Wie stellt man eine Schutzbrille her?

As one of the China’s leading safety goggles manufacturers since 2009, we would like to share how to produce high quality safety goggles.  Safety goggles plays a significant role in protecting the eyes from from flying debris, chemicals, harmful radiation, and impact injuries.  They are wanted in various workplaces like construction sites, laboratories, and manufacturing facilities. Wearing safety glasses can boost up not only the overall safety, but also the compliance with health regulations. Additionally, they contribute to better productivity without the distraction of potential eye damages. Some might be curious how the safety glasses are manufactured. The blog is to explore the safety glasses manufacturing process.  

 Raw Materials Preparation

Generally speaking, safety glasses consist of PC lenses and PC, PU or nylon legs.  We must show great attention to the material properties to meet the eye protection safety standards.

1.1 Optical Transparency

The PC materials shall be of high optical transparency to ensure clear vision without distortion. ANSI Z87.1 (USA) specifies that safety glasses must have a minimum light transmission of 90% for clear lenses and 70% for tinted lenses. And EN 166 (Europe) includes classifications for optical quality, with markings indicating the level of distortion and optical class. Lenses must be marked with a “1” for optical quality, ensuring minimal distortion. Not only CE EN166, but also ANSI Z87.1 emphasizes the importance of minimal distortion to ensure that the wearer can see objects clearly without visual aberrations.

1.2 UV Protection

Meanwhile, the PC shall be UV resistant to block harmful ultraviolet (UV) radiation for eye safety. Both ANSI and EN166 pay great attention to the UV protection of safety glasses. The marking “U” followed by a number under EN166 indicates the level of UV protection.  Below is a list for guidance on UV protection levels under NE166.

U1: Blocks at least 99% of UV radiation (UVA and UVB).

U2: Blocks at least 95% of UV radiation.

U3: Blocks at least 90% of UV radiation.

U4: Blocks at least 80% of UV radiation.

1.3 Impact Resistance

Besides, impact resistance of the PC materials is a must. Below is a brief review on the impact resistance requirements under ANSI and EN166 for safety glasses.

Under ANSI Z87.1 (USA), safety glasses must pass a high-impact test, where a 1-inch steel ball is dropped from a height of 50 inches (127 cm) onto the lens. Lenses must maintain optical clarity and resist shattering upon impact. And glasses that meet ANSI standards are marked with “Z87” to indicate compliance.

EN 166 puts safety eyewear in different categories based on impact resistance from a 0.86g steel ball in diameter of 6mm.

F: Low energy impact (minimum impact of 45 m/s).  it’s applicable to all types of protective eyewear.

B: Medium energy impact (minimum impact of 120 m/s). it’s only applicable to goggles and face shields.

A: High energy impact (minimum impact of 190 m/s).

 Manufacturing Process of Safety glasses

Safety glasses manufacturing can be roughly divided into 4 steps. Below are the details for further exploration.

2.1 Design and Prototyping

For 100% original custom safety goggles, we need a design in CAD with data for 3D preview.  Then we could use 3D printing technology to get prototypes for reference in case of any changes of the data.

2.2 Safety Glasses Lens Production

1) Start with lens blanks, which are flat pieces of material.Use CNC (Computer Numerical Control) machines or automatic cutting machines to cut the lenses to the required shape and size based on the frame specifications. 2) Grind the lenses to achieve the desired curvature and thickness. This can involve: surface grinding, edge grinding to fit into the frame, sanding and polishing for optical clarity and smoothness. 3) Thoroughly clean the lenses to remove any dust or contaminants first. And use spray or dip methods to apply anti-scratch, anti-fog, and UV protection coatings. Then, cure or dry the safety glasses lenses. Finally inspect the shaped lenses to ensure that they meet optical standards and fit specifications.

2.3 Frame Production

The PC or nylon plastics are molten and injected into molds for frame production of safety glasses. Be aware that the safety glasses frame must be impact resistant and marked with the appropriate EN or ANSI standard.  And the frame shall support lens without distorting vision. The adjustable nylon legs shall be neither too tight, not too loose for a snug fit and an easy adjustment. Also safety glasses legs could be printed with clients’ logo.  

2.4 Montage and Inspection

Assemble the lenses and frames. Ensure the screws are tight enough and in proper place.  The screws shall never be too long, which could punch through the safety glasses legs and hurt the users.

As for quality inspection, here’s a table to tell the differences of inspection on safety glasses under CE (EN166) and ANSI (Z87.1):

 Custom Package of Safety Glassess

Regular package would be 1pc/opp bag, 300 pcs/white box.   The plastic bag could be customized with the designated printing.  We also support any other custom packages like blister card packaging and poly bags with hanging hole and custom printing.

Schlussfolgerung

All in all, follow the ANSI Z87.1 standards for safety glasses in US market. Different from EN166, chemical resistance and lateral protection of safety glasses shall be highlighted.  And produce the safety glasses according to EN166 standards for EU markets.

If any doubts of safety glasses, contact us freely.