line.

5. Bottle Bottom Defects

   Cracks on bottle bottom: Shallow cracks on the bottom of the bottle.

   Radial cracks: Deep cracks in any direction on the bottom of the bottle, mostly radial.

   Concave bottom: The center of the bottom of the bottle is abnormally concave.

   Convex bottom: The center of the bottom of the bottle protrudes outwards, and the bottle is placed on a flat plate, swinging unevenly.

   Sloping bottom: The inside of the bottle bottom is sloped, but the inclination exceeds the specified requirements. Usually the bottom ratio is controlled at 1:2mm.

   Thin bottom: The bottom glass is not thick enough to meet the design requirements, and a thin bottom may sometimes occur.
   
   

6. Measurement Defects

   Bottle too big: The bottle body diameter exceeds the upper limit of the standard. When the bottle body is dented, it may also cause the body diameter to be larger at some point.

   Bottleneck blockage (narrow neck): The inner diameter of the bottleneck is smaller than the specified requirement. Some products are marked with the effective length of the inner plug on the design drawing according to the customer’s filling tube requirements. If a narrow neck appears, it is unacceptable. For products without special requirements, it is judged by visual inspection.

   Bottle mouth inner diameter too small: The inner diameter of the bottle mouth is less than the specified requirements. This can be measured with a plug gauge or vernier caliper. The inner double mouth may cause the inner diameter of the mouth to be smaller.

   Super Tall: The bottle height exceeds the upper limit of the standard. The elongated neck may also cause the bottle height to exceed the standard.
   
   Bottle short: The height of the bottle does not reach the standard lower limit, the bottle shrinks too much or the bottom of the base will cause the bottle to be short.

   Bottle body is not round: Ovalency is a deformation of the bottle cross section from a circle to an ellipse, usually expressed by the difference between the major and minor axes of the ellipse. That is, the difference between the maximum and minimum values ​​of the same initial measurement surface after one rotation exceeds the standard range of the bottle’s out-of-roundness.

   Bottle bulge: The bottle is deformed and bulges outward beyond the specified requirements.