| 
       in CHF 1 000  | 
    
       Notes  | 
    
       31.12.2022  | 
    
       in %  | 
    
       31.12.2021  | 
    
       in %  | 
  
| 
       Assets  | 
    
       
  | 
    
       
  | 
    
       
  | 
    
       
  | 
    
       
  | 
  
| 
       Property, plant and equipment  | 
    
       (5)  | 
    
       53 142  | 
    
       14.5  | 
    
       49 553  | 
    
       15.4  | 
  
| 
       Intangible assets  | 
    
       (6)  | 
    
       58 342  | 
    
       15.9  | 
    
       68 547  | 
    
       21.3  | 
  
| 
       Other non-current assets  | 
    
       
  | 
    
       545  | 
    
       0.1  | 
    
       -  | 
    
       0.0  | 
  
| 
       Deferred tax assets  | 
    
       (11)  | 
    
       3 284  | 
    
       0.9  | 
    
       3 158  | 
    
       1.0  | 
  
| 
       Non-current assets  | 
    
       
  | 
    
       115 313  | 
    
       31.4  | 
    
       121 258  | 
    
       37.7  | 
  
| 
       Inventories  | 
    
       (7)  | 
    
       117 364  | 
    
       32.0  | 
    
       80 109  | 
    
       24.9  | 
  
| 
       Trade accounts receivable  | 
    
       (8)  | 
    
       50 606  | 
    
       13.8  | 
    
       44 080  | 
    
       13.7  | 
  
| 
       Other accounts receivable  | 
    
       (8)  | 
    
       5 558  | 
    
       1.5  | 
    
       5 924  | 
    
       1.8  | 
  
| 
       Prepaid expenses and accruals  | 
    
       
  | 
    
       2 403  | 
    
       0.7  | 
    
       1 721  | 
    
       0.5  | 
  
| 
       Cash and cash equivalents  | 
    
       (9)  | 
    
       75 491  | 
    
       20.6  | 
    
       68 797  | 
    
       21.4  | 
  
| 
       Current assets  | 
    
       
  | 
    
       251 422  | 
    
       68.6  | 
    
       200 631  | 
    
       62.3  | 
  
| 
       Total assets  | 
    
       
  | 
    
       366 735  | 
    
       100.0  | 
    
       321 889  | 
    
       100.0  | 
  
| 
       
  | 
    
       
  | 
    
       
  | 
    
       
  | 
    
       
  | 
    
       
  | 
  
| 
       Liabilities and shareholders’ equity  | 
    
       
  | 
    
       
  | 
    
       
  | 
    
       
  | 
    
       
  | 
  
| 
       Share capital  | 
    
       
  | 
    
       34 095  | 
    
       9.3  | 
    
       30 695  | 
    
       9.5  | 
  
| 
       Mandatory convertible note  | 
    
       
  | 
    
       59 069  | 
    
       16.1  | 
    
       -  | 
    
       0.0  | 
  
| 
       Capital reserves  | 
    
       
  | 
    
       113 162  | 
    
       30.9  | 
    
       109 024  | 
    
       33.9  | 
  
| 
       Treasury shares  | 
    
       
  | 
    
       –2 422  | 
    
       –0.7  | 
    
       –6  | 
    
       –0.0  | 
  
| 
       Cash flow hedging reserve  | 
    
       
  | 
    
       –58  | 
    
       –0.0  | 
    
       -  | 
    
       0.0  | 
  
| 
       Retained earnings  | 
    
       
  | 
    
       –38 916  | 
    
       –10.6  | 
    
       –43 156  | 
    
       –13.4  | 
  
| 
       Translation reserve  | 
    
       
  | 
    
       –16 039  | 
    
       –4.4  | 
    
       –7 670  | 
    
       –2.4  | 
  
| 
       Total equity  | 
    
       
  | 
    
       148 891  | 
    
       40.6  | 
    
       88 887  | 
    
       27.6  | 
  
| 
       Long-term provisions  | 
    
       (10)  | 
    
       4 006  | 
    
       1.1  | 
    
       3 596  | 
    
       1.1  | 
  
| 
       Deferred tax liabilities  | 
    
       (11)  | 
    
       7 364  | 
    
       2.0  | 
    
       8 895  | 
    
       2.8  | 
  
| 
       Long-term financial liabilities  | 
    
       (12)  | 
    
       101 950  | 
    
       27.8  | 
    
       114 502  | 
    
       35.6  | 
  
| 
       Liabilities for post-employment benefits  | 
    
       (13)  | 
    
       1 695  | 
    
       0.5  | 
    
       1 906  | 
    
       0.6  | 
  
| 
       Non-current liabilities  | 
    
       
  | 
    
       115 015  | 
    
       31.4  | 
    
       128 899  | 
    
       40.1  | 
  
| 
       Short-term financial liabilities  | 
    
       (12)  | 
    
       18 063  | 
    
       4.9  | 
    
       15 354  | 
    
       4.8  | 
  
| 
       Trade accounts payable  | 
    
       
  | 
    
       39 539  | 
    
       10.8  | 
    
       39 691  | 
    
       12.3  | 
  
| 
       Other current liabilities  | 
    
       (14)  | 
    
       26 436  | 
    
       7.2  | 
    
       23 130  | 
    
       7.2  | 
  
| 
       Accruals  | 
    
       (14)  | 
    
       14 903  | 
    
       4.1  | 
    
       13 355  | 
    
       4.1  | 
  
| 
       Short-term provisions  | 
    
       (10)  | 
    
       2 013  | 
    
       0.5  | 
    
       12 067  | 
    
       3.7  | 
  
| 
       Income tax payable  | 
    
       
  | 
    
       1 875  | 
    
       0.5  | 
    
       506  | 
    
       0.2  | 
  
| 
       Current liabilities  | 
    
       
  | 
    
       102 829  | 
    
       28.0  | 
    
       104 103  | 
    
       32.3  | 
  
| 
       Total liabilities  | 
    
       
  | 
    
       217 844  | 
    
       59.4  | 
    
       233 002  | 
    
       72.4  | 
  
| 
       Total equity and liabilities  | 
    
       
  | 
    
       366 735  | 
    
       100.0  | 
    
       321 889  | 
    
       100.0  |